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Therapeutic Exercises for Equine Sacroiliac Joint Pain and Dysfunction. Vet Clin North Am Equine Pract 2022; 38:569-584. [DOI: 10.1016/j.cveq.2022.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Dang L, Zhu J, Liu Z, Liu X, Jiang L, Wei F, Song C. A new approach to the treatment of spinal instability: Fusion or structural reinforcement without surgery? Med Hypotheses 2020; 144:109900. [PMID: 32562916 DOI: 10.1016/j.mehy.2020.109900] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/24/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023]
Abstract
Spinal instability related low back pain is a common condition resulting from degeneration and loss of stiffness of the intervertebral joint. In order to restore stability, highly invasive surgical fusion is needed for patients who are not responding to conservative treatment. Given the risk and complications of surgery, there has been the urge for improvement with a less invasive solution. Formation of vertebral body osteophytes is a common observation that has been treated as a degenerative condition. However, recent studies have associated it with reduced motion of spinal segments. Unlike the traditional view, we regard it as adaptive reactions aiming to repair and hypothesize that the spinal segments could be stabilized or fused by intentionally induced osteophytes growth at the mobile parts of the intervertebral joint. This could be achieved by injecting Bone Morphogenetic Proteins to the anterior ends of the vertebral bodies and/or the facet joints on both sides of two consecutive vertebrae percutaneously. If verified, it would be the first time that fusion could be achieved without surgery. Hence it would provide a valuable alternative to current treatments of spinal instability. Preliminary test in favor of this hypothesis is presented and we recommend that a formal study with sufficient number of samples is needed for verification.
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Affiliation(s)
- Lei Dang
- Department of Orthopedics, Peking University 3rd Hospital, Beijing Key Laboratory of Spinal Disease Research, No. 49 North Garden Rd., Haidian District, Beijing 100191, PR China
| | - Jinglin Zhu
- Department of Orthopedics, Beijing Shijitan Hospital, No. 10 Tieyi Rd., Yangfangdian Subdistrict, Haidian District, Beijing, PR China
| | - Zhongjun Liu
- Department of Orthopedics, Peking University 3rd Hospital, Beijing Key Laboratory of Spinal Disease Research, No. 49 North Garden Rd., Haidian District, Beijing 100191, PR China
| | - Xiaoguang Liu
- Department of Orthopedics, Peking University 3rd Hospital, Beijing Key Laboratory of Spinal Disease Research, No. 49 North Garden Rd., Haidian District, Beijing 100191, PR China
| | - Liang Jiang
- Department of Orthopedics, Peking University 3rd Hospital, Beijing Key Laboratory of Spinal Disease Research, No. 49 North Garden Rd., Haidian District, Beijing 100191, PR China
| | - Feng Wei
- Department of Orthopedics, Peking University 3rd Hospital, Beijing Key Laboratory of Spinal Disease Research, No. 49 North Garden Rd., Haidian District, Beijing 100191, PR China
| | - Chunli Song
- Department of Orthopedics, Peking University 3rd Hospital, Beijing Key Laboratory of Spinal Disease Research, No. 49 North Garden Rd., Haidian District, Beijing 100191, PR China.
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Soriano Sánchez JA, Soriano Solis S, Soto Garcia ME, Romero Rangel JAI. Scientific Contributions of the Mexican Association of Spine Surgeons (Asociación Mexicana de Cirujanos de Columna-AMCICO) to the Global Medical Literature: A 21-Year Systematic Review. World Neurosurg 2020; 138:e223-e240. [PMID: 32112941 DOI: 10.1016/j.wneu.2020.02.090] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 02/12/2020] [Accepted: 02/14/2020] [Indexed: 01/30/2023]
Abstract
BACKGROUND Contributions from Latin America to the global literature are scarce; until 2011, spine surgeons had published 320 articles in indexed journals. METHODS This systematic review evaluates the scientific production of the Mexican Association of Spine Surgeons (Asociación Mexicana de Cirujanos de Columna-AMCICO) from its inception in 1998 to 2018 with the PRISMA statement using PubMed and Google Scholar search engines. The inclusion criteria were spine-related articles in indexed journals providing any (or no) level of evidence with ≥1 AMCICO member as an author. Journal metrics, article metrics, and author variables were analyzed using SPSS version 25. RESULTS Of the 444 surgeons historically belonging to AMCICO, only 126 members contributed a total of 441 articles between 1998 and 2018. An average of 21.00 annual publications with an annual scientific output per capita of 0.05 was found. The most frequent evidence level was III (211 articles, 48%), the highest level was I (12 articles, 3%). The main study objective was clinical research, with 308 articles (70%), and the main study foci was trauma, with 103 articles (23%). An average impact factor of 0.16 and 0.92 was obtained for publications in Spanish and English, respectively. CONCLUSIONS Scientific publications by AMCICO members are scarce, with a per capita annual index of 0.05 from a total of 441 articles in indexed journals. Second, the impact factor of these journals is low, with a mean value of 0.53. Further strategies should be implemented to increase the number and track the record of Mexican contributions to the scientific literature.
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Affiliation(s)
- José Antonio Soriano Sánchez
- Mexican Association of Spine Surgeons (AMCICO), CDMX, Mexico; Mexican Society of Neurological Surgery (SMCN), CDMX, Mexico; American British Cowdray Medical Center I.A.P. Campus Santa Fe, CDMX, Mexico; Minimally Invasive Spine Surgery, National Autonomous University of Mexico (UNAM), CDMX, Mexico
| | - Sergio Soriano Solis
- Mexican Association of Spine Surgeons (AMCICO), CDMX, Mexico; American British Cowdray Medical Center I.A.P. Campus Santa Fe, CDMX, Mexico; Minimally Invasive Spine Surgery, National Autonomous University of Mexico (UNAM), CDMX, Mexico
| | - Manuel Eduardo Soto Garcia
- Mexican Association of Spine Surgeons (AMCICO), CDMX, Mexico; Mexican Society of Neurological Surgery (SMCN), CDMX, Mexico; American British Cowdray Medical Center I.A.P. Campus Santa Fe, CDMX, Mexico; Minimally Invasive Spine Surgery, National Autonomous University of Mexico (UNAM), CDMX, Mexico
| | - José Alberto Israel Romero Rangel
- Mexican Association of Spine Surgeons (AMCICO), CDMX, Mexico; Mexican Society of Neurological Surgery (SMCN), CDMX, Mexico; American British Cowdray Medical Center I.A.P. Campus Santa Fe, CDMX, Mexico; Minimally Invasive Spine Surgery, National Autonomous University of Mexico (UNAM), CDMX, Mexico; Regional General Hospital #25 of the National Institute of Social Security (IMSS), CDMX, Mexico.
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Stolworthy DK, Zirbel SA, Howell LL, Samuels M, Bowden AE. Characterization and prediction of rate-dependent flexibility in lumbar spine biomechanics at room and body temperature. Spine J 2014; 14:789-98. [PMID: 24290312 DOI: 10.1016/j.spinee.2013.08.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Revised: 06/08/2013] [Accepted: 08/23/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT The soft tissues of the spine exhibit sensitivity to strain-rate and temperature, yet current knowledge of spine biomechanics is derived from cadaveric testing conducted at room temperature at very slow, quasi-static rates. PURPOSE The primary objective of this study was to characterize the change in segmental flexibility of cadaveric lumbar spine segments with respect to multiple loading rates within the range of physiologic motion by using specimens at body or room temperature. The secondary objective was to develop a predictive model of spine flexibility across the voluntary range of loading rates. STUDY DESIGN This in vitro study examines rate- and temperature-dependent viscoelasticity of the human lumbar cadaveric spine. METHODS Repeated flexibility tests were performed on 21 lumbar function spinal units (FSUs) in flexion-extension with the use of 11 distinct voluntary loading rates at body or room temperature. Furthermore, six lumbar FSUs were loaded in axial rotation, flexion-extension, and lateral bending at both body and room temperature via a stepwise, quasi-static loading protocol. All FSUs were also loaded using a control loading test with a continuous-speed loading-rate of 1-deg/sec. The viscoelastic torque-rotation response for each spinal segment was recorded. A predictive model was developed to accurately estimate spine segment flexibility at any voluntary loading rate based on measured flexibility at a single loading rate. RESULTS Stepwise loading exhibited the greatest segmental range of motion (ROM) in all loading directions. As loading rate increased, segmental ROM decreased, whereas segmental stiffness and hysteresis both increased; however, the neutral zone remained constant. Continuous-speed tests showed that segmental stiffness and hysteresis are dependent variables to ROM at voluntary loading rates in flexion-extension. To predict the torque-rotation response at different loading rates, the model requires knowledge of the segmental flexibility at a single rate and specified temperature, and a scaling parameter. A Bland-Altman analysis showed high coefficients of determination for the predictive model. CONCLUSIONS The present work demonstrates significant changes in spine segment flexibility as a result of loading rate and testing temperature. Loading rate effects can be accounted for using the predictive model, which accurately estimated ROM, neutral zone, stiffness, and hysteresis within the range of voluntary motion.
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Affiliation(s)
- Dean K Stolworthy
- 435 CTB, Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Shannon A Zirbel
- 435 CTB, Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Larry L Howell
- 435 CTB, Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Marina Samuels
- 435 CTB, Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602, USA
| | - Anton E Bowden
- 435 CTB, Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602, USA.
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Oktenoglu T, Erbulut D, Kiapour A, Ozer A, Lazoglu I, Kaner T, Sasani M, Goel V. Pedicle screw-based posterior dynamic stabilisation of the lumbar spine:in vitrocadaver investigation and a finite element study. Comput Methods Biomech Biomed Engin 2014; 18:1252-1261. [DOI: 10.1080/10255842.2014.890187] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Dynamic stabilization for challenging lumbar degenerative diseases of the spine: a review of the literature. Adv Orthop 2013; 2013:753470. [PMID: 23662211 PMCID: PMC3639681 DOI: 10.1155/2013/753470] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Accepted: 03/07/2013] [Indexed: 12/14/2022] Open
Abstract
Fusion and rigid instrumentation have been currently the mainstay for the surgical treatment of degenerative diseases of the spine over the last 4 decades. In all over the world the common experience was formed about fusion surgery. Satisfactory results of lumbar spinal fusion appeared completely incompatible and unfavorable within years. Rigid spinal implants along with fusion cause increased stresses of the adjacent segments and have some important disadvantages such as donor site morbidity including pain, wound problems, infections because of longer operating time, pseudarthrosis, and fatigue failure of implants. Alternative spinal implants were developed with time on unsatisfactory outcomes of rigid internal fixation along with fusion. Motion preservation devices which include both anterior and posterior dynamic stabilization are designed and used especially in the last two decades. This paper evaluates the dynamic stabilization of the lumbar spine and talks about chronologically some novel dynamic stabilization devices and thier efficacies.
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Jahng TA, Kim YE, Moon KY. Comparison of the biomechanical effect of pedicle-based dynamic stabilization: a study using finite element analysis. Spine J 2013; 13:85-94. [PMID: 23266148 DOI: 10.1016/j.spinee.2012.11.014] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 03/23/2012] [Accepted: 11/08/2012] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Recently, nonfusion pedicle-based dynamic stabilization systems (PBDSs) have been developed and used in the management of degenerative lumbar spinal diseases. Still effects on spinal kinematics and clinical effects are controversial. Little biomechanical information exists for providing biomechanical characteristics of pedicle-based dynamic stabilization according to the PBDS design before clinical implementation. PURPOSE To investigate the effects of implanting PBDSs into the spinal functional unit and elucidate the differences in biomechanical characteristics according to different materials and design. STUDY DESIGN The biomechanical effects of implantation of PBDS were investigated using the nonlinear three-dimensional finite element model of L4-L5. METHODS An already validated three-dimensional, intact osteoligamentous L4-L5 finite element model was modified to incorporate the insertion of pedicle screws. The implanted models were constructed after modifying the intact model to simulate postoperative changes using four different fixation systems. Four models instrumented with PBDS (Dynesys, NFlex, and polyetheretherketone [PEEK]) and rigid fixation systems (conventional titanium rod) were developed for comparison. The instrumented models were compared with those of the intact and rigid fixation model. Range of motion (ROM) in three motion planes, center of rotation (COR), force on the facet joint, and von Mises stress distribution on the vertebral body and implants with flexion-extension were compared among the models. RESULTS Simulated results demonstrated that implanted segments with PBDSs have limited ROM when compared with the intact spine. Flexion motion was the most limited, and axial rotation was the least limited, after device implantation. Among the PBDS selected in this analysis, the NFlex system had the closest instantaneous COR compared with the intact model and a higher ROM compared with other PBDS. Contact force on the facet joint in extension increased with an increase of moment in Dynesys and NFlex; however, the rigid or PEEK rod fixation revealed no facet contact force. CONCLUSIONS Implanted segments with PBDSs have limited ROM when compared with the intact spine. Center of rotation and stress distribution differed according to the design and materials used. These biomechanical effects produced a nonphysiological stress on the functional spinal unit when they were implanted. The biomechanical effects of current PBDSs should be carefully considered before clinical implementation.
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Affiliation(s)
- Tae-Ahn Jahng
- Department of Neurosurgery, Seoul National University, 300 Gumi-dong, Bundang-gu, Seongnam-si, Gyeonggi-do 464-707, Korea
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Pedicle screw-based posterior dynamic stabilization: literature review. Adv Orthop 2012; 2012:424268. [PMID: 23227349 PMCID: PMC3514803 DOI: 10.1155/2012/424268] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 10/30/2012] [Indexed: 11/30/2022] Open
Abstract
Posterior dynamic stabilization (PDS) indicates motion preservation devices that are aimed for surgical treatment of activity related mechanical low back pain. A large number of such devices have been introduced during the last 2 decades, without biomechanical design rationale, or clinical evidence of efficacy to address back pain. Implant failure is the commonest complication, which has resulted in withdrawal of some of the PDS devices from the market. In this paper the authors presented the current understanding of clinical instability of lumbar motions segment, proposed a classification, and described the clinical experience of the pedicle screw-based posterior dynamic stabilization devices.
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Interpedicular travel in the evaluation of spinal implants: an application in posterior dynamic stabilization. Spine (Phila Pa 1976) 2012; 37:923-31. [PMID: 22024893 DOI: 10.1097/brs.0b013e31823a3b56] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN In vitro flexibility testing of the lumbar spine. OBJECTIVE The goal of this study was to evaluate a motion-preserving posterior dynamic stabilization (PDS) implant based on newly defined parameters describing interpedicular kinematics. SUMMARY OF BACKGROUND DATA PDS implants have been designed as either motion-preserving or adjunct-to-fusion devices to treat various degenerative spinal pathologies. The ambiguity of design and evaluation goals and the inability of traditional biomechanical parameters to appropriately describe the behavior of PDS devices in vitro have served as the impetus to develop kinematic parameters more specific to this class of device. METHODS Flexibility testing of 6 fresh-frozen human lumbar spines was conducted before and after destabilization of the index level (L4-L5). Testing under the same protocol was repeated after treatment at the index level with a 1-level PDS device, extension of the device to the adjacent inferior level (L5-S1), and treatment with a hybrid construct consisting of the PDS implant at L4-L5 and rigid fixation at L5-S1. The kinematic response was recorded using an optoelectric tracking system and reported in terms of intervertebral range of motion (ROM) and newly developed parameters describing interpedicular motion. RESULTS Based on ROM and interpedicular kinematics, the devices implanted at L4-L5 provide significant but not differing stabilization in flexion-extension with implantation after a significant destabilization procedure. Interpedicular kinematic results indicate that the 2-level construct contributes to significantly more motion at L5-S1 compared with rigid fixation. This result was not detected when evaluated by the ROM metric. CONCLUSION Those involved in the design and evaluation of PDS devices may benefit from evaluation of interpedicular kinematics. Evaluating intervertebral motion from the perspective of the pedicle screw allows for a direct and intuitive translation between in vitro test results and design parameters. Furthermore, these parameters may provide additional clinical insight into the biomechanics of the healthy and pathological spine. The study presented indicates that this approach may be more sensitive in detecting differences in implant motion between PDS devices.
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Dodgen E, Stratton E, Bowden A, Howell L. Spinal Implant Development, Modeling, and Testing to Achieve Customizable and Nonlinear Stiffness. J Med Device 2012. [DOI: 10.1115/1.4006543] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The spine naturally has a nonlinear force-deflection characteristic which facilitates passive stability, and thus there is a need for spinal implants that duplicate this behavior to provide stabilization when the spine loses stiffness through injury, degeneration, or surgery. Additionally, due to the complexity and variability in the mechanics of spinal dysfunction, implants could potentially benefit from incorporating a customizable stiffness into their design. This paper presents a spinal implant with contact-aided inserts that provide a customizable nonlinear stiffness. An analytical model was utilized to optimize the device design, and the model was then verified using a finite element model. Validation was performed on physical prototypes, first in isolation using a tensile tester and then using cadaveric testing on an in-house spine tester. Testing confirmed the performance of the implant and it was observed that the device increased mechanical stability to the spinal segment in flexion-extension and lateral-bending.
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Affiliation(s)
- Eric Dodgen
- Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602
| | - Eric Stratton
- Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602
| | - Anton Bowden
- Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602
| | - Larry Howell
- Department of Mechanical Engineering, Brigham Young University, Provo, UT 84602
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Sandu N, Schaller B, Arasho B, Orabi M. Wallis interspinous implantation to treat degenerative spinal disease: description of the method and case series. Expert Rev Neurother 2011; 11:799-807. [PMID: 21651328 DOI: 10.1586/ern.10.187] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The Wallis interspinous implant is most commonly used in the treatment of intervertebral disc herniation and for tears in the outer layer of the disc. The dynamic vertebral fixation concept was first initiated in 1984 with the goal of imitating the physiologic spinal kinetic. A total of 15 years later, a second generation of implant has been developed, termed the 'Wallis interspinous Implant', which aims to preserve the mobility of the operated spinal segment. To underline our own experience, a retrospective review of 15 patients that were treated with 'Wallis implantation' at our institution between January 2006 and March 2008. Our main inclusion criterion for Wallis implantation was low back pain because of degenerative lumbar spinal stenosis associated with segmental instability along with Modic changes 0-1 and with UCLA arthritic grade <II, while the main exclusion criteria were previous lumbar surgery, severe osteoporosis or degeneration UCLA grade >II in the adjacent two segments cephalad to implantation. The outcome was analyzed according to clinical and radiological parameters. One (n = 9), two (n = 4) and three levels (n = 2) were operated on using Wallis implantation, ranging from L2-L3 to L5-S1. We used implants of 8-14 mm in size. There was a reduction in low back pain (73 vs 43%) and gait disturbances (73 vs 14%) at the 3-month follow-up compared with preoperative values. In line with these results, the modified Japan Orthopedic Association Score (mJAOS) was increased from 12 preoperatively to 18 at 3 months and 20 at 12 months postoperatively. A reduction in low back pain could only be demonstrated for implants that were 10 mm in size or greater at 3 months and 12-15 months postoperatively. An improvement was seen in Modic grades after the operations as compared with those observed at preoperative MRI. The outcome in our patients was rated as good or excellent according to Odom's criteria in all cases, independent of the levels that were used. Wallis implantation is therefore a safe procedure with a good to excellent outcome in the short- and mid-term follow-up and can lead to disc rehydration, as confirmed by postoperative MRI. Principal postoperative (clinical) success is based on the correct implant size.
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Affiliation(s)
- Nora Sandu
- Department of Neurosurgery, Lariboisière University Hospital, Paris, France
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Strube P, Tohtz S, Hoff E, Gross C, Perka C, Putzier M. Dynamic stabilization adjacent to single-level fusion: part I. Biomechanical effects on lumbar spinal motion. 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 2010; 19:2171-80. [PMID: 20683625 DOI: 10.1007/s00586-010-1549-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 06/16/2010] [Accepted: 07/25/2010] [Indexed: 10/19/2022]
Abstract
Progression of superior adjacent segment degeneration (PASD) could possibly be avoided by dynamic stabilization of an initially degenerated adjacent segment (AS). The current study evaluates ex vivo the biomechanics of a circumferential fixation connected to posterior dynamic stabilization at the AS. 6 human cadaver spines (L2-S1) were stabilized stepwise through the following conditions for comparison: intact spine (ISP), single-level fixation L5-S1 (SLF), SLF + dynamic AS fixation L4-L5 (DFT), and two-level fixation L4-S1 (TLF). For each condition, the moments required to reach the range of motion (ROM) of the intact whole spine segment under ±10 Nm (WSP10) were compared for all major planes of motion within L2-S1. The ROM at segments L2/3, L3/4, and L4/5 when WSP10 was applied were also compared for each condition. The moments needed to maintain WSP10 increased with each stage of stabilization, from ISP to SLF to DFT to TLF (p < 0.001), in all planes of motion within L2-S1. The ROM increased in the same order at L3/4 (extension, flexion, and lateral bending) and L2/3 (all except right axial rotation, left lateral bending) during WSP10 application with 300 N axial preload (p < 0.005 in ANOVA). At L4/5, while applying WSP10, all planes of motion were affected by stepwise stabilization (p < 0.001): ROM increased from ISP to SLF and decreased from SLF to DFT to TLF (partially p < 0.05). The moments required to reach WSP10 increase dependent on the number of fixated levels and the fixation stiffness of the implants used. Additional fixation shifts motion to the superior segment, according to fixation stiffness. Therefore, dynamic instrumentation cannot be recommended if prevention of hyper-mobility in the adjacent levels is the main target.
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Affiliation(s)
- Patrick Strube
- Clinic for Orthopaedics, Center for Musculoskeletal Surgery, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
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Putzier M, Hoff E, Tohtz S, Gross C, Perka C, Strube P. Dynamic stabilization adjacent to single-level fusion: part II. No clinical benefit for asymptomatic, initially degenerated adjacent segments after 6 years follow-up. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2010; 19:2181-9. [PMID: 20632044 DOI: 10.1007/s00586-010-1517-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2010] [Revised: 06/16/2010] [Accepted: 07/01/2010] [Indexed: 12/17/2022]
Abstract
Progression of degeneration is often described in patients with initially degenerated segment adjacent to fusion (iASD) at the time of surgery. The aim of the present study was to compare dynamic fixation of a clinically asymptomatic iASD, with circumferential lumbar fusion alone. 60 patients with symptomatic degeneration of L5/S1 or L4/L5 (Modic ≥ 2°) and asymptomatic iASD (Modic = 1°, confirmed by discography) were divided into two groups. 30 patients were treated with circumferential single-level fusion (SLF). In dynamic fixation transition (DFT) patients, additional posterior dynamic fixation of iASD was performed. Preoperatively, at 12 months, and at a mean follow-up of 76.4 (60-91) months, radiological (MRI, X-ray) and clinical (ODI, VAS, satisfaction) evaluations assessed fusion, progression of adjacent segment degeneration (PASD), radiologically adverse events, functional outcome, and pain. At final follow-up, two non-fusions were observed in both groups. 6 SLF patients and 1 DFT patient presented a PASD. In two DFT patients, a PASD occurred in the segment superior to the dynamic fixation, and in one DFT patient, a fusion of the dynamically fixated segment was observed. 4 DFT patients presented radiological implant failure. While no differences in clinical scores were observed between groups, improvement from pre-operative conditions was significant (all p < 0.001). Clinical scores were equal in patients with PASD and/or radiologically adverse events. We do not recommend dynamically fixating the adjacent segment in patients with clinically asymptomatic iASD. The lower number of PASD with dynamic fixation was accompanied by a high number of implant failures and a shift of PASD to the superior segment.
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Affiliation(s)
- Michael Putzier
- Clinic for Orthopaedics, Center for Musculoskeletal Surgery, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
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