1
|
Gelvez D, Dong K, Redlich N, Williams J, Bhandutia A, Shamassian B. Treatment Strategies in the Osteoporotic Spine. Orthop Clin North Am 2024; 55:403-413. [PMID: 38782511 DOI: 10.1016/j.ocl.2024.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
This article reviews the appropriate assessment and management of osteoporotic compression fractures and discusses the implications of osteoporosis on initial patient evaluation, medical optimization for surgery, selection of instrumentation, and surgical technique. Adverse outcomes associated with osteoporosis are discussed. Failure to appropriately evaluate, optimize, and treat spine patients with osteoporotic bone can lead to disastrous complications. Weakened bone can lead to implant failure through cage subsidence and screw pullout, as well as, peri-implant fractures, failure of deformity correction, and proximal kyphosis. These risks must be taken into account when considering operative interventions in these patients.
Collapse
Affiliation(s)
- Daniel Gelvez
- LSU-HSC Department of Orthopaedics, 2021 Perdido Street, 7th Floor, New Orleans, LA 70112, USA.
| | - Katherine Dong
- LSU-HSC Department of Orthopaedics, 2021 Perdido Street, 7th Floor, New Orleans, LA 70112, USA
| | - Nathan Redlich
- LSU-HSC Department of Orthopaedics, 2021 Perdido Street, 7th Floor, New Orleans, LA 70112, USA
| | - Jestin Williams
- LSU-HSC Department of Orthopaedics, 2021 Perdido Street, 7th Floor, New Orleans, LA 70112, USA
| | - Amit Bhandutia
- LSU-HSC Department of Orthopaedics, 2021 Perdido Street, 7th Floor, New Orleans, LA 70112, USA
| | - Berje Shamassian
- LSU-HSC Department of Neurosurgery, 2021 Perdido Street, 7th Floor, New Orleans, LA 70112, USA
| |
Collapse
|
2
|
von Atzigen M, Liebmann F, Cavalcanti NA, Anh Baran T, Wanivenhaus F, Spirig JM, Rauter G, Snedeker J, Farshad M, Fürnstahl P. Reducing residual forces in spinal fusion using a custom-built rod bending machine. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2024; 247:108096. [PMID: 38447314 DOI: 10.1016/j.cmpb.2024.108096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/17/2024] [Accepted: 02/19/2024] [Indexed: 03/08/2024]
Abstract
BACKGROUND AND OBJECTIVE As part of spinal fusion surgery, shaping the rod implant to align with the anatomy is a tedious, error-prone, and time-consuming manual process. Inadequately contoured rod implants introduce stress on the screw-bone interface of the pedicle screws, potentially leading to screw loosening or even pull-out. METHODS We propose the first fully automated solution to the rod bending problem by leveraging the advantages of augmented reality and robotics. Augmented reality not only enables the surgeons to intraoperatively digitize the screw positions but also provides a human-computer interface to the wirelessly integrated custom-built rod bending machine. Furthermore, we introduce custom-built test rigs to quantify per screw absolute tensile/compressive residual forces on the screw-bone interface. Besides residual forces, we have evaluated the required bending times and reducer engagements, and compared our method to the freehand gold standard. RESULTS We achieved a significant reduction of the average absolute residual forces from for the freehand gold standard to (p=0.0015) using the bending machine. Moreover, our bending machine reduced the average time to instrumentation per screw from to . Reducer engagements per rod were significantly decreased from an average of 1.00±1.14 to 0.11±0.32 (p=0.0037). CONCLUSION The combination of augmented reality and robotics has the potential to improve surgical outcomes while minimizing the dependency on individual surgeon skill and dexterity.
Collapse
Affiliation(s)
- Marco von Atzigen
- Research in Orthopedic Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Laboratory for Orthopaedic Biomechanics, ETH Zurich, Zurich, Switzerland.
| | - Florentin Liebmann
- Research in Orthopedic Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Laboratory for Orthopaedic Biomechanics, ETH Zurich, Zurich, Switzerland
| | - Nicola A Cavalcanti
- Research in Orthopedic Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - The Anh Baran
- Research in Orthopedic Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Computer Aided Medical Procedures (CAMP), Technical University of Munich, Munich, Germany
| | - Florian Wanivenhaus
- Orthopaedic Department, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; University Spine Center Zurich, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - José Miguel Spirig
- Orthopaedic Department, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; University Spine Center Zurich, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Georg Rauter
- Bio-Inspired RObots for MEDicine-Lab, University of Basel, Basel, Switzerland
| | - Jess Snedeker
- Laboratory for Orthopaedic Biomechanics, ETH Zurich, Zurich, Switzerland; Orthopaedic Department, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Mazda Farshad
- Orthopaedic Department, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; University Spine Center Zurich, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| | - Philipp Fürnstahl
- Research in Orthopedic Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland
| |
Collapse
|
3
|
Hsieh MK, Lee DM, Chen WP, Li YD, Kao FC, Lin YC, Tsai TT, Lai PL, Tai CL. Forcefully engaging rods into tulips with gap discrepancy leading to pedicle screw loosening-a biomechanical analysis using long porcine spine segments. Spine J 2024:S1529-9430(24)00118-9. [PMID: 38499068 DOI: 10.1016/j.spinee.2024.03.008] [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: 11/29/2023] [Revised: 02/05/2024] [Accepted: 03/12/2024] [Indexed: 03/20/2024]
Abstract
BACKGROUND CONTEXT Long-segment pedicle screw instrumentation is widely used to treat complex spinal disorders. Rods are routinely precontoured to maximize assistance on the correcting side of the deformity, but there often exists a residual gap discrepancy between the precontoured rods and screw tulips. No previous research has investigated the diminished pullout strength of the most proximal or distal pedicle screw resulting from a mismatched rod in long-segment pedicle screw instrumentation. PURPOSE The present study aimed to investigate the decreased pullout force of pedicle screws affected by the gap discrepancy when forcefully engaging a mismatched rod into a tulip in a normal-density porcine spine. STUDY DESIGN The pedicle screw fixation strength under axial pullout force was compared among three different gap discrepancies between rods and tulips using long porcine spine segments. METHODS Twelve porcine lumbar vertebrae (L3-L6) were implanted with pedicle screws and rods. Screws on one side had no gap between the tulip and rod (0-mm group), while the most proximal screw on the other side had an intentional gap of 3 mm (3-mm group) or 6 mm (6-mm group). Three hours after forcefully engaging the rod into the tulips at room temperature, the set screws in all specimens were loosened, and each specimen was dissected into individual vertebrae for subsequent pullout testing. RESULTS The control group exhibited significantly greater pullout strength (1987.68 ± 126.80 N) than the groups from different rod-tulip configurations (p<.05), with significantly greater strength in the 3-mm group (945.62 ± 97.43 N) than the 6-mm group (655.30 ± 194.49 N) (p<.05). Only 47.6% and 33.0% of the pullout strength was retained in the 3-mm and 6-mm groups, respectively, compared to the control group. CONCLUSIONS Gap discrepancies between rods and tulips can significantly reduce pedicle screw pullout strength, with a correlation between decreased strength and increased gaps. Surgeons should avoid forcefully engaging mismatched rods and consider well-fitted contoured rods in spinal surgery to minimize the risk of screw loosening. CLINICAL SIGNIFICANCE The gap discrepancy between rod and tulip significantly affected pullout strength, with greater gaps leading to reduced strength. Forcefully engaging mismatched rods into tulips in degenerative spinal surgery should be avoided to minimize the risk of early screw pullout.
Collapse
Affiliation(s)
- Ming-Kai Hsieh
- Department of Orthopaedic Surgery, Spine Section, Bone and Joint Research Center, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 5, Fushing St., Kweishan Dist., Taoyuan City 33305, Taiwan
| | - De-Mei Lee
- Department of Mechanical Engineering, Chang Gung University, No. 259, Wenhua 1(st) Rd., Kweishan Dist., Taoyuan City 33302, Taiwan
| | - Weng-Pin Chen
- Department of Mechanical Engineering, National Taipei University of Technology, No. 1, Sec. 3, Zhongxiao E. Rd., Daan Dist., Taipei City 10608, Taiwan
| | - Yun-Da Li
- Department of Orthopaedic Surgery, Spine Section, Bone and Joint Research Center, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 5, Fushing St., Kweishan Dist., Taoyuan City 33305, Taiwan; Department of Biomedical Engineering, Chang Gung University, No. 259, Wenhua 1(st) Rd., Kweishan Dist., Taoyuan City 33302, Taiwan
| | - Fu-Cheng Kao
- Department of Orthopaedic Surgery, Spine Section, Bone and Joint Research Center, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 5, Fushing St., Kweishan Dist., Taoyuan City 33305, Taiwan
| | - Yue-Chen Lin
- Department of Mechanical Engineering, Chang Gung University, No. 259, Wenhua 1(st) Rd., Kweishan Dist., Taoyuan City 33302, Taiwan
| | - Tsung-Ting Tsai
- Department of Orthopaedic Surgery, Spine Section, Bone and Joint Research Center, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 5, Fushing St., Kweishan Dist., Taoyuan City 33305, Taiwan
| | - Po-Liang Lai
- Department of Orthopaedic Surgery, Spine Section, Bone and Joint Research Center, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 5, Fushing St., Kweishan Dist., Taoyuan City 33305, Taiwan
| | - Ching-Lung Tai
- Department of Orthopaedic Surgery, Spine Section, Bone and Joint Research Center, Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No. 5, Fushing St., Kweishan Dist., Taoyuan City 33305, Taiwan; Department of Biomedical Engineering, Chang Gung University, No. 259, Wenhua 1(st) Rd., Kweishan Dist., Taoyuan City 33302, Taiwan.
| |
Collapse
|
4
|
Noriega DC, Eastlack RK, Hernández GL, Kafchitsas K, Ryang YM, Spitz SM, Lite IS. Does the interfacing angle between pedicle screws and support rods affect clinical outcomes after posterior thoracolumbar fusion? A retrospective clinical study. Spine J 2024; 24:125-131. [PMID: 37726089 DOI: 10.1016/j.spinee.2023.09.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 09/05/2023] [Accepted: 09/11/2023] [Indexed: 09/21/2023]
Abstract
BACKGROUND CONTEXT Proper alignment and tightening of the pedicle screw/rod assembly after instrumented posterior fusion of the lower spine is known to be crucial in order to achieve satisfactory clinical results. Such interfacing angle mismatches indicate stress overloading of the implant system. PURPOSE The objective of this study is to investigate the incidence of postoperative screw/rod interfacing angle mismatch and to analyze the impact of mismatches on clinical outcome in terms of (1) revision surgery, (2) adjacent segment degeneration (ASD), and (3) pain. STUDY DESIGN This is a monocentric retrospective observational study. PATIENT SAMPLE Patients underwent fusion surgery with pedicle screw/rod systems for predominantly degenerative pathologies. OUTCOME MEASURES Pedicle screw/rod interfacing angle mismatch (mismatch is the angular deviation from 90° formed by the rod axis and the pedicle screw head axis as an indicator for missing form-fit) revision rate, ASD at the immediately adjacent cranial segment and VAS pain. METHODS Revision refers to subsequent procedures in which all or part of the original implant configuration is changed or removed. Radiographic parameters are evaluated using a/p and lateral radiographs at final follow-up. The interfacing angle mismatch between pedicle screw and rod is measured as the angle between two parallel lines on either side of each pedicle screw head and a line laterally along the associated rod. Multiple comparisons are counteracted by Bonferroni correction, adjusted significance level is at *p<.01. RESULTS Pedicle screw and rod interfacing angle mismatch was found in 171/406 (42.1%) of patients undergoing fusion surgery, affecting 613/3016 (20.3%) screws. The overall revision incidence was 11.8% (48/406), and a new ASD occurred in 12.1% of all patients (49/406) with an average follow-up of 5 years. Mean VAS pain score at final follow-up was 2.0. Comparison of the two groups with and without mismatches revealed statistically significantly higher (1) numbers of revision procedures performed (26.9% vs 0.9%), (2) numbers of new ASD developed (27.5% vs 3.8%), and (3) higher VAS pain scores (2.8/10 vs 1.4/10) for cases with mismatch. When comparing patients who underwent intraoperative correction and/or reduction with those who did not, statistically significant more screw mismatches (63.4% vs 39.7%) and revision surgeries (29.3% vs 9.9%) were noted in patients who had these forceful maneuvers. CONCLUSIONS Pedicle screw/rod interfacing angle mismatch is a frequent occurrence after fusion surgery. Mismatches indicate that the construct was assembled under mechanical stress. All preventable mechanical stresses, for example, unintentional uncontrolled forces on the instrumentation, should be avoided as much as possible, as they can negatively influence the clinical outcome.
Collapse
Affiliation(s)
- David C Noriega
- Department of Orthopaedics, University Hospital of Valladolid, Calle Ramon y Cajal, Valladolid, Spain.
| | - Robert K Eastlack
- Department of Orthopaedics, Scripps Clinic, N Torrey Pines Rd, La Jolla, CA, USA
| | | | | | - Yu-Mi Ryang
- Department of Neurosurgery and Center for Spine Therapy, Helios Clinic Berlin-Buch, Schwanebecker Chaussee, Berlin, Germany
| | - Steven M Spitz
- Department of Neurosurgery, Northside Hospital, Northside Cherokee Blvd, Canton, GA, USA
| | - Israel Sánchez Lite
- Department of Radiology, University Hospital of Valladolid, Calle Ramon y Cajal, Valladolid, Spain
| |
Collapse
|
5
|
Antes S, Moringlane R, von Eckardstein KL. Augmented Reality-Supported Rod Bending in Multilevel Spinal Fusion Using the ADVISE Software. World Neurosurg 2023; 178:96-100. [PMID: 37454904 DOI: 10.1016/j.wneu.2023.07.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 07/18/2023]
Abstract
BACKGROUND One of the most common reasons for poor patient outcomes and revision surgery in spinal fusion is hardware failure. Screw loosening or pullout occurs in up to one-quarter of all cases. It is known that even small screw-rod misalignments can cause significant mechanical overloads during rod fixation, which can result in hardware failure. To address this crucial surgical step, a novel augmented reality-assisted software was developed to generate custom rod templates that are precisely adapted to the individual patient. METHODS The novel software, which runs on a tablet, is used in spinal fusion surgery and is based on the use of a specific pedicle screw system, in which the polyaxial screw heads are connected to detachable guides. These guides can be recognized by the tablet camera and a light detection and ranging scanner. This image information is processed to determine the spatial positions of the screw heads and to calculate an ideally fitting rod template. RESULTS The calculated rod template is displayed in a 1-to-1 scale on the tablet screen. This template is used to cut and bend the rods of the pedicle screw system. Finally, the custom bent rod can be inserted into the screw heads without tension. CONCLUSIONS The augmented reality-assisted software is intended to give surgeons access to patient-specific intraoperative real-time data, helping them in bending rods that are more precisely adapted to the individual patient compared with the freehand technique.
Collapse
Affiliation(s)
- Sebastian Antes
- Department of Neurosurgery, Westpfalz-Klinikum GmbH, Kaiserslautern, Germany.
| | - Rene Moringlane
- Department of Neurosurgery, Westpfalz-Klinikum GmbH, Kaiserslautern, Germany
| | - Kajetan L von Eckardstein
- Department of Neurosurgery, Westpfalz-Klinikum GmbH, Kaiserslautern, Germany; Department of Neurosurgery, Universitätsmedizin Mannheim, Mannheim, Germany
| |
Collapse
|
6
|
Sawa AGU, Wangsawatwong P, Lehrman JN, Hostetler T, de Andrada Pereira B, Godzik J, Hlubek RJ, Uribe JS, Turner JD, Kelly BP. Rod Attachment Induces Significant Strain in Lumbosacral Fixation. Clin Spine Surg 2023; 36:E247-E251. [PMID: 36788442 DOI: 10.1097/bsd.0000000000001438] [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: 05/18/2022] [Accepted: 12/01/2022] [Indexed: 02/16/2023]
Abstract
STUDY DESIGN This was a laboratory investigation. OBJECTIVE Rod attachment can induce significant pedicle screw-and-rod pre- strain that may predispose the instrumentation to failure. This study investigated how in vitro L5-S1 rod strain and S1 screw strain during rod-screw attachment (pre-strain) compared with strains recorded during pure-moment bending ( test- strain). SUMMARY OF BACKGROUND DATA The lumbosacral junction is highly vulnerable to construct failure due to rod fatigue fracture, sacral screw pull-out, and screw fatigue fracture. MATERIALS AND METHODS Twelve cadaveric specimens were instrumented with L2-ilium pedicle screws and rod. Strain gauges on contoured rods and sacral screws recorded strains during sequential rod-to-screw tightening (pre-strains). The same instrumented constructs were immediately tested in a 6-degree-of-freedom apparatus under continuous loading to 7.5 Nm in multidirectional bending while recording instrumentation test-strains. Rod and screw pre-strains and test-strains were compared using 1-way repeated-measures analysis of variance followed by Holm-Šidák paired analysis (significant at P <0.05). RESULTS The mean first (171±192 µE) and second (322±269 µE) rod attachment pre-strains were comparable to mean test-strains during flexion (265±109 µE) and extension (315±125 µE, P ≥0.13). The mean rod attachment pre-strain was significantly greater than mean test-strains during bidirectional lateral bending (40±32 µE ipsilateral and 39±32 µE contralateral, P <0.001) and axial rotation (72±60 µE ipsilateral and 60±57 µE contralateral, P <0.001). The mean first and second sacral screw pre-strains during rod attachment (1.03±0.66 and 1.39±1.00 Nm, respectively) did not differ significantly ( P =0.41); however, the mean sacral screw pre-strain during final (second) rod attachment was significantly greater than screw test-strains during all directions of movement (≤0.81 Nm, P ≤0.03). CONCLUSIONS Instrumentation pre-strains imposed during in vitro rod-screw attachment of seemingly well-contoured rods in L2-ilium fixation are comparable to, and at times greater than, strains experienced during in vitro bending. Spine surgeons should be aware of the biomechanical consequences of rod contouring and attachment on construct vulnerability.
Collapse
Affiliation(s)
- Anna G U Sawa
- Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ
| | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
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.
Collapse
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.
| |
Collapse
|
8
|
Schömig F, Becker L, Schönnagel L, Völker A, Disch AC, Schnake KJ, Pumberger M. Avoiding Spinal Implant Failures in Osteoporotic Patients: A Narrative Review. Global Spine J 2023; 13:52S-58S. [PMID: 37084355 PMCID: PMC10177307 DOI: 10.1177/21925682231159066] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/23/2023] Open
Abstract
STUDY DESIGN Narrative review. OBJECTIVES With an aging population, the prevalence of osteoporosis is continuously rising. As osseous integrity is crucial for bony fusion and implant stability, previous studies have shown osteoporosis to be associated with an increased risk for implant failure and higher reoperation rates after spine surgery. Thus, our review's purpose was to provide an update of evidence-based solutions in the surgical treatment of osteoporosis patients. METHODS We summarize the existing literature regarding changes associated with decreased bone mineral density (BMD) and resulting biomechanical implications for the spine as well as multidisciplinary treatment strategies to avoid implant failures in osteoporotic patients. RESULTS Osteoporosis is caused by an uncoupling of the bone remodeling cycle based on an unbalancing of bone resorption and formation and resulting reduced BMD. The reduction in trabecular structure, increased porosity of cancellous bone and decreased cross-linking between trabeculae cause a higher risk of complications after spinal implant-based surgeries. Thus, patients with osteoporosis require special planning considerations, including adequate preoperative evaluation and optimization. Surgical strategies aim towards maximizing screw pull-out strength, toggle resistance, as well as primary and secondary construct stability. CONCLUSIONS As osteoporosis plays a crucial role in the fate of patients undergoing spine surgery, surgeons need to be aware of the specific implications of low BMD. While there still is no consensus on the best course of treatment, multidisciplinary preoperative assessment and adherence to specific surgical principles help reduce the rate of implant-related complications.
Collapse
Affiliation(s)
- Friederike Schömig
- Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Luis Becker
- Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Lukas Schönnagel
- Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Anna Völker
- Department of Orthopaedic, Trauma and Plastic Surgery, University Hospital Leipzig, Leipzig, Germany
| | - Alexander C Disch
- University Comprehensive Spine Center, University Center for Orthopedics, Traumatology and Plastic Surgery, Universitätsklinikum Carl Gustav Carus, Dresden, Germany
| | - Klaus John Schnake
- Center for Spinal and Scoliosis Surgery, Malteser Waldkrankenhaus St Marien gGmbH, Erlangen, Germany
- Department of Orthopedics and Traumatology, Paracelsus Private Medical University Nuremberg, Nuremberg, Germany
| | - Matthias Pumberger
- Center for Musculoskeletal Surgery, Charité - Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
9
|
New approaches to proven technology: force control posterior thoracolumbar fusion with an innovative pedicle screw system. INTERDISCIPLINARY NEUROSURGERY 2022. [DOI: 10.1016/j.inat.2022.101701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
10
|
Kim YH, Ha KY, Park HY, Ihm JS, Kim SI. Rod Fracture After Pedicle Subtraction Osteotomy Using a Side-Tightening Pedicle Screw System in Consecutive Case Series. World Neurosurg 2022; 165:e643-e649. [PMID: 35779749 DOI: 10.1016/j.wneu.2022.06.112] [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: 05/08/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 12/14/2022]
Abstract
OBJECTIVE The objective of this study was to investigate the incidence and risk factors of rod fractures (RFs) after a single-level lumbar pedicle subtraction osteotomy (PSO) using a side-tightening (ST) pedicle screw system. METHODS Fifty-seven consecutive patients who underwent a single-level lumbar PSO for the degenerative sagittal imbalance at a single institution were retrospectively reviewed. All surgeries were performed by a single surgeon using an ST pedicle screw system. Demographic, surgical, and radiographic data were analyzed to investigate the incidence and risk factors for RF. RESULTS Seven (12.3%) patients showed RF after PSO. Four patients had bilateral RFs, and 3 patients had unilateral RFs. The location of the RF was at the PSO level in 6 of 7 patients. The ratio of adjacent interbody fusion was significantly different between the group with RF and the group without RF (16.7% vs. 74.0%, P = 0.004). The preoperative segmental angle at the PSO vertebra (-6.1° ± 5.5° vs. -1.7° ± 4.6°, P = 0.049) and postsurgical change in lumbar lordosis (48.4° ± 8.8° vs. 37.8° ± 11.9°, P = 0.033) were significantly different between the 2 groups. Risk factor analysis using stepwise logistic regression analysis revealed that the absence of an adjacent interbody cage (odds ratio = 0.011, 95% confidence interval = 0.000-0.390, P = 0.013) was a significant risk factor. CONCLUSIONS The incidence of RF after a single-level lumbar PSO using the ST pedicle screw system was 12.3% in our cohort. The absence of an adjacent interbody cage was a significant risk factor for RF.
Collapse
Affiliation(s)
- Young-Hoon Kim
- Department of Orthopedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - Kee-Yong Ha
- Department of Orthopedic Surgery, Kyung-Hee University Hospital at Gangdong, Kyung-Hee University, Seoul, Republic of Korea
| | - Hyung-Youl Park
- Department of Orthopedic Surgery, Eunpyeong St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - Joon-Soo Ihm
- Department of Orthopedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea
| | - Sang-Il Kim
- Department of Orthopedic Surgery, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
| |
Collapse
|
11
|
Prost S, Pesenti S, Farah K, Tropiano P, Fuentes S, Blondel B. Sagittal reduction of spinal deformity: Superior versus lateral screw-rod connection. Orthop Traumatol Surg Res 2021; 107:102954. [PMID: 33951541 DOI: 10.1016/j.otsr.2021.102954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 08/28/2020] [Accepted: 11/16/2020] [Indexed: 02/03/2023]
Abstract
INTRODUCTION Spinal malalignment can greatly impact a patient's quality of life. Various sagittal parameters are used as realignment goals; however, about 50% of patients end up being under-corrected postoperatively. To improve the correction, prebent rods are available with a radius of curvature corresponding to the patient's "ideal" sagittal alignment. But no studies have been done on how the radius of curvature changes according to the type of connection between the pedicle screws and rods. The goal of this experimental study was to quantify how much prebent rods flatten based on the method used to connect the screw and rod: top-loading screw vs. dome screw with lateral connector. METHODS The experiment was done on a material testing system in axial compression on three constructs consisting of two rods secured with top-loading screws and three other constructs consisting of two rods secured with dome screws and lateral connector. The maximum angle of the construct was measured during loading and after removing the load. The primary outcome measure was the mean angle in each construct at each step. RESULTS The mean angle of the constructs with top-loading screws when subjected to 500 N load was significantly less than in the constructs with dome screws and lateral connector: 18.6° vs. 24.5° respectively (p<0.0003). The mean angle of the constructs with top-loading screws after removing the load was significantly less than in the constructs with dome screws and lateral connector: 25.7° vs. 32.3° respectively, (p<0.0005). CONCLUSION In vitro, top-loading screws produced significantly greater flattening than dome screws with lateral connector. These findings must be confirmed in vivo. Understanding the behavior of rods as a function of the type of screw connection can be an important factor to minimize the risk of under-correction in the sagittal plane. LEVEL OF EVIDENCE III.
Collapse
Affiliation(s)
- Solène Prost
- Aix-Marseille Université, APHM, CNRS, ISM, CHU Timone, Unité de chirurgie rachidienne, 264, rue Saint-Pierre, 13005 Marseille, France
| | - Sébastien Pesenti
- Service de chirurgie orthopédique pédiatrique, Aix-Marseille Université, APHM, CNRS, ISM, CHU Timone, 264, rue Saint-Pierre, 13005 Marseille, France
| | - Kaissar Farah
- Aix-Marseille Université, APHM, CNRS, ISM, CHU Timone, Unité de chirurgie rachidienne, 264, rue Saint-Pierre, 13005 Marseille, France
| | - Patrick Tropiano
- Aix-Marseille Université, APHM, CNRS, ISM, CHU Timone, Unité de chirurgie rachidienne, 264, rue Saint-Pierre, 13005 Marseille, France
| | - Stéphane Fuentes
- Aix-Marseille Université, APHM, CNRS, ISM, CHU Timone, Unité de chirurgie rachidienne, 264, rue Saint-Pierre, 13005 Marseille, France
| | - Benjamin Blondel
- Aix-Marseille Université, APHM, CNRS, ISM, CHU Timone, Unité de chirurgie rachidienne, 264, rue Saint-Pierre, 13005 Marseille, France.
| |
Collapse
|
12
|
Evaluation of the reduction, tightening and gripping performance of an innovative set screw technology for instrumented posterior lumbar fusion: A biomechanical study. Orthop Traumatol Surg Res 2021; 107:102918. [PMID: 33812093 DOI: 10.1016/j.otsr.2021.102918] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/21/2020] [Accepted: 12/30/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND Instrumented posterior lumbar fusion with top-loading pedicle screw systems (PSS) requires fully tightened set screws to achieve a secure fixation and symmetric load condition. This assumes a complete reduction of the rod by 90°, which is not always attainable in situ, especially under constraint. The objective of this work is to compare the mechanical performance of different innovative set screw technologies, which should improve the tightening process. HYPOTHESIS The hypotheses of the study are that modifications to the screw and screwdriver unit can (1) improve the quality of set screw tightening and (2) increase the axial gripping capacity of the construct. MATERIALS AND METHODS The four set screw technologies under investigation include a standard set screw with a flat surface (F-S; control group), a set screw with a convex surface (C-S) and a shaft tip method screwdriver used in combination with both flat (F-STM) and convex set screws (C-STM). The quality of set screw tightening is categorized as follows: failed=the rod is not completely reduced; reduced=the rod is successfully reduced but the set screw is not correctly fixed; good=remaining cases. An axial gripping capacity test is performed by a universal testing machine (Instron®) with a force capacity of 5kN. RESULTS Regarding the quality of set screw tightening, comparisons between F-S vs. F-STM, F-S vs. C-STM and between C-S vs. C-STM show statistically significant differences (p<0.001). The axial gripping capacity test shows mean gripping forces of 1223N (STD 331) in the F-STM group and of 1724N (STD 168) in the C-STM group with statistically significant differences between both groups (p=0.003). DISCUSSION Several biomechanical and clinical case studies have identified possible effects of misaligned rod-screw interfaces such as screw pull-out during rod reduction, screw loosening, screw or rod breakage, misalignment, adjacent segment degeneration and worsening of the clinical outcome. C-STM-technology thus supports controlled fixation in the sense of applying appropriate forces for correction or fixation during PSS assembly as well as friction-reduced final alignment and tightening with the aim to reduce implant loosening, hardware failure and reoperations, while respecting anatomical and biomechanical balance.
Collapse
|
13
|
Tanaka M, Singh M, Fujiwara Y, Uotani K, Arataki S, Yamauchi T, Nakanishi K. Minimally Invasive Thoracolumbar Corpectomy and Percutaneous Pedicle Screw Fixation with Computer-Assisted Rod-Bending System in Single Lateral Position: Technical Note. World Neurosurg 2021; 151:138-144. [PMID: 34020059 DOI: 10.1016/j.wneu.2021.05.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/08/2021] [Accepted: 05/10/2021] [Indexed: 11/18/2022]
Abstract
BACKGROUND Thoracolumbar corpectomy and percutaneous pedicle screw (PPS) fixation is becoming the standard method for correcting and stabilizing malalignment of spine, as is often seen in osteoporotic vertebral fracture. Nowadays, this procedure can be performed in a single lateral position with navigation. For an osteoporotic spine, accurate rod bending is necessary to prevent screw back-out. We describe a new technique using the spinal rod-bending system in a single lateral position. METHODS A 71-year-old woman presented with severe back pain and impending paraplegia secondary to L1 osteoporotic vertebral fracture. We performed minimally invasive L1 corpectomy with an expandable vertebral cage and short-segment PPS with computer-assisted rod bending in a single lateral position under navigation guidance. RESULTS The patient was successfully treated with surgery, and her low back pain improved. Her clinical outcomes improved; the Oswestry Disability Index went from 54% to 26%, and her low back pain visual analog scale score went from 78 mm to 19 mm at the 2-year final follow-up. CONCLUSIONS Minimally invasive surgery thoracolumbar corpectomy using a computer-assisted spinal rod-bending system is a valuable technique to reduce screw back-out for osteoporotic vertebrae. With this new technique, the rod bending becomes easy, even for long PPS fusion with the severe osteoporotic or deformity patient in a single lateral position.
Collapse
Affiliation(s)
- Masato Tanaka
- Department of Orthopaedic Surgery, Okayama Rosai Hospital, Okayama, Japan.
| | - Mahendra Singh
- Department of Orthopaedic Surgery, Okayama Rosai Hospital, Okayama, Japan
| | - Yoshihiro Fujiwara
- Department of Orthopaedic Surgery, Okayama Rosai Hospital, Okayama, Japan
| | - Koji Uotani
- Department of Orthopaedic Surgery, Okayama Rosai Hospital, Okayama, Japan
| | - Shinya Arataki
- Department of Orthopaedic Surgery, Okayama Rosai Hospital, Okayama, Japan
| | - Taro Yamauchi
- Department of Orthopaedic Surgery, Okayama Rosai Hospital, Okayama, Japan
| | - Kazuo Nakanishi
- Department of Orthopaedic Surgery, Kawasaki Medical University, Kurashiki, Japan
| |
Collapse
|
14
|
Loenen ACY, Noriega DC, Ruiz Wills C, Noailly J, Nunley PD, Kirchner R, Ito K, van Rietbergen B. Misaligned spinal rods can induce high internal forces consistent with those observed to cause screw pullout and disc degeneration. Spine J 2021; 21:528-537. [PMID: 33007470 DOI: 10.1016/j.spinee.2020.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/31/2020] [Accepted: 09/24/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Manual contouring of spinal rods is often required intraoperatively for proper alignment of the rods within the pedicle screw heads. Residual misalignments are frequently reduced by using dedicated reduction devices. The forces exerted by these devices, however, are uncontrolled and may lead to excessive reaction forces. As a consequence, screw pullout might be provoked and surrounding tissue may experience unfavorable biomechanical loads. The corresponding loads and induced tissue deformations are however not well identified. Additionally, whether the forced reduction alters the biomechanical behavior of the lumbar spine during physiological movements postoperatively, remains unexplored. PURPOSE To predict whether the reduction of misaligned posterior instrumentation might result in clinical complications directly after reduction and during a subsequent physiological flexion movement. STUDY DESIGN Finite element analysis. METHODS A patient-specific, total lumbar (L1-S1) spine finite element model was available from previous research. The model consists of poro-elastic intervertebral discs with Pfirrmann grade-dependent material parameters, with linear elastic bone tissue with stiffness values related to the local bone density, and with the seven major ligaments per spinal motion segment described as nonlinear materials. Titanium instrumentation was implemented in this model to simulate a L4, L5, and S1 posterolateral fusion. Next, coronal and sagittal misalignments of 6 mm each were introduced between the rod and the screw head at L4. These misalignments were computationally reduced and a physiological flexion movement of 15° was prescribed. Non-instrumented and well-aligned instrumented models were used as control groups. RESULTS Pulling forces up to 1.0 kN were required to correct the induced misalignments of 6 mm. These forces affected the posture of the total lumbar spine, as motion segments were predicted to rotate up to 3 degrees and rotations propagated proximally to and even affect the L1-2 level. The facet contact pressures in the corrected misaligned models were asymmetrical suggesting non-physiological joint loading in the misaligned models. In addition, the discs and vertebrae experienced abnormally high forces as a result of the correction procedure. These effects were more pronounced after a 15° flexion movement following forced reduction. CONCLUSIONS The results of this study indicate that the correction of misaligned posterior instrumentation can result in high forces at the screws consistent with those reported to cause screw pullout, and may cause high-tissue strains in adjacent and downstream spinal segments. CLINICAL SIGNIFICANCE Proper alignment of spinal posterior instrumentation may reduce clinical complications secondary to unfavorable biomechanics.
Collapse
Affiliation(s)
- Arjan C Y Loenen
- Department of Orthopaedic Surgery, Laboratory for Experimental Orthopaedics, CAPHRI, Maastricht University Medical Centre, Maastricht, the Netherlands; Department of Biomedical Engineering, Orthopaedic Biomechanics, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - David C Noriega
- Spine-Unit, University Hospital of Valladolid, Valladolid, Spain
| | - Carlos Ruiz Wills
- Department of Information and Communication Technologies, Barcelona Centre for New Medical Technologies (BCN MedTech), Universitat Pompeu Fabra, Barcelona, Spain
| | - Jérôme Noailly
- Department of Information and Communication Technologies, Barcelona Centre for New Medical Technologies (BCN MedTech), Universitat Pompeu Fabra, Barcelona, Spain
| | | | - Rainer Kirchner
- Department of Orthopaedic Surgery and Trauma Surgery, Clinics Husum and Niebüll, Husum, Germany
| | - Keita Ito
- Department of Biomedical Engineering, Orthopaedic Biomechanics, Eindhoven University of Technology, Eindhoven, the Netherlands
| | - Bert van Rietbergen
- Department of Orthopaedic Surgery, Laboratory for Experimental Orthopaedics, CAPHRI, Maastricht University Medical Centre, Maastricht, the Netherlands; Department of Biomedical Engineering, Orthopaedic Biomechanics, Eindhoven University of Technology, Eindhoven, the Netherlands.
| |
Collapse
|
15
|
Omar Pacha T, Omar M, Graulich T, Suero E, Mathis SchrÖder B, Krettek C, Stubig T. Comparison of Preoperative Pedicle Screw Measurement Between Computed Tomography and Magnet Resonance Imaging. Int J Spine Surg 2020; 14:671-680. [PMID: 33097582 DOI: 10.14444/7098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Pedicle screw fixation is commonly used in the treatment of spinal pathologies. While the biomechanical factors that affect bone fixation have been frequently described, questions remain as to which imaging modality is the ideal medium for preoperative planning. Due to its perceived superiority in assessing bony changes, computed tomography (CT) scan is assumed to be the gold standard for preparative planning, and we hypothesize that magnetic resonance imaging (MRI) is sufficiently accurate to predict screw length and diameter compared to CT. METHODS We retrospectively measured the length and diameter of vertebral bodies in the lumbar region in both MRI and CT and tested for differences between the modalities as well as for confounding effects of age, sex, and the presence of spondyloarthrosis. RESULTS We found a significant difference in pedicle screw length between CT and MRI measurements for both sides. For the left pedicle, the mean difference was 1.89 mm (95% confidence interval [CI] -3.03 to -0.75; P < .002), while for the right pedicle, the mean difference was 2.05 mm (95% CI -3.27 to -0.84; P = .001). We also found a significant difference in diameter measurements between CT and MRI for the left pedicle (0.53 mm; 95% CI 0.13 to 0.93; P = .011) but not for the right pedicle (0.36 mm; 95% CI -0.06 to 0.78; P = .094). We identified no significant effect of sex, age or spondyloarthrosis on the results (P > .05). CONCLUSIONS Pedicle screw planning measurements were more accurate using CT images compared to MRI images. CT scan remains the gold standard for pedicle screw planning in trauma surgery. When using MRI images, the surgeon should be aware of the differences in screw length and diameter compared to CT in order to avoid intra- and postoperative risks.
Collapse
Affiliation(s)
- Tarek Omar Pacha
- Trauma Department, Hannover Medical School(MHH); Lower Saxony, Germany
| | - Mohamed Omar
- Trauma Department, Hannover Medical School(MHH); Lower Saxony, Germany
| | - Tilmann Graulich
- Trauma Department, Hannover Medical School(MHH); Lower Saxony, Germany
| | - Eduardo Suero
- Department of General, Trauma and Reconstructive Surgery, University Hospital, LMU Munich, Munich, Germany
| | | | - Christian Krettek
- Trauma Department, Hannover Medical School(MHH); Lower Saxony, Germany
| | - Timo Stubig
- Trauma Department, Hannover Medical School(MHH); Lower Saxony, Germany
| |
Collapse
|
16
|
Funao H, Isogai N, Sasao Y, Nishiyama M, Ishii K. Vertebroplasty with posterior spinal fusion for osteoporotic vertebral fracture using computer-assisted rod contouring system: A new minimally invasive technique. Int J Surg Case Rep 2020; 72:301-305. [PMID: 32563090 PMCID: PMC7305354 DOI: 10.1016/j.ijscr.2020.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/04/2020] [Accepted: 06/04/2020] [Indexed: 11/25/2022] Open
Abstract
Surgical treatment of osteoporotic vertebral fracture (OVF) is challenging. A new minimally invasive technique of posterior spinal fusion was performed for OVF. This technique would be beneficial for elderly or immunocompromised patients.
Introduction Surgical treatment of osteoporotic vertebral fracture (OVF) has been challenging for spine surgeons, because there are potential risks of instrumentation failure; such as screw loosening, loss of correction, or pseudarthrosis, due to bone fragility in elderly patients with several comorbidities. Presentation of case A 68-year-old female presented with a severe low back pain and bilateral thigh pain. She had a history of systemic scleroderma, which was complicated by interstitial lung disease. Although she initially underwent non-surgical treatment with bracing for 7 months, her symptoms had progressively deteriorated, and her radiographs showed non-union at L1 and progressive kyphotic deformity at the thoracolumbar spine. Because an anterior approach was inadvisable due to interstitial lung disease, vertebroplasty with posterior spinal fusion was performed using percutaneous pedicle screws (PPS) at the upper most and lowest instrumented vertebra combined with sublaminar taping and computer-assisted rod contouring system. Good bony union was achieved with no screw loosening at 1-year follow-up. Discussion Various surgical procedures have been applied according to the fracture type or medical condition of the patient. Minimally invasive posterior spinal fusion would be a less invasive approach in patients with poor medical condition. PPS can prevent the excessive dissection of paravertebral muscles, and this is especially advantageous at the proximal and distal end of long constructs. A recent computer-assisted rod contouring system accurately matches each screw head resulting in reduced strength of the screw-bone interface. Conclusion This technique would be beneficial in the elderly or immunocompromised patients with OVF.
Collapse
Affiliation(s)
- Haruki Funao
- Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare, Japan; Spine and Spinal Cord Center, International University of Health and Welfare Mita Hospital, Japan.
| | - Norihiro Isogai
- Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare, Japan; Spine and Spinal Cord Center, International University of Health and Welfare Mita Hospital, Japan
| | - Yutaka Sasao
- Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare, Japan; Spine and Spinal Cord Center, International University of Health and Welfare Mita Hospital, Japan
| | - Makoto Nishiyama
- Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare, Japan; Spine and Spinal Cord Center, International University of Health and Welfare Mita Hospital, Japan
| | - Ken Ishii
- Department of Orthopaedic Surgery, School of Medicine, International University of Health and Welfare, Japan; Spine and Spinal Cord Center, International University of Health and Welfare Mita Hospital, Japan
| |
Collapse
|
17
|
Schulze M, Riesenbeck O, Vordemvenne T, Raschke MJ, Evers J, Hartensuer R, Gehweiler D. Complex biomechanical properties of non-augmented and augmented pedicle screws in human vertebrae with reduced bone density. BMC Musculoskelet Disord 2020; 21:151. [PMID: 32143605 PMCID: PMC7060638 DOI: 10.1186/s12891-020-3158-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/24/2020] [Indexed: 11/26/2022] Open
Abstract
Background In osteoporotic bone, the quality of the bone-to-implant interface is decreased, which may lead to early implant failure. Screw anchorage can be improved by augmentation. This effect is mainly investigated with a pull-out test. To our knowledge, the effect of cement augmentation in an in vivo physiological setup focusing on screw movement has not been investigated to date. The aim of this work was to investigate and compare augmented and native screw behavior in a physiologically related setup. Methods Twelve fresh-frozen human lumbar vertebrae were divided into two groups. Each vertebra was bilaterally instrumented with either non-augmented or augmented pedicle screw systems and loaded in a recently developed test setup that provided cyclic conditions comparable to a physiological gait. The cyclic loading should test the primary implant stability, comparable to the postoperative period of two months in a worst-case scenario in the absence of osseous remodeling. Screws were tracked optically, and screw movement and failure patterns were observed. Results Mutual influence between the left and right sides resulted in a successive, rather than simultaneous, failure. Augmentation of the screws in vertebrae with poor bone quality reduced screw subsidence and thus improved the rigidity of the screw-to-implant interface by up to six-fold. The non-augmented condition was significantly related to early screw failure. Conclusions Pedicle screw system failure involves a complex bilateral-coupled mechanism. The cyclic loading based on physiological conditions during walking has allowed the postoperative conditions and clinical failure mechanisms to be simulated in vitro and clarified. Future implant systems should be investigated with a physiologically related setup.
Collapse
Affiliation(s)
- Martin Schulze
- University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, 48149, Münster, Germany. .,University Hospital Münster, Department of General Orthopaedics and Tumor Orthopaedics, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.
| | - Oliver Riesenbeck
- University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - Thomas Vordemvenne
- University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.,Evangelical Hospital Bethel GmbH, Department of Trauma Surgery and Orthopaedics, Bielefeld, Germany
| | - Michael J Raschke
- University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - Julia Evers
- University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - René Hartensuer
- University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, 48149, Münster, Germany
| | - Dominic Gehweiler
- University Hospital Münster, Department of Trauma, Hand and Reconstructive Surgery, Albert-Schweitzer-Campus 1, 48149, Münster, Germany.,AO Research Institute Davos, Davos, Switzerland
| |
Collapse
|
18
|
Hitchon PW, Mahoney JM, Harris JA, Hussain MM, Klocke NF, Hao JC, Drazin D, Bucklen BS. Biomechanical evaluation of traditional posterior versus anterior spondylolisthesis reduction in a cadaveric grade I slip model. J Neurosurg Spine 2019; 31:246-254. [PMID: 31051462 DOI: 10.3171/2019.2.spine18726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 02/25/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Posterior reduction with pedicle screws is often used for stabilization of unstable spondylolisthesis to directly reduce misalignment or protect against micromotion while fusion of the affected level occurs. Optimal treatment of spondylolisthesis combines consistent reduction with a reduced risk of construct failure. The authors compared the reduction achieved with a novel anterior integrated spacer with a built-in reduction mechanism (ISR) to the reduction achieved with pedicle screws alone, or in combination with an anterior lumbar interbody fusion (ALIF) spacer, in a cadaveric grade I spondylolisthesis model. METHODS Grade I slip was modeled in 6 cadaveric L5-S1 segments by creation of a partial nucleotomy and facetectomy and application of dynamic cyclic loading. Following the creation of spondylolisthesis, reduction was performed under increasing axial loads, simulating muscle trunk forces between 50 and 157.5 lbs, in the following order: bilateral pedicle screws (BPS), BPS with an anterior spacer (BPS+S), and ISR. Percent reduction and reduction failure load-the axial load at which successful reduction (≥ 50% correction) was not achieved-were recorded along with the failure mechanism. Corrections were evaluated using lateral fluoroscopic images. RESULTS The average loads at which BPS and BPS+S failed were 92.5 ± 6.1 and 94.2 ± 13.9 lbs, respectively. The ISR construct failed at a statistically higher load of 140.0 ± 27.1 lbs. Reduction at the largest axial load (157.5 lbs) by the ISR device was tested in 67% (4 of 6) of the specimens, was successful in 33% (2 of 6), and achieved 68.3 ± 37.4% of the available reduction. For the BPS and BPS+S constructs, the largest axial load was 105.0 lbs, with average reductions of 21.3 ± 0.0% (1 of 6) and 32.4 ± 5.7% (3 of 6) respectively. CONCLUSIONS While both posterior and anterior reduction devices maintained reduction under gravimetric loading, the reduction capacity of the novel anterior ISR device was more effective at greater loads than traditional pedicle screw techniques. Full correction was achieved with pedicle screws, with or without ALIF, but under significantly lower axial loads. The anterior ISR may prove useful when higher reduction forces are required; however, additional clinical studies will be needed to evaluate the effectiveness of anterior devices with built-in reduction mechanisms.
Collapse
Affiliation(s)
| | - Jonathan M Mahoney
- 2Musculoskeletal Education and Research Center, A Division of Globus Medical, Inc., Audubon, Pennsylvania
| | - Jonathan A Harris
- 2Musculoskeletal Education and Research Center, A Division of Globus Medical, Inc., Audubon, Pennsylvania
| | - Mir M Hussain
- 2Musculoskeletal Education and Research Center, A Division of Globus Medical, Inc., Audubon, Pennsylvania
| | - Noelle F Klocke
- 2Musculoskeletal Education and Research Center, A Division of Globus Medical, Inc., Audubon, Pennsylvania
| | - John C Hao
- 3School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, Pennsylvania; and
| | - Doniel Drazin
- 4Evergreen Hospital Neuroscience Institute, Kirkland, Washington
| | - Brandon S Bucklen
- 2Musculoskeletal Education and Research Center, A Division of Globus Medical, Inc., Audubon, Pennsylvania
| |
Collapse
|
19
|
Solitro GF, Whitlock K, Amirouche F, Mehta AI, McDonnell A. Currently Adopted Criteria for Pedicle Screw Diameter Selection. Int J Spine Surg 2019; 13:132-145. [PMID: 31131212 DOI: 10.14444/6018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background Transpedicular screw insertion has become widely accepted for the correction of spinal deformity as well as degenerative and traumatic injury, but adoption of this technique has remained less widespread in the thoracic compared to the lumbar spine. This is thought to be associated with the relative technical difficulty of screw insertion into the narrower widths of the thoracic pedicles and the neurologic and mechanical risks associated with breach of the pedicle wall. The surgical decision making involves determining the appropriate sized screw for maximum fixation strength while simultaneously respecting the structural integrity of the vertebral pedicles to prevent a breach and provide better fixation. This paper presents a systematic review of criteria for thoracic pedicle screw diameter (SD) selection in order to orient inexperienced surgeons on the impact of this selection on pedicle breaching and fixation strength. Methods We performed a systematic literature review focused on studies reporting SD selection in relation to pedicle dimensions, measures of fixation strength, and breach rate. Results Twenty-nine articles that measured fixation strength, breach rate, and/or provided SD in relation to pedicle width were selected for inclusion. Conclusions A commonly accepted criteria for pedicle SD selection has not yet been proposed. Screw diameters approximately 80% of the pedicle width have been adopted, but this proportion is rarely reported in the midthoracic vertebrae for which smaller pedicles and inadequate hardware specificity result in higher breach rates. Depending upon the insertion technique adopted, greater specificity in diameter selection by vertebral level should be pursued in order to maximally target cortical bone purchase. Clinical Relevance Based on this review of the literature, we believe that proper selection of the SD for individual vertebral level directly affects the insertion technique and the potential breach.
Collapse
Affiliation(s)
- Giovanni F Solitro
- Department of Orthopaedics, Louisiana State University Health Science Center, Shreveport, Louisiana
| | - Keith Whitlock
- College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Farid Amirouche
- Department of Orthopaedics, University of Illinois at Chicago, Chicago, Illinois
| | - Ankit I Mehta
- Department of Neurosurgery, University of Illinois at Chicago, Chicago, Illinois
| | - Annie McDonnell
- Department of Mechanical Engineering, University of Illinois at Chicago, Chicago, Illinois
| |
Collapse
|
20
|
Kaliya-Perumal AK, Limthongkul W, Oh JYL. Utilization of Spinal Navigation to Facilitate Hassle-Free Rod Placement during Minimally-Invasive Long-Construct Posterior Instrumentation. Asian Spine J 2019; 13:511-514. [PMID: 30691260 PMCID: PMC6547385 DOI: 10.31616/asj.2018.0233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 10/21/2018] [Indexed: 11/23/2022] Open
Abstract
During minimally-invasive long-construct posterior instrumentation, it may be challenging to contour and place the rod as the screw heads are not visualized. To overcome this, we utilized the image data merging (IDM) facility of our spinal navigation system to visualize a coherent whole image of the construct throughout the procedure. Here, we describe this technique that was used for a patient in whom L1-L5 posterior instrumentation was performed. Using an IDM facility, screws are color coded and after placement, the final image is saved. Saved images of all previous screws are displayed and observed while placing the subsequent screws. Therefore, the entry point, depth, and mediolateral alignment of subsequent screws can be adjusted to fall in line with previous screws such that the rod can be placed without hassle. Moreover, final adjustments to the construct are kept to a minimum. The possibility of screw pullout due to force engaging the rod on poorly aligned screws is thus avoided.
Collapse
Affiliation(s)
- Arun-Kumar Kaliya-Perumal
- Spine Division, Department of Orthopaedic Surgery, Tan Tock Seng Hospital, Singapore.,Department of Orthopaedic Surgery, Melmaruvathur Adhiparasakthi Institute of Medical Sciences and Research, Affiliated to The Tamil Nadu Dr MGR Medical University, Chennai, India
| | - Worawat Limthongkul
- Department of Orthopaedics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Jacob Yoong-Leong Oh
- Spine Division, Department of Orthopaedic Surgery, Tan Tock Seng Hospital, Singapore
| |
Collapse
|
21
|
Albanese K, Ordway NR, Albanese SA, Lavelle WF. Effect of Pedicle Fill on Axial Pullout Strength in Spinal Fixation After Rod Reduction. Orthopedics 2017; 40:e990-e995. [PMID: 28968476 DOI: 10.3928/01477447-20170925-02] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 08/08/2017] [Indexed: 02/03/2023]
Abstract
Rod reduction to pedicle screws is used for a variety of spinal fixation procedures; however, it can alter the integrity of the screw-bone interface. The authors investigated the effect of pedicle fill (ratio of pedicle screw diameter to pedicle diameter) on the strength of the screw-bone interface after simulated rod reduction on 17 vertebrae (3 thoracolumbar spine specimens). Pedicle diameter was measured with standard clinical computed tomography scan protocols. The authors determined the minimum pedicle diameter for each level. Polyaxial pedicle screws were surgically placed bilaterally with a freehand technique with standard clinical anatomic landmarks. The pedicle pairs were instrumented with pedicle screws of predetermined diameter, 1 with greater than 80% fill and 1 with less than 80% fill. A simulated reduction maneuver was performed with a 5-mm gap followed by an axial pullout test to assess screw interface strength. Comparison of insertion torque between less than 80% fill and greater than 80% fill did not show significant increases. A significant difference in pullout load (P=.043) occurred with greater than 80% fill (791±637 N) compared with less than 80% fill (636±492 N). No significant difference in stiffness was noted (P=.154) with pedicle fill of greater than 80% (427±134 N/mm) compared with less than 80% (376±178 N/mm). The current findings support the use of greater than 80% pedicle fill for optimal screw anchoring in pedicle screw-based constructs involving rod reduction. Surgeons should consider placing screws that can safely fill vertebral pedicles, especially at the apex of the curve and the proximal and distal levels of constructs, where excessive forces are imparted to the screws. [Orthopedics. 2017; 40(6):e990-e995.].
Collapse
|
22
|
Kang DG, Lehman RA, Wagner SC, Bevevino AJ, Tracey RW, Gaume RE, Dmitriev AE. Effects of rod reduction on pedicle screw fixation strength in the setting of Ponte osteotomies. Spine J 2015; 15:146-52. [PMID: 25088957 DOI: 10.1016/j.spinee.2014.07.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 06/10/2014] [Accepted: 07/29/2014] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT The use of a rod reduction device can have deleterious consequences on pedicle screw pullout strength (POS) in the thoracic spine. However, posterior-only osteotomies in the thoracic spine are often performed to improve flexibility of the spine and offset forces of deformity correction maneuvers. PURPOSE To investigate the effect on pedicle screw POS caused by the rod reduction technique in the presence of facet osteotomies in the thoracic spine. STUDY DESIGN/SETTING The study is a biomechanical study using human cadaveric spine specimens. METHODS Thoracic Ponte osteotomies were performed on 3 thoracic levels in 15 cadaveric specimens. The right rod was contoured with a 5-mm residual gap at the middle level and was reduced using a rod reduction device. On the left side (paired control), a rod with no mismatch was placed. Biomechanical testing was performed with tensile load to failure "in line" with the screw axis and POS measured in Newtons (N). RESULTS After rod reduction, thoracic pedicle screw POS was significantly decreased (40%) compared with the control (419±426 N vs. 708±462 N, p=.002) and remained statistically significant after adjusting for bone mineral density (BMD) (p=.05). Eleven (73%) of the pedicle screws had visible pullout/failure during the reduction attempt and occurred irrespective of BMD. CONCLUSIONS Despite thoracic Ponte osteotomies and increased flexibility of the spinal segments, the rod reduction device still significantly decreased pedicle screw POS, typically resulting in outright failure of the screw-bone interface. Therefore, rod reduction technique of any kind should be performed with caution as it frequently results in suboptimal pedicle screw fixation.
Collapse
Affiliation(s)
- Daniel G Kang
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bldg 19, Rm #2101, Bethesda, MD 20889, USA
| | - Ronald A Lehman
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bldg 19, Rm #2101, Bethesda, MD 20889, USA; Division of Orthopaedics, Department of Surgery, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.
| | - Scott C Wagner
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bldg 19, Rm #2101, Bethesda, MD 20889, USA
| | - Adam J Bevevino
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bldg 19, Rm #2101, Bethesda, MD 20889, USA
| | - Robert W Tracey
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bldg 19, Rm #2101, Bethesda, MD 20889, USA
| | - Rachel E Gaume
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bldg 19, Rm #2101, Bethesda, MD 20889, USA
| | - Anton E Dmitriev
- Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, 8901 Wisconsin Ave., Bldg 19, Rm #2101, Bethesda, MD 20889, USA; Division of Orthopaedics, Department of Surgery, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA
| |
Collapse
|
23
|
Lamerain M, Bachy M, Delpont M, Kabbaj R, Mary P, Vialle R. CoCr rods provide better frontal correction of adolescent idiopathic scoliosis treated by all-pedicle screw fixation. 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 2014; 23:1190-6. [PMID: 24448894 DOI: 10.1007/s00586-014-3168-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 01/02/2014] [Accepted: 01/04/2014] [Indexed: 11/26/2022]
Abstract
PURPOSE Pedicle screw fixation is considered biomechanically advantageous in adolescent idiopathic scoliosis (AIS) correction, because it uses as an anchor the pedicle, which is the hardest part of the vertebral body. The ability of the rod to correct and hold the correction is a key factor in the selection of rod material. The goal of this study was to compare the results obtained by stainless steel (SS) and cobalt-chromium (CoCr) rods materials for the treatment of AIS curves. METHODS Ninety patients were retrospectively included. Sixty-four patients (group 1) were operated on using CoCr rods. Twenty-six patients (group 2) were operated on using SS rods. All the patients were treated by the same surgeon using all-pedicle screw constructs. RESULTS In group 1, the correction was respectively 41.03° and 35.78° for main and secondary curves. In group 2, the correction was respectively 30.98° and 24.42° for main and secondary curves. Statistical analysis showed improved correction rates in patients operated with CoCr rods for main (P < 0.0001) and secondary (P = 0.0003) curves with a lower loss of correction at final follow-up. Regarding the sagittal profile, postoperative T4T12 thoracic kyphosis was 28.04° in CoCr group compared to 22.79° in SS group (P = 0. 0.0038). DISCUSSION The present study confirms the ability of the all-pedicle screw construct to reach the maximum coronal plane correction and prevent deformity progression while maintaining balance. CoCr rods have the ability to exert higher corrective forces on the spine with relatively small amounts of rod deformation. Our findings confirm that CoCr rods have the ability to produce higher correction rates in frontal plane compared to SS rods of the same diameter.
Collapse
Affiliation(s)
- Mayalen Lamerain
- Department of Pediatric Orthopaedics, Armand Trousseau Hospital, Université Pierre et Marie Curie Paris6, 26 Avenue du Dr Arnold Netter, 75571, Paris Cedex 12, France
| | | | | | | | | | | |
Collapse
|