1
|
Boucas P, Mamdouhi T, Rizzo SE, Megas A. Cement Augmentation of Pedicle Screw Instrumentation: A Literature Review. Asian Spine J 2023; 17:939-948. [PMID: 37788974 PMCID: PMC10622820 DOI: 10.31616/asj.2022.0216] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 11/03/2022] [Accepted: 11/07/2022] [Indexed: 10/05/2023] Open
Abstract
This literature review aimed to review the current understanding, indications, and limitations of pedicle screw instrumentation cement augmentation. Since they were first reported in the 1980s, pedicle screw cement augmentation rates have been increasing. Several studies have been published to date that describe various surgical techniques and the biomechanical changes that occur when cement is introduced through the screw-bone interface. This article provides a concise review of the uses, biomechanical properties, cost analysis, complications, and surgical techniques used for pedicle screw cement augmentation to help guide physician practices. A comprehensive review of the current literature was conducted, with key studies, and contributions from throughout history being highlighted. Patients with low bone mineral density are the most well-studied indication for pedicle screw cement augmentation. Many studies show that cement augmentation can improve pullout strength in patients with low bone mineral density; however, the benefit varies inversely with pathology severity and directly with technique. The various screw types are discussed, with each having its own mechanical advantages. Cement distribution is largely dependent on the filling method and volume of cement used. Cement composition and timing of cement use after mixing are critical considerations in practice because they can significantly alter the bone-cement and screw-cement interfaces. Overall, studies have shown that pedicle screw cement augmentation has a low complication rate and increased pullout strength, justifying its universal use in patients with a suboptimal bone-implant interface.
Collapse
Affiliation(s)
- Peter Boucas
- Department of Orthopaedic Surgery, Huntington Hospital Northwell Health, Huntington, NY,
USA
- Department of Orthopaedic Surgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY,
USA
| | - Tania Mamdouhi
- Department of Orthopaedic Surgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY,
USA
| | - Sarah E. Rizzo
- Department of Orthopaedic Surgery, Huntington Hospital Northwell Health, Huntington, NY,
USA
- Department of Orthopaedic Surgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY,
USA
| | - Andrew Megas
- Department of Orthopaedic Surgery, Grewal Orthopaedic and Spine Care, East Meadow, NY,
USA
| |
Collapse
|
2
|
Arlettaz Y. Augmented osteosynthesis in fragility fracture. Orthop Traumatol Surg Res 2023; 109:103461. [PMID: 36404483 DOI: 10.1016/j.otsr.2022.103461] [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: 12/01/2021] [Revised: 04/14/2022] [Accepted: 04/14/2022] [Indexed: 11/06/2022]
Abstract
Due to poor bone quality and complexity, some fractures are difficult to treat, with high risk of failure. Moreover, general health is often poor in elderly patients with multiple comorbidity and poor compliance, necessitating perfect first-line management to avoid re-operation. The armamentarium comprises specific internal fixation implants and also complementary methods such as autologous, homologous or heterologous bone graft or bone substitutes with varying mechanical and biological characteristics. Associating these options is what is mean by "augmented fixation". The present review of augmented osteosynthesis addresses the following questions: What are the characteristics of fragility fractures? Fragility fracture is caused by low-energy trauma on bone with poor structural quality and low mineral density. Treatment aims to enable early mobilization and weight-bearing while avoiding mechanical failure of fixation. Prolonged bedrest, loss of mobility and surgical revision are aggravating and sometimes fatal factors in these fragile patients. What are the biological techniques of fixation augmentation in fragility fracture? Autologous or homologous bone graft are the most widely used biological augmentation techniques. They fill spaces and promote osteoconduction and consolidation. Some bone-like phosphocalcic structures are opening up promising lines of research. What are the non-biological techniques of fixation augmentation in fragility fracture? Hydroxyapatite, phosphocalcic cement and acrylic cement are the most widely used synthetic materials. Biological and mechanical effects are variable according to composition, requiring specific implementation. What are the mechanical techniques of fixation augmentation in fragility fracture? There is at present no consensus as to the augmentation techniques to be applied in fragility fracture. Cerclage or complementary plating, or external fixation associated to internal fixation are possibilities. However, the literature consists only of small series reporting surgical techniques specific to a given surgeon or team. When and how should osteosynthesis for fragility fracture be augmented? The choice of augmentation depends on fracture location, comminution, available material and local experience. The more severe the fracture, the more complex the fixation. The approach needs to be adapted to the preoperative planning and the associated mechanical means (plate, complementary cerclage) and prosthetic replacement should be considered in certain joint fractures or fractures close to load-bearing surfaces. LEVEL OF EVIDENCE: V; expert opinion.
Collapse
Affiliation(s)
- Yvan Arlettaz
- SANTECHABLAIS, Chemin Du Verger 3, 1868 Collombey, Switzerland.
| |
Collapse
|
3
|
Peng JC, Guo HZ, Zhan CG, Huang HS, Ma YH, Zhang SC, Xu YR, Mo GY, Tang YC. Comparison of pedicle screw fixation with or without cement augmentation for treating single-segment isthmic spondylolisthesis in the osteoporotic spine. Sci Rep 2023; 13:827. [PMID: 36646752 PMCID: PMC9842729 DOI: 10.1038/s41598-023-27539-x] [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] [Received: 03/31/2022] [Accepted: 01/04/2023] [Indexed: 01/18/2023] Open
Abstract
The present study examined the necessity of cement-augmented pedicle screw fixation in osteoporotic patients with single-segment isthmic spondylolisthesis.Fifty-nine cases were reviewed retrospectively. Thirty-three cases were in the polymethylmethacrylate-augmented pedicle screw (PMMA-PS) group, and the other 26 cases were in the conventional pedicle screw (CPS) group. Evaluation data included operation time, intraoperative blood loss, hospitalization cost, hospitalization days, rates of fusion, screw loosening, bone cement leakage, visual analogue scale (VAS) scores, Oswestry disability index (ODI), lumbar lordosis (LL), pelvic tilt (PT) and sacral slope (SS).The operation time and blood loss in the CPS group decreased significantly compared to those in the PMMA-PS group. The average hospitalization cost of the PMMA-PS group was significantly higher than that of the CPS group. There was no significant difference in the average hospital stay between the 2 groups. The initial and last follow-up postoperative VAS and ODI scores improved significantly in the two groups. There were no significant differences in VAS and ODI between the 2 groups at each time point. The last postoperative spine-pelvic parameters were significantly improved compared with those preoperatively. In the PMMA-PS group, the fusion rate was 100%. The fusion rate was 96.15% in the CPS group. No significant difference was found between the two groups for the fusion rate. Nine patients in the PMMA-PS group had bone cement leakage. There was no screw loosening in the PMMA-PS group. There were 2 cases of screw loosening in the CPS group. There were no significant differences in screw loosening, postoperative adjacent segment fractures, postoperative infection or postoperative revision between the 2 groups. The use of PMMA-PS on a regular basis is not recommended in posterior lumbar interbody fusion for the treatment of single-segment isthmic spondylolisthesis with osteoporosis.
Collapse
Affiliation(s)
- Jian-Cheng Peng
- Longgang Orthopedics Hospital of Shenzhen, Shenzhen, 518100, China
| | - Hui-Zhi Guo
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China.,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China
| | - Chen-Guang Zhan
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China.,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China
| | - Hua-Sheng Huang
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China.,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China
| | - Yan-Huai Ma
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China.,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China
| | - Shun-Cong Zhang
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China.,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China
| | - Yue-Rong Xu
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China.,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China
| | - Guo-Ye Mo
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China.,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China
| | - Yong-Chao Tang
- The 1St Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, 12 Airport Road, Baiyun District, Guangzhou, 510405, Guangdong, China. .,Spine Surgery Department, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510407, China.
| |
Collapse
|
4
|
Iamthanaporn K, Aonsong W, Tuntarattanapong P, Yuenyongviwat V. Screw inserting in different phase of cement affect the pull-out strength of cement augmented screws. Orthop Traumatol Surg Res 2022; 108:103060. [PMID: 34537392 DOI: 10.1016/j.otsr.2021.103060] [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: 10/20/2020] [Revised: 03/17/2021] [Accepted: 04/15/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND For large bone defects, after curettage of aggressive bone tumors; such as giant-cell tumors, cementation with supplement internal fixation was used to prevent subsequent collapse of the cement-bone constructs. The purpose of this study is to compare the pull-out strength of cement augmented screws between inserting screws in the working phase or hard phase of bone cement. HYPOTHESIS Timing at which completed screw insertion takes place affecting the pull-out strength of cement augmented screws. METHODS Pull-out strength was compared between screws; inserted within the working phases of cement, and after the cement was hardened in high viscos cement blocks. Each group consists of 10 cortex screws, 10 cancellous screws and 10 locking screws. The pull-out strength test was followed using the instructions of ASTM F543-13e1 Standard Specification and Test Methods, for Metallic Medical Bone Screws. RESULTS Screws that were inserted in the working phases of cement had significantly higher pull-out strength, than those inserted in hard cement (p=0.021). The pull-out strength was statistically significant in difference among the types of screws (p<0.001), with locking screws having the highest pull-out strength. Furthermore, the pull-out strength of locking screws revealed no significant difference when either; inserted during the working or hardened phases of bone cement. CONCLUSION Insertion of screws during the working periods of PMMA cement had higher pull out strength compared to the hard phase of cement. Hence, we recommend performing internal fixation before cementation after curettage of aggressive bone tumors. However, if the surgeon prefers to pack the cement first, for the benefit of avoiding residual bone defects, we suggest using a locking plate system to achieve comparable pull-out strength. LEVEL OF EVIDENCE In-vitro study.
Collapse
Affiliation(s)
- Khanin Iamthanaporn
- Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, 90110 Hat Yai, Songkhla, Thailand.
| | - Wachirakorn Aonsong
- Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, 90110 Hat Yai, Songkhla, Thailand
| | - Pakjai Tuntarattanapong
- Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, 90110 Hat Yai, Songkhla, Thailand
| | - Varah Yuenyongviwat
- Department of Orthopaedic Surgery and Physical Medicine, Faculty of Medicine, Prince of Songkla University, 90110 Hat Yai, Songkhla, Thailand
| |
Collapse
|
5
|
Lim KX, Wu K. First-ever intraosseous ancient schwannoma of the proximal ulna successfully treated using the cement technique. J Int Med Res 2021; 49:300060520987732. [PMID: 33567958 PMCID: PMC7883163 DOI: 10.1177/0300060520987732] [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] [Indexed: 11/30/2022] Open
Abstract
Schwannoma or neurilemmoma is a common soft tissue neoplasm arising from the neural sheath of Schwann cells. However, intraosseous schwannoma is rare, accounting for less than 0.2% of primary bone tumours. Several variants of schwannoma have been reported; among them, intraosseous schwannoma with ancient change is extremely rare. This current report presents an extremely rare case of ancient intraosseous neurilemmoma. The patient presented with right elbow pain and disability. A radiolucent, well-defined, lobulated lesion with a thin sclerotic rim in the proximal ulnar metaphysis that had caused a pathological fracture was noted. The mass was surgically excised using marginal resection and bone curettage was undertaken. The bone deficit was grafted with hydroxyapatite and β-tricalcium phosphate and augmented with bone cement. There were no signs of any recurrence after 3 years. This is the first case of an ancient intraosseous schwannoma of the proximal ulna. Although rare, intraosseous schwannoma should be considered in the differential diagnosis of radiographically benign-appearing osseous tumours in the bone. The cement technique is recommended for the treatment of intraosseous schwannoma.
Collapse
Affiliation(s)
- Kai Xuan Lim
- Department of Orthopaedic Surgery, Far Eastern Memorial Hospital, New Taipei City
| | - Karl Wu
- Department of Orthopaedic Surgery, Far Eastern Memorial Hospital, New Taipei City
| |
Collapse
|
6
|
Jin JY, Yoon TR, Park KS, Jin SY, Jung DM, Li QS. The results of screw augmentation of acetabular cement spacers for the treatment of periprosthetic hip joint infection. J Orthop Surg Res 2020; 15:443. [PMID: 32993705 PMCID: PMC7523058 DOI: 10.1186/s13018-020-01950-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Accepted: 09/07/2020] [Indexed: 11/13/2022] Open
Abstract
Introduction Prosthesis of antibiotic-loaded acrylic cement (PROSTALAC) is widely used in two-stage revision arthroplasty in periprosthetic joint infection (PJI) after total hip arthroplasty (THA). In our institution, we encountered several cases of acetabular cement spacer dislodgement. The aim of this study was to compare the results of two-stage revision arthroplasties with antibiotic-loaded cement spacers with or without screws on the acetabulum for PJI. Patients and methods This retrospective study included 44 patients who underwent a two-stage revision THA for PJI from June 2007 to May 2017. We divided the patients into two groups: group 1 consisted of 21 patients (21 hips) who underwent two-stage revision arthroplasty with screw augmentation, while group 2 consisted of 23 patients (23 hips) who underwent the same surgery without screw augmentation at the acetabular cement spacer. We compared the migration and dislodgement of the acetabular cement spacer between the two groups. Results Before the second-stage surgery, there was less vertical migration of the cement spacer in group 1 compared to group 2 (1.2 mm vs 3.1 mm, p < 0.001). There was also less medial migration of the cement spacer in group 1 (0.6 mm vs 1.6 mm, p = 0.001). After the first stage, the mean Harris Hip score was significantly higher in group 1 than in group 2 (75 vs 65, p = 0.033). Cement spacer rotation or total movement out of the acetabular area occurred in six patients, all in group 2. After first stage reinfection occurred in two patients, one in each group. Conclusions Screw augmentation to the acetabulum in the first-stage surgery provides better stability of acetabular antibiotic cement spacers without increasing reinfection rate.
Collapse
Affiliation(s)
- Jing-Yao Jin
- Department of Orthopedic Surgery, Center for Joint Disease at Chonnam National University Hwasun Hospital, 322, Seo Yang-Ro, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, Republic of Korea
| | - Taek-Rim Yoon
- Department of Orthopedic Surgery, Center for Joint Disease at Chonnam National University Hwasun Hospital, 322, Seo Yang-Ro, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, Republic of Korea.
| | - Kyung-Soon Park
- Department of Orthopedic Surgery, Center for Joint Disease at Chonnam National University Hwasun Hospital, 322, Seo Yang-Ro, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, Republic of Korea
| | - Sheng-Yu Jin
- Department of Orthopedic Surgery, Center for Joint Disease at Chonnam National University Hwasun Hospital, 322, Seo Yang-Ro, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, Republic of Korea
| | - Dong-Min Jung
- Department of Orthopedic Surgery, Center for Joint Disease at Chonnam National University Hwasun Hospital, 322, Seo Yang-Ro, Hwasun-Eup, Hwasun-Gun, Jeonnam, 519-809, Republic of Korea
| | - Qing-Song Li
- Department of Orthopedic Surgery, Center for Joint Disease, Affiliated Hospital of Yanbian University, Yanji, China
| |
Collapse
|
7
|
Ratinam R, Quayle M, Crock J, Lazarus M, Fogg Q, McMenamin P. Challenges in creating dissectible anatomical 3D prints for surgical teaching. J Anat 2019; 234:419-437. [PMID: 30710355 DOI: 10.1111/joa.12934] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2018] [Indexed: 01/17/2023] Open
Abstract
Three-dimensional (3D) printing, or additive manufacturing, is now a widely used tool in pre-operative planning, surgical teaching and simulator training. However, 3D printing technology that produces models with accurate haptic feedback, biomechanics and visuals for the training surgeon is not currently available. Challenges and opportunities in creating such surgical models will be discussed in this review paper. Surgery requires proper tissue handling as well as knowledge of relevant anatomy. To prepare doctors properly, training models need to take into account the biomechanical properties of the anatomical structures that will be manipulated in any given operation. This review summarises and evaluates the current biomechanical literature as it relates to human tissues and correlates the impact of this knowledge on developing high fidelity 3D printed surgical training models. We conclude that, currently, a printer technology has not yet been developed which can replicate many of the critical qualities of human tissue. Advances in 3D printing technology will be required to allow the printing of multi-material products to achieve the mechanical properties required.
Collapse
Affiliation(s)
- Ratheesraj Ratinam
- Department of Anatomy and Developmental Biology, Centre for Human Anatomy Education, Monash University, Clayton, Vic., Australia
| | - Michelle Quayle
- Department of Anatomy and Developmental Biology, Centre for Human Anatomy Education, Monash University, Clayton, Vic., Australia
| | - John Crock
- Department of Surgery, Monash University, Clayton, Vic., Australia
| | - Michelle Lazarus
- Department of Anatomy and Developmental Biology, Centre for Human Anatomy Education, Monash University, Clayton, Vic., Australia
| | - Quentin Fogg
- Department of Anatomy and Developmental Biology, Centre for Human Anatomy Education, Monash University, Clayton, Vic., Australia.,Department of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Vic., Australia
| | - Paul McMenamin
- Department of Anatomy and Developmental Biology, Centre for Human Anatomy Education, Monash University, Clayton, Vic., Australia
| |
Collapse
|
8
|
Kim JW, Park SW, Kim YB, Ko MJ. The Effect of Postoperative Use of Teriparatide Reducing Screw Loosening in Osteoporotic Patients. J Korean Neurosurg Soc 2018; 61:494-502. [PMID: 29724093 PMCID: PMC6046574 DOI: 10.3340/jkns.2017.0216] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 09/23/2017] [Indexed: 11/27/2022] Open
Abstract
Objective The loosening of pedicle screws (PS) is one of the frequent problems of spinal surgery in the patients with osteoporosis. Previous studies had revealed that intermittent injection of teriparatide could reduce PS loosening by improving bone mass and quality when their patients took parathyroid hormone for a considerable duration before surgery. However, although the teriparatide is usually used after spine surgery in most clinical situations, there was no report on the efficacy of teriparatide treatment started after spine surgery. The purpose of this retrospective study was to examine the efficacy of teriparatide treatment started immediately after lumbar spinal surgery to prevent pedicle screw loosening in patients with osteoporosis. Methods We included 84 patients with osteoporosis and degenerative lumbar disease who underwent transforaminal interbody fusion and PS fixation and received parathyroid hormone or bisphosphonate (BP) postoperatively. They were divided into teriparatide group (daily injection of 20 μg of teriparatide for 6 months, 33 patients, 172 screws) and BP group (weekly oral administration of 35 mg of risedronate, 51 patients, 262 screws). Both groups received calcium (500 mg/day) and cholecalciferol (1000 IU/day) together. The screw loosening was evaluated with simple radiographic exams at 6 and 12 months after the surgery. We counted the number of patients with PS loosening and the number of loosened PS, and compared them between the two groups. Clinical outcomes were evaluated using visual analog scale (VAS) and Oswestry disability index (ODI) preoperatively, and at 12 months after surgery. Results There was no significant difference in the age, sex, diabetes, smoking, bone mineral density, body mass index, and the number of fusion levels between the two groups. The number of PS loosening within 6 months after surgery did not show a significant difference between the teriparatide group (6.9%, 12/172) and the BP group (6.8%, 18/272). However, during 6-12 months after surgery, it was significantly lower in the teriparatide group (2.3%, 4/172) than the BP group (9.2%, 24/272) (p<0.05). There was no significant difference in the number of patients showing PS loosening between the teriparatide and BP groups. The teriparatide group showed a significantly higher degree of improvement of the bone mineral density (T-score) than that of BP group (p<0.05). There was no significant difference in the pre- and post-operative VAS and ODI between the groups. Conclusion Our data suggest that the teriparatide treatment starting immediately after lumbar spinal fusion surgery could reduce PS loosening compared to BP.
Collapse
Affiliation(s)
- Jae Wook Kim
- Department of Neurosurgery, Chung-Ang University Hospital, Seoul, Korea
| | - Seung Won Park
- Department of Neurosurgery, Chung-Ang University Hospital, Seoul, Korea
| | - Young Baeg Kim
- Department of Neurosurgery, Chung-Ang University Hospital, Seoul, Korea
| | - Myeong Jin Ko
- Department of Neurosurgery, Chung-Ang University Hospital, Seoul, Korea
| |
Collapse
|
9
|
Bacaksız T, Kazimoglu C, Reisoglu A, Turgut A, Kumtepe E, Agus H. Optimum Screw Configuration for the Fixation of Sanders Type IIC Tongue-Type Fractures? A Biomechanical Study. J Am Podiatr Med Assoc 2018; 108:20-26. [PMID: 29547039 DOI: 10.7547/16-140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND The minimally invasive technique (percutaneous screw fixation) is one of the options for treating tongue-type IIC fractures successfully. The aim of this study was to assess the biomechanics of four different screw configurations used for the fixation of tongue-type IIC calcaneal fractures. METHODS Identical osteotomies, recapitulating a type IIC injury, were created in synthetic calcaneus specimens using a saw. The specimens were randomly assigned to one of the four fixation groups (n = 7 per group): two divergent screws, two parallel screws, two parallel screws plus one screw axially oriented toward the sustentaculum tali, and three parallel screws. A load test was performed on all of the groups, and the specimens were then tested using offset axial loading until 2, 4, and 5 mm of fracture displacement occurred. RESULTS Mean force values for the three-parallel screw construct at 2-, 4-, and 5-mm fracture displacements were found to be significantly higher compared with those for the other groups. CONCLUSIONS The use of a three-parallel screw construct seems to provide more stability in the treatment of tongue-type IIC fractures.
Collapse
Affiliation(s)
- Tayfun Bacaksız
- Department of Orthopaedics and Traumatology, İzmir Tepecik Training and Research Hospital, İzmir, Turkey
| | - Cemal Kazimoglu
- Department of Orthopaedics, İzmir Katip Celebi University, İzmir, Turkey
| | - Ali Reisoglu
- Department of Orthopaedics and Traumatology, İzmir Tepecik Training and Research Hospital, İzmir, Turkey
| | - Ali Turgut
- Department of Orthopaedics and Traumatology, İzmir Tepecik Training and Research Hospital, İzmir, Turkey
| | - Erdem Kumtepe
- Department of Biomechanics, Dokuz Eylül Ünivercity, Institute of Health Science, İzmir, Turkey
| | - Haluk Agus
- Department of Orthopaedics and Traumatology, İzmir Tepecik Training and Research Hospital, İzmir, Turkey
| |
Collapse
|
10
|
Schmid SL, Bachmann E, Fischer M, Meyer DC, Gerber CA, Snedeker JG, Farshad M. Pedicle screw augmentation with bone cement enforced Vicryl mesh. J Orthop Res 2018; 36:212-216. [PMID: 28608580 DOI: 10.1002/jor.23631] [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: 12/05/2016] [Accepted: 05/28/2017] [Indexed: 02/04/2023]
Abstract
Achieving sufficient mechanical purchase of pedicle screws in osteoporotic or previously instrumented bone is technically and biologically challenging. Techniques using different kinds of pedicle screws or methods of cement augmentation have been used to address this challenge, but are associated with difficult revisions and complications. The purpose of this biomechanical trial was to investigate the use of biocompatible textile materials in combination with bone cement to augment pullout strength of pedicle screws while reducing the risk of cement extrusion. Pedicle screws (6/40 mm) were either augmented with standard bone-cement (Palacos LV + G) in one group (BC, n = 13) or with bone-cement enforced by Vicryl mesh in another group (BCVM, n = 13) in osteoporosis-like saw bone blocks. Pullout testing was subsequently performed. In a second experimental phase, similar experiments were performed using human cadaveric lumbar vertebrae (n = 10). In osteoporosis-like saw bone blocks, a mean screw pullout force of 350 N (±125) was significantly higher with the Bone cement (BC) compared to bone-cement enforced by Vicryl mesh (BCVM) technique with 240 N (±64) (p = 0.030). In human cadaveric lumbar vertebrae the mean screw pullout force was 784 ± 366 N with BC and not statistically different to BCVM with 757 ± 303 N (p = 0.836). Importantly, cement extrusion was only observed in the BC group (40%) and never with the BCVM technique. In vitro textile reinforcement of bone cement for pedicle screw augmentation successfully reduced cement extrusion compared to conventionally delivered bone cement. The mechanical strength of textile delivered cement constructs was more reproducible than standard cementing. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:212-216, 2018.
Collapse
Affiliation(s)
- Samuel L Schmid
- Department of Orthopedics, Balgrist University Hospital, University of Zürich, Forchstrasse 340, Zürich 8008, Switzerland
| | - Elias Bachmann
- Department of Orthopedics, Balgrist University Hospital, University of Zürich, Forchstrasse 340, Zürich 8008, Switzerland.,Laboratory for Orthopedic Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Michael Fischer
- Department of Orthopedics, Balgrist University Hospital, University of Zürich, Forchstrasse 340, Zürich 8008, Switzerland
| | - Dominik C Meyer
- Department of Orthopedics, Balgrist University Hospital, University of Zürich, Forchstrasse 340, Zürich 8008, Switzerland
| | - Christoph A Gerber
- Department of Orthopedics, Balgrist University Hospital, University of Zürich, Forchstrasse 340, Zürich 8008, Switzerland
| | - Jess G Snedeker
- Department of Orthopedics, Balgrist University Hospital, University of Zürich, Forchstrasse 340, Zürich 8008, Switzerland.,Laboratory for Orthopedic Biomechanics, ETH Zürich, Zürich, Switzerland
| | - Mazda Farshad
- Department of Orthopedics, Balgrist University Hospital, University of Zürich, Forchstrasse 340, Zürich 8008, Switzerland
| |
Collapse
|
11
|
Schmoelz W, Heinrichs CH, Schmidt S, Piñera AR, Tome-Bermejo F, Duart JM, Bauer M, Galovich LÁ. Timing of PMMA cement application for pedicle screw augmentation affects screw anchorage. 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; 26:2883-2890. [PMID: 28374330 DOI: 10.1007/s00586-017-5053-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/13/2017] [Accepted: 03/17/2017] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Cement augmentation is an established method to increase the pedicle screw (PS) anchorage in osteoporotic vertebral bodies. The ideal timing for augmentation when a reposition maneuver is necessary is controversial. While augmentation of the PS before reposition maneuver may increase the force applied it on the vertebrae, it bears the risk to impair PS anchorage, whereas augmenting the PS after the maneuver may restore this anchorage and prevent early screw loosening. The purpose of the present study was to evaluate the effect of cement application timing on PS anchorage in the osteoporotic vertebral body. METHODS Ten lumbar vertebrae (L1-L5) were used for testing. The left and right pedicles of each vertebra were instrumented with the same PS size and used for pairwise comparison of the two timing points for augmentation. For the reposition maneuver, the left PS was loaded axially under displacement control (2 × ±2 mm, 3 × ±6 mm, 3 × ±10 mm) to simulate a reposition maneuver. Subsequently, both PS were augmented with 2 ml PMMA cement. The same force as measured during the left PS maneuver was applied to the previously augmented right hand side PS [2 × F (±2 mm), 3 × F (±6 mm), 3 × F (±10 mm)]. Both PS were cyclically loaded with initial forces of +50 and -50 N, while the lower force was increased by 5 N every 100 cycles until total failure of the PS. The PS motion was measured with a 3D motion analysis system. After cyclic loading stress, X-rays were taken to identify the PS loosening mechanism. RESULTS In comparison with PS augmented prior to the reposition maneuver, PS augmented after the reposition maneuver showed a significant higher number of load cycles until failure (5930 ± 1899 vs 3830 ± 1706, p = 0.015). The predominant loosening mechanism for PS augmented after the reposition maneuver was PS toggling with the attached cement cloud within the trabecular bone. While PS augmented prior to the reposition, maneuver showed a motion of the screw within the cement cloud. CONCLUSION The time of cement application has an effect on PS anchorage in the osteoporotic vertebral body if a reposition maneuver of the instrumented vertebrae is carried out. PS augmented after the reposition maneuver showed a significant higher number of load cycles until screw loosening.
Collapse
Affiliation(s)
- Werner Schmoelz
- Department of Trauma Surgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria.
| | - Christian Heinz Heinrichs
- Department of Trauma Surgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - Sven Schmidt
- Orthopaedic University Hospital Friedrichsheim, Frankfurt am Main, Germany
| | - Angel R Piñera
- Spine Service, Fundacion Jimenez Diaz University Hospital, Madrid, Spain
| | - Felix Tome-Bermejo
- Spine Service, Fundacion Jimenez Diaz University Hospital, Madrid, Spain
| | - Javier M Duart
- Spine Service, Fundacion Jimenez Diaz University Hospital, Madrid, Spain
| | - Marlies Bauer
- Division of Clinical and Functional Anatomy, Department of Anatomy, Histology and Embryology, Medical University of Innsbruck, Innsbruck, Austria
| | | |
Collapse
|
12
|
Hoppe S, Keel MJB. Pedicle screw augmentation in osteoporotic spine: indications, limitations and technical aspects. Eur J Trauma Emerg Surg 2016; 43:3-8. [PMID: 27995283 DOI: 10.1007/s00068-016-0750-x] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 12/12/2016] [Indexed: 12/23/2022]
Abstract
PURPOSE The need for spinal instrumented fusion in osteoporotic patients is rising. In this review, we try to give an overview of the current spectrum of pedicle screw augmentation techniques, safety aspects and indications. METHODS Review of literature and discussion of indications, limitations and technical aspects. RESULTS Various studies have shown higher failure rates in osteoporotic patients, most probably due to reduced bone quality and a poor bone-screw interface. Augmentation of pedicle screws with bone cement, such as polymethylmethacrylate or calcium based cements, is one valid option to enhance fixation if required. CONCLUSIONS Crucial factors for success in the use of augmented screws are careful patient selection, a proper technique and choice of the ideal cement augmentation option.
Collapse
Affiliation(s)
- S Hoppe
- Department of Orthopedic and Trauma Surgery, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
| | - M J B Keel
- Department of Orthopedic and Trauma Surgery, Inselspital, University Hospital, University of Bern, Bern, Switzerland
| |
Collapse
|
13
|
Juvonen T, Nuutinen JP, Koistinen AP, Kröger H, Lappalainen R. Biomechanical evaluation of bone screw fixation with a novel bone cement. Biomed Eng Online 2015. [PMID: 26219663 PMCID: PMC4518640 DOI: 10.1186/s12938-015-0069-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Bone cement augmentation is commonly used to improve the fixation stability of orthopaedic implants in osteoporotic bone. The aim of this study was to evaluate the effect of novel bone cements on the stability of bone screw fixation by biomechanical testing and to compare them with a conventional Simplex®P bone cement and requirements of the standards. Methods Basic biomechanical properties were compared with standard tests. Adhesion of bone cements were tested with polished, glass blasted and corundum blasted stainless steel surfaces. Screw pullout testing with/without cement was carried out using a synthetic bone model and cancellous and cortical bone screws. Results All the tested bone cements fulfilled the requirements of the standard for biomechanical properties and improved the screw fixation stability. Even a threefold increase in shear and tensile strength was achieved with increasing surface roughness. The augmentation improved the screw pullout force compared to fixation without augmentation, 1.2–5.7 times depending on the cement and the screw type. The good biomechanical properties of novel bone cement for osteoporotic bone were confirmed by experimental testing. Conclusion Medium viscosity of the bone cements allowed easy handling and well-controlled penetration of bone cement into osteoporotic bone. By proper parameters and procedures it is possible to achieve biomechanically stable fixation in osteoporotic bone. Based on this study, novel biostable bone cements are very potential biomaterials to enhance bone screw fixation in osteoporotic bone. Novel bone cement is easy to use without hand mixing using a dual syringe and thus makes it possibility to use it as required during the operation.
Collapse
Affiliation(s)
- Tiina Juvonen
- Department of Applied Physics, University of Eastern Finland, Kuopio Campus, Kuopio, Finland.
| | | | - Arto P Koistinen
- Department of Applied Physics, University of Eastern Finland, Kuopio Campus, Kuopio, Finland. .,SIB Labs, University of Eastern Finland, Kuopio Campus, Kuopio, Finland.
| | - Heikki Kröger
- Department of Orthopaedics Traumatology and Handsurgery, Kuopio University Hospital, Kuopio, Finland.
| | - Reijo Lappalainen
- Department of Applied Physics, University of Eastern Finland, Kuopio Campus, Kuopio, Finland. .,SIB Labs, University of Eastern Finland, Kuopio Campus, Kuopio, Finland.
| |
Collapse
|
14
|
Variability of the pullout strength of cancellous bone screws with cement augmentation. Clin Biomech (Bristol, Avon) 2015; 30:500-6. [PMID: 25794899 DOI: 10.1016/j.clinbiomech.2015.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 02/07/2023]
Abstract
BACKGROUND Orthopaedic surgeons often face clinical situations where improved screw holding power in cancellous bone is needed. Injectable calcium phosphate cements are one option to enhance fixation. METHODS Paired screw pullout tests were undertaken in which human cadaver bone was augmented with calcium phosphate cement. A finite element model was used to investigate sensitivity to screw positional placement. FINDINGS Statistical analysis of the data concluded that the pullout strength was generally increased by cement augmentation in the in vitro human cadaver tests. However, when comparing the individual paired samples there were surprising results with lower strength than anticipated after augmentation, in apparent contradiction to the generally expected conclusion. Investigation using the finite element model showed that these strength reductions could be accounted for by small screw positional changes. A change of 0.5mm might result in predicted pullout force changes of up to 28%. INTERPRETATION Small changes in screw position might lead to significant changes in pullout strength sufficient to explain the lower than expected individual pullout values in augmented cancellous bone. Consequently whilst the addition of cement at a position of low strength would increase the pullout strength at that point, it might not reach the pullout strength of the un-augmented paired test site. However, the overall effect of cement augmentation produces a significant improvement at whatever point in the bone the screw is placed. The use of polymeric bone-substitute materials for tests may not reveal the natural variation encountered in tests using real bone structures.
Collapse
|
15
|
Elder BD, Lo SFL, Holmes C, Goodwin CR, Kosztowski TA, Lina IA, Locke JE, Witham TF. The biomechanics of pedicle screw augmentation with cement. Spine J 2015; 15:1432-45. [PMID: 25797809 DOI: 10.1016/j.spinee.2015.03.016] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 01/08/2015] [Accepted: 03/16/2015] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT A persistent challenge in spine surgery is improving screw fixation in patients with poor bone quality. Augmenting pedicle screw fixation with cement appears to be a promising approach. PURPOSE The purpose of this study was to survey the literature and assess the previous biomechanical studies on pedicle screw augmentation with cement to provide in-depth discussions of the biomechanical benefits of multiple parameters in screw augmentation. STUDY DESIGN/SETTING This is a systematic literature review. METHODS A search of Medline was performed, combining search terms of pedicle screw, augmentation, vertebroplasty, kyphoplasty, polymethylmethacrylate, calcium phosphate, or calcium sulfate. The retrieved articles and their references were reviewed, and articles dealing with biomechanical testing were included in this article. RESULTS Polymethylmethacrylate is an effective material for enhancing pedicle screw fixation in both osteoporosis and revision spine surgery models. Several other calcium ceramics also appear promising, although further work is needed in material development. Although fenestrated screw delivery appears to have some benefits, it results in similar screw fixation to prefilling the cement with a solid screw. Some differences in screw biomechanics were noted with varying cement volume and curing time, and some benefits from a kyphoplasty approach over a vertebroplasty approach have been noted. Additionally, in cadaveric models, cemented-augmented screws were able to be removed, albeit at higher extraction torques, without catastrophic damage to the vertebral body. However, there is a risk of cement extravasation leading to potentially neurological or cardiovascular complications with cement use. A major limitation of these reviewed studies is that biomechanical tests were generally performed at screw implantation or after a limited cyclic loading cycle; thus, the results may not be entirely clinically applicable. This is particularly true in the case of the bioactive calcium ceramics, as these biomechanical studies would not have measured the effects of osseointegration. CONCLUSIONS Polymethylmethacrylate and various calcium ceramics appear promising for the augmentation of pedicle screw fixation biomechanically in both osteoporosis and revision spine surgery models. Further translational studies should be performed, and the results summarized in this review will need to be correlated with the clinical outcomes.
Collapse
Affiliation(s)
- Benjamin D Elder
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA.
| | - Sheng-Fu L Lo
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Christina Holmes
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Courtney R Goodwin
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Thomas A Kosztowski
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Ioan A Lina
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA
| | - John E Locke
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA
| | - Timothy F Witham
- Department of Neurosurgery, The Johns Hopkins University School of Medicine, 1800 Orleans St, Baltimore, MD 21287, USA
| |
Collapse
|
16
|
Wang W, Baran GR, Garg H, Betz RR, Moumene M, Cahill PJ. The Benefits of Cement Augmentation of Pedicle Screw Fixation Are Increased in Osteoporotic Bone: A Finite Element Analysis. Spine Deform 2014; 2:248-259. [PMID: 27927345 DOI: 10.1016/j.jspd.2014.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 02/03/2014] [Accepted: 03/17/2014] [Indexed: 10/25/2022]
Abstract
STUDY DESIGN Biomechanical study using a finite element model of a normal and osteoporotic lumbar vertebrae comparing resistance with axial pullout and bending forces on polymethylmethacrylate-augmented and non-augmented pedicle screws. OBJECTIVE To compare the effect of cement augmentation of pedicle screw fixation in normal and osteoporotic bone with 2 different techniques of cement delivery. SUMMARY OF BACKGROUND DATA Various clinical and biomechanical studies have addressed the benefits of cement augmentation of pedicle screws, but none have evaluated whether this effect is similar, magnified, or attenuated in osteoporotic bone compared with normal bone. In addition, no study has compared the biomechanical strength of augmented pedicle screws using cement delivery through the pedicle screw with delivery through a pilot hole. METHODS This study was funded by a grant from DePuy Synthes Spine. Normal and osteoporotic lumbar vertebrae with pedicle screws were simulated. The models were tested for screw pullout strength with and without cement augmentation. Two methods of cement delivery were also tested. Both methods were tested using 1 and 2.5 cm3 volume of cement infiltrated in normal and osteoporotic bone. RESULTS The increase in screw pullout force was proportionally greater in osteoporotic bone with equivalent volumes of cement delivered. The researchers found that 1 and 2.5 cm3 of cement infiltrated bone volume resulted in an increase in pullout force by about 50% and 120% in normal bone, and by about 64% and 156% in osteoporotic bone, respectively. The delivery method had only a minimal effect on pullout force when 2.5 cm3 of cement was injected (<4% difference). CONCLUSIONS Cement augmentation increases the fixation strength of pedicle screws, and this effect is proportionately greater in osteoporotic bone. Cement delivery through fenestrated screws and delivery through a pilot hole result in comparable pullout strength at higher cement volumes.
Collapse
Affiliation(s)
- Wenhai Wang
- Department of Mechanical Engineering, College of Engineering, Temple University, 1947 North 12th Street, Philadelphia, PA 19104, USA
| | - George R Baran
- Department of Mechanical Engineering, College of Engineering, Temple University, 1947 North 12th Street, Philadelphia, PA 19104, USA
| | - Hitesh Garg
- Artemis Health Institute, Sector 51, Gurgaon 122001, Haryana, India
| | - Randal R Betz
- Shriners Hospitals for Children-Philadelphia, 3551 North Broad Street, Philadelphia, PA 19140, USA
| | - Missoum Moumene
- DePuy Synthes Spine, Inc., 325 Paramount Drive, Raynham, MA 02767, USA
| | - Patrick J Cahill
- Shriners Hospitals for Children-Philadelphia, 3551 North Broad Street, Philadelphia, PA 19140, USA.
| |
Collapse
|
17
|
Wähnert D, Hofmann-Fliri L, Schwieger K, Brianza S, Raschke MJ, Windolf M. Cement augmentation of lag screws: an investigation on biomechanical advantages. Arch Orthop Trauma Surg 2013; 133:373-9. [PMID: 23263012 DOI: 10.1007/s00402-012-1676-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Indexed: 11/26/2022]
Abstract
BACKGROUND In trauma surgery, lag screws are commonly used. However, in osteoporotic bone, anchorage can be considerably compromised. This study investigates the biomechanical potential of cement augmentation in terms of improved fixation. METHODS 36 Surrogate osteoporotic bone specimens were utilised in three biomechanical experiments, each comparing 6 augmented with 6 non-augmented samples. Standard partially-threaded lag screws (Synthes) were placed following surgical standard. For the augmented groups, 0.4 ml of polymethylmethacrylate was injected into the pre-drilled hole prior to screw placement. Interfragmentary compression was determined using a cannulated ring compression sensor. Maximum torque was recorded with a torque wrench. Compressive relaxation after 24 h, relaxation after loosening and re-tightening the screw as well as maximum compression and torque at failure were measured. FINDINGS Mean relaxation was significantly lower for the augmented group (p < 0.01). After 24 h, a remaining fragmental compression of 62 % for the augmented and 52 % for the non-augmented specimens was found. Loosening and re-tightening of the screw did not affect the compressive relaxation when augmentation was applied (p = 0.529), compared to an increased relaxation after re-tightening in the non-augmented group (p = 0.04). The mean maximum compression and torque until failure were significantly higher for the augmented group (p < 0.001). INTERPRETATION Cement augmentation of lag screws can improve fixation stability in terms of installing and maintaining interfragmentary compression. Effects of relaxation can be reduced and re-tightening of screws is possible without compromising the fixation. Particularly in reduced bone mass, augmentation of lag screws can markedly increase the security of the technique.
Collapse
Affiliation(s)
- D Wähnert
- AO Foundation, AO Research Institute, Clavadelerstrasse 8, Davos, Switzerland.
| | | | | | | | | | | |
Collapse
|
18
|
Enhanced bone screw fixation with biodegradable bone cement in osteoporotic bone model. J Appl Biomater Funct Mater 2012; 10:113-8. [PMID: 22798235 DOI: 10.5301/jabfm.2012.9269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/21/2011] [Indexed: 12/30/2022] Open
Abstract
PURPOSE The purpose of this study was to study the potential of novel biodegradable PCL bone cement to improve bone screw fixation strength in osteoporotic bone. METHODS The biomechanical properties of bone cement (ε-polycaprolactone, PCL) and fixation strength were studied using biomechanical tests and bone screws fixed in an osteoporotic bone model. Removal torques and pullout strengths were assessed for cortical, self-tapping, and cancellous screws inserted in the osteoporotic bone model (polyurethane foam blocks with polycarbonate plate) with and without PCL bone cement. Open cell and cellular rigid foam blocks with a density of 0.12 g/cm3 were used in this model. RESULTS Removal torques were significantly (more than six-fold) improved with bone cement for cancellous screws. Furthermore, the bone cement improved pullout strengths three to 12 times over depending on the screw and model material. CONCLUSIONS Biodegradable bone cement turned out to be a very potential material to stabilize screw fixation in osteoporotic bone. The results warrant further research before safe clinical use, especially to clarify clinically relevant factors using real osteoporotic bone under human body conditions and dynamic fatigue testing for long-term performance.
Collapse
|
19
|
Brown CJ, Sinclair RA, Day A, Hess B, Procter P. An approximate model for cancellous bone screw fixation. Comput Methods Biomech Biomed Engin 2011; 16:443-50. [PMID: 22149043 DOI: 10.1080/10255842.2011.624516] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
This paper presents a finite element (FE) model to identify parameters that affect the performance of an improved cancellous bone screw fixation technique, and hence potentially improve fracture treatment. In cancellous bone of low apparent density, it can be difficult to achieve adequate screw fixation and hence provide stable fracture fixation that enables bone healing. Data from predictive FE models indicate that cements can have a significant potential to improve screw holding power in cancellous bone. These FE models are used to demonstrate the key parameters that determine pull-out strength in a variety of screw, bone and cement set-ups, and to compare the effectiveness of different configurations. The paper concludes that significant advantages, up to an order of magnitude, in screw pull-out strength in cancellous bone might be gained by the appropriate use of a currently approved calcium phosphate cement.
Collapse
Affiliation(s)
- C J Brown
- School of Engineering and Design, Brunel University, Uxbridge, UB8 3PH, UK.
| | | | | | | | | |
Collapse
|
20
|
Yánez A, Garcés GL, Carta JA, Cuadrado A. A New System to Improve Screw Fixation to Bones. J Med Device 2011. [DOI: 10.1115/1.4005227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Plates and non-locked screws used in the treatment of osteoporotic bone fractures frequently become loose due to everyday mechanical demands. Currently, locking plates and screws are the gold standard treatment for these fractures. However, their use has several limitations and complications as they are technically demanding, and their cost is very expensive. To improve the fixation strength of traditional unlocked plate and screw constructs, we have developed a new fixation system based on a very old concept. The system consists of a screw locking element (SLE) manufactured from PEEK, which is attached to the end of the screw shaft once it has traversed both bone cortices. A specially designed tool is used to facilitate its attachment to the screw. This tool makes it possible for the screw to traverse an osteosynthesis plate or lockwasher as well as both bone cortices and to easily find the SLE, fixing it against the far cortex. We tested the pull-out strength of SLEs and compared the results with previously published data for human femoral cortex pull-out strength. Our laboratory tests demonstrate that the mean SLE pull-out strength was 3864 ± 47.61 N, while that observed for a human femoral diaphysis cortex was 4071.54 ± 1461.69 N. This difference was not significant (p > 0.05). This new system can easily be used with any type of osteosynthesis in osteoporotic or osteopenic bones, with the screws being placed on weakened areas of the bone (e.g., fissure lines, previous orifices, or thinned metaphyseal bone cortex), or to replace over-torqued screws. It is particularly suitable for veterinary trauma, where immediate weight-bearing protection after fracture treatment is nearly impossible.
Collapse
Affiliation(s)
- A. Yánez
- Department of Mechanical Engineering, Biomechanical Laboratory, Las Palmas University, Engineering Departmental Building, Campus de Tafira Baja, 35017 Las Palmas de Gran Canaria, Spain e-mail:
| | - G. L. Garcés
- Hospital Perpetuo Socorro and Department of Medical and Surgical Science, Las Palmas de Gran Canaria University, c/León y Castillo 407, 35017 Las Palmas de Gran Canaria, Spain
| | | | - A. Cuadrado
- Department of Mechanical Engineering, Biomechanical Laboratory, Las Palmas University, Engineering Departmental Building, Campus de Tafira Baja, 35017 Las Palmas de Gran Canaria, Spain
| |
Collapse
|
21
|
Weiss KR, Bhumbra R, Biau DJ, Griffin AM, Deheshi B, Wunder JS, Ferguson PC. Fixation of pathological humeral fractures by the cemented plate technique. ACTA ACUST UNITED AC 2011; 93:1093-7. [PMID: 21768635 DOI: 10.1302/0301-620x.93b8.26194] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Pathological fractures of the humerus are associated with pain, morbidity, loss of function and a diminished quality of life. We report our experience of stabilising these fractures using polymethylmethacrylate and non-locking plates. We undertook a retrospective review over 20 years of patients treated at a tertiary musculoskeletal oncology centre. Those who had undergone surgery for an impending or completed pathological humeral fracture with a diagnosis of metastatic disease or myeloma were identified from our database. There were 63 patients (43 men, 20 women) in the series with a mean age of 63 years (39 to 87). All had undergone intralesional curettage of the tumour followed by fixation with intramedullary polymethylmethacrylate and plating. Complications occurred in 14 patients (22.2%) and seven (11.1%) required re-operation. At the latest follow-up, 47 patients (74.6%) were deceased and 16 (25.4%) were living with a mean follow-up of 75 months (1 to 184). A total of 54 (86%) patients had no or mild pain and 50 (80%) required no or minimal assistance with activities of daily living. Of the 16 living patients none had pain and all could perform activities of daily living without assistance. Intralesional resection of the tumour, filling of the cavity with cement, and plate stabilisation of the pathological fracture gives immediate rigidity and allows an early return of function without the need for bony union. The patient's local disease burden is reduced, which may alleviate tumour-related pain and slow the progression of the disease. The cemented-plate technique provides a reliable option for the treatment of pathological fractures of the humerus.
Collapse
Affiliation(s)
- K R Weiss
- Department of Orthopaedic Surgery, Division of Musculoskeletal Oncology, Shadyside Medical Center, 5200 Centre Avenue, Suite 415, Pittsburgh, Pennsylvania 15232, USA.
| | | | | | | | | | | | | |
Collapse
|
22
|
Puri A, Gulia A. An inexpensive reconstruction method after resection in tumors of the proximal humerus with extensive involvement of the diaphysis. INTERNATIONAL JOURNAL OF SHOULDER SURGERY 2011; 5:44-6. [PMID: 21897583 PMCID: PMC3157097 DOI: 10.4103/0973-6042.83196] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Limb salvage is now the norm for a large majority of malignant bone tumors. The proximal humerus is the third most common site for the occurrence of malignant tumors of bone. In tumors of the proximal humerus with large volume disease, extensive involvement of the diaphysis is not infrequent. Resection may often extend as far as the distal metaphysis in order to obtain adequate oncologic margins. A very small distal stump of bone poses unique challenges in reconstruction where conventional reconstruction modalities may be difficult to apply. We describe the use of a customised plate to reconstruct these defects which offers an inexpensive, easy to use, durable reconstruction option. It provides adequate shoulder and arm stability and ensures excellent hand and elbow motion with good functional results.
Collapse
Affiliation(s)
- Ajay Puri
- Department of Orthopedic Oncology, Tata Memorial Hospital, Mumbai, India
| | | |
Collapse
|
23
|
Biomechanical evaluation of a novel fenestrated pedicle screw augmented with bone cement in osteoporotic spines. Spine (Phila Pa 1976) 2011; 36:E1210-4. [PMID: 21325986 DOI: 10.1097/brs.0b013e318205e3af] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Comparative biomechanical study was conducted in osteoporotic human cadaveric spines. OBJECTIVE Determine the influence of the volume of polymethyl methacrylate injected through a fenestrated pedicle screw on the pullout strength and on the ability to safely remove the implant. SUMMARY OF BACKGROUND DATA Pedicle screw fixation in the osteoporotic spine can be improved by the addition of bone cement. Various injection techniques have been used. While improvement has been shown for the pullout strength, the optimal volume of cement to inject has not been previously studied. METHODS Seven osteoporotic spines were instrumented with a standard and a fenestrated pedicle screw augmented with polymethyl methacrylate at each level (T7-L5). Three volumes of bone cement were randomly injected and stratified to the thoracic (0.5 cc, 1.0 cc, and 1.5 cc) and lumbar spine (1.5 cc, 2.0 cc, and 2.5 cc). Axial pullout strength and removal torque of the pedicle screws were quantified. RESULTS The pullout strength of the fenestrated screw was normalized with respect to its contralateral control. Student paired t tests were conducted and a statistically significant increase was noted for 1.0 cc (186 ± 45%) and 1.5 cc (158 ± 46%) in the thoracic spine and for 1.5 cc (264 ± 193%), 2.0 cc (221 ± 93%), and 2.5 cc (198 ± 42%) in the lumbar spine. There was no significant difference with higher volumes of cement. The median removal torque was 0.34 Nm for the standard and 1.83 Nm for the augmented screws. When the augmented implants were removed, the bone cement sheared completely off at the fenestrations in 15 of the 17 cases. CONCLUSION Significant increases in pullout strength can be accomplished by injecting a limited quantity of bone cement through a fenestrated screw while minimizing the risks associated with higher volume. The majority of implants were removed without damaging the vertebra as the bone cement sheared off at the fenestrations.
Collapse
|
24
|
Biomechanical comparison of 4 fixation techniques of sacral pedicle screw in osteoporotic condition. ACTA ACUST UNITED AC 2010; 23:404-9. [PMID: 20087222 DOI: 10.1097/bsd.0b013e3181b63f4d] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
STUDY DESIGN An in vitro biomechanical cadaver study. OBJECTIVES To compare the subsidence displacement after cyclic loading among 4 sacral pedicle screw fixations of bicortical, tricortical, standard polymethylmethacrylate (PMMA) augmentation, and sub-endplate PMMA augmentation in osteoporotic condition. SUMMARY OF BACKGROUND DATA Implant failure caused by screw loosening is a clinical problem for lumbosacral fusions, especially in osteoporotic patients. To improve sacral screw anchoring strength, the main fixation techniques need to be evaluated biomechanically. METHODS For this study, 11 fresh osteoporotic cadaver sacra were harvested and bone mineral density was measured with dual-energy radiograph absorptiometry. A 7 mm diameter monoaxial pedicle screw (S1) was randomly assigned by side (left vs. right) and placed bicortically or tricortically. The 2 screws, followed 2000 cyclic compression loading of 30 to 250 N, were removed. The screw tracts were filled up with PMMA, then, screws 5 mm shorter than the bicortical or tricortical fixation were reinserted (defined as standard and sub-endplate PMMA augmented sacral screw fixations, respectively). The PMMA augmented screws were then retested as before. Screw subsidence displacement after 2000 cyclic loading was measured and compared. RESULTS The average bone mineral density of 11 specimens was 0.71 g/cm, ranged from 0.65 to 0.78 g/cm. No significant difference of subsidence displacement was detected between tricortical and standard PMMA augmented screws (P>0.05), however, the 2 fixations exhibited markedly less subsidence than bicortical screw (P<0.05). Sub-endplate PMMA augmented screw showed the least subsidence among all the screws (P<0.05). CONCLUSIONS PMMA augmentation can increase the bonding strength of sacral screw-bone interface and the sub-endplate PMMA augmented sacral screw could obtain the highest stability among the 4 fixation techniques in osteoporotic condition.
Collapse
|
25
|
Effect of the degree of osteoporosis on the biomechanical anchoring strength of the sacral pedicle screws: an in vitro comparison between unaugmented bicortical screws and polymethylmethacrylate augmented unicortical screws. Spine (Phila Pa 1976) 2010; 35:E925-31. [PMID: 20098349 DOI: 10.1097/brs.0b013e3181c5fb21] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN An in vitro laboratory study. OBJECTIVE (i) To evaluate the effect of osteoporotic degree in determining the strength of sacral screw fixation and (ii) to compare the strength of unaugmented bicortical pedicle screw and polymethylmethacrylate (PMMA) augmented unicortical pedicle screw in sacral fixation. SUMMARY OF BACKGROUND DATA Screw loosening is a clinical problem in lumbosacral fusions, especially in osteoporotic patients. To improve the screw anchoring strength of sacrum, bicortical and PMMA augmented sacral pedicle screw fixation techniques are widely used in clinical practice. However, the biomechanical strength of the bicortical and PMMA augmented sacral screw fixations remains undetermined in different degrees of osteoporosis. METHODS Twenty-five fresh osteoporotic cadavers were used in this study. According to the value of lumbar bone mineral density (BMD) assessed by DEXA, specimens were divided into 3 groups: group A (N=9): BMD=0.7 to 0.8 g/cm, group B (N=8): BMD=0.6 to 0.7 g/cm, and group C (N=8): BMD<0.6 g/cm. In each specimen, S1 pedicle screw was inserted bicortically on the left side, and S1 pedicle screw with PMMA augmentation was inserted unicortically on the right side of the sacrum. Following a dynamic cyclic loading from 30 to 250 N on the screw head for 2000 cycles, the subsidence displacement and axial pull-out strength of each screw were measured. RESULTS No anchoring failure (defined as the subsidence displacement exceeding 2 mm within 2000 loading cycles) occurred in group A and B. However, in group C, 6 cases (75%) in bicortical fixation and 5 cases (63%) in PMMA augmented fixation failed during cyclic loading. In group A, no significant difference between the bicortical and PMMA augmented fixations was detected in terms of the subsidence and maximal pull-out strength. In group B, significantly less subsidence and higher maximal pull-out strength were demonstrated in the PMMA augmented technique than that in the bicortical fixation. Both techniques exhibited lower subsidence of the screw in group A than in group B. The bicortical technique exhibited higher maximum pull-out strength in group A than that in group B. However, statistical difference in terms of PMMA augmentation was not detected between group A and B. CONCLUSION For BMD value more than 0.70 g/cm, bicortical sacral pedicle screw fixation could obtain sufficient anchoring strength comparable with the PMMA augmented technique. When BMD value is within 0.6 to 0.7 g/cm, the PMMA augmented technique would be more beneficial in improving the fixation strength than the bicortical fixation. For BMD values less than 0.6 g/cm, early screw loosening may occur in both bicortical and PMMA augmented fixations.
Collapse
|
26
|
Yánez A, Carta J, Garcés G. Biomechanical evaluation of a new system to improve screw fixation in osteoporotic bones. Med Eng Phys 2010; 32:532-41. [DOI: 10.1016/j.medengphy.2010.02.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 02/15/2010] [Accepted: 02/16/2010] [Indexed: 11/25/2022]
|
27
|
Moon BJ, Cho BY, Choi EY, Zhang HY. Polymethylmethacrylate-augmented screw fixation for stabilization of the osteoporotic spine : a three-year follow-up of 37 patients. J Korean Neurosurg Soc 2009; 46:305-11. [PMID: 19893717 DOI: 10.3340/jkns.2009.46.4.305] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 08/17/2009] [Accepted: 10/04/2009] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE The purpose of this study was to determine the efficacy, radiological findings, clinical outcomes and complications in patients with lumbar stenosis and osteoporosis after the use of polymethylmethacrylate (PMMA) augmentation of a cannulated pedicle screw. METHODS Thirty-seven patients with degenerative spinal stenosis and osteoporosis (T-score < -2.5) underwent lumbar fusion using the Dream Technology Pedicle Screw (DTPS, Dream Spine Total Solutions, Dream STS, Seoul, Korea) between 2005 and 2007. The clinical outcomes were evaluated by using the visual analog scale (VAS) and the Prolo scale. Radiologic findings were documented through computed tomography (CT) and plain films. RESULTS Thirty-seven patients were evaluated and included, 2 males and 35 females with an average bone mineral density (BMD) of 0.47g/cm(2). The average age of the patients was 68.7 (range, 57-88). The preoperative VAS for low back and leg pain (7.87 +/- 0.95 and 8.82 +/- 0.83) were higher as compared with postoperative VAS (2.30 +/- 1.61 and 1.42 +/- 0.73) with statistical significance (p = 0.006, p = 0.003). According to the Prolo scale, 11, 22, one and three patients were in excellent, good, fair and poor conditions, respectively. The average amount of the injected cement per one cannulated screw was 1.83 +/- 0.11 mL. CONCLUSION The results show favorable outcome both clinically and radiographically for 37 patients who underwent lumbar fusion using DTPS and PMMA. Based on the results, the use of this surgical method can be a safe and effective option for the operation on the osteoporotic spine.
Collapse
Affiliation(s)
- Bong Ju Moon
- Department of Neurosurgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea
| | | | | | | |
Collapse
|
28
|
Gallimore CH, McConnell AJ, Zdero R, Koo H, McKee MD, Schemitsch EH. The effect of cement mixing time on the biomechanics of cement augmented plated fractures in canine femora. J Orthop Trauma 2008; 22:637-42. [PMID: 18827594 DOI: 10.1097/bot.0b013e31817e49d1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE The goal of this study was to determine the effect of cement mixing time and, hence, cement viscosity on the biomechanical behavior of femoral fracture fixation. DESIGN Cadaveric plated canine femoral fracture model, comparing treatments in matched pairs. SETTING Orthopaedic biomechanics laboratory. INTERVENTION Cement was inserted both as a liquid and as a paste in standard and oversized screw holes to augment fixation with plates and screws. MAIN OUTCOME MEASUREMENTS Standard 4-point bending tests were performed to obtain stiffness and failure load values. RESULTS Liquid cement had a 1.38 times increase in stiffness and a failure load 1.84 times greater compared with paste cement, regardless of hole size with a gap at the fracture site (P < 0.05). Liquid cement had a force to failure of 1.77 and 1.91 times in the standard-sized and oversized holes, respectively, when compared with paste cement (P < 0.05). CONCLUSIONS When the cement was inserted in a liquid state in a plated femoral diaphyseal fracture with a gap, screw purchase augmentation achieved greater bending stiffness and resisted a greater failure load.
Collapse
Affiliation(s)
- Chris H Gallimore
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
| | | | | | | | | | | |
Collapse
|
29
|
Frankel BM, Jones T, Wang C. Segmental polymethylmethacrylate-augmented pedicle screw fixation in patients with bone softening caused by osteoporosis and metastatic tumor involvement: a clinical evaluation. Neurosurgery 2007; 61:531-7; discussion 537-8. [PMID: 17881965 DOI: 10.1227/01.neu.0000290899.15567.68] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE Instrumentation of the osteoporotic spine may result in bone failure because of pedicle screw loosening and pullout. A clinical evaluation of a novel fenestrated bone tap used in pedicle screw augmentation was performed to determine the performance and safety of this technique. METHODS Over a 2.5-year period, the clinical and radiographic results of 119 consecutive patients who underwent instrumented arthrodesis were reviewed. Of these patients, 23 had bone softening secondary to osteoporosis and/or metastatic spinal tumor involvement. These patients underwent surgical decompression and spinal instrumentation. RESULTS Six patients (26%) had metastatic spine disease (squamous cell lung carcinoma, renal cell carcinoma, bladder carcinoma, breast, prostate, and uterine adenocarcinoma); five patients (22%) had a degenerative spondylolisthesis; and 12 patients (52%) had burst fractures, eight as a result of benign causes and four as a result of metastatic disease. Four (17%) patients underwent revision surgery of previous pedicle screw failure resulting from bone softening and pseudarthrosis. A total of 98 levels were fused using 158 polymethylmethacrylate-augmented screws. None of the patients experienced operative death, myocardial infarction, hypoxemia, intraoperative hypotension, radiculopathy, or myelopathy. Asymptomatic anterior cement extravasation was observed in nine patients (39%). There was one asymptomatic polymethylmethacrylate pulmonary embolus and one wound infection. There was no significant relationship between cement extravasation and the quantity used, levels augmented, or location (P > 0.05). There were no construct failures. CONCLUSION Polymethylmethacrylate-augmented pedicle screw fixation reduces the likelihood of pedicle screw loosening and pullout in patients with osteoporosis requiring instrumented arthrodesis.
Collapse
Affiliation(s)
- Bruce M Frankel
- Department of Neurosurgery, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
| | | | | |
Collapse
|
30
|
Frankel BM, D'Agostino S, Wang C. A biomechanical cadaveric analysis of polymethylmethacrylate-augmented pedicle screw fixation. J Neurosurg Spine 2007; 7:47-53. [PMID: 17633487 DOI: 10.3171/spi-07/07/047] [Citation(s) in RCA: 113] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Instrumentation of the osteoporotic spine can be fraught with complications such as hardware failure. A cadaver study was performed to determine the biomechanical performance of polymethylmethacrylate (PMMA)–augmented pedicle screws.
Methods
Three osteoporotic human cadaveric specimens with a mean bone mineral density of 0.70 g/cm2 were used to evaluate the performance of a novel fenestrated bone tap in pedicle screw augmentation. On this device, tap threads serve a dual purpose in preventing backflow of cement toward neural elements while allowing for a custom form for subsequent screw placement. The tap was used to inject a mean volume of 3.7 ml PMMA/pedicle (range 2–8.0 ml PMMA/pedicle) followed by pedicle screw placement between L-5 and T-5, alternating between augmented and nonaugmented instrumentation. Axial pullout testing was then performed.
Results
Pedicle screw pullout strength was increased in both primary and salvage procedures by 119% (p = 0.001) and 162% (p = 0.01), respectively, after PMMA augmentation. Additionally, the injected cement volumes were divided into two groups, a low-cement group (≤ 2.8 ml/pedicle) and a high-cement group (≥ 5.5 ml/pedicle). Interestingly, the pullout strength did not significantly change with increased cement usage between the two groups (p > 0.05 for all comparisons).
Conclusions
Polymethylmethacrylate-augmented pedicle screw fixation results in a significant increase in the axial pullout strength of augmented pedicle screws in both primary and revision procedures. This technique may be a valuable adjunct in cases in which bolstering of the screw–bone interface is necessary.
Collapse
Affiliation(s)
- Bruce M Frankel
- Department of Neurosurgery, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
| | | | | |
Collapse
|
31
|
Zdero R, Rose S, Schemitsch EH, Papini M. Cortical screw pullout strength and effective shear stress in synthetic third generation composite femurs. J Biomech Eng 2007; 129:289-93. [PMID: 17408335 DOI: 10.1115/1.2540926] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND The use of artificial bone analogs in biomechanical testing of orthopaedic fracture fixation devices has increased, particularly due to the recent development of commercially available femurs such as the third generation composite femur that closely reproduce the bulk mechanical behavior of human cadaveric and/or fresh whole bone. The purpose of this investigation was to measure bone screw pullout forces in composite femurs and determine whether results are comparable to cadaver data from previous literature. METHOD OF APPROACH The pullout strengths of 3.5 and 4.5 mm standard bicortical screws inserted into synthetic third generation composite femurs were measured and compared to existing adult human cadaveric and animal data from the literature. RESULTS For 3.5 mm screws, the measured extraction shear stress in synthetic femurs (23.70-33.99 MPa) was in the range of adult human femurs and tibias (24.4-38.8 MPa). For 4.5 mm screws, the measured values in synthetic femurs (26.04-34.76 MPa) were also similar to adult human specimens (15.9-38.9 MPa). Synthetic femur results for extraction stress showed no statistically significant site-to-site effect for 3.5 and 4.5 mm screws, with one exception. Overall, the 4.5 mm screws showed statistically higher stress required for extraction than 3.5 mm screws. CONCLUSIONS The third generation composite femurs provide a satisfactory biomechanical analog to human long-bones at the screw-bone interface. However, it is not known whether these femurs perform similarly to human bone during physiological screw "toggling."
Collapse
Affiliation(s)
- Radovan Zdero
- Martin Orthopaedic Biomechanics Lab, St. Michael's Hospital, Toronto, ON, Canada
| | | | | | | |
Collapse
|
32
|
Hutchinson GS, Griffon DJ, Siegel AM, Pijanowski GJ, Kurath P, Eurell JAC, Johnson AL. Evaluation of an osteoconductive resorbable calcium phosphate cement and polymethylmethacrylate for augmentation of orthopedic screws in the pelvis of canine cadavers. Am J Vet Res 2005; 66:1954-60. [PMID: 16334956 DOI: 10.2460/ajvr.2005.66.1954] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To evaluate the effect of an osteoconductive resorbable calcium phosphate cement (CPC) on the holding power of bone screws in canine pelvises and to compare the effect with that for polymethylmethacrylate (PMMA). SAMPLE POPULATION 35 pelvises obtained from canine cadavers. PROCEDURE Each pelvis was sectioned longitudinally. Within each pair of hemipelvises, one 4.0-mm cancellous screw was placed in the sacroiliac (SI) region and another in the iliac body. Similar regions on the contralateral-matched hemipelvis were assigned 1 of 3 augmentation techniques (CPC-augmented 4.0-mm cancellous screws, PMMA-augmented 4.0-mm cancellous screws, and CPC-augmented 3.5-mm cortical screws). Pullout force was compared between matched screws and between treatment groups prior to examination of cross sections for evaluation of cement filling and noncortical bone-to-cortical bone ratio. RESULTS CPC and PMMA augmentation significantly increased pullout force of 4.0-mm screws inserted in the SI region by 19.5% and 33.2%, respectively, and CPC augmentation significantly increased pullout force of 4.0-mm cancellous screws inserted in the iliac body by 21.2%. There was no difference in the mean percentage augmentation between treatment groups at either location. Cement filling was superior in noncortical bone, compared with filling for cortical bone. Noncortical bone-to-cortical bone ratio was significantly greater in the sacrum (6.1:1) than the ilium (1.3:1). CONCLUSIONS AND CLINICAL RELEVANCE CPC and PMMA improve the ex vivo holding strength of 4.0-mm cancellous screws in the SI and iliac body regions and SI region, respectively. Cement augmentation may be more effective in areas with greater noncortical bone-to-cortical bone ratios.
Collapse
Affiliation(s)
- Geoffrey S Hutchinson
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana 61802, USA
| | | | | | | | | | | | | |
Collapse
|
33
|
Roth SE, Kreder H, Stephen D, Whyne CM. Biomechanical stability of intramedullary nailed high proximal third tibial fractures with cement augmented proximal screws. J Orthop Trauma 2005; 19:457-61. [PMID: 16056077 DOI: 10.1097/01.bot.0000164337.71390.29] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Intramedullary nailing of nonarticular proximal tibia fractures can be affected by bone density resulting in loss of stability, fixation, and malalignment in osteopenic bone. This study was designed to quantify the biomechanical effects of augmenting proximal screws with cement in intramedullary nailing of high proximal third tibial fractures. DESIGN In vitro biomechanical study using anatomic specimens. METHODS Reamed nails were inserted into seven pairs of fresh-frozen cadaveric proximal tibiae and secured using two oblique and two transverse proximal screws. Paired tibiae were randomly assigned into two groups: cemented and noncemented proximal screw-holes. Bone cement was injected into the screw-holes before screw insertion in the cemented tibiae. Specimens were then tested in flexion/extension and varus/valgus to 12 Nm and in torsion to 7 Nm. Physical measurements of bone density were obtained to determine the effect of density on stability. MAIN OUTCOME MEASURES Stability of the construct in both groups was analyzed and compared statistically using paired t tests. RESULTS Cement augmentation of the proximal screws significantly increased mechanical stability in torsion and varus/valgus load configurations, with average decreases in rotational motion of 5.4 degrees +/- 1.6 degrees and 5.1 degrees +/- 5 degrees respectively. No change in stability was observed in flexion/extension loading. A trend toward decreased stability was seen in the uncemented construct in varus/valgus; cement augmentation of the proximal screws eliminated this effect. CONCLUSIONS Lower bone density decreased the stability of the uncemented construct; however, cement augmentation of the proximal screws showed a trend to eliminate this effect in the varus/valgus loading configuration and should be considered when nailing proximal third tibial fractures in osteoporotic patients.
Collapse
Affiliation(s)
- Sandra E Roth
- Orthopaedic Biomechanics Laboratory, Sunnybrook & Women's College Health Sciences Centre, 2075 Bayview Avenue, U-Basement, Toronto, ON, M4N 3M5, Canada
| | | | | | | |
Collapse
|
34
|
Griffon DJ, Stoller A, Schaeffer DJ, Seddighi MR, Johnson AL, Kurath P. Evaluation of 2 Cement Techniques for Augmentation of Stripped 1.5 mm Screw Sites in the Distal Metaphysis of Feline Radii. Vet Surg 2005; 34:223-30. [PMID: 16115078 DOI: 10.1111/j.1532-950x.2005.00034.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the effect of 2 cement augmentation techniques on pullout strength of 1.5 mm screws placed in stripped 1.5 mm screw sites in the distal metaphysis of feline radii. STUDY DESIGN Experimental study. SAMPLE POPULATION Feline radii (21 pairs). METHODS Treatment groups (n=4) were allocated according to a Latin square design to 4 sites in each pair of radii. Positive and negative controls were a 1.5 mm screw and a screw of the same diameter in a previously stripped screw hole, respectively. Treatment groups were a 1.5 mm screw implanted in a previously stripped screw hole after injection of polymethylmethacrylate (PMMA) or a bioresorbable calcium phosphate cement (CPC, Norian skeletal repair system (SRS)). The ultimate pullout strength was compared between groups. RESULTS The mean (+/-SEM) pullout strength of screws augmented with either bone cement was less than that of the positive control group and greater than that of the negative control. Injection of CPC or PMMA before screw implantation increased the pullout strength of the negative control by 86.8+/-22.9% and 104.1+/-32.1%, respectively. Holding power of the positive control screws differed from these 2 groups, and was 274.8+/-39.17% higher than that of the negative control. CONCLUSION Injection of CPC or PMMA increases but does not restore the holding power of stripped 1.5 mm diameter screws. CLINICAL RELEVANCE The use of CPC (Norian SRS) augmentation of stripped 1.5 mm diameter screws warrants clinical investigation as it combines biomechanical results similar to PMMA with osteoconduction and resorbability.
Collapse
Affiliation(s)
- Dominique J Griffon
- Departments of Veterinary Clinical Sciences and Veterinary Biosciences, College of Veterinary Medicine, University of Illinois, 1008 W. Hazelwood Drive, Urbana, IL 61802, USA.
| | | | | | | | | | | |
Collapse
|
35
|
Abstract
The purpose of this study was to assess 4 methods of fixation for the offset V osteotomy. Maximum load, failure energy, and stiffness were determined in a control group and in 4 different test models. There were 10 specimens for each group. The control group consisted of intact first ray sawbones. An offset V osteotomy was performed on each specimen in each of the 4 test groups. The osteotomies were fixated either with two 2.0-mm cortical screws, two 2.7-mm cortical screws, two 3.5-mm cortical screws, or one 2.7-mm cortical screw and a 0.045-in Kirschner wire, respectively. Each model was then loaded to failure with a computerized hydraulic-tensile testing machine. Results for maximum load to failure for all 4 fixation constructs showed a mean ranging from 113.0 to 144.0 N, a mean energy to failure ranging from 272.2 to 365.0 J, and a mean stiffness ranging from 21.3 to 27.0 N/mm. There were no statistically significant differences detected among the individual constructs. In the group fixated with 3.5-mm screws, there were statistically significant differences in all 3 parameters compared with the control group. In the groups fixated with 2.7-mm screws, 2.0-mm screws, and the 2.7-mm screw and Kirschner wire, there were statistically significant differences in the maximum load and the failure energy, but not in stiffness, when compared with the control group. These findings suggest that all 4 constructs provide similar mechanical properties when utilized for the fixation of the offset V osteotomy.
Collapse
Affiliation(s)
- Jane Khuri
- St. John North Shores Hospital, Harrison Township, MI, and Michigan State University, East Lansing, MI, USA
| | | | | | | |
Collapse
|
36
|
|
37
|
Eriksson F, Mattsson P, Larsson S. The effect of augmentation with resorbable or conventional bone cement on the holding strength for femoral neck fracture devices. J Orthop Trauma 2002; 16:302-10. [PMID: 11972072 DOI: 10.1097/00005131-200205000-00003] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To compare maximum extraction torque and pull-out load for femoral neck fracture implants inserted with standard technique or after augmentation with polymethylmethacrylate (PMMA) or calcium phosphate cement (Norian SRS). DESIGN Biomechanical study using synthetic bone. INTERVENTION Implants were inserted in foam blocks with three different densities for simulation of normal bone or slight or severe osteoporosis. Tested implants included three screws (AO, Olmed, Hansson), one screw with both threads and a barb (Hybrid), and one pin with a hook (LIH hook-pin). Implants were inserted by standard technique and after augmentation with PMMA or Norian SRS. MAIN OUTCOME MEASUREMENT The effect of (a) density of the synthetic bone (low, medium, high), (b) augmentation (none, PMMA, SRS), and (c) type of implant (AO, Olmed, Hansson, Hybrid, LIH) on the maximum extraction torque and pull-out load was determined using a material testing machine. Analysis of variance with Fisher's PLSD post hoc test was used to determine statistical differences. RESULTS PMMA significantly increased maximum torque and pull-out load for all implants and block densities when compared without cement (p < 0.0001), whereas enhancement with SRS was far less pronounced and most obvious in low density blocks. For screws normally inserted without predrilling (Olmed and Hansson) the use of SRS in high density blocks caused a significant reduction in maximum torque (p < 0.0001) and pull-out load (p < 0.0001). SRS-augmented specimens failed through the cement at the periphery of the threads, whereas PMMA-augmented specimens failed between the cement and the synthetic bone. CONCLUSION This study suggests that augmentation with PMMA around femoral neck fracture implants will increase the holding power significantly when compared with standard insertion technique as well as augmentation with calcium phosphate cement. Augmentation with calcium phosphate cement like SRS will increase the holding characteristics mainly in low density bone, whereas in high density bone it might even reduce the maximum torque because of the need for predrilling when using the cement for augmentation.
Collapse
Affiliation(s)
- Fredrik Eriksson
- Department of Orthopedics, Uppsala University Hospital, SE-751 85 Uppsala, Sweden
| | | | | |
Collapse
|
38
|
Nasson S, Shuff C, Palmer D, Owen J, Wayne J, Carr J, Adelaar R, May D. Biomechanical comparison of ankle arthrodesis techniques: crossed screws vs. blade plate. Foot Ankle Int 2001; 22:575-80. [PMID: 11503983 DOI: 10.1177/107110070102200708] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Many different techniques for ankle arthrodesis have been described. Experience at our institution with crossed screws internal fixation has not met the 90+% union rate reported in the literature. A compression blade plate is one technique for ankle arthrodesis which has not been evaluated biomechanically. A biomechanical study comparing two groups of sawbone ankle fusion constructs fixed with crossed screws and compression blade plates was performed in order to evaluate the stiffness and rigidity of these two arthrodesis techniques. The crossed screws construct demonstrated superior stiffness during dorsiflexion (p < 0.001) and valgus (p < 0.001) loading. The two constructs were found to have equal strength in resisting plantarflexion, varus and torsional loads although there was a trend for greater resistance by the crossed screws construct. These findings lend biomechanical support to the use of crossed screws for tibiotalar arthrodesis.
Collapse
Affiliation(s)
- S Nasson
- Department of Biomedical Engineering, Virginia Commonwealth University, Richmond 23298, USA.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Lam CK, Wu WC, Ip FK. An unorthodox solution to an intra-operative complication of hip fracture fixation. Injury 1998; 29:248-9. [PMID: 9709431 DOI: 10.1016/s0020-1383(97)00216-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- C K Lam
- Department of Orthopaedics and Traumatology, Pamela Youde Nethersole Eastern Hospital, Chai Wan, Hong Kong
| | | | | |
Collapse
|