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Al Rashdan A, Alessa M, Ababneh F, Al Taimeh F, Althunaibat Z. Effectiveness of Facetectomy in Correction of Adolescent Idiopathic Scoliosis. Cureus 2024; 16:e55768. [PMID: 38463404 PMCID: PMC10921130 DOI: 10.7759/cureus.55768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2024] [Indexed: 03/12/2024] Open
Abstract
INTRODUCTION Surgical correction of adolescent idiopathic scoliosis (AIS) using the facetectomy technique with the utilization of segmental pedicle screws aims to achieve correction of coronal and sagittal imbalances and preserve normal neurological function. In this study, we aimed to certify the effectiveness of the facetectomy technique in the correction of AIS by analyzing technique outcomes. METHODS This is a retrospective, single-center study. From January 2018 to March 2022, a total of 51 patients with AIS who underwent inferior facetectomy with segmental pedicle screw constructs at the Royal Rehabilitation Center were reviewed. Radiological parameters including the major curve Cobb angle, and global coronal balance were evaluated preoperatively, postoperatively, and at the final follow-up. Surgical parameters and complications were also reported. RESULTS The mean major curve Cobb angle was 59.5 ± 4.9° preoperatively, 13.6 ± 2.7° postoperatively, and 14.5 ± 2.6° at the final follow-up, with correction rates of 77.2% and 75.7%, respectively. The mean global coronal balance was 2.7 ± 1.1 cm preoperatively, 1.7 ± 0.73 cm postoperatively, and 1.4 ± 0.55 cm at the final follow-up. Two cases of pleural injuries were reported intraoperatively. Postoperatively, two cases experienced superficial wound infections, one experienced pulmonary embolism, and one patient had revision surgery due to the loosening of a single screw. None of these complications lasted long. CONCLUSIONS When combined with posterior segmental pedicle screw constructs, inferior facetectomy can provide an effective rate of correction in a reasonably safe manner.
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Affiliation(s)
| | - Monther Alessa
- Department of Orthopedics, Royal Medical Services, Amman, JOR
| | - Faris Ababneh
- Department of Orthopedics, Royal Medical Services, Amman, JOR
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Solla F, Ilharreborde B, Clément JL, Rose EO, Monticone M, Bertoncelli CM, Rampal V. Patient-Specific Surgical Correction of Adolescent Idiopathic Scoliosis: A Systematic Review. CHILDREN (BASEL, SWITZERLAND) 2024; 11:106. [PMID: 38255419 PMCID: PMC10814112 DOI: 10.3390/children11010106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/03/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024]
Abstract
The restoration of sagittal alignment is fundamental to the surgical correction of adolescent idiopathic scoliosis (AIS). Despite established techniques, some patients present with inadequate postoperative thoracic kyphosis (TK), which may increase the risk of proximal junctional kyphosis (PJK) and imbalance. There is a lack of knowledge concerning the effectiveness of patient-specific rods (PSR) with measured sagittal curves in achieving a TK similar to that planned in AIS surgery, the factors influencing this congruence, and the incidence of PJK after PSR use. This is a systematic review of all types of studies reporting on the PSR surgical correction of AIS, including research articles, proceedings, and gray literature between 2013 and December 2023. From the 28,459 titles identified in the literature search, 81 were assessed for full-text reading, and 7 studies were selected. These included six cohort studies and a comparative study versus standard rods, six monocentric and one multicentric, three prospective and four retrospective studies, all with a scientific evidence level of 4 or 3. They reported a combined total of 355 AIS patients treated with PSR. The minimum follow-up was between 4 and 24 months. These studies all reported a good match between predicted and achieved TK, with the main difference ranging from 0 to 5 degrees, p > 0.05, despite the variability in surgical techniques and the rods' properties. There was no proximal junctional kyphosis, whereas the current rate from the literature is between 15 and 46% with standard rods. There are no specific complications related to PSR. The exact role of the type of implants is still unknown. The preliminary results are, therefore, encouraging and support the use of PSR in AIS surgery.
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Affiliation(s)
- Federico Solla
- Paediatric Orthopaedic Unit, Lenval Foundation, 57, Avenue de la Californie, 06200 Nice, France; (J.-L.C.); (C.M.B.); (V.R.)
| | - Brice Ilharreborde
- Paediatric Orthopaedic Unit, Hôpital Robert Debré, AP-HP, 75019 Paris, France;
| | - Jean-Luc Clément
- Paediatric Orthopaedic Unit, Lenval Foundation, 57, Avenue de la Californie, 06200 Nice, France; (J.-L.C.); (C.M.B.); (V.R.)
| | - Emma O. Rose
- Krieger School of Arts & Sciences, Homewood Campus, John Hopkins University, Baltimore, MD 21218, USA
| | - Marco Monticone
- Department of Surgical Sciences, University of Cagliari, 09124 Cagliari, Italy;
| | - Carlo M. Bertoncelli
- Paediatric Orthopaedic Unit, Lenval Foundation, 57, Avenue de la Californie, 06200 Nice, France; (J.-L.C.); (C.M.B.); (V.R.)
| | - Virginie Rampal
- Paediatric Orthopaedic Unit, Lenval Foundation, 57, Avenue de la Californie, 06200 Nice, France; (J.-L.C.); (C.M.B.); (V.R.)
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Levy HA, Pinter ZW, Honig R, Salmons HI, Hobson SL, Karamian BA, Freedman BA, Elder BD, Fogelson JL, Nassr AN, Sebastian AS. A Standardized Curriculum Improves Trainee Rod Bending Proficiency in Spinal Deformity Surgery. Results of a Prospective Randomized Controlled Educational Study. J Am Acad Orthop Surg 2024; 32:e17-e25. [PMID: 37494716 DOI: 10.5435/jaaos-d-23-00294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/19/2023] [Indexed: 07/28/2023] Open
Abstract
INTRODUCTION Surgical simulation is increasingly being accepted as a training platform to promote skill development and a safe surgical technique. Preliminary investigations in spine surgery show that simulation paired with educational intervention can markedly improve trainee performance. This study used a newly developed thoracolumbar fusion rod bending model to assess the effect of a novel educational curriculum and simulator training on surgical trainee rod bending speed and proficiency. METHODS Junior (PGY1 to 2) and senior (PGY3-fellow) surgical trainees at a single academic institution were prospectively enrolled in a rod bending simulation using a T7-pelvis spinal fusion model. Participants completed two simulations, with 1 month between first and second attempts. Fifty percent of surgeons in each training level were randomized to receive an educational curriculum (rod bending technique videos and unlimited simulator practice) between simulation attempts. Rod bending simulation proficiency was determined by the percentage of participants who completed the task (conclusion at 20 minutes), time to task completion or conclusion, and number of incomplete set screws at task conclusion. Participants completed a preparticipation and postparticipation survey. Univariate analysis compared rod bending proficiency and survey results between education and control cohorts. RESULTS Forty trainees (20 junior and 20 senior) were enrolled, with 20 participants randomized to the education and control cohorts. No notable differences were observed in the first simulation rod bending proficiency or preparticipation survey results between the education and control cohorts. In the second simulation, the education versus the control cohort demonstrated a significantly higher completion rate ( P = 0.01), shorter task time ( P = 0.009), fewer incomplete screws ( P = 0.003), and greater experience level ( P = 0.008) and comfort level ( P = 0.002) on postparticipation survey. DISCUSSION Trainees who participated in a novel educational curriculum and simulator training relative to the control cohort improved markedly in rod bending proficiency and comfort level. Rod bending simulation could be incorporated in existing residency and fellowship surgical skills curricula. LEVEL OF EVIDENCE I.
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Affiliation(s)
- Hannah A Levy
- From the Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN (Levy, Pinter, Honig, Salmons, Freedman, Nassr, and Sebastian), the Department of Neurologic Surgery, Mayo Clinic, Rochester, MN (Elder and Fogelson), the Department of Orthopaedic Surgery, Emory University, Atlanta, GA (Hobson), and the Department of Orthopaedic Surgery, University of Utah, Salt Lake City, UT (Karamian)
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Wang X, Schwend RM, Ritzman T, Floccari L, Aubin CE. Concave rod first vs. convex rod first in AIS instrumentation with differential rod contouring: computer modeling and simulations based on ten AIS surgical cases. Spine Deform 2023; 11:1317-1324. [PMID: 37433978 DOI: 10.1007/s43390-023-00727-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/24/2023] [Indexed: 07/13/2023]
Abstract
PURPOSE To assess biomechanical differences between AIS instrumentations using concave vs. convex rod first. METHODS Instrumentations of ten AIS patients were simulated first with major correction maneuvers using the concave rod then with convex rod. Correction maneuvers were concave/convex rod translation, followed by apical vertebral derotation and then convex/concave rod translation. The concave/convex rods were 5.5/5.5 and 6.0/5.5 mm diameter Co-Cr and contoured to 35°/15°, 55°/15°, 75°/15° and 85°/15°, respectively. RESULTS Differences in simulated thoracic Cobb angle (MT), thoracic kyphosis (TK) and apical vertebral rotation (AVR) were less than 5° between the two techniques; mean bone-screw force difference was less then 15N (p > 0.1). Increasing differential contouring angle from 35°/15° to 85°/15°, the MT changed from 14 ± 7° to 15 ± 8°, AVR from 12 ± 4° to 6 ± 5°, TK from 23 ± 4° to 42 ± 4°, and bone-screw forces from 159 ± 88N to 329 ± 170N (P < 0.05). Increasing the concave rod diameter from 5.5 to 6 mm, the mean MT correction improvement for both techniques was less than 2°, the AVR correction was improved by 2°, the TK increased by 4° and bone-screw force increased by about 25N (p < 0.05). CONCLUSION There was no significant difference in deformity corrections and bone-screw forces between the two techniques. Increasing differential contouring angle and rod diameter improved AVR and TK corrections with no significant effect on the MT Cobb angle. Although this study simplified the complexity of a generic surgical technique, the main effects of a limited number of identical steps were replicated for each case in a systematic manner to analyze the main first-order effects.
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Affiliation(s)
- Xiaoyu Wang
- Department of Mechanical Engineering, Polytechnique Montreal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada
- Sainte-Justine University Hospital Center, 3175 Cote Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada
| | - Richard M Schwend
- Children's Mercy Hospital, 2401 Gillham Rd, Kansas City (Missouri), 64108, USA
| | - Todd Ritzman
- Akron Children's Hospital, 215 West Bowery Street, Akron, OH, 44308, USA
| | - Lorena Floccari
- Akron Children's Hospital, 215 West Bowery Street, Akron, OH, 44308, USA
| | - Carl-Eric Aubin
- Department of Mechanical Engineering, Polytechnique Montreal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada.
- Sainte-Justine University Hospital Center, 3175 Cote Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada.
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Seki S, Makino H, Yahara Y, Kamei K, Futakawa H, Yasuda T, Suzuki K, Nakano M, Kawaguchi Y. Rod Rotation with Outrigger Is Substantial for Correcting Apical Hypokyphosis in Patients with Adolescent Idiopathic Scoliosis: Novel Outrigger Device for Concave Rod Rotation. J Clin Med 2023; 12:6780. [PMID: 37959244 PMCID: PMC10650767 DOI: 10.3390/jcm12216780] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/15/2023] Open
Abstract
The apical hypokyphosis of scoliotic patients is thought to lead to decreased lung capacity and cause shortness of breath. Additionally, concave rod curve reduction is a problem in the correction of apical hypokyphosis in posterior spinal fusion surgery in adolescent idiopathic scoliosis (AIS). We investigated the contributions of rod rotation (RR) with an outrigger device, followed by differential rod contouring (DRC) with the outrigger attached to the concave rod, designed to prevent concave rod curve-flattening. We analyzed and compared the results of segmental pedicle screw fixation without the outrigger in 41 AIS patients with thoracic curves (Lenke type I, 25; type II, 16) to those corrected using the outrigger in 36 patients (Lenke type I, 24; type II,12). The changes in the Cobb angle, apical kyphosis of five vertebrae, thoracic kyphosis (TK, T4-12), correction rate, correction angle of apical vertebral rotation, spinal penetration index (SPi), and rib hump index (RHi) before and after surgery were measured, and the contribution of the outrigger was analyzed. The mean scoliosis correction rates without and with the outrigger were 72.1° and 75.6°, respectively (p = 0.03). Kyphosis of the five apical vertebrae and TK were significantly greater in the surgery with the outrigger (p = 0.002). Significantly greater improvements in SPi and RHi were also noted in the surgery with the outrigger (p < 0.05). The use of concave RR and convex DRC with the outrigger appear to be advantageous for correcting apical hypokyphosis, followed by the subsequent formation of TK. As a result, breathing problems are less likely to occur during daily life because of improvements in SPi and RHi.
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Affiliation(s)
- Shoji Seki
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; (H.M.); (K.K.); (H.F.); (T.Y.); (K.S.); (Y.K.)
| | - Hiroto Makino
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; (H.M.); (K.K.); (H.F.); (T.Y.); (K.S.); (Y.K.)
| | - Yasuhito Yahara
- WPI-Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan;
| | - Katsuhiko Kamei
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; (H.M.); (K.K.); (H.F.); (T.Y.); (K.S.); (Y.K.)
| | - Hayato Futakawa
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; (H.M.); (K.K.); (H.F.); (T.Y.); (K.S.); (Y.K.)
| | - Taketoshi Yasuda
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; (H.M.); (K.K.); (H.F.); (T.Y.); (K.S.); (Y.K.)
| | - Kayo Suzuki
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; (H.M.); (K.K.); (H.F.); (T.Y.); (K.S.); (Y.K.)
| | - Masato Nakano
- Department of Orthopaedic Surgery, Takaoka City Hospital, Toyama 933-8550, Japan;
| | - Yoshiharu Kawaguchi
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama 930-0194, Japan; (H.M.); (K.K.); (H.F.); (T.Y.); (K.S.); (Y.K.)
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Langlais T, Bouy A, Eloy G, Mainard N, Skalli W, Vergari C, Vialle R. Sagittal plane assessment of manual concave rod bending for posterior correction in adolescents with idiopathic thoracic scoliosis (Lenke 1 and 3). Orthop Traumatol Surg Res 2023; 109:103654. [PMID: 37399990 DOI: 10.1016/j.otsr.2023.103654] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 06/01/2022] [Accepted: 06/03/2022] [Indexed: 07/05/2023]
Abstract
OBJECTIVES The objectives of this study were to evaluate the repeatability and reproducibility of a method for measuring freehand rod bending and to analyze the relationship between the rod's bend and the resulting sagittal correction. MATERIALS AND METHODS All the children who underwent correction by posterior translation using pedicle screws at all levels were included prospectively in 2018 and 2019. The rod's sagittal parameters were measured retrospectively by three independent surgeons on two separate occasions using the same protocol. After the rods were bent but before they were inserted, the surgeon traced the contours of the rods on a sheet of paper that was later scanned and analyzed semiautomatically. The spinal parameters were calculated based on biplanar radiographs taken preoperatively, postoperatively and at the final follow-up visit. Patients who had less than 10° thoracic kyphosis (T5-T12) made up the "Lenke N-" subgroup. RESULTS Thirty patients were included (14 of whom were Lenke N-) who had a Cobb angle of 59.2±11.3° preoperatively and 13.3±8.4° postoperatively (p<0.00001). The inter- and intrarater ICC for the rod measurements were>0.9 (excellent). The mean kyphosis of the concave rod was 48.4±5.7° (38.3-60.9°). The mean change in T5-T12 kyphosis was 9.7±10.8° (-14.3-30.8°) (p<0.0001) in the entire population, while it was 17.7±7.1° (5.5-30.8°) (p<0.0001) in the Lenke N- subgroup. The change in thoracic kyphosis was positively correlated with the kyphosis of the concave rod (rho=0.52; p=0.003). CONCLUSION This study found excellent reproducibility and repeatability of measuring freehand rod bending. The kyphosis applied to the concave rod is positively correlated to the change in the resulting kyphosis and made it possible to restore satisfactory thoracic kyphosis. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Tristan Langlais
- Service d'orthopédie pédiatrique, hôpital Armand-Trousseau, Sorbonne université, Paris, France; Institut de Biomécanique Humaine Georges Charpak-IBHGC, Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, HESAM Université, 75013 Paris, France; Service d'orthopédie pédiatrique, hôpital des Enfants, Purpan, Toulouse université, Toulouse, France.
| | - Alois Bouy
- Service d'orthopédie pédiatrique, hôpital Armand-Trousseau, Sorbonne université, Paris, France
| | - Gauthier Eloy
- Service d'orthopédie pédiatrique, hôpital Armand-Trousseau, Sorbonne université, Paris, France
| | - Nicolas Mainard
- Service d'orthopédie pédiatrique, hôpital Armand-Trousseau, Sorbonne université, Paris, France
| | - Wafa Skalli
- Institut de Biomécanique Humaine Georges Charpak-IBHGC, Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, HESAM Université, 75013 Paris, France
| | - Claudio Vergari
- Institut de Biomécanique Humaine Georges Charpak-IBHGC, Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, HESAM Université, 75013 Paris, France
| | - Raphaël Vialle
- Service d'orthopédie pédiatrique, hôpital Armand-Trousseau, Sorbonne université, Paris, France
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Ishikawa Y, Kanai S, Ura K, Kokabu T, Yamada K, Abe Y, Tachi H, Suzuki H, Ohnishi T, Endo T, Ukeba D, Takahata M, Iwasaki N, Sudo H. Development of Notch-Free, Pre-Bent Rod Applicable for Posterior Corrective Surgery of Thoracolumbar/Lumbar Adolescent Idiopathic Scoliosis. J Clin Med 2023; 12:5750. [PMID: 37685817 PMCID: PMC10488454 DOI: 10.3390/jcm12175750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 08/31/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
Adolescent idiopathic scoliosis (AIS), the most common pediatric musculoskeletal disorder, causes a three-dimensional spine deformity. Lenke type 5 AIS is defined as a structural thoracolumbar/lumbar curve with nonstructural thoracic curves. Although a rod curvature will affect clinical outcomes, intraoperative contouring of the straight rod depends on the surgeon's knowledge and experience. This study aimed to determine the optimum rod geometries to provide a pre-bent rod system for posterior spinal surgery in patients with Lenke type 5 AIS. These pre-bent rods will be beneficial for achieving proper postoperative outcomes without rod contouring based on surgeon experience. We investigated 20 rod geometries traced in posterior spinal reconstruction in patients with Lenke type 5 AIS. The differences between the center point clouds in each cluster were evaluated using the iterative closest point (ICP) method with modification. Before the evaluation using the ICP method, the point clouds were divided into four clusters based on the rod length using a hierarchical cluster analysis. Because the differences in the values derived from the ICP method were <5 mm for each length-based cluster, four representative rod shapes were generated from the length-based clusters. We identified four optimized rod shapes that will reduce operation time, leading to a decreased patient and surgeon burden.
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Affiliation(s)
- Yoko Ishikawa
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
- Department of Orthopaedic Surgery, Eniwa Hospital, 2-1-1 Kogane-Chuo, Eniwa 061-1449, Hokkaido, Japan;
| | - Satoshi Kanai
- Division of Systems Science and Informatics, Hokkaido University Graduate School of Information Science and Technology, N14W9, Sapporo 060-0814, Hokkaido, Japan
| | - Katsuro Ura
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
| | - Terufumi Kokabu
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
- Department of Orthopaedic Surgery, Eniwa Hospital, 2-1-1 Kogane-Chuo, Eniwa 061-1449, Hokkaido, Japan;
| | - Katsuhisa Yamada
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
| | - Yuichiro Abe
- Department of Orthopaedic Surgery, Eniwa Hospital, 2-1-1 Kogane-Chuo, Eniwa 061-1449, Hokkaido, Japan;
| | - Hiroyuki Tachi
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
- Department of Orthopaedic Surgery, Eniwa Hospital, 2-1-1 Kogane-Chuo, Eniwa 061-1449, Hokkaido, Japan;
| | - Hisataka Suzuki
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
- Department of Orthopaedic Surgery, Eniwa Hospital, 2-1-1 Kogane-Chuo, Eniwa 061-1449, Hokkaido, Japan;
| | - Takashi Ohnishi
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
| | - Tsutomu Endo
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
| | - Daisuke Ukeba
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
| | - Masahiko Takahata
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
| | - Hideki Sudo
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo 060-8638, Hokkaido, Japan; (Y.I.); (K.U.); (T.K.); (K.Y.); (H.T.); (H.S.); (T.O.); (T.E.); (D.U.); (M.T.); (N.I.)
- Department of Advanced Medicine for Spine and Spinal Cord Disorders, Faculty of Medicine, Graduate School of Medicine, Hokkaido University, N15W7, Sapporo 060-8638, Hokkaido, Japan
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Wan SHT, Wong DLL, To SCH, Meng N, Zhang T, Cheung JPY. Patient and surgical predictors of 3D correction in posterior spinal fusion: a systematic review. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2023; 32:1927-1946. [PMID: 37079078 DOI: 10.1007/s00586-023-07708-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/18/2023] [Accepted: 04/07/2023] [Indexed: 04/21/2023]
Abstract
BACKGROUND Restoration of three-dimensional (3D) alignment is critical in correcting patients with adolescent idiopathic scoliosis using posterior spinal fusion (PSF). However, current studies mostly rely on 2D radiographs, resulting in inaccurate assessment of surgical correction and underlying predictive factors. While 3D reconstruction of biplanar radiographs is a reliable and accurate tool for quantifying spinal deformity, no study has reviewed the current literature on its use in evaluating surgical prognosis. PURPOSE To summarize the current evidence on patient and surgical factors affecting sagittal alignment and curve correction after PSF based on 3D parameters derived from reconstruction of biplanar radiographs. METHODS A comprehensive search was conducted by three independent investigators on Medline, PubMed, Web of Science, and Cochrane Library to obtain all published information on predictors of postoperative alignment and correction after PSF. Search items included "adolescent idiopathic scoliosis," "stereoradiography," "three-dimensional," "surgical," and "correction." The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool, and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations approach. 989 publications were identified, with 444 unique articles subjected to full-text screening. Ultimately, 41 articles were included. RESULTS Strong predictors of better curve correction included preoperative normokyphosis (TK > 15°), a corresponding rod contour, intraoperative vertebral rotation and translation, and upper and lower instrumented vertebrae selected based on sagittal and axial inflection points. For example, for Lenke 1 patients with junctional vertebrae above L1, fusion to NV-1 (1 level above the neutral vertebra) achieved optimal curve correction while preserving motion segments. Pre-op coronal Cobb angle and axial rotation, distal junctional kyphosis, pelvic incidence, sacral slope, and type of instrument were identified as predictors with moderate evidence. For Lenke 1C patients, > 50% LIV rotation was found to increase spontaneous lumbar curve correction. Pre-op thoracolumbar apical translation and lumbar lordosis, Ponte osteotomies, and rod material were found to be predictors with low evidence. CONCLUSIONS Rod contouring and UIV/LIV selection should be based on preoperative 3D TK in order to achieve normal postoperative alignment. Specifically, Lenke 1 patients with high-lying rotations should be fused distally at NV-1, while hypokyphotic patients with large lumbar curves and truncal shift should be fused at NV to improve lumbar alignment. Lenke 1C curves should be corrected using > 50% LIV rotation counterclockwise to the lumbar rotation. Further investigation should compare surgical correction between pedicle-screw and hybrid constructs using matched cohorts. DJK and overbending rods are potential predictors of postoperative alignment.
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Affiliation(s)
- Sandra Hiu-Tung Wan
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Darren Li-Liang Wong
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Samuel Ching-Hang To
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Nan Meng
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Teng Zhang
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Jason Pui-Yin Cheung
- Department of Orthopaedics and Traumatology, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
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9
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Han L, Ma H, Li Q, Yuan J, Yang H, Qin Y, Lu X. The association of rod curvature with postoperative outcomes in patients undergoing posterior lumbar interbody fusion for spinal stenosis: a retrospective case-control study. BMC Musculoskelet Disord 2023; 24:304. [PMID: 37072780 PMCID: PMC10111816 DOI: 10.1186/s12891-023-06404-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 04/06/2023] [Indexed: 04/20/2023] Open
Abstract
BACKGROUND Restoration of sagittal balance is a crucial consideration in posterior lumbar interbody fusion (PLIF) surgery and adverse postoperative outcomes are associated with inadequate restoration of sagittal alignment. However, there remains a shortage of substantial evidence regarding the effect of rod curvature on both sagittal spinopelvic radiographic parameters and clinical outcomes. METHOD A retrospective case-control study was conducted in this study. Patient demographics (age, gender, height, weight and BMI), surgical characteristics (number of fused levels, surgical time, blood loss and hospital stay) and radiographic parameters (lumbar lordosis [LL], sacral slope [SS], pelvic incidence [PI], pelvic tilt [PT], PI-LL, Cobb angle of fused segments [Cobb], rod curvature [RC], Posterior tangent angle of fused segments [PTA] and RC-PTA) were analyzed. RESULTS Patients in the abnormal group had older mean age and suffered more blood loss than those in the normal group. In addition, RC and RC-PTA were significantly lower in the abnormal group compared to the normal group. Multivariate regression analysis revealed that lower age (OR = 0.94; 95% CI: 0.89-0.99; P = 0.0187), lower PTA (OR = 0.91; 95% CI: 0.85-0.96; P = 0.0015) and higher RC (OR = 1.35; 95% CI: 1.20-1.51; P < 0.0001) were related to higher odds of better surgical outcomes. The receiver operating characteristic curve analysis showed that the ROC curve (AUC) for predicting outcomes of surgery by RC classifier was 0.851 (0.769-0.932). CONCLUSIONS In patients who underwent PLIF surgery for lumbar spinal stenosis, those who had a satisfactory postoperative outcome tended to be younger, had lower blood loss, and higher values of RC and RC-PTA compared to those who had poor recovery and required revision surgery. Additionally, RC was found to be a reliable predictor of postoperative outcomes.
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Affiliation(s)
- Lin Han
- Department of Orthopaedics, Third Affiliated Hospital of Naval Medical University, Shanghai, 200433, China
- Department of Orthopaedics, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Hongdao Ma
- Department of Orthopaedics, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Qisheng Li
- Department of Orthopaedics, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Jincan Yuan
- Department of Orthopaedics, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Haisong Yang
- Department of Orthopaedics, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China
| | - Yuchen Qin
- Department of Health Statistics, Second Military Medical University, Shanghai, 200003, China.
| | - Xuhua Lu
- Department of Orthopaedics, Shanghai Changzheng Hospital, Second Military Medical University, Shanghai, 200003, China.
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10
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Berlin C, Quante M, Halm H. [Increased risk of thoracic hypokyphosis after posterior spinal correction and fusion in adolescent idiopathic scoliosis with thoracic double curve]. ORTHOPADIE (HEIDELBERG, GERMANY) 2023; 52:233-242. [PMID: 36645436 DOI: 10.1007/s00132-022-04339-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/16/2022] [Indexed: 01/17/2023]
Abstract
BACKGROUND Adolescent idiopathic scoliosis (AIS) is often associated with thoracic hypokyphosis or even lordosis. OBJECTIVES To analyze the influence of posterior correction and fusion in thoracic, structurally double-curved AIS. MATERIAL AND METHODS Out of 127 thoracic AIS (Lenke types 1 and 2) recorded prospectively, idiopathic double thoracic curve AIS were analyzed retrospectively. Surgery 2010-2019 with pedicle screw double rod systems in a scoliosis center. Follow-up (FU) at least 2 years. Frontal and sagittal angles (whole-spine radiographs, 2 planes): thoracic curve (MK), proximal-thoracic curve (PK) and lumbar curve (LK), thoracic kyphosis (TK), lumbar lordosis (LL). STATISTICAL ANALYSIS values as MW ± SD, students t‑test (significance a = 0.05), Pearson's correlation, sub-analysis with sagittal modifiers (-, N, +). RESULTS A total of 47 AIS-double thoracic curve were identified, mean FU 29.3 ± 12.2 months, mean age 14 ± 1.5 years. The mean correction (FU-preop) of MK was 67%, PK 53%, LK 73%, each significant, (p < 0.05). On average, TK (FU-preop) decreased by -6.5 ± 11.6° (p < 0.05), no significant change from FU (p = 0.6). TK (FU-preop) increased by 8.6 ± 5.0° (p < 0.05) in hypokyphotic cases, significantly decreased by -4.8 ± 9.6° in normokyphotic AIS and -25.3 ± 11.1° in hyperkyphotic cases, respectively (p < 0.05). In hypokyphosis: moderately strong correlation between correction PK (r = -0.5) and spontaneous correction LK (r = 0.8) (frontal plane) and change from pre- to postop TK (sagittal plane) (p < 0.05). Moderate correlation for hyperkyphosis: correction PK (r = -0.5) and postop TK (p < 0.05). No relevant correlations for normokyphosis. 17% had postop hypokyphosis, of which 0% had preop hypokyphosis. Rod diameter (5.5 mm vs. 6 mm) had no significant effect on TC. CONCLUSIONS Posterior instrumented correction and fusion (pedicle screw dual rod systems) can significantly correct both lateral curves in idiopathic double thoracic curves, although it is associated with an increased risk of postop thoracic hypokyphosis, especially in preoperatively normokyphotic patients.
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Affiliation(s)
- Clara Berlin
- Wirbelsäulenchirurgie mit Skoliosezentrum, Schön Klinik Neustadt, Am Kiebitzberg 10, 23730, Neustadt in Holstein, Deutschland.
| | - Markus Quante
- Wirbelsäulenchirurgie mit Skoliosezentrum, Schön Klinik Neustadt, Am Kiebitzberg 10, 23730, Neustadt in Holstein, Deutschland
| | - Henry Halm
- Wirbelsäulenchirurgie mit Skoliosezentrum, Schön Klinik Neustadt, Am Kiebitzberg 10, 23730, Neustadt in Holstein, Deutschland
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11
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Sardi JP, Ames CP, Coffey S, Good C, Dahl B, Kraemer P, Gum J, Devito D, Brayda-Bruno M, Lee R, Bell CP, Bess S, Smith JS. Accuracy of Rod Contouring to Desired Angles With and Without a Template: Implications for Achieving Desired Spinal Alignment and Outcomes. Global Spine J 2023; 13:425-431. [PMID: 33631976 PMCID: PMC9972287 DOI: 10.1177/2192568221998371] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
STUDY DESIGN Biomechanical Study. OBJECTIVE The search for optimal spinal alignment has led to the development of sophisticated formulas and software for preoperative planning. However, preoperative plans are not always appropriately executed since rod contouring during surgery is often subjective and estimated by the surgeon. We aimed to assess whether rods contoured to specific angles with a French rod bender using a template guide will be more accurate than rods contoured without a template. METHODS Ten experienced spine surgeons were requested to contour two 125 × 5.5 mm Ti64 rods to 40°, 60° and 80° without templates and then 2 more rods using 2D metallic templates with the same angles. Rod angles were then measured for accuracy and compared. RESULTS Average angles for rods bent without a template to 40°, 60° and 80° were 60.2°, 78.9° and 97.5°, respectively. Without a template, rods were overbent by a mean of 18.9°. When using templates of 40°, 60° and 80°, mean bend angles were 41.5°, 59.1° and 78.7°, respectively, with an average underbend of 0.2°. Differences between the template and non-template groups for each target angle were all significant (p < 0.001). CONCLUSIONS Without the template, surgeons tend to overbend rods compared to the desired angle, while surgeons improved markedly with a template guide. This tendency to overbend could have significant impact on patient outcomes and risk of proximal junctional failure and warrants further research to better enable surgeons to more accurately execute preoperative alignment plans.
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Affiliation(s)
- Juan Pablo Sardi
- Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA
| | - Christopher P. Ames
- Department of Neurosurgery, University of California San Francisco, San Francisco, CA, USA
| | - Skye Coffey
- University of Virginia School of Medicine, Charlottesville, VA, USA
| | | | - Benny Dahl
- Department of Orthopedic Surgery, Texas Children’s Hospital & Baylor College of Medicine, Houston, TX, USA
| | | | - Jeffrey Gum
- Norton Leatherman Spine Center, Louisville, KY, USA
| | | | - Marco Brayda-Bruno
- Scoliosis Department, IRCCS Orthopaedic Institute Galeazzi, Spine Surgery, Milano, Italy
| | - Robert Lee
- Department of Spinal Surgery, Royal National Orthopaedic Hospital, Stanmore, UK
| | | | - Shay Bess
- Denver International Spine Center, Presbyterian St. Luke’s/Rocky Mountain Hospital for Children, Denver, CO, USA
| | - Justin S. Smith
- Department of Neurosurgery, University of Virginia, Charlottesville, VA, USA,Justin S. Smith, MD, PhD, Department of Neurosurgery, University of Virginia Health Sciences Center, PO Box 800212 Charlottesville, VA 22908, USA.
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12
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Berlin C, Quante M, Halm H. Influence of posterior instrumented correction with pedicle screw dual rod systems on thoracic kyphosis in Lenke 1 and 2 curves: minimum 2 years follow-up. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2023; 32:1187-1195. [PMID: 36856867 DOI: 10.1007/s00586-023-07617-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 02/13/2023] [Accepted: 02/18/2023] [Indexed: 03/02/2023]
Abstract
PURPOSE Adolescent idiopathic scoliosis (AIS) often correspond with hypo thoracic kyphosis (TK) or even lordosis. The aim of this study was to analyze the influence of posterior instrumentation in thoracic AIS. METHODS Analysis of prospectively collected AIS-data with structural thoracic curves (Lenke type 1 & 2), operated 2010-2019 with pedicle screw dual rod systems in one scoliosis center. Follow-up (FU) minimum 24 months. Coronal and sagittal angles measured based on standing long-cassette-X-rays: thoracic major (MC), proximal thoracic (PC) and lumbar curve (LC), TK, lumbar lordosis (LL). STATISTICAL ANALYSIS values as mean ± SD, differences by student's t-test (significancy a = 0.05), Pearson's correlation, sub-analysis with sagittal modifier (-, N, +). RESULTS A total of 127 AIS could be identified (63% type 1, 37% type 2). Mean FU 32.2 ± 16.6 months, mean age 14 ± 1.5 years. Mean Correction of MC 73 ± 12%, PC 51 ± 17%, LC 69 ± 21% with a significantly better correction of PC in Lenke 2 curves(p < 0.05). On average, TK (FU-preop) decreased by -2.1 ± 12.1°(p < 0.05) in all AIS. Whereas TK in type 1 was unchanged (p = 0.9), TK significantly decreased by - 6.0 ± 12.7°(p < 0.05) in type 2. No significant difference in LL. TK in hypokyphotic cases increased by 9.5 ± 5.5°(p < 0.05), stayed almost unchanged (- 1.4 ± 9.1°,p = 0.2) in normokyphotic, decreased by - 17.2 ± 14.2°(p < 0.05) in hyperkyphotic cases. Only hypokyphotic cases had a moderately strong correlation between correction of LC (r = 0.6) and PC (r = - 0.4) (frontal plane) and change from pre- to postoperative TK (sagittal plane) (r = 0.6). No relevant correlations for normo- and hyperkyphotic AIS. Postoperative hypokyphosis was significantly more often in Lenke 2 (16.3% vs. 2.6%, p < 0.05). Rod diameter (5,5 mm versus 6 mm) had no significant influence. CONCLUSION Significant correction of hypo- and hyperkyphosis can be achieved with posterior spinal fusion (pedicle screw dual rod systems), whereas normokyphotic spines stay unchanged. However, Lenke 2 curves have a significantly higher risk for a postoperative thoracic hypokyphosis.
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Affiliation(s)
- Clara Berlin
- Spine Surgery with Scoliosis Center, Schön Klinik Neustadt, Am Kiebitzberg 10, 23730, Neustadt in Holstein, Germany.
| | - Markus Quante
- Spine Surgery with Scoliosis Center, Schön Klinik Neustadt, Am Kiebitzberg 10, 23730, Neustadt in Holstein, Germany
| | - Henry Halm
- Spine Surgery with Scoliosis Center, Schön Klinik Neustadt, Am Kiebitzberg 10, 23730, Neustadt in Holstein, Germany
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13
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Lopez Poncelas M, La Barbera L, Rawlinson JJ, Polly DW, Aubin CE. Influence of spinal lordosis correction location on proximal junctional failure: a biomechanical study. Spine Deform 2023; 11:49-58. [PMID: 36083462 DOI: 10.1007/s43390-022-00571-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 08/13/2022] [Indexed: 10/14/2022]
Abstract
STUDY DESIGN Assessment of sagittal lordosis distribution on mechanical proximal junctional failure-related risks through computer-based biomechanical models. OBJECTIVE To biomechanically assess how lordosis distribution influences radiographical and biomechanical indices related to Proximal Junctional Failure (PJF). The "optimal" patient-specific targets to restore the sagittal balance in posterior spinal fusion are still not known. Among these, the effect of the lumbar lordosis correction strategy on complications such as PJF remain uncertain. METHODS In this computational biomechanical study, five adult spinal deformity patients who underwent posterior spinal fixation were retrospectively reviewed. Their surgery, first erect posture and flexion movement were simulated with a patient-specific multibody model. Three pedicle subtraction osteotomy (PSO) levels (L3, L4, and L5) were simulated, with consistent global lordosis for a given patient and pelvic tilt adjusted accordingly to the actual surgery. Computed loads on the anterior spine and instrumentation were analyzed and compared using Kruskal-Wallis statistical tests and Spearman correlations. RESULTS In these models, no significant correlations were found between the lordosis distribution index (LDI), PSO level and biomechanical PJF-related indices. However, increasing the sagittal vertical axis (SVA) and thoracolumbar junction angle (TLJ) and decreasing the sacral slope (SS) increased the bending moment sustained by the rods at the proximal instrumented level (r = 0.52, 0.57, - 0.56, respectively, p < 0.05). There was a negative correlation between SS and the bending moment held by the adjacent proximal segment (r = - 0.71, p < 0.05). CONCLUSION Based on these biomechanical simulations, there was no correlation between the lordosis distribution and PJF-associated biomechanical factors. However, increasing SS and flattening the TLJ, as postural adjustment strategies required by a more distal PSO, did decrease such PJF-related factors. Sagittal restoration and PJF risks remain multifactorial, and the use of patient-specific biomechanical models may help to better understand the complex interrelated mechanisms.
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Affiliation(s)
- Maeva Lopez Poncelas
- Department of Mechanical Engineering, Polytechnique Montréal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada.,Research Center, Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada
| | - Luigi La Barbera
- Department of Mechanical Engineering, Polytechnique Montréal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada.,Research Center, Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada.,Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Piazza Leonardo da Vinci, 32 20133, Milan, MI, Italy
| | - Jeremy J Rawlinson
- Department of Mechanical Engineering, Polytechnique Montréal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada.,Spine Applied Research, Cranial and Spinal Technologies Medtronic, 18400 Pyramid Place, Memphis, TN, 38132, USA
| | - David W Polly
- Department of Orthopaedic Surgery, University of Minnesota, 2512 South 7th Street, Suite R200, Minneapolis, MN, 55455, USA
| | - Carl-Eric Aubin
- Department of Mechanical Engineering, Polytechnique Montréal, Downtown Station, P.O. Box 6079, Montreal, QC, H3C 3A7, Canada. .,Research Center, Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal, QC, H3T 1C5, Canada.
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14
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Proximal junctional failure after surgical instrumentation in adult spinal deformity: biomechanical assessment of proximal instrumentation stiffness. Spine Deform 2023; 11:59-69. [PMID: 36083461 DOI: 10.1007/s43390-022-00574-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 08/13/2022] [Indexed: 10/14/2022]
Abstract
STUDY DESIGN Assessment of different proximal instrumentation stiffness features to minimize the mechanical proximal junctional failure-related risks through computer-based biomechanical models. OBJECTIVE To biomechanically assess variations of proximal instrumentation and loads acting on the spine and construct to minimize proximal junctional failure (PJF) risks. The use of less-stiff fixation such as hooks or tensioned bands, compared to pedicle screws, at the proximal instrumentation level are considered to allow for a gradual transition in stiffness with the adjacent levels, but the impact of such flexible fixation on the loads balance and complications such as PJF remain uncertain. METHODS Six patients with adult spine deformity who underwent posterior spinal instrumentation were used to numerically model and simulate the surgical steps, erected posture, and flexion functional loading in patient-specific multibody analyses. Three types of upper-level fixation (pedicle screws (PS), supralaminar hooks (SH), and sublaminar bands (SB) with tensions of 50, 250, and 350 N) and rod stiffness (CoCr/6 mm, CoCr/5.5 mm, Ti/5.5 mm) were simulated. The loads acting on the spine and implants of the 90 simulated configurations were analyzed using Kruskal-Wallis statistical tests. RESULTS Simulated high-tensioned bands decreased the sagittal moment at the adjacent level proximal to the instrumentation (1.3 Nm at 250 N; 2.5 Nm at 350 N) compared to screws alone (PS) (15.6 Nm). At one level above, the high-tensioned SB increased the sagittal moment (17.7 Nm-SB vs. 15.5 Nm-PS) and bending moment on the rods (5.4 Nm and 5.7 Nm vs. 0.6 Nm) (p < 0.05). SB with 50 N tension yielded smaller changes in load transition compared to higher tension, with moments of 8.1 Nm and 16.8 Nm one and two levels above the instrumentation. The sagittal moment at the upper implant-vertebra connection decreased with the rod stiffness (1.0 Nm for CoCr/6 mm vs. 0.7 Nm for Ti/5.5 mm; p < 0.05). CONCLUSION Simulated sublaminar bands with lower tension produced smaller changes in the load transition across proximal junctional levels. Decreasing the rod stiffness further modified these changes, with a decrease in loads associated with bone failure, however, lower stiffness did increase the rod breakage risk. LEVEL OF EVIDENCE N/A.
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15
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Thomas ES, Boyer N, Meyers A, Aziz H, Aminian A. Restoration of thoracic kyphosis in adolescent idiopathic scoliosis with patient-specific rods: did the preoperative plan match postoperative sagittal alignment? EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2023; 32:190-201. [PMID: 36357540 DOI: 10.1007/s00586-022-07437-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 09/17/2022] [Accepted: 10/25/2022] [Indexed: 11/12/2022]
Abstract
PURPOSE To determine if the planned sagittal profile for thoracic kyphosis (TK) restoration was achieved after adolescent idiopathic scoliosis (AIS) surgery using a novel hybrid construct with apical double bands and precontoured patient-specific rods (PSR) made according to the detailed surgical plan for the desired sagittal plane. METHODS AIS patients with a Lenke type 1-4 primary right thoracic curve who underwent corrective surgery by a single surgeon and had minimum 24-month follow-up were analyzed retrospectively from a prospective database. All patients underwent simultaneous translation on two rods with apical double bands and PSR. Clinical outcomes in terms of sagittal 2D TK (T4-T12), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), PI-LL mismatch, rod angle, and rod deflection were compared between preoperative, planned, and 24-month data, while 3D apical rotation, 3D TK (T5-T12), sagittal thoracolumbar angle, degree of curvature at L1-L4 and L4-S1, proximal junctional angle, and distal junctional angle were compared at baseline and at 6 and 24 months postoperatively. SRS-22 questionnaire scores were obtained at baseline and 24 months postoperatively. RESULTS Forty-eight patients were included. Study patients had a median coronal thoracic curve of 62.7° preoperatively and 22.4° at 24-month follow-up (p < 0.001). Median TK gain was 6.5° for the entire cohort (n = 48) and 19.1° in the Lenke type 1 and 2 hypokyphotic subgroup (n = 14). Both groups had no significant changes between planned and 24-month TK (p = 0.068 and p = 0.943, respectively), rod angle (p = 0.776 and p = 0.548, respectively), or rod deflection (p = 0.661 and p = 0.850, respectively). For the overall study cohort, median LL gain was 7.0° (p < 0.001), 3D apical derotation was 10.7° (p < 0.001), and change in 3D TK was 36° (p < 0.001). No instance of proximal junctional kyphosis was observed. SRS-22 scores for pain, self-image, and satisfaction differed significantly between the preoperative and 24-month follow-up time-points. CONCLUSIONS With sagittal plane planning, desired TK, improved reciprocal changes in LL, and minimal changes in rod shape can be achieved in patients with AIS.
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Affiliation(s)
- Evelyn S Thomas
- Department of Orthopedic Surgery, Children's Hospital of Orange County, 1201 W La Veta Ave, Orange, CA, 92868, USA. .,Department of Orthopedic Surgery, Kettering Health Dayton, Dayton, OH, USA.
| | - Noah Boyer
- Department of Orthopedic Surgery, Children's Hospital of Orange County, 1201 W La Veta Ave, Orange, CA, 92868, USA
| | - Andrew Meyers
- Department of Orthopedic Surgery, Community Memorial Hospital, Ventura, CA, USA
| | - Hossein Aziz
- Department of Orthopedic Surgery, Children's Hospital of Orange County, 1201 W La Veta Ave, Orange, CA, 92868, USA.,Department of Orthopedic Surgery, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Afshin Aminian
- Department of Orthopedic Surgery, Children's Hospital of Orange County, 1201 W La Veta Ave, Orange, CA, 92868, USA
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16
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Bowden D, Michielli A, Merrill M, Will S. Systematic review and meta-analysis for the impact of rod materials and sizes in the surgical treatment of adolescent idiopathic scoliosis. Spine Deform 2022; 10:1245-1263. [PMID: 35737287 PMCID: PMC9579082 DOI: 10.1007/s43390-022-00537-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/28/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE To assess surgical and safety outcomes associated with different rod materials and diameters in adolescent idiopathic scoliosis (AIS) surgery. METHODS A systematic literature review and meta-analysis evaluated the surgical management of AIS patients using pedicle screw fixation systems (i.e., posterior rods and pedicle screws) with rods of different materials and sizes. Postoperative surgical outcomes (e.g., kyphosis and coronal correction) and complications (i.e., hyper/hypo-lumbar lordosis, proximal junctional kyphosis, revisions, reoperations, and infections) were assessed. Random-effects models (REMs) pooled data for outcomes reported in ≥ 2 studies. RESULTS Among 75 studies evaluating AIS surgery using pedicle screw fixation systems, 46 described rod materials and/or diameters. Two studies directly comparing titanium (Ti) and cobalt-chromium (CoCr) rods found that CoCr rods provided significantly better postoperative kyphosis angle correction vs. Ti rods during a shorter follow-up (0-3 months, MD = - 2.98°, 95% CI - 5.79 to - 0.17°, p = 0.04), and longer follow-up (≥ 24 months, MD = - 3.99°, 95% CI - 6.98 to - 1.00, p = 0.009). Surgical infection varied from 2% (95% CI 1.0-3.0%) for 5.5 mm rods to 4% (95% CI 2.0-7.0%) for 6 mm rods. Reoperation rates were lower with 5.5 mm rods 1% (95% CI 0.0-3.0%) vs. 6 mm rods [6% (95% CI 2.0-9.0%); p = 0.04]. Differences in coronal angle, lumbar lordosis, proximal junctional kyphosis, revisions, and infections did not differ significantly (p > 0.05) among rods of different materials or diameters. CONCLUSION For AIS, CoCr rods provided better correction of thoracic kyphosis compared to Ti rods. Patients with 5.5 mm rods had fewer reoperations vs. 6.0 and 6.35 mm diameter rods. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Dawn Bowden
- DePuy Synthes Spine, Johnson & Johnson Medical Devices, 325 Paramount Drive, Raynham, MA, 02767, USA.
| | - Annalisa Michielli
- DePuy Synthes Spine, Johnson & Johnson Medical Devices, 325 Paramount Drive, Raynham, MA, 02767, USA
| | - Michelle Merrill
- DePuy Synthes Spine, Johnson & Johnson Medical Devices, 325 Paramount Drive, Raynham, MA, 02767, USA
| | - Steven Will
- DePuy Synthes Spine, Johnson & Johnson Medical Devices, 325 Paramount Drive, Raynham, MA, 02767, USA
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17
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Assessment of Rod Bending Accuracy for Sagittal Spinal Deformity Correction on 3D Printed Moulage. ARCHIVES OF NEUROSCIENCE 2022. [DOI: 10.5812/ans-129307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background: One of the most important objectives in the deformity correction surgery of spine is to achieve appropriate sagittal alignment, to improve patient outcome and reduce the risk of junctional failure. Intra-operative rod bending is crucial to achieve desired alignment. Objectives: Assessment of accuracy of rod bending by spine surgeons with or with-out template and/or correction. Methods: Spine surgeons were asked to bend two rods; one in-situ on three-dimensional (3D) printed moulage, designed based on schematic representation of a patient with Kyphoscoliosis, the other rod was asked to bend with correction angles. The differences were measured and correlated with experience and specialty. Results: 21 fellowship trained spine surgeons participated in this study, for in-situ rod, mean thoracic and lumbar bend were 65.2 (P = 0.033) and 49.3 (P = 0.077) degrees, respectively and for the correction rod, mean bend in thoracic and lumbar were 53.8 (P = 0.001) and 51.8 (P = 0.004) degrees, respectively, with significant difference from cut-off point. Each curve was over-bend and it was more pronounce in thoracic, both on in-situ and correction rods, 61.9 and 71.1 %, respectively. Level of experience showed positive correlation with degree of rod bending more than five years in thoracic in-situ bend (P = 0.003) and thoracic bend with correction (P = 0.004). Field of specialty showed positive correlation as well; with orthopedic in-situ bend (P = 0.002) and with correction (P = 0.003). Conclusions: Spine surgeons tend to over-bend rods, when given target angles and when correction is needed. However, when provided with template, a 3D printed moulage in our study, accuracy of rod bending improved significantly.
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18
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The Sagittal Plane in Spinal Fusion for Adolescent Idiopathic Scoliosis. J Am Acad Orthop Surg 2022; 30:e957-e967. [PMID: 35797683 DOI: 10.5435/jaaos-d-21-01060] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 04/24/2022] [Indexed: 02/01/2023] Open
Abstract
Sagittal balance is widely recognized as the primary determinant of optimal outcomes in adult spinal deformity. In adolescent idiopathic scoliosis (AIS), coronal correction risks being obtained at the expense of sagittal malalignment after posterior spinal fusion. Apical lordosis, often underestimated on two-dimensional imaging, is the primary deforming factor in AIS. Failure to restore thoracic kyphosis and lumbar lordosis during posterior spinal fusion contributes to problematic early surgical complications, including proximal or distal junctional kyphosis and failure. Although adolescent patients often compensate for sagittal imbalance in the short-term and mid-term, late sequelae of iatrogenic sagittal imbalance include flatback syndrome, disk degeneration, cervical kyphosis, and late decompensation. Objective criteria using spinopelvic parameters and preoperative three-dimensional planning can guide sagittal plane correction during PSF for AIS. Technical caveats can help avoid sagittal plane complications, including instrumentation level selection, anchor type, and anatomic protection of adjacent levels. Other surgical techniques to optimize restoration of thoracic kyphosis include higher implant density, stiffer rod material, Ponte osteotomies, and deformity correction technique.
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19
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Harfouch EB, Bunyan RF, Al Faraidy M, Dajim NB, Al Mulhim FA, Alnemari HH, Bashir S. The Effect of Ponte Osteotomies on the Sagittal Shape of Rods and Spine Derotation in Adolescent Idiopathic Scoliosis: A Single-Center, Retrospective Cohort Study. World Neurosurg X 2022; 15:100125. [PMID: 35620483 PMCID: PMC9126986 DOI: 10.1016/j.wnsx.2022.100125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/19/2022] [Indexed: 11/16/2022] Open
Abstract
Background Adding a Ponte osteotomy (PO) to other surgical techniques for correcting adolescent idiopathic scoliosis (AIS) profoundly affects the entire sagittal shape of the rod. POs are an effective procedure for correcting thoracic hypokyphosis in patients with AIS. Methods A retrospective review of 40 patients with AIS was conducted. The sample was divided into 2 groups: PO and non-PO. On a lateral radiograph, the rod end angle (A) was calculated using the intersections of the tangents with the rod end points. The maximal deflection (D) was obtained for each rod. In addition, the rod apex angle (B) was calculated using the intersection of the tangents at 2 points, each 1 cm to 1 side of the rod apex; the distance between the rods at the apex was then measured. Results Concave rods tended to be straight or even lordotic at the apex in the non-PO group (−0.9° vs. +5.9° in the PO group; P = 0.000). The rod end angle and deflection were significantly lower in the non-PO group (15.2° and 7.1 mm vs. 26.3° and 17.8 mm in the PO group; P = 0.000 and P = 0.000). The convex rods were less kyphotic in the non-PO group; for the non-PO group, the end angle and deflection were 27.6° and 16 mm versus 33.4° and 23.8 mm in the PO group (P = 0.03 and P = 0.000). No significant difference between the groups was observed for the convex rod apex angle (P = 0.8). The rod apices were more superimposed in the PO group (2.9 mm vs. 9.3 mm in the non-PO group; P = 0.000). Conclusions POs increase the overall sagittal kyphosis and improve the three-dimensional derotation of the apex in patients with AIS.
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Affiliation(s)
| | - Reem Fahd Bunyan
- Department of Neurology, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Mona Al Faraidy
- Department of Anesthesia, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | - Nayef Bin Dajim
- Department of Spine, King Fahad Specialist Hospital, Dammam, Saudi Arabia
| | | | - Haitham H Alnemari
- Department of Spine, King Faisal Medical City, Abha, Saudi Arabia.,Department of Spine, McMaster University, Hamilton, Ontario, Canada
| | - Shahid Bashir
- Neuroscience Center, King Fahad Specialist Hospital, Dammam, Saudi Arabia
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20
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Eltes PE, Turbucz M, Fayad J, Bereczki F, Szőke G, Terebessy T, Lacroix D, Varga PP, Lazary A. A Novel Three-Dimensional Computational Method to Assess Rod Contour Deformation and to Map Bony Fusion in a Lumbopelvic Reconstruction After En-Bloc Sacrectomy. Front Surg 2022; 8:698179. [PMID: 35071306 PMCID: PMC8766313 DOI: 10.3389/fsurg.2021.698179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction: En-bloc resection of a primary malignant sacral tumor with wide oncological margins impacts the biomechanics of the spinopelvic complex, deteriorating postoperative function. The closed-loop technique (CLT) for spinopelvic fixation (SPF) uses a single U-shaped rod to restore the spinopelvic biomechanical integrity. The CLT method was designed to provide a non-rigid fixation, however this hypothesis has not been previously tested. Here, we establish a computational method to measure the deformation of the implant and characterize the bony fusion process based on the 6-year follow-up (FU) data. Materials and Methods: Post-operative CT scans were collected of a male patient who underwent total sacrectomy at the age of 42 due to a chordoma. CLT was used to reconstruct the spinopelvic junction. We defined the 3D geometry of the implant construct. Using rigid registration algorithms, a common coordinate system was created for the CLT to measure and visualize the deformation of the construct during the FU. In order to demonstrate the cyclical loading of the construct, the patient underwent gait analysis at the 6th year FU. First, a region of interest (ROI) was selected at the proximal level of the construct, then the deformation was determined during the follow-up period. In order to investigate the fusion process, a single axial slice-based voxel finite element (FE) mesh was created. The Hounsfield values (HU) were determined, then using an empirical linear equation, bone mineral density (BMD) values were assigned for every mesh element, out of 10 color-coded categories (1st category = 0 g/cm3, 10th category 1.12 g/cm3). Results: Significant correlation was found between the number of days postoperatively and deformation in the sagittal plane, resulting in a forward bending tendency of the construct. Volume distributions were determined and visualized over time for the different BMD categories and it was found that the total volume of the elements in the highest BMD category in the first postoperative CT was 0.04 cm3, at the 2nd year, FU was 0.98 cm3, and after 6 years, it was 2.30 cm3. Conclusion: The CLT provides a non-rigid fixation. The quantification of implant deformation and bony fusion may help understate the complex lumbopelvic biomechanics after sacrectomy.
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Affiliation(s)
- Peter Endre Eltes
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Buda Health Center, Budapest, Hungary
- Department of Spine Surgery, Semmelweis University, Budapest, Hungary
- *Correspondence: Peter Endre Eltes
| | - Mate Turbucz
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Buda Health Center, Budapest, Hungary
- School of PhD Studies, Semmelweis University, Budapest, Hungary
| | - Jennifer Fayad
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Buda Health Center, Budapest, Hungary
- Department of Industrial Engineering, Alma Mater Studiorum, Universita di Bologna, Bologna, Italy
| | - Ferenc Bereczki
- In Silico Biomechanics Laboratory, National Center for Spinal Disorders, Buda Health Center, Budapest, Hungary
- School of PhD Studies, Semmelweis University, Budapest, Hungary
| | - György Szőke
- Department of Orthopaedics, Semmelweis University, Budapest, Hungary
| | - Tamás Terebessy
- Department of Orthopaedics, Semmelweis University, Budapest, Hungary
| | - Damien Lacroix
- INSIGNEO Institute for In Silico Medicine, Department of Mechanical Engineering, The University of Sheffield, Sheffield, United Kingdom
| | - Peter Pal Varga
- National Center for Spinal Disorders, Buda Health Center, Budapest, Hungary
| | - Aron Lazary
- Department of Spine Surgery, Semmelweis University, Budapest, Hungary
- National Center for Spinal Disorders, Buda Health Center, Budapest, Hungary
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21
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Tachi H, Kato K, Abe Y, Kokabu T, Yamada K, Iwasaki N, Sudo H. Surgical Outcome Prediction Using a Four-Dimensional Planning Simulation System With Finite Element Analysis Incorporating Pre-bent Rods in Adolescent Idiopathic Scoliosis: Simulation for Spatiotemporal Anatomical Correction Technique. Front Bioeng Biotechnol 2021; 9:746902. [PMID: 34712654 PMCID: PMC8546212 DOI: 10.3389/fbioe.2021.746902] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 09/09/2021] [Indexed: 01/15/2023] Open
Abstract
An optimal surgical strategy for adolescent idiopathic scoliosis (AIS) is to provide maximal deformity correction while preserving spinal mobile segments as much as possible and obtaining a balanced posture. From a spatiotemporal deformity correction standpoint, we recently showed that anatomical four-dimensional (4D) spinal correction could be accomplished by curving the rod. In the surgical procedure, two rods are bent identically to confirm spinal anatomical alignment without referring to the intraoperative alignment of the deformity. Therefore, anatomically designed rods have been developed as notch-free, pre-bent rods for easier anatomical reconstruction. In addition to providing the best spinal instrumentation configurations as pre-bent rods, prediction of surgical outcome along with its biomechanical impact can be obtained by simulation of the surgical procedures with computer modeling. However, an objective model that can simulate the surgical outcome in patients with AIS has not been completely elucidated. The present study aimed to compare simulated deformity corrections based on our newly developed spatiotemporal morphological 4D planning simulation system incorporating pre-bent rods and actual deformity corrections in patients with AIS. A consecutive series of 47 patients who underwent anatomical posterior correction for AIS curves were prospectively evaluated. After multilevel facetectomy, except for the lowest instrumented segment, 11 types of pre-bent rods were used. Patient demographic data, radiographic measurements, and sagittal rod angles were analyzed within 1 week of surgery. Our simulation system incorporating pre-bent rods showed a significant correlation with the actual postoperative spinal alignment. The present study demonstrated the feasibility of our simulation system and the ability to simulate the surgical procedure using the pre-bent rods. The simulation system can be used to minimize the differences between the optimal and possible outcomes related to the instrumentation levels and rod shapes. Preoperative assumption of rod shape and length can contribute to a reduction in operative time which decreases blood loss and risk of infection. The results of the finite element analysis in the simulation system measured for each individual patient would also provide a more realistic representation of the surgical procedures.
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Affiliation(s)
- Hiroyuki Tachi
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.,Department of Orthopaedic Surgery, Eniwa Hospital, Eniwa, Japan
| | - Koji Kato
- Department of Systems Information Science, Future University Hakodate, Hakodate, Japan
| | - Yuichiro Abe
- Department of Orthopaedic Surgery, Eniwa Hospital, Eniwa, Japan
| | - Terufumi Kokabu
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Katsuhisa Yamada
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Hideki Sudo
- Department of Orthopaedic Surgery, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan.,Department of Advanced Medicine for Spine and Spinal Cord Disorders, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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22
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Inoue G, Saito W, Miyagi M, Imura T, Shirasawa E, Ikeda S, Mimura Y, Kuroda A, Yokozeki Y, Inoue S, Akazawa T, Nakazawa T, Uchida K, Takaso M. Prevalence and location of endplate fracture and subsidence after oblique lumbar interbody fusion for adult spinal deformity. BMC Musculoskelet Disord 2021; 22:880. [PMID: 34649548 PMCID: PMC8518321 DOI: 10.1186/s12891-021-04769-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 10/04/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Recently, Oblique lumbar interbody fusion (OLIF) is commonly indicated to correct the sagittal and coronal alignment in adult spinal deformity (ASD). Endplate fracture during surgery is a major complication of OLIF, but the detailed location of fracture in vertebral endplate in ASD has not yet been determined. We sought to determine the incidence and location of endplate fracture and subsidence of the OLIF cage in ASD surgery, and its association with fusion status and alignment. METHODS We analyzed 75 levels in 27 patients were analyzed using multiplanar CT to detect the endplate fracture immediately after surgery and subsidence at 1 year postoperatively. The prevalence was compared between anterior and posterior, approach and non-approach sides, and concave and convex side. Their association with fusion status, local and global alignment, and complication was also investigated. RESULTS Endplate fracture was observed in 64 levels (85.3%) in all 27 patients, and the incidence was significantly higher in the posterior area compared with the anterior area (85.3 vs. 68.0%, p=0.02) of affected vertebra in the sagittal plane. In the coronal plane, there was no significant difference in incidence between left (approach) and right (non-approach) sides (77.3 and 81.3%, respectively), or concave and convex sides (69.4 and 79.6%) of wedged vertebra. By contrast, cage subsidence at 1 year postoperatively was noted in 14/75 levels (18.7%), but was not associated with endplate fracture. Fusion status, local and global alignment, and complications were not associated with endplate fracture or subsidence. CONCLUSION Endplate fracture during OLIF procedure in ASD cases is barely avoidable, possibly induced by the corrective maneuver with ideal rod counter and cantilever force, but is less associated with subsequent cage subsidence, fusion status, and sustainment of corrected alignment in long fusion surgery performed even for elderly patients.
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Affiliation(s)
- Gen Inoue
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan.
| | - Wataru Saito
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan.,Department of Orthopaedic Surgery, Kitasato University Medical Center, Kitamoto, Saitama, Japan
| | - Masayuki Miyagi
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Takayuki Imura
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Eiki Shirasawa
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Shinsuke Ikeda
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Yusuke Mimura
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Akiyoshi Kuroda
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Yuji Yokozeki
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Sho Inoue
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Tsutomu Akazawa
- Department of Orthopaedic Surgery, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan
| | - Toshiyuki Nakazawa
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
| | - Kentaro Uchida
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan.,Shonan University of Medical Sciences Research Institute, Chigasaki, Kanagawa, Japan
| | - Masashi Takaso
- Department of Orthopaedic Surgery, Kitasato University School of Medicine, 1-15-1, Kitazato, Minami-ku, Sagamihara, Kanagawa, 252-0374, Japan
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23
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Lopez Poncelas M, La Barbera L, Rawlinson JJ, Crandall D, Aubin CE. Credibility assessment of patient-specific biomechanical models to investigate proximal junctional failure in clinical cases with adult spine deformity using ASME V&V40 standard. Comput Methods Biomech Biomed Engin 2021; 25:543-553. [PMID: 34427119 DOI: 10.1080/10255842.2021.1968380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Computational models are increasingly used to assess spine biomechanics and support surgical planning. However, varying levels of model verification and validation, along with characterization of uncertainty effects limit the level of confidence in their predictive potential. The objective was to assess the credibility of an adult spine deformity instrumentation model for proximal junction failure (PJF) analysis using the ASME V&V40:2018 framework. To assess model applicability, the surgery, erected posture, and flexion movement of actual clinical cases were simulated. The loads corresponding to PJF indicators for a group of asymptomatic patients and a group of PJF patients were compared. Model consistency was demonstrated by finding PJF indicators significantly higher for the simulated PJF vs. asymptomatic patients. A detailed sensitivity analysis and uncertainty quantification were performed to further establish the model credibility.
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Affiliation(s)
- M Lopez Poncelas
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Quebec, Canada.,Research Center, Sainte-Justine University Hospital Center, Montréal, Quebec, Canada
| | - L La Barbera
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Quebec, Canada.,Research Center, Sainte-Justine University Hospital Center, Montréal, Quebec, Canada.,Department of Chemistry and Chemical Engineering, Politecnico di Milano, Milano, Italy
| | - J J Rawlinson
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Quebec, Canada.,Applied Research, Medtronic Spine, Memphis, TN, USA
| | - D Crandall
- Sonoran Spine Center, Tempe, AZ, USA.,Mayo Clinic School of Medicine, Phoenix, AZ, USA.,School of Medicine, University of Arizona, Phoenix, AZ, USA
| | - C E Aubin
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Quebec, Canada.,Research Center, Sainte-Justine University Hospital Center, Montréal, Quebec, Canada
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24
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Sudo H, Tachi H, Kokabu T, Yamada K, Iwata A, Endo T, Takahata M, Abe Y, Iwasaki N. In vivo deformation of anatomically pre-bent rods in thoracic adolescent idiopathic scoliosis. Sci Rep 2021; 11:12622. [PMID: 34135445 PMCID: PMC8209019 DOI: 10.1038/s41598-021-92187-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 06/07/2021] [Indexed: 11/18/2022] Open
Abstract
Some surgical strategies can maintain or restore thoracic kyphosis (TK); however, next-generation surgical schemes for adolescent idiopathic scoliosis (AIS) should consider anatomical corrections. A four-dimensional correction could be actively achieved by curving the rod. Thus, anatomically designed rods have been developed as notch-free, pre-bent rods for easier anatomical reconstruction. This study aimed to compare the initial curve corrections obtained using notch-free rods and manually bent, notched rods for the anatomical reconstruction of thoracic AIS. Two consecutive series of 60 patients who underwent anatomical posterior correction for main thoracic AIS curves were prospectively followed up. After multilevel facetectomy, except for the lowest instrumented segment, either notch-free or notched rods were used. Patient demographic data, radiographic measurements, and sagittal rod angles were analyzed within 1 week after surgery. Patients with notch-free rods had significantly higher postoperative TK than patients with notched rods (P < .001), but both groups achieved three-dimensional spinal corrections and significantly increased postoperative rates of patients with T6–T8 TK apex (P = .006 for notch-free rods and P = .008 for notched rods). The rod deformation angle at the concave side was significantly lower in the notch-free rods than in the notched rods (P < .001). The notch-free, pre-bent rod can maintain its curvature, leading to better correction or maintenance of TK after anatomical spinal correction surgery than the conventional notched rod. These results suggest the potential benefits of anatomically designed notch-free, pre-bent rods over conventional, manually bent rods.
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Affiliation(s)
- Hideki Sudo
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan. .,Department of Orthopaedic Surgery, Faculty of Medicine, Graduate School of Medicine, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan.
| | - Hiroyuki Tachi
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan.,Department of Orthopaedic Surgery, Eniwa Hospital, Koganechuo 2-1-1, Eniwa, Hokkaido, 061-1449, Japan
| | - Terufumi Kokabu
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan.,Department of Orthopaedic Surgery, Eniwa Hospital, Koganechuo 2-1-1, Eniwa, Hokkaido, 061-1449, Japan
| | - Katsuhisa Yamada
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan
| | - Akira Iwata
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan.,Department of Orthopaedic Surgery, Faculty of Medicine, Graduate School of Medicine, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan
| | - Tsutomu Endo
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan.,Department of Orthopaedic Surgery, Faculty of Medicine, Graduate School of Medicine, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan
| | - Masahiko Takahata
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan.,Department of Orthopaedic Surgery, Faculty of Medicine, Graduate School of Medicine, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan
| | - Yuichiro Abe
- Department of Orthopaedic Surgery, Eniwa Hospital, Koganechuo 2-1-1, Eniwa, Hokkaido, 061-1449, Japan
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Hospital, N15W7, Sapporo, Hokkaido, 060-8638, Japan.,Department of Orthopaedic Surgery, Faculty of Medicine, Graduate School of Medicine, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan
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La Barbera L, Larson AN, Aubin CE. How do spine instrumentation parameters influence the 3D correction of thoracic adolescent idiopathic scoliosis? A patient-specific biomechanical study. Clin Biomech (Bristol, Avon) 2021; 84:105346. [PMID: 33848703 DOI: 10.1016/j.clinbiomech.2021.105346] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/24/2021] [Accepted: 03/29/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND Patient-specific models promises to support the surgical decision-making process, particularly in adolescent idiopathic scoliosis. The present computational biomechanical study investigates how specific instrumentation parameters impact 3D deformity correction in thoracic scoliosis. METHODS 1080 instrumentation simulations of a representative patient were run. The independent instrumentation parameters were: screw pattern, upper and lower instrumented vertebrae, rod curvature and rod stiffness. ANOVA and correlation analyses analyzed how the instrumentation parameters influenced the 3D correction. FINDINGS Coronal plane correction was affected by the lower instrumented vertebra and rod stiffness (explaining 84% and 11%, respectively, of its overall variance). The sagittal profile was controlled by rod curvature and the upper vertebra (56% and 36%). The transverse plane vertebral rotation was influenced by lower, upper instrumented vertebra and screw pattern (35%, 32% and 19%). The Cobb angle correction was strongly correlated with the number of fused vertebrae, particularly when grouped by the upper instrumented vertebra (r = -0.91) and rod stiffness (r = -0.73). Thoracic kyphosis was strongly correlated with the number of fused vertebrae grouped by rod curvature (r = 0.84). Apical vertebral rotation was moderately correlated with the number of fused vertebrae grouped by upper/lower instrumented vertebra (r = 0.55/0.58), although variations were minimal. INTERPRETATION Instrumenting the last vertebra touching the central sacral vertical line improves 3D correction. A trade-off between a more cranial vs. caudal upper instrumented vertebra, respectively beneficial for coronal/sagittal vs. transverse plane correction, is required. High rod stiffness, differential rod contouring, and screw pattern were effective for coronal correction, thoracic kyphosis, and axial vertebral derotation, respectively.
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Affiliation(s)
- Luigi La Barbera
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Québec, Canada; Sainte-Justine University Hospital Centre, Montréal, Québec, Canada; Department of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Milan, Italy.
| | - A Noelle Larson
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Carl-Eric Aubin
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Québec, Canada; Sainte-Justine University Hospital Centre, Montréal, Québec, Canada
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Three-dimensional analysis of spinal deformity correction in adolescent idiopathic scoliosis: comparison of two distinct techniques. Childs Nerv Syst 2021; 37:555-560. [PMID: 32839853 DOI: 10.1007/s00381-020-04868-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 08/20/2020] [Indexed: 10/23/2022]
Abstract
PURPOSE To compare 3D postoperative deformity correction using two distinct commonly utilized techniques for the treatment of adolescent idiopathic scoliosis (AIS). METHODS AIS patients with major thoracic (Lenke 1-2) curves at two sites who underwent deformity correction via posterior spinal instrumented fusion using one of two distinct techniques were retrospectively reviewed. Patients were matched 1:1 between sites for Lenke type (95% Lenke 1) and follow-up time. The "band site" performed posteromedial translation using thoracic sublaminar bands and 5.5-mm rods. The "screw site" performed spine derotation using differential rod contouring with pedicle screws and 5.5-mm rods. 3D measures of deformity from spinal reconstructions were compared between sites. RESULTS Preoperatively, the groups had similar thoracic curve magnitudes (band, 55 ± 12° vs. screw, 52 ± 10°; p > 0.05); the "screw site" had less T5-T12 kyphosis (2 ± 14° vs. 7 ± 12°, p = 0.05) and greater thoracic apical rotation (- 19 ± 7° vs. - 14 ± 8°, p = 0.007). Postoperatively, the "screw site" had greater percent correction (61% vs. 76%, p < 0.001) and kyphosis restoration (p = 0.002). The groups achieved a similar amount of apical derotation (p = 0.9). The "band site" used cobalt chromium rods exclusively; the "screw site" used cobalt chromium (3%) and stainless steel (97%; p < 0.001). The "band site" performed significantly longer fusions. CONCLUSIONS Significant variations were found between two commonly utilized techniques in AIS surgery, including rod material, correction mechanisms, and fusion levels. Significantly, a greater 3D deformity correction of the coronal and sagittal planes was observed at the "screw site" compared to the "band site", but with no difference in axial plane correction.
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La Barbera L, Larson AN, Rawlinson J, Aubin CE. In silico patient-specific optimization of correction strategies for thoracic adolescent idiopathic scoliosis. Clin Biomech (Bristol, Avon) 2021; 81:105200. [PMID: 33317937 DOI: 10.1016/j.clinbiomech.2020.105200] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/13/2020] [Accepted: 10/19/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND With modelling and simulation (or in silico) techniques, patient-specific optimization algorithms represent promising tools to support the surgical decision-making process, particularly in 3D correction of adolescent idiopathic scoliosis, where the best intraoperative instrumentation strategy and the correction goals are debated. METHODS 1080 biomechanical intraoperative simulations of a representative pediatric thoracic curve were run according to a full-factorial design approach. Widely accepted instrumentation configurations (5 screw patterns, 4 upper and 3 lower instrumented vertebrae, 6 rod curvatures and 3 rod stiffnesses) were analyzed, assuming concave rod rotation and en bloc derotation as main correction maneuvers. Results in terms of 3D correction and mobility were rated using an objective function for thoracic scoliosis also including surgeon-dependent correction objectives. An extensive sensitivity analysis on correction objectives was performed. FINDINGS Multiple optimal strategies were identified, depending on the selected correction objective. They provided significantly better coronal (67% vs. 55%) correction, using comparable instrumented levels (9.9 ± 1.6 vs. 10.7 ± 2.1), screw patterns and significantly higher implant density (1.6 ± 0.3 vs. 1.4 ± 0.2 screws/vertebra) compared to worst ones. Optimal strategies typically included the neutral and the last touching vertebrae in the construct and high stiffness (CoCr, 6 mm) differentially/highly contoured rods. INTERPRETATION The computerized algorithm determined the best instrumentation parameters to achieve optimal correction for the considered thoracic case. Multiple clinically equivalent strategies may be used, as supported by the variety of considered correction objectives. The current approach could be translated to any scoliotic curves, including surgeon preferences in terms of instrumentation parameters, intraoperative correction maneuvers and correction objectives.
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Affiliation(s)
- Luigi La Barbera
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Québec, Canada; Sainte-Justine University Hospital Centre, Montréal, Québec, Canada.
| | - A Noelle Larson
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
| | - Jeremy Rawlinson
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Québec, Canada; Medtronic, Spinal Applied Research, Memphis, TN, USA
| | - Carl-Eric Aubin
- Department of Mechanical Engineering, Polytechnique Montréal, Montréal, Québec, Canada; Sainte-Justine University Hospital Centre, Montréal, Québec, Canada
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A 3D Parameter Can Guide Concave Rod Contour for the Correction of Hypokyphosis in Adolescent Idiopathic Scoliosis. Spine (Phila Pa 1976) 2020; 45:E1264-E1271. [PMID: 32453225 DOI: 10.1097/brs.0000000000003566] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective. OBJECTIVE To evaluate the effect of preoperative rod shape on 3D spinal deformity correction. SUMMARY OF BACKGROUND DATA Differential rod contouring is a surgeon-dependent process based on an estimate of 3D deformity correction sought and the flexibility of the spine. An objective measure to this otherwise subjective scoliosis correction technique is lacking. METHODS A series of adolescent idiopathic scoliosis (AIS) patients with right, thoracic major curves, preoperative rod contour tracings, and EOS imaging was evaluated. All patients underwent posterior spinal fusion with 5.5 mm steel rods contoured prior to insertion. 3D reconstructions were generated pre- and postoperatively using sterEOS software (EOS Imaging) and imported into MATLAB (Mathworks) for analysis. A new measurement of the maximum perpendicular distance from the preinsertion concave rod contour to the preoperative 3D sagittal spinal reconstruction was defined as rod to 3D spine distance (RSD). Linear regressions were used to identify relationships between pre and postoperative parameters, including RSD and 3D thoracic kyphosis. RESULTS Ninety-nine patients were included. Average preoperative concave rod angle decreased from (48 ± 10°) preoperatively to 26 ± 6° postoperatively (P < 0.001) for an average flattening of ∼20°. Average convex rod angle increased from 30 ± 6° to 34 ± 5° (P < 0.001). Average preoperative thoracic curve magnitude and apical vertebral rotation were 57 ± 8° and 16 ± 5° and decreased to 11 ± 6° and 5 ± 6° (P < 0.001). Average 2D and 3D thoracic kyphosis increased from 19 ± 14° and 2 ± 12° to 27 ± 6° and 22 ± 5° (P < 0.001). Preoperative RSD strongly correlated with 3D thoracic kyphosis change (P < 0.001, r = 0.796, R = 0.633). CONCLUSION On average, the concave rod flattened ∼20° after connection to the spine. Similarly, kyphosis increased ∼20° following rod insertion. A strong correlation was identified between RSD and 3D thoracic kyphosis restoration. This novel 3D parameter can guide the degree of concave rod bend necessary to achieve a desired increase in thoracic kyphosis in AIS. LEVEL OF EVIDENCE 2.
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Comparison of Effectiveness between Cobalt Chromium Rods versus Titanium Rods for Treatment of Patients with Spinal Deformity: A Systematic Review and Meta-Analysis. Adv Orthop 2020; 2020:8475910. [PMID: 32963834 PMCID: PMC7491467 DOI: 10.1155/2020/8475910] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 06/01/2020] [Accepted: 07/24/2020] [Indexed: 11/18/2022] Open
Abstract
Background Biomechanical properties of rods determine their ability to correct spinal deformity and prevention of postoperative sagittal and coronal changes. The selection of a proper rod material is crucial due to their specific mechanical properties that influence the surgical outcome. The purpose of this study is to compare the effectiveness of cobalt chromium rods versus titanium rods for the treatment of spinal deformity by a systematic review and meta-analysis. Methods PubMed, EMBASE, and the Cochrane library were searched for observational and biomechanical studies comparing cobalt chromium and titanium rods in terms of correction rate, thoracic kyphosis, lumbar lordosis, incidence of rod fracture, fatigue life of contoured rod, bending stiffness of rods, and occurrence of proximal junctional kyphosis. The demographic data and mean values of outcomes of interest were extracted from each group and compared by their mean difference as an overall outcome measure. The Review Manager software (RevMan 5.3) was utilized at a 95% significance level. Results Eleven eligible studies with 641 participants for 7 observational studies and 35 samples for 4 biomechanical studies were identified. There were no significant differences between cobalt chromium and titanium rods in the correction rate of spinal deformity. Postoperative thoracic kyphosis was well restored in the cobalt chromium group with statistical significance (p value = 0.009). The incidence of rod fracture was high in titanium rods compared to cobalt chromium rods with significant difference (p value = 0.0001). Proximal junctional kyphosis occurs more in the cobalt chromium group with a significant difference (p value = 0.0009). No statistical significance between two materials in terms of lumbar lordosis, fatigue of life, and bending stiffness of rods. Conclusion The cobalt chromium rod is better than titanium rod for effective correction of spinal deformity and postoperative stability of the spine. However, the use of cobalt chromium rods is associated with increased risk of proximal junctional kyphosis.
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A novel scoliosis instrumentation using special superelastic nickel-titanium shape memory rods: a biomechanical analysis using a calibrated computer model and data from a clinical trial. Spine Deform 2020; 8:369-379. [PMID: 32096138 DOI: 10.1007/s43390-020-00075-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 11/01/2019] [Indexed: 10/24/2022]
Abstract
STUDY DESIGN Biomechanical analysis of scoliosis instrumentation using superelastic Nickel-titanium shape memory (SNT) rods. OBJECTIVE To compare SNT with conventional Titanium (Ti) and Cobalt-chrome (Co-Cr) rods. A clinical trial has documented comparable efficacy between two adolescent idiopathic scoliosis (AIS) cohorts instrumented using SNT versus conventional Ti rods. The shape memory and superelasticity of the SNT rod are thought to allow easy rod insertion, progressive curve correction, and correction from spinal tissue relaxation, but study is yet to be done to assess the effects of the shape memory and superelasticity. METHODS Instrumentations of AIS patients from the clinical trial were computationally simulated using SNT, Ti and Co-Cr rods (5.5 or 6 mm; 30°, 50° or 60° sagittal contouring angles; 0°, 25° or 50° coronal over-contouring angles). Curve correction, its improvement from stress relaxation in the spine, and loads in the instrumentation constructs were computed and compared. RESULTS The simulated main thoracic Cobb angles (MT) and thoracic kyphosis with the SNT rods were 4°-7° higher and 1°-2° lower than the Ti and Co-Cr rods, respectively. Bone-implant forces with Ti and Co-Cr rods were higher than the SNT rods by 84% and 130% at 18 °C and 35% and 65% at 37 °C, respectively (p < 0.001). Further corrections of the MT from the simulated stress relaxation in the spine were 4°-8° with the SNT rods versus 2°-5° with the Ti and Co-Cr rods (p < 0.001). CONCLUSION This study concurs with clinical observation that the SNT rods are easier to insert and can result in similar correction to the conventional rods. The SNT rods allow significantly lower bone-implant forces and have the ability to take advantage of post-instrumentation correction as the tissues relax.
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Seki S, Yahara Y, Makino H, Kobayashi K, Nakano M, Hirano N, Watanabe K, Takahashi J, Kawaguchi Y, Kimura T. Differential rod contouring on thoracolumbar/lumbar curvature in patients with adolescent idiopathic scoliosis: An analysis with intraoperative acquisition of three-dimensional imaging. J Orthop Sci 2019; 24:780-786. [PMID: 30683452 DOI: 10.1016/j.jos.2019.01.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 11/22/2018] [Accepted: 01/06/2019] [Indexed: 11/26/2022]
Abstract
BACKGROUND Differential rod contouring (DRC) is useful for periapical vertebral derotation and decreasing rib hump in patients with thoracic adolescent idiopathic scoliosis (AIS). However, it is unknown whether DRC in the thoracolumbar/lumbar spine also contributes to derotation. We assessed the contributions of rod contouring and of DRC to the reduction of apical axial vertebral body rotation in patients with AIS with thoracolumbar/lumbar curvatures. METHODS Forty-five (Lenke type 3 or 4, 17; Lenke type 5 or 6, 28) were analyzed for the contribution of DRC to thoracolumbar/lumbar spinal derotation. Rod contouring was assessed by comparing the preinsertion x-ray with the post-operative CT images. Intraoperative C-arm fluoroscopic scans of the periapical vertebrae of the thoracolumbar/lumbar curve of the scoliosis (135 vertebrae) were taken post-rod rotation (RR) and post-DRC in all patients. Three-dimensional images were automatically reconstructed from the taken x-ray images. The angle of vertebral body rotation in these apical vertebrae was measured, and the contribution of DRC to apical vertebral body derotation and rib hump index (RHi) for lumbar prominence was analyzed. RESULTS The pre-implantation convex rod curvatures of both Lenke 3/4 and 5/6 groups decreased after surgery. The mean further reductions in vertebral rotation with post-RR DRC were 3.7° for Lenke 3/4 and 4.4° for Lenke 5/6 (P < 0.01). Both changes in apical vertebral rotation and in RHi for evaluating lumbar prominence were significantly correlated with the difference between concave and convex rod curvature in preimplantation. Vertebral derotation was significantly higher in curves with a difference >20° (P < 0.05). CONCLUSIONS DRC following rod rotation contributed substantial additional benefit to reducing vertebral rotation and decreasing lumbar prominence in thoracolumbar/lumbar scoliosis.
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Affiliation(s)
- Shoji Seki
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan.
| | - Yasuhito Yahara
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Hiroto Makino
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Kenji Kobayashi
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Masato Nakano
- Department of Orthopaedic Surgery, Takaoka City Hospital, Toyama, 933-8550, Japan
| | - Norikazu Hirano
- Department of Orthopaedic Surgery, Toyama Rosai Hospital, 662 Rokuromaru, Uozu, Toyama, 937-0042, Japan
| | - Kei Watanabe
- Department of Orthopedic Surgery, Niigata University Medicine and Dental General Hospital, 1-754 Asahimachidori, Chuo Ward, Niigata, 951-8520 Japan
| | - Jun Takahashi
- Department of Orthopaedic Surgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
| | - Yoshiharu Kawaguchi
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
| | - Tomoatsu Kimura
- Department of Orthopaedic Surgery, Faculty of Medicine, University of Toyama, Toyama, 930-0194, Japan
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Newton PO, Wu KW, Bastrom TP, Bartley CE, Upasani VV, Yaszay B. What Factors Are Associated With Kyphosis Restoration in Lordotic Adolescent Idiopathic Scoliosis Patients? Spine Deform 2019; 7:596-601. [PMID: 31202377 DOI: 10.1016/j.jspd.2018.11.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 11/08/2018] [Accepted: 11/11/2018] [Indexed: 11/25/2022]
Abstract
STUDY DESIGN Review of a prospective adolescent idiopathic scoliosis (AIS) multicenter registry. OBJECTIVE To evaluate predictors of surgical thoracic kyphosis restoration in AIS patients with lordotic preoperative thoracic sagittal profiles. SUMMARY OF BACKGROUND DATA Prior work on kyphosis-producing techniques has yielded mixed findings and has focused on the sagittal plane in 2D. METHODS A validated formula to predict 3D T5-T12 sagittal alignment using standard 2D measures was applied in a cohort of 1614 Lenke 1-4 patients treated with posterior instrumentation using 5.5-mm-diameter rods. Patients with 3D kyphosis 1 standard deviation (12.2°) below the mean (5.3°) were identified as the study cohort. Predictors of 3D T5-T12 kyphosis at two years were evaluated using univariate analysis followed by Classification and Regression Tree (CART). RESULTS There were 134 patients identified. All had preoperative 3D T5-T12 kyphosis of <-7°. The average 3D kyphosis was -13° ± 5° preoperatively and 20° ± 7° at two years (p < .001). The thoracic coronal curve improved from 62° ± 12° to 21° ± 8° at two years (p < .001). Of 15 variables analyzed, multivariate CART analysis identified only surgeon as a predictor of 2-year kyphosis. Two surgeon groups were identified by CART which included those who restored more kyphosis versus those who restored less. Subsequent analysis demonstrated significant differences between groups in the rate of Ponte osteotomies used (p < .023), stainless steel versus cobalt chromium rods (p < .001), and segmental screw fixation (p < .001). CONCLUSION Kyphosis restoration in patients with preoperative lordosis in the thoracic sagittal plane is possible. In this analysis, there was not one single technique identified as being solely responsible for the ability to restore kyphosis. The most predictive factor identified was the surgeon performing the correction, which is likely a reflection of focus on deformity correction in three planes, as well as a combination of methods used to restore kyphosis. LEVEL OF EVIDENCE Level III, therapeutic.
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Affiliation(s)
- Peter O Newton
- Department of Orthopedics, Rady Children's Hospital-San Diego, 3020 Children's Way, San Diego, CA 92123, USA; Department of Orthopedics, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA.
| | - Kuan Wen Wu
- Department of Orthopaedic Surgery, National Taiwan University Hospital, No. 7, Zhongshan South Road, Zhongzheng District, Taipei City, Taiwan 100
| | - Tracey P Bastrom
- Department of Orthopedics, Rady Children's Hospital-San Diego, 3020 Children's Way, San Diego, CA 92123, USA
| | - Carrie E Bartley
- Department of Orthopedics, Rady Children's Hospital-San Diego, 3020 Children's Way, San Diego, CA 92123, USA
| | - Vidyadhar V Upasani
- Department of Orthopedics, Rady Children's Hospital-San Diego, 3020 Children's Way, San Diego, CA 92123, USA; Department of Orthopedics, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
| | - Burt Yaszay
- Department of Orthopedics, Rady Children's Hospital-San Diego, 3020 Children's Way, San Diego, CA 92123, USA; Department of Orthopedics, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
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- Setting Scoliosis Straight Foundation, 2535 Camino del Rio S, San Diego, CA 92108, USA
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Sia U, Tan BB, Teo YY, Wong CC. Post-implantation Deformation of Titanium Rod and Cobalt Chrome Rod in Adolescent Idiopathic Scoliosis. Malays Orthop J 2019; 13:14-19. [PMID: 31001378 PMCID: PMC6459034 DOI: 10.5704/moj.1903.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Introduction: Post-implantation rod deformation is anticipated in scoliosis surgery but the difference in rod deformation between titanium and cobalt chrome rod has not been elucidated. This study aims to compare the difference in rod deformation between two groups. Materials and Methods: Twenty-one adolescent idiopathic scoliosis (AIS) patients were recruited from a single center. The over-contoured concave rods were traced prior to insertion. Post-operative sagittal rod shape was determined from lateral radiographs. Rod deformation was determined using maximal rod deflection and angle of the tangents to rod end points. The differences between pre- and post-operative rod contour were analysed statistically. Rod deformation and thoracic kyphosis between two types of implants were analysed. Results: Both rods exhibited significant change of rod angle and deflection post-operatively. Curvature of the titanium rod and cobalt chrome rod decreased from 60.5° to 37°, and 51° to 28° respectively. Deflection of titanium rod and cobalt chrome rod reduced from 28mm to 23.5mm and 30mm to 17mm respectively. There was no significant difference between titanium and cobalt chrome groups with regard to rod angle (p=0.173) and deflection (p=0.654). Thoracic kyphosis was increased from 20° to 26° in titanium group but a reduction from 25° to 23° was noticed in cobalt chrome group, but these findings were not statistically significant. Conclusion: There was no statistical difference in rod deformation between the two groups. Thus, the use of titanium rod in correction of sagittal profile is not inferior in outcome compared with cobalt chrome but with lower cost.
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Affiliation(s)
- U Sia
- Department of Orthopaedics, Kementerian Kesihatan Malaysia, Hospital Umum Sarawak, Kuching, Malaysia.,Department of Orthopaedics, Universiti Malaysia Sarawak, Kota Samarahan, Malaysia
| | - B B Tan
- Department of Orthopaedics, Universiti Malaysia Sarawak, Kota Samarahan, Malaysia
| | - Y Y Teo
- Department of Orthopaedics, Universiti Malaysia Sarawak, Kota Samarahan, Malaysia
| | - C C Wong
- Department of Orthopaedics, Kementerian Kesihatan Malaysia, Hospital Umum Sarawak, Kuching, Malaysia.,Department of Orthopaedics, Universiti Malaysia Sarawak, Kota Samarahan, Malaysia
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Kokabu T, Kanai S, Abe Y, Iwasaki N, Sudo H. Identification of optimized rod shapes to guide anatomical spinal reconstruction for adolescent thoracic idiopathic scoliosis. J Orthop Res 2018; 36:3219-3224. [PMID: 30062779 DOI: 10.1002/jor.24118] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 07/21/2018] [Indexed: 02/04/2023]
Abstract
Adolescent idiopathic scoliosis (AIS), the most common pediatric musculoskeletal disorder, causes a three-dimensional deformity of the spine. Although rod curvature could play an important role in anatomical spinal reconstruction in patients with thoracic AIS, intraoperative contouring of the straight rod induces notches into the rod, leading to decreased fatigue strength. Here, we analyzed pre-bent rod geometries from 46 intraoperative tracings of the rod geometry, which can provide anatomical spinal reconstruction in patients with thoracic AIS. The center point clouds of the rod shapes were extracted and approximated as arcs and straight lines. The difference between the center point clouds were evaluated using the iterative closest point methods. When the rod shapes were divided into six groups based on length followed by hierarchical cluster analysis, 10 representative rod shapes were obtained with a difference value of 5 mm. Thus, we identified optimized rod shapes to guide anatomical spinal reconstruction for thoracic AIS, which will reduce not only the risk of rod breakage but also operation time, leading to decreased patient burden. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3219-3224, 2018.
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Affiliation(s)
- Terufumi Kokabu
- Faculty of Medicine and Graduate of Medicine, Department of Orthopaedic Surgery, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan.,Department of Orthopaedic Surgery, Eniwa Hospital, Koganechuo 2-1-1, Eniwa, Hokkaido, 061-1449, Japan
| | - Satoshi Kanai
- Division of Systems Science and Informatics, Hokkaido University Graduate School of Information Science and Technology, N14W9, Sapporo, Hokkaido, 060-0814, Japan
| | - Yuichiro Abe
- Department of Orthopaedic Surgery, Eniwa Hospital, Koganechuo 2-1-1, Eniwa, Hokkaido, 061-1449, Japan
| | - Norimasa Iwasaki
- Faculty of Medicine and Graduate of Medicine, Department of Orthopaedic Surgery, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan
| | - Hideki Sudo
- Faculty of Medicine and Graduate of Medicine, Department of Advanced Medicine for Spine and Spinal Cord Disorders, Hokkaido University, N15W7, Sapporo, Hokkaido, 060-8638, Japan
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Feng J, Zhou J, Huang M, Xia P, Liu W. Clinical and radiological outcomes of the multilevel Ponte osteotomy with posterior selective segmental pedicle screw constructs to treat adolescent thoracic idiopathic scoliosis. J Orthop Surg Res 2018; 13:305. [PMID: 30497489 PMCID: PMC6267836 DOI: 10.1186/s13018-018-1001-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Accepted: 11/12/2018] [Indexed: 11/10/2022] Open
Abstract
Background To compare the clinical and radiological outcomes of the surgical correction of Lenke type 1 to 4 scoliosis by using a multilevel Ponte osteotomy procedure with posterior selective segmental pedicle screw constructs or posterior release and selective segmental pedicle screw constructs only in patients with adolescent thoracic idiopathic scoliosis. Methods Retrospective analysis of 65 patients, 32 treated with the multilevel Ponte procedure (Group A) and 33 with posterior soft tissue release only (Group B). The groups were compared with regard to the change in spinal alignment from preoperative to postoperative assessment and over the follow-up period. Results A correction rate of the main thoracic curve of 63.9 ± 4.5% was obtained for group A and 65.2 ± 2.4% for group B (P = 0.17). However, the Cincinnati correction index was greater for group A (1.8 ± 0.3) than that for group B (1.4 ± 0.2, P < 0.001), with a smaller change in angle over the period from 1 week postoperatively to the 2-year follow-up (P < 0.05). The operative time, volume of blood loss, and volume of transfusion were greater for group A than for group B (P < 0.05). Conclusion The multilevel Ponte osteotomy procedure, with posterior selective segmental pedicle screw constructs, improves the Cincinnati correction index and restores the thoracic kyphosis in patients with adolescent thoracic idiopathic scoliosis.
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Affiliation(s)
- Jing Feng
- Department of Orthopaedics, First Hospital of Wuhan, No. 215 Zhongshan Road, Wuhan, 430022, China
| | - Juan Zhou
- Department of Orthopaedics, First Hospital of Wuhan, No. 215 Zhongshan Road, Wuhan, 430022, China
| | - Mi Huang
- Department of Orthopaedics, First Hospital of Wuhan, No. 215 Zhongshan Road, Wuhan, 430022, China
| | - Ping Xia
- Department of Orthopaedics, First Hospital of Wuhan, No. 215 Zhongshan Road, Wuhan, 430022, China.
| | - Wei Liu
- Department of Orthopaedics, First Hospital of Wuhan, No. 215 Zhongshan Road, Wuhan, 430022, China.
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Ohrt-Nissen S, Dahl B, Gehrchen M. Choice of Rods in Surgical Treatment of Adolescent Idiopathic Scoliosis: What Are the Clinical Implications of Biomechanical Properties? - A Review of the Literature. Neurospine 2018; 15:123-130. [PMID: 29991241 PMCID: PMC6104735 DOI: 10.14245/ns.1836050.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/01/2018] [Indexed: 11/23/2022] Open
Abstract
The surgical treatment of adolescent idiopathic scoliosis (AIS) involves 3-dimensional curve correction with multisegmental pedicle screws attached to contoured bilateral rods. The substantial corrective forces exert a high level of stress on the rods, and the ability of the rod to withstand these forces without undergoing permanent deformation relies on its biomechanical properties. These properties, in turn, are dependent on the material, diameter, and shape of the rod. The surgical treatment of AIS is characterized by the requirement for a special biomechanical profile that may differ substantially from what is needed for adult deformity surgery. This overview summarizes the current knowledge of rod biomechanics in frequently used rod constructs, with a particular focus on translational research between biomechanical studies and clinical applicability in AIS patients.
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Affiliation(s)
- Søren Ohrt-Nissen
- Department of Orthopedic Surgery, Spine Unit, Copenhagen University Hospital, Copenhagen, Denmark
| | - Benny Dahl
- Department of Orthopedics and Scoliosis Surgery, Texas Children's Hospital, Houston, TX, USA
| | - Martin Gehrchen
- Department of Orthopedic Surgery, Spine Unit, Copenhagen University Hospital, Copenhagen, Denmark
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Differential Rod Contouring is Essential for Improving Vertebral Rotation in Patients With Adolescent Idiopathic Scoliosis: Thoracic Curves Assessed With Intraoperative CT. Spine (Phila Pa 1976) 2018; 43:E585-E591. [PMID: 28953709 DOI: 10.1097/brs.0000000000002428] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A case series. OBJECTIVE We investigated the contributions of rod contouring and differential rod contouring (DRC) to the reduction of apical axial vertebral body rotation in patients with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA DRC is used for posterior spinal correction and fusion. The contribution of DRC to vertebral body derotation is unclear. METHODS We analyzed the results of intraoperative computed tomography (CT) in 40 consecutive AIS patients with thoracic curves (Lenke type I or II, 35; type III or IV, 5). Rod contour before initial rod rotation was analyzed by x-ray. Periapical rod contour between concave and convex rod rotation (RR) were analyzed by cone-beam CT imaging. To analyze the reduction of vertebral body rotation with DRC, intraoperative cone-beam CT scans of the three apical vertebrae of the major curve of the scoliosis (120 vertebrae) were taken post-concave RR and post-convex DRC in all patients. The angle of vertebral body rotation was measured. In addition, the contribution of rod contouring to apical vertebral body derotation was analyzed. Rib hump indices (RHi) were measured by pre- and postoperative CT. RESULTS The mean vertebral body rotation angles post-concave RR and post-convex DRC were 15.3° and 9.3°, respectively, for a mean reduction of vertebral rotation in convex DRC after concave RR of 6.0° for thoracic curves (P < 0.001). The RHi was significantly improved by DRC (P < 0.05). Improved apical vertebral rotation was significantly correlated with the difference of apical rod curvature between concave and convex. Vertebral derotation was significantly higher in curves with > 10° difference between concave and convex rod curvature than differences < 10°. CONCLUSION DRC contributed substantially to axial derotation and reducing rib hump in thoracic scoliosis. The degree of apical rod curvature correlated with the degree of apical vertebral derotation. LEVEL OF EVIDENCE 4.
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Tambe AD, Panikkar SJ, Millner PA, Tsirikos AI. Current concepts in the surgical management of adolescent idiopathic scoliosis. Bone Joint J 2018; 100-B:415-424. [DOI: 10.1302/0301-620x.100b4.bjj-2017-0846.r2] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Adolescent idiopathic scoliosis (AIS) is a complex 3D deformity of the spine. Its prevalence is between 2% and 3% in the general population, with almost 10% of patients requiring some form of treatment and up to 0.1% undergoing surgery. The cosmetic aspect of the deformity is the biggest concern to the patient and is often accompanied by psychosocial distress. In addition, severe curves can cause cardiopulmonary distress. With proven benefits from surgery, the aims of treatment are to improve the cosmetic and functional outcomes. Obtaining correction in the coronal plane is not the only important endpoint anymore. With better understanding of spinal biomechanics and the long-term effects of multiplanar imbalance, we now know that sagittal balance is equally, if not more, important. Better correction of deformities has also been facilitated by an improvement in the design of implants and a better understanding of metallurgy. Understanding the unique character of each deformity is important. In addition, using the most appropriate implant and applying all the principles of correction in a bespoke manner is important to achieve optimum correction. In this article, we review the current concepts in AIS surgery. Cite this article: Bone Joint J 2018;100-B:415–24.
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Affiliation(s)
- A. D. Tambe
- Royal Manchester Children’s Hospital & Salford Royal Foundation Trust, Upper Brook Street, Manchester M13 9WL, UK
| | - S. J. Panikkar
- Salford Royal Foundation Trust, Stott
Lane, Salford M6 8HD, UK
| | - P. A. Millner
- Leeds Teaching Hospitals, Great
George Street, Leeds LS1 3EX, UK
| | - A. I. Tsirikos
- Edinburgh Royal Hospital for Sick Children, Sciennes
Road, Edinburgh EH9 1LF, UK
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Luo M, Jiang H, Wang W, Li N, Shen M, Li P, Xu G, Xia L. Influence of screw density on thoracic kyphosis restoration in hypokyphotic adolescent idiopathic scoliosis. BMC Musculoskelet Disord 2017; 18:526. [PMID: 29237433 PMCID: PMC5729421 DOI: 10.1186/s12891-017-1877-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2017] [Accepted: 11/28/2017] [Indexed: 11/10/2022] Open
Abstract
Background Previous studies have reported that rod composition and diameter, as well as the correction technique are key factors associated with thoracic kyphosis (TK) restoration. However, few study has analyzed the correlation between screw density and TK restoration in hypokyphotic adolescent idiopathic scoliosis (AIS). Methods Fifty-seven thoracic AIS patients with preoperative TK < 10° treated with all pedicle screw fixation with a minimum 2-year follow-up were recruited. Preoperative and postoperative radiographic measurements, and information of posterior instrumentation were reviewed. Pearson and Spearman correlation coefficient analysis were used to assess relationships between change in TK and number of variables. Then, the included patients were classified into two groups (Group 1: postoperative TK ≥ 20°; Group 2: postoperative TK < 20°) to evaluate the influence factors of TK restoration. Results The average preoperative TK was 4.75°, which was significantly restored to 17.30° (P < 0.001). Significant correlations were found between change in TK and flexibility of major thoracic curve (r = 0.357, P = 0.006), preoperative TK (r = −0.408, P = 0.002), and screw density of concave side (r = 0.306, P = 0.021), respectively. In the subgroup comparison, 17 patients (29.8%) maintain the postoperative TK ≥ 20°, increased flexibility of major thoracic curve (P < 0.001), screw number of concave side (P = 0. 029), and cobalt chromium rods (P = 0.041) were found in the group of postoperative TK ≥ 20°. Conclusions TK restoration remains a challenge for AIS patients with hypokyphosis, especially for the poor flexibility ones. Except for thicker and cobalt chromium rods, screw density of concave side might be another positive predictor of restoring normal kyphosis, which provides a stronger corrective force on the sagittal plane with more pedicle screws.
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Affiliation(s)
- Ming Luo
- Institute of Spinal Deformity, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China
| | - Honghui Jiang
- Department of Orthopaedic Surgery, Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, People's Republic of China
| | - Wengang Wang
- Institute of Spinal Deformity, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China
| | - Ning Li
- Institute of Spinal Deformity, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China
| | - Mingkui Shen
- Institute of Spinal Deformity, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China
| | - Peng Li
- Institute of Spinal Deformity, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China
| | - Genzhong Xu
- Institute of Spinal Deformity, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China
| | - Lei Xia
- Institute of Spinal Deformity, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, 450052, People's Republic of China.
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Hill G, Nagaraja S, Akbarnia BA, Pawelek J, Sponseller P, Sturm P, Emans J, Bonangelino P, Cockrum J, Kane W, Dreher M. Retrieval and clinical analysis of distraction-based dual growing rod constructs for early-onset scoliosis. Spine J 2017; 17:1506-1518. [PMID: 28456673 DOI: 10.1016/j.spinee.2017.04.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/15/2017] [Accepted: 04/21/2017] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Growing rod constructs are an important contribution for treating patients with early-onset scoliosis. These devices experience high failure rates, including rod fractures. PURPOSE The objective of this study was to identify the failure mechanism of retrieved growing rods, and to identify differences between patients with failed and intact constructs. STUDY DESIGN/SETTING Growing rod patients who had implant removal and were previously enrolled in a multicenter registry were eligible for this study. PATIENT SAMPLE Forty dual-rod constructs were retrieved from 36 patients across four centers, and 34 of those constructs met the inclusion criteria. Eighteen constructs failed due to rod fracture. Sixteen intact constructs were removed due to final fusion (n=7), implant exchange (n=5), infection (n=2), or implant prominence (n=2). OUTCOME MEASURES Analyses of clinical registry data, radiographs, and retrievals were the outcome measures. METHODS Retrievals were analyzed with microscopic imaging (optical and scanning electron microscopy) for areas of mechanical failure, damage, and corrosion. Failure analyses were conducted on the fracture surfaces to identify failure mechanism(s). Statistical analyses were performed to determine significant differences between the failed and intact groups. RESULTS The failed rods fractured due to bending fatigue under flexion motion. Construct configuration and loading dictate high bending stresses at three distinct locations along the construct: (1) mid-construct, (2) adjacent to the tandem connector, or (3) adjacent to the distal anchor foundation. In addition, high torques used to insert set screws may create an initiation point for fatigue. Syndromic scoliosis, prior rod fractures, increase in patient weight, and rigid constructs consisting of tandem connectors and multiple crosslinks were associated with failure. CONCLUSION This is the first study to examine retrieved, failed growing rod implants across multiple centers. Our analysis found that rod fractures are due to bending fatigue, and that stress concentrations play an important role in rod fractures. Recommendations are made on surgical techniques, such as the use of torque-limiting wrenches or not exceeding the prescribed torques. Additional recommendations include frequent rod replacement in select patients during scheduled surgeries.
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Affiliation(s)
- Genevieve Hill
- US Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD 20993, USA; Fischell Department of Bioengineering, University of Maryland, Room 2330, Jeong H. Kim Engineering Building, Bldg #225, College Park, MD 20742, USA.
| | - Srinidhi Nagaraja
- US Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD 20993, USA; Fischell Department of Bioengineering, University of Maryland, Room 2330, Jeong H. Kim Engineering Building, Bldg #225, College Park, MD 20742, USA
| | - Behrooz A Akbarnia
- Growing Spine Study Group, 6190 Cornerstone Ct East, Suite 212, San Diego, CA 92121, USA
| | - Jeff Pawelek
- Growing Spine Study Group, 6190 Cornerstone Ct East, Suite 212, San Diego, CA 92121, USA
| | - Paul Sponseller
- Growing Spine Study Group, 6190 Cornerstone Ct East, Suite 212, San Diego, CA 92121, USA; Johns Hopkins Hospital, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Peter Sturm
- Growing Spine Study Group, 6190 Cornerstone Ct East, Suite 212, San Diego, CA 92121, USA; Cincinnati Children's Hospital, 3333 Burnet Ave, MLC 2017, Cincinnati, OH 45229, USA
| | - John Emans
- Growing Spine Study Group, 6190 Cornerstone Ct East, Suite 212, San Diego, CA 92121, USA; Boston Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA
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- Growing Spine Study Group, 555 East Wells St, Suite 1100, Milwaukee, WI 53202, USA
| | - Pablo Bonangelino
- US Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD 20993, USA
| | - Joshua Cockrum
- US Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD 20993, USA
| | - William Kane
- Exponent, Inc., 3440 Market St, Suite 600, Philadelphia, PA 19104, USA
| | - Maureen Dreher
- US Food and Drug Administration, 10903 New Hampshire Ave, Silver Spring, MD 20993, USA; Fischell Department of Bioengineering, University of Maryland, Room 2330, Jeong H. Kim Engineering Building, Bldg #225, College Park, MD 20742, USA
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A randomized double-blinded clinical trial to evaluate the safety and efficacy of a novel superelastic nickel-titanium spinal rod in adolescent idiopathic scoliosis: 5-year follow-up. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2017; 27:327-339. [PMID: 28776134 DOI: 10.1007/s00586-017-5245-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 07/12/2017] [Accepted: 07/27/2017] [Indexed: 10/19/2022]
Abstract
PURPOSE To evaluate the safety and efficacy of a superelastic shape-memory alloy (SNT) rod used in the treatment of adolescent idiopathic scoliosis (AIS). METHODS AIS Patients with Lenke 1 curves undergoing fusion surgery were randomized (1:1) at the time of surgery to receive either the SNT or a conventional titanium alloy (CTA) rod. Radiographs were obtained preoperatively and postoperatively up to 5 years of follow-up. Parameters assessed included coronal and sagittal Cobb angles, and overall truncal and shoulder balance. Sagittal profiles were subcategorized into Types A (<20°), B (20-40°), and C (>40°). RESULTS Twenty-four patients with mean age of 15 years were recruited. A total of 87.0% of subjects were followed up till postoperative 5 years, but all patients had minimum 2 years of follow-up. The fulcrum-bending correction index for the SNT group was 113% at postoperative day 4 and 127% at half-year, while the CTA group was 112% at postoperative day 4 and only 106% at half-year. In terms of sagittal profile, the SNT group moved toward type B profile at half-year follow-up with a mean correction of 7.6°, while no significant change was observed in the CTA group (-0.7°). Nickel levels remained normal, and there were no complications. CONCLUSIONS This is the first randomized clinical trial of a novel SNT rod for treating patients with AIS, noting it to be safe and has potential to gradually correct scoliosis over time. This study serves as a pilot and platform to properly power future large-scale studies to demonstrate efficacy and superiority.
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Are There 3D Changes in Spine and Rod Shape in the 2 Years After Adolescent Idiopathic Scoliosis Instrumentation? Spine (Phila Pa 1976) 2017; 42:1158-1164. [PMID: 28746140 DOI: 10.1097/brs.0000000000002056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective analysis of spine and rods 3D shape in the 2 years after adolescent idiopathic scoliosis (AIS) posterior surgical instrumentation. OBJECTIVE To evaluate spine and rod shape 3D changes in the 2 years after AIS instrumentation with different rod materials. SUMMARY OF BACKGROUND DATA Postoperative loss of correction has been reported with modern segmental instrumentation. The postoperative 3D rod shape changes of different rod materials and their implication in postoperative loss of correction have never been studied. METHODS A total of 42 Lenke 1 AIS cases who underwent surgery all with pedicle screws and 5.5 mm rods of three different materials were retrospectively reviewed (14 cases for each of the three rod material subgroups: titanium, cobalt-chromium, stainless steel). 3D reconstructions of the spine were performed using biplanar radiographs preoperatively, 1-week postoperatively (1WPO), and 2 years follow-up (2YFU). Rods 3D shape also was reconstructed at 1WPO and 2YFU. The spine and rods shapes were analyzed and compared between time points. RESULTS An average of 1.93 implant per vertebra was used. The main thoracic curve (61° ± 9°) was corrected on average by 75% (15° ± 6°, P < 0.01) with no change at 2YFU (17° ± 7°, P = 0.14). The apical vertebral rotation (23° ± 7°) was corrected by 44% (13° ± 9°, P < 0.01) with no change at 2YFU (14° ± 9°, P = 0.64). The thoracic kyphosis (24° ± 12°) remained unchanged (P = 0.78). The orientation of the planes of maximal curvature with respect to the sagittal plane of the main thoracic curve (39° ± 15°) and of the rods (concave: 28° ± 23°, convex: 12° ± 10°) at 1WPO was unchanged at 2YFU (all P > 0.05). Rod curvature and deflection also remained unchanged (all P > 0.05). 3D curve correction was maintained in the 2YFU for all rod materials subgroups (all P > 0.05). The lumbar lordosis changed from 1WPO (47° ± 8°) to 2YFU (56° ± 9°, P < 0.01). At preoperatively, 57% of the cases had a balanced posture (sacral vertical axis/sacral femoral distance ≤0.5 and sacral vertical axis ≤0), 33% at 1WPO and 79% at 2YFU. CONCLUSION There was no significant 3D shape change of the instrumented thoracic spine or of the rods postoperatively for any of the segmental pedicle screw constructs with titanium, stainless steel, and cobalt-chromium rods. Patients overall unbalanced sagittal posture documented immediately after surgery came back to balanced 2 years after surgery. LEVEL OF EVIDENCE 3.
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Le Navéaux F, Aubin CE, Parent S, O. Newton P, Labelle H. 3D rod shape changes in adolescent idiopathic scoliosis instrumentation: how much does it impact correction? EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2017; 26:1676-1683. [DOI: 10.1007/s00586-017-4958-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 11/24/2016] [Accepted: 01/15/2017] [Indexed: 11/30/2022]
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Le Navéaux F, Larson AN, Labelle H, Wang X, Aubin CÉ. How does implant distribution affect 3D correction and bone-screw forces in thoracic adolescent idiopathic scoliosis spinal instrumentation? Clin Biomech (Bristol, Avon) 2016; 39:25-31. [PMID: 27639485 DOI: 10.1016/j.clinbiomech.2016.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2016] [Revised: 09/01/2016] [Accepted: 09/05/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Optimal implant densities and configurations for thoracic spine instrumentation to treat adolescent idiopathic scoliosis remain unknown. The objective was to computationally assess the biomechanical effects of implant distribution on 3D curve correction and bone-implant forces. METHODS 3D patient-specific biomechanical spine models based on a multibody dynamic approach were created for 9 Lenke 1 patients who underwent posterior instrumentation (main thoracic Cobb: 43°-70°). For each case, a factorial design of experiments was used to generate 128 virtual implant configurations representative of existing implant patterns used in clinical practice. All instances except implant configuration were the same for each surgical scenario simulation. FINDINGS Simulation of the 128 implant configurations scenarios (mean implant density=1.32, range: 0.73-2) revealed differences of 2° to 10° in Cobb angle correction, 2° to 7° in thoracic kyphosis and 2° to 7° in apical vertebral rotation. The use of more implants, at the concave side only, was associated with higher Cobb angle correction (r=-0.41 to -0.90). Increased implant density was associated with higher apical vertebral rotation correction for seven cases (r=-0.20 to -0.48). It was also associated with higher bone-screw forces (r=0.22 to 0.64), with an average difference between the least and most constrained instrumentation constructs of 107N per implant at the end of simulated instrumentation. INTERPRETATION Low-density constructs, with implants mainly placed on the concave side, resulted in similar simulated curve correction as the higher-density patterns. Increasing the number of implants allows for only limited improvement of 3D correction and overconstrains the instrumentation construct, resulting in increased forces on the implants.
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Affiliation(s)
- Franck Le Navéaux
- Polytechnique Montréal, Department of Mechanical Engineering, P.O. Box 6079, Downtown Station, Montréal, Québec H3C 3A7, Canada; Research Center, Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montréal, Québec H3T 1C5, Canada
| | | | - Hubert Labelle
- Research Center, Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montréal, Québec H3T 1C5, Canada
| | - Xiaoyu Wang
- Polytechnique Montréal, Department of Mechanical Engineering, P.O. Box 6079, Downtown Station, Montréal, Québec H3C 3A7, Canada; Research Center, Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montréal, Québec H3T 1C5, Canada
| | - Carl-Éric Aubin
- Polytechnique Montréal, Department of Mechanical Engineering, P.O. Box 6079, Downtown Station, Montréal, Québec H3C 3A7, Canada; Research Center, Sainte-Justine University Hospital Center, 3175, Côte Sainte-Catherine Road, Montréal, Québec H3T 1C5, Canada.
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Wang X, Boyer L, Le Naveaux F, Schwend RM, Aubin CE. How does differential rod contouring contribute to 3-dimensional correction and affect the bone-screw forces in adolescent idiopathic scoliosis instrumentation? Clin Biomech (Bristol, Avon) 2016; 39:115-121. [PMID: 27750078 DOI: 10.1016/j.clinbiomech.2016.10.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Revised: 09/25/2016] [Accepted: 10/04/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Differential rod contouring is used to achieve 3-dimensional correction in adolescent idiopathic scoliosis instrumentations. How vertebral rotation correction is correlated with the amount of differential rod contouring is still unknown; too aggressive differential rod contouring may increase the risk of bone-screw connection failure. The objective was to assess the 3-dimensional correction and bone-screw forces using various configurations of differential rod contouring. METHODS Computerized patient-specific biomechanical models of 10 AIS cases were used to simulate AIS instrumentations using various configurations of differential rod contouring. The tested concave/convex rod configurations were 5.5/5.5 and 6.0/5.5mm diameter Cobalt-chrome rods with contouring angles of 35°/15°, 55°/15°, 75°/15°, and 85°/15°, respectively. 3-dimensional corrections and bone-screw forces were computed and analyzed. FINDINGS Increasing the difference between the concave and convex rod contouring angles from 25° to 60°, the apical vertebral rotation correction increased from 35% (SD 17%) to 68% (SD 24%), the coronal plane correction changed from 76% (SD 10%) to 72% (SD 12%), the thoracic kyphosis creation from 27% (SD 60%) to 144% (SD 132%), and screw pullout forces from 94N (SD 68N) to 252N (SD 159N). Increasing the concave rod diameter to 6mm resulted in increased transverse and coronal plane corrections, higher thoracic kyphosis, and screw pullout forces. INTERPRETATIONS Increasing the concave rod contouring angle and diameter with respect to the convex rod improved the transverse plane correction but with significant increase of screw pullout forces and thoracic kyphosis. Rod contouring should be planned by also taking into account the 3-dimensional nature and stiffness of the curves and combined with osteotomy procedures, which remains to be studied.
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Affiliation(s)
- Xiaoyu Wang
- Polytechnique Montréal, Department of Mechanical Engineering, P.O. Box 6079, Downtown Station, Montreal (Quebec), H3C 3A7, Canada; Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal (Quebec), H3T 1C5, Canada
| | - Laure Boyer
- Polytechnique Montréal, Department of Mechanical Engineering, P.O. Box 6079, Downtown Station, Montreal (Quebec), H3C 3A7, Canada; Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal (Quebec), H3T 1C5, Canada
| | - Franck Le Naveaux
- Polytechnique Montréal, Department of Mechanical Engineering, P.O. Box 6079, Downtown Station, Montreal (Quebec), H3C 3A7, Canada; Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal (Quebec), H3T 1C5, Canada
| | - Richard M Schwend
- Children's Mercy Hospital, 2401, Gillham Rd, Kansas City, (Missouri) 64108, USA
| | - Carl-Eric Aubin
- Polytechnique Montréal, Department of Mechanical Engineering, P.O. Box 6079, Downtown Station, Montreal (Quebec), H3C 3A7, Canada; Sainte-Justine University Hospital Center, 3175, Cote Sainte-Catherine Road, Montreal (Quebec), H3T 1C5, Canada.
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Kokabu T, Sudo H, Abe Y, Ito M, Ito YM, Iwasaki N. Effects of Multilevel Facetectomy and Screw Density on Postoperative Changes in Spinal Rod Contour in Thoracic Adolescent Idiopathic Scoliosis Surgery. PLoS One 2016; 11:e0161906. [PMID: 27564683 PMCID: PMC5001696 DOI: 10.1371/journal.pone.0161906] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 08/12/2016] [Indexed: 12/02/2022] Open
Abstract
Flattening of the preimplantation rod contour in the sagittal plane influences thoracic kyphosis (TK) restoration in adolescent idiopathic scoliosis (AIS) surgery. The effects of multilevel facetectomy and screw density on postoperative changes in spinal rod contour have not been documented. This study aimed to evaluate the effects of multilevel facetectomy and screw density on changes in spinal rod contour from before implantation to after surgical correction of thoracic curves in patients with AIS prospectively. The concave and convex rod shapes from patients with thoracic AIS (n = 49) were traced prior to insertion. Postoperative sagittal rod shape was determined by computed tomography. The angle of intersection of the tangents to the rod end points was measured. Multiple stepwise linear regression analysis was used to identify variables independently predictive of change in rod contour (Δθ). Average Δθ at the concave and convex side were 13.6° ± 7.5° and 4.3° ± 4.8°, respectively. The Δθ at the concave side was significantly greater than that of the convex side (P < 0.0001) and significantly correlated with Risser sign (P = 0.032), the preoperative main thoracic Cobb angle (P = 0.031), the preoperative TK angle (P = 0.012), and the number of facetectomy levels (P = 0.007). Furthermore, a Δθ at the concave side ≥14° significantly correlated with the postoperative TK angle (P = 0.003), the number of facetectomy levels (P = 0.021), and screw density at the concave side (P = 0.008). Rod deformation at the concave side suggests that corrective forces acting on that side are greater than on the convex side. Multilevel facetectomy and/or screw density at the concave side have positive effects on reducing the rod deformation that can lead to a loss of TK angle postoperatively.
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Affiliation(s)
- Terufumi Kokabu
- Department of Orthopaedic Surgery, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
| | - Hideki Sudo
- Department of Orthopaedic Surgery, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
- * E-mail:
| | | | - Manabu Ito
- Department of Spine and Spinal Cord Disorders, Hokkaido Medical Center, Sapporo, Hokkaido, Japan
| | - Yoichi M. Ito
- Department of Biostatistics, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Hospital, Sapporo, Hokkaido, Japan
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The effect of sublaminar wires on the rib hump deformity during scoliosis correction manoeuvres. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY 2016; 26:771-7. [PMID: 27549661 DOI: 10.1007/s00590-016-1841-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Accepted: 08/15/2016] [Indexed: 10/21/2022]
Abstract
INTRODUCTION During thoracic curve correction, the tightening of the sublaminar wires through concavity creates a medial and a dorsal translation of the spine. However, little is known about the effect of the sublaminar wires on the axial plane. METHODS This is prospective case series analysis of 30 consecutive surgical patients with main thoracic adolescent idiopathic scoliosis. All of the patients were fused with hybrid instrumentation (apical concavity-sublaminar wires) and differential rod contouring (over-kyphosis concavity/under-kyphosis convexity). The degrees of the rib hump were measured with a scoliometer placed at the apex of the deformity at five different times: (1) preoperatively through the Adam's test, and during surgery (sterilised scoliometer), (2) with the patient lying prone, (3) after the Ponte osteotomies, (4) after the apical sublaminar tightening, and (5) after convexity apical derotation and compression manoeuvres. RESULTS (1) Preoperatively, the Adam's test was 16.3° ± 4.6. (2) Lying prone and under general anaesthesia, it decreased to 11.4° ± 3.9. (3) After exposure and Ponte osteotomies, it was 7.1° ± 4. (4) After the wire tightening, it was 10.8° ± 4.7. (5) After the convexity manoeuvres, it was 4.8° ± 3.7. The degrees of the rib hump final correction were 11.6° ± 4 (70 % correction). The tightening of the sublaminar wires increased the rib hump by 3.5°. CONCLUSIONS The sublaminar wire tightening towards the concave rod seemed to create an effect opposite of the desired effect, increasing the apical rotation and the thoracic rib hump deformity. Convexity manoeuvres (apical screw derotation and compression) are necessary and must be coupled with an under-bending of the convex rod to neutralise this effect.
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Borkowski SL, Sangiorgio SN, Bowen RE, Scaduto AA, He B, Bauer KL, Ebramzadeh E. Strength of Thoracic Spine Under Simulated Direct Vertebral Rotation: A Biomechanical Study. Spine Deform 2016; 4:85-93. [PMID: 27927550 DOI: 10.1016/j.jspd.2015.09.044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Revised: 08/12/2015] [Accepted: 09/13/2015] [Indexed: 10/22/2022]
Abstract
BACKGROUND Direct vertebral rotation (DVR) has gained increasing popularity for deformity correction surgery. Despite large moments applied intraoperatively during deformity correction and failure reports including screw plow, aortic abutment, and pedicle fracture, to our knowledge, the strength of thoracic spines has been unknown. Moreover, the rotational response of thoracic spines under such large torques has been unknown. PURPOSE Simulate DVR surgical conditions to measure torsion to failure on thoracic spines and assess surgical forces. STUDY DESIGN Biomechanical simulation using cadaver spines. METHODS Fresh-frozen thoracic spines (n = 11) were evaluated using radiographs, magnetic resonance imaging (MRI) and dual-energy x-ray absorptiometry. An apparatus simulating DVR was attached to pedicle screws at T7-T10 and transmitted torsion to the spine. T11-T12 were potted and rigidly attached to the frame. Strain gages measured the simulated surgical forces to rotate spines. Torsional load was increased incrementally till failure at T10-T11. Torsion to failure at T10-T11 and corresponding forces were obtained. RESULTS The T10-T11 moment at failure was 33.3 ± 12.1 Nm (range = 13.7-54.7 Nm). The mean applied force to produce failure was 151.7 ± 33.1 N (range = 109.6-202.7 N), at a distance of approximately 22 cm where surgeons would typically apply direct vertebral rotation forces. Mean right rotation at T10-T11 was 11.6°±5.6°. The failure moment was significantly correlated with bone mineral density (Pearson coefficient 0.61, p = .047). Failure moment also positively correlated with radiographic degeneration grade (Spearman rho > 0.662, p < .04) and MRI degeneration grade (Spearman rho = 0.742, p = .01). CONCLUSION The present study indicated that with the advantage of lever arms provided with DVR techniques, relatively small surgical forces, <200 N, can produce large moments that cause irreversible injury. Although further studies are required to establish the safety of surgical deformity correction surgeries, the present study provides a first step in the quantification of thoracic spine strength.
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Affiliation(s)
- Sean L Borkowski
- Lucideon, 2210 Technology Dr, Schenectady, NY 12308, USA; The J. Vernon Luck, Sr., M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, 403 West Adams Blvd, Los Angeles, CA 90007, USA
| | - Sophia N Sangiorgio
- The J. Vernon Luck, Sr., M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, 403 West Adams Blvd, Los Angeles, CA 90007, USA
| | - Richard E Bowen
- Orthopaedic Institute for Children and the Department of Orthopaedic Surgery, University of California, 403 West Adams Blvd, Los Angeles, CA 90007, USA
| | - Anthony A Scaduto
- Orthopaedic Institute for Children and the Department of Orthopaedic Surgery, University of California, 403 West Adams Blvd, Los Angeles, CA 90007, USA
| | - Bo He
- The J. Vernon Luck, Sr., M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, 403 West Adams Blvd, Los Angeles, CA 90007, USA
| | - Kathryn L Bauer
- The J. Vernon Luck, Sr., M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, 403 West Adams Blvd, Los Angeles, CA 90007, USA; Orthopaedic Institute for Children and the Department of Orthopaedic Surgery, University of California, 403 West Adams Blvd, Los Angeles, CA 90007, USA
| | - Edward Ebramzadeh
- The J. Vernon Luck, Sr., M.D. Orthopaedic Research Center, Orthopaedic Institute for Children/UCLA, 403 West Adams Blvd, Los Angeles, CA 90007, USA.
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Pizones J, Núñez-Medina A, Sánchez-Mariscal F, Zúñiga L, Izquierdo E. Thoracic sagittal plane variations between patients with thoracic adolescent idiopathic scoliosis and healthy adolescents. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2016; 25:3095-3103. [PMID: 26821145 DOI: 10.1007/s00586-016-4400-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Revised: 01/11/2016] [Accepted: 01/15/2016] [Indexed: 11/30/2022]
Abstract
PURPOSE To analyze the sagittal thoracic parameters of different types of progressive thoracic adolescent idiopathic scoliosis (AIS) patients and compare them with healthy adolescents. METHODS 115 AIS patients with main thoracic curves (Cobb: 59.4 ± 12.7) were prospectively compared with 116 healthy adolescents. The AIS and control (C) groups were homogeneous in terms of age and gender. Standing sagittal radiographs were analyzed for differences in T5-T12 kyphosis, T5-T8 and T9-T12 segmental kyphosis, the change between these two angles, and the double rib contour sign. Statistical analyses were performed using the χ 2, one-way ANOVA, Mann-Whitney U and Student's t tests. RESULTS The sagittal parameters of Lenke 1 curves did not differ from healthy adolescents (T5-T8: 17.1 ± 10 vs C: 16 ± 7; T9-T12: 6.3 ± 7 vs C: 7.9 ± 5; T5-T12: 23.9 ± 14 vs C: 23.9 ± 8). Compared with the controls, Lenke type 3 curves were globally more hypokyphotic (T5-T12: 18.9 ± 12 vs C: 23.9 ± 8, P = 0.027) due to a "lordosis" of the lower thoracic segment (T9-T12: 0.9 ± 10 vs C: 7.9 ± 5, P = 0.001). Type 2 curves tended to exhibit more pronounced upper thoracic kyphosis (T5-T8: 20.7 ± 12 vs C: 16 ± 7). Both types 2 and 3 require a marked TK changes in the transition between the upper and lower thoracic segments to compensate for global (T5-T12) kyphosis. CONCLUSIONS In this 2D analysis of moderate AIS, Lenke 1 curves exhibited normal thoracic sagittal parameters, which brings into question the effect of lordosis on the development of single thoracic curves. Lenke 3 curves exhibited lower thoracic segmental hypokyphosis, and the type 2 showed upper segmental hyperkyphosis. These results should be considered when planning a surgical strategy.
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Affiliation(s)
- Javier Pizones
- Spine Unit, Department of Orthopaedic Surgery, Hospital Universitario de Getafe, Carretera de Toledo Km. 12.5, 28905, Madrid, Spain.
| | - Alberto Núñez-Medina
- Spine Unit, Department of Orthopaedic Surgery, Hospital Universitario de Getafe, Carretera de Toledo Km. 12.5, 28905, Madrid, Spain
| | - Felisa Sánchez-Mariscal
- Spine Unit, Department of Orthopaedic Surgery, Hospital Universitario de Getafe, Carretera de Toledo Km. 12.5, 28905, Madrid, Spain
| | - Lorenzo Zúñiga
- Spine Unit, Department of Orthopaedic Surgery, Hospital Universitario de Getafe, Carretera de Toledo Km. 12.5, 28905, Madrid, Spain
| | - Enrique Izquierdo
- Spine Unit, Department of Orthopaedic Surgery, Hospital Universitario de Getafe, Carretera de Toledo Km. 12.5, 28905, Madrid, Spain
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Henao J, Aubin CÉ, Labelle H, Arnoux PJ. Patient-specific finite element model of the spine and spinal cord to assess the neurological impact of scoliosis correction: preliminary application on two cases with and without intraoperative neurological complications. Comput Methods Biomech Biomed Engin 2015; 19:901-10. [DOI: 10.1080/10255842.2015.1075010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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