1
|
Vogt M, Mehren C, Hackenbroch C, Wilke HJ. Influence of cervical total disc replacement on motion in the target and adjacent segments. Spine J 2024; 24:1313-1322. [PMID: 38301903 DOI: 10.1016/j.spinee.2024.01.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 01/10/2024] [Accepted: 01/22/2024] [Indexed: 02/03/2024]
Abstract
BACKGROUND CONTEXT The motion limitation after cervical discectomy and fusion alters the spine´s kinematics. Unphysiological strains may be the result and possible explanation for adjacent segment degeneration. Alterations to cervical kinematics due to cervical total disc replacement (TDR), especially two-level, are still under investigated. PURPOSE To investigate cervical motion including coupled motions after one-level and two-level TDR in the treated and also the adjacent segments. STUDY DESIGN An in-vitro study using pure moment loading of human donor spines. METHODS Seven fresh frozen human cervical spine specimens (C4-T1, median age 46 with range 19-60 years, four female) were included in this study. Specimens were tested in the intact condition first, followed by one-level TDR at C5-6 which was subsequently extended one level further caudal (C5-7). Each specimen was quasistatically loaded with pure moments up to 1.5 Nm in flexion/extension (FE), lateral bending (LB), and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. During the tests three dimensional motion tracking was performed for each vertebral body individually. From that, the primary and coupled ROM of each spinal level during the third full cycle of motion were evaluated. Nonparametric statistical analysis was performed using a Friedman-test and post hoc correction with Dunn-Bonferroni-tests (p<.05). Ethics approval was obtained in advance. RESULTS In FE, one-level TDR (C5-6) moderately increased primary FE in all four segments, but only significantly at the cranial adjacent level C4-5. Additional TDR at C6-7 further increased the ROM at the target segment without much influence on the other levels. Increasing implant height at C6-7 partially counteracted the increased FE. Coupled motions were minimal in all test conditions at all levels. In LB, coupled AR was observed in all test conditions at all levels. One-level TDR decreased primary LB at the target segment C5-6 significantly, without much influence on the other levels. Extending TDR to C6-7 decreased ROM in the target segment but without gaining statistical significance. Increasing implant height at C6-7 further decreased primary LB at the target segment, still without significance. Notably, coupled AR was significantly decreased at the cranial adjacent segment C4-5 compared to the intact condition. In AR, coupled LB was observed in all test conditions at the levels C4-5, C5-6, and C6-7, while the transition level to the thoracic spine C7-T1 showed only little coupled LB. Both one-level and two-level TDR showed little influence on primary AR or coupled motions at any level. Only after increasing implant height at C6-7 was the motion of the caudally adjacent level C7-T1 significantly altered. CONCLUSION Evaluating primary FE, LB, and AR together with the associated coupled motions revealed widespread influence of cervical TDR not only on the motion of the treated level but also at the adjacent segments. The influence of two-level TDR is more widespread and involves more levels than one-level TDR. CLINICAL SIGNIFICANCE The prevention of unphysiological strains due to altered kinematics after cervical fusion, which could possibly explain adjacent segment degeneration, were a driving factor in the development of TDR. These experimental findings suggest cervical TDR influences the whole cervical spine, not only the treated segment. The effect becomes more extensive, involving more levels and motion directions, after two-level than after one-level TDR.
Collapse
Affiliation(s)
- Morten Vogt
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, University of Ulm, Helmholtzstr. 14, 89081 Ulm, Germany
| | - Christoph Mehren
- Spine Center, Schoen Clinic Munich-Harlaching, Harlachinger Str. 51, 81547 Munich, Germany; Academic Teaching Hospital of the Ludwig-Maximilians-University (LMU), Marchioninistr. 15, 81377 Munich, Germany; Academic Teaching Hospital of the Paracelsus Medical University (PMU), Strubergasse 21, 5020 Salzburg, Austria
| | - Carsten Hackenbroch
- Department of Diagnostic and Interventional Radiology and Neuroradiology, German Armed Forces Hospital of Ulm, Oberer Eselsberg 40, 89081 Ulm, Germany; Department of Diagnostic and Interventional Radiology, University Hospital Ulm, Albert-Einstein-Allee 23, 89081 Ulm, Germany
| | - Hans-Joachim Wilke
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, University of Ulm, Helmholtzstr. 14, 89081 Ulm, Germany.
| |
Collapse
|
2
|
Meng B, Zhao X, Wang XL, Wang J, Xu C, Lei W. Does the novel artificial cervical joint complex resolve the conflict between stability and mobility after anterior cervical surgery? a finite element study. Front Bioeng Biotechnol 2024; 12:1400614. [PMID: 38887613 PMCID: PMC11180832 DOI: 10.3389/fbioe.2024.1400614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 05/10/2024] [Indexed: 06/20/2024] Open
Abstract
Background and objective Our group has developed a novel artificial cervical joint complex (ACJC) as a motion preservation instrument for cervical corpectomy procedures. Through finite element analysis (FEA), this study aims to assess this prosthesis's mobility and stability in the context of physiological reconstruction of the cervical spine. Materials and methods A finite element (FE)model of the subaxial cervical spine (C3-C7) was established and validated. ACJC arthroplasty, anterior cervical corpectomy and fusion (ACCF), and two-level cervical disc arthroplasty (CDA) were performed at C4-C6. Range of motion (ROM), intervertebral disc pressure (IDP), facet joint stress (FJS), and maximum von Mises stress on the prosthesis and vertebrae during loading were compared. Results Compared to the intact model, the ROM in all three surgical groups demonstrated a decline, with the ACCF group exhibiting the most significant mobility loss, and the highest compensatory motion in adjacent segments. ACJC and artificial cervical disc prosthesis (ACDP) well-preserved cervical mobility. In the ACCF model, IDP and FJS in adjacent segments increased notably, whereas the index segments experienced the most significant FJS elevation in the CDA model. The ROM, IDP, and FJS in both index and adjacent segments of the ACJC model were intermediate between the other two. Stress distribution of ACCF instruments and ACJC prosthesis during the loading process was more dispersed, resulting in less impact on the adjacent vertebrae than in the CDA model. Conclusion The biomechanical properties of the novel ACJC were comparable to the ACCF in constructing postoperative stability and equally preserved physiological mobility of the cervical spine as CDA without much impact on adjacent segments and facet joints. Thus, the novel ACJC effectively balanced postoperative stability with cervical motion preservation.
Collapse
Affiliation(s)
- Bing Meng
- Department of Orthopedics, Xijing Hospital, The Air Force Medical University, Xi’an, Shaanxi Province, China
| | - Xiong Zhao
- Department of Orthopedics, Xijing Hospital, The Air Force Medical University, Xi’an, Shaanxi Province, China
| | - Xin-Li Wang
- Department of Orthopedics, Xijing Hospital, The Air Force Medical University, Xi’an, Shaanxi Province, China
| | - Jian Wang
- Department of Orthopedics, Affiliated Hospital of NCO School of Army Medical University, Shijiazhuang, Hebei Province, China
| | - Chao Xu
- Department of Knee Joint Surgery, Honghui Hospital, Xi’an Jiaotong University, Xi’an, Shaanxi, China
- Department of Health Statistics, Faculty of Preventive Medicine, the Air Force Military Medical University, Xi’an, Shaanxi, China
| | - Wei Lei
- Department of Orthopedics, Xijing Hospital, The Air Force Medical University, Xi’an, Shaanxi Province, China
| |
Collapse
|
3
|
Shahzad H, Alvarez PM, Pallumeera M, Bhatti N, Yu E, Phillips FM, Khan SN, Singh VK. Exploring the incidence and risk factors of reoperation for symptomatic adjacent segment disease following cervical decompression and fusion. NORTH AMERICAN SPINE SOCIETY JOURNAL 2024; 17:100305. [PMID: 38264153 PMCID: PMC10803933 DOI: 10.1016/j.xnsj.2023.100305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 11/15/2023] [Accepted: 12/17/2023] [Indexed: 01/25/2024]
Abstract
Background Patients with long-term follow-up after cervical decompression and fusion have often been noted to have development of adjacent segment degeneration with a smaller subset of these patients progressing to adjacent segment disease (ASD), which results in the development of new symptomatic radiculopathy or myelopathy referable to a site either directly above or below a prior fused segment. The cause of ASD is multifactorial often involving natural age-related progression of spondylosis, accelerated progression following cervical decompression and fusion, operative technique, and patient-related factors. The effect of age at the time of index cervical decompression and fusion on the need for reoperation for ASD is not fully understood. This study aims to establish underlying risk factors for the development of symptomatic cervical ASD following cervical decompression and fusion requiring reoperation in patients of various age groups. Methods A retrospective database review of patients aged 20 or greater with insurance claims of primary cervical decompression and fusion over the course of 11 years and 10 months (January 01, 2010-October 31, 2022) was conducted using an insurance claims database. The primary outcome was to evaluate the incidence of cervical ASD requiring reoperation amongst patients stratified by age at the time of their primary procedure. Secondary outcomes included an evaluation of various risk factors for ASD following cervical decompression and fusion including surgeon-controlled factors such as the number of levels fused and approach taken, patient cervical pathology including cervical disc disorder and cervical spondylosis, and underlying patient medical comorbidities including osteoporosis and vitamin D deficiency, and substance use. Results A total of 60,292 patient records were analyzed, where the overall reoperation incidence for symptomatic ASD was 6.57%, peaking at 8.12% among those aged 30 to 39 and decreasing with age. Regression analysis revealed ages lower than 50 years as more predictive for the development of symptomatic ASD requiring reoperation. Multivariate regression analysis identified predictive factors for reoperation, including age, Elixhauser Comorbidity Index (ECI), multiple-level surgery, cervical spondylosis, cervical disc disorder, osteoporosis, and vitamin D deficiency. Notably, these factors had a variable impact across various age groups, as revealed by subgroup analysis. Conclusions The incidence of reoperation secondary to symptomatic ASD is 6.57%, highest in those aged 30 to 39. The surgical approach had no significant impact on the need for reoperation, but multiple-level fusions posed a consistent risk in the development of symptomatic ASD requiring reoperation. Patient factors like degenerative disc disease, spondylosis, osteoporosis, and vitamin D deficiency were associated, urging further age-specific risk assessment and nonoperative intervention exploration.
Collapse
Affiliation(s)
- Hania Shahzad
- Department of Orthopedics, The Ohio State University, Wexner Medical Center, 241 W 11th Ave, Suite 6081, Columbus, OH 43201, USA
| | - Paul M. Alvarez
- Department of Orthopedics, The Ohio State University, Wexner Medical Center, 241 W 11th Ave, Suite 6081, Columbus, OH 43201, USA
| | | | - Nazihah Bhatti
- Department of Orthopedics, The Ohio State University, Wexner Medical Center, 241 W 11th Ave, Suite 6081, Columbus, OH 43201, USA
| | - Elizabeth Yu
- Department of Orthopedics, The Ohio State University, Wexner Medical Center, 241 W 11th Ave, Suite 6081, Columbus, OH 43201, USA
| | - Frank M. Phillips
- Department of Orthopedics, Rush University Medical Center, 1611 W Harrison St., Chicago, IL 60612, USA
| | - Safdar N. Khan
- Department of Orthopedics, The Ohio State University, Wexner Medical Center, 241 W 11th Ave, Suite 6081, Columbus, OH 43201, USA
| | - Varun K. Singh
- Department of Orthopedics, The Ohio State University, Wexner Medical Center, 241 W 11th Ave, Suite 6081, Columbus, OH 43201, USA
| |
Collapse
|
4
|
Vogt M, Zengerle L, Jonas R, Wilke HJ. The move-C cervical artificial disc can restore intact range of motion and 3-D kinematics. Spine J 2024; 24:340-351. [PMID: 37660895 DOI: 10.1016/j.spinee.2023.08.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 08/15/2023] [Accepted: 08/29/2023] [Indexed: 09/05/2023]
Abstract
BACKGROUND CONTEXT In contrast to cervical discectomy and fusion, total disc replacement (TDR) aims at preserving the motion at the treated vertebral level. Spinal motion is commonly evaluated with the range of motion (ROM). However, more qualitative information about cervical kinematics before and after TDR is still lacking. PURPOSE The aim of this in vitro study was to investigate the influence of cervical TDR on ROM, instantaneous centers of rotation (ICR) and three-dimensional helical axes. STUDY DESIGN An in vitro study with human spine specimens under pure moment loading was conducted to evaluate the kinematics of the intact cervical spine and compare it to cervical TDR. METHODS Six fresh frozen human cervical specimens (C4-5, median age 28 years, range 19-47 years, two female and four male) were biomechanically characterized in the intact state and after implantation of a cervical disc prosthesis (MOVE-C, NGMedical, Germany). To mimic in vivo conditions regarding temperature and humidity, water steam was used to create a warm and humid test environment with 37°C. Each specimen was quasistatically loaded with pure moments up to ±2.5 Nm in flexion/extension (FE), lateral bending (LB) and axial rotation (AR) in a universal spine tester for 3.5 cycles at 1 °/s. For each third cycle of motion the ROM was evaluated and an established method was used to determine the helical axis and COR and to project them into three planar X-rays. Statistical analysis was conducted using a Friedman-test and post hoc correction with Dunn-Bonferroni-tests (p<.05). RESULTS After TDR, total ROM was increased in FE from 19.1° to 20.1°, decreased in LB from 14.6° to 12.6° and decreased in AR from 17.7° to 15.5°. No statistical differences between the primary ROM in the intact condition and ROM after TDR were detected. Coupled rotation between LB and AR were also maintained. The position and orientation of the helical axes after cervical TDR was in good agreement with the results of the intact specimens in all three motion directions. The ICR in FE and AR before and after TDR closely matched, while in LB the ICR after TDR were more caudal. The intact in vitro kinematics we found also resembled in vivo results of healthy individuals. CONCLUSION The results of this in vitro study highlight the potential of artificial cervical disc implants to replicate the quantity as well as the quality of motion of the intact cervical spine. CLINICAL SIGNIFICANCE Physiological motion preservation was a driving factor in the development of cervical TDR. Our results demonstrate the potential of cervical TDR to replicate in vivo kinematics in all three motion directions.
Collapse
Affiliation(s)
- Morten Vogt
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, University of Ulm, Ulm, Germany
| | - Laura Zengerle
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, University of Ulm, Ulm, Germany
| | - René Jonas
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, University of Ulm, Ulm, Germany
| | - Hans-Joachim Wilke
- Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre Ulm, University of Ulm, Ulm, Germany.
| |
Collapse
|
5
|
Jiang W, Zhao F, Rahman WU, Dong T, Yang G. Comparison of the effects of different artificial discs on hybrid surgery: A finite element analysis. Proc Inst Mech Eng H 2024; 238:78-89. [PMID: 38102922 DOI: 10.1177/09544119231215721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
In recent years, artificial cervical discs have been used in intervertebral disc replacement surgery and hybrid surgery (HS). The advantages and disadvantages of different artificial cervical discs in artificial cervical disc replacement surgery have been compared. However, few scholars have studied the biomechanical effects of various artificial disc prostheses on the human cervical spine in HS which include the Anterior Cervical Discectomy and Fusion (ACDF) and Cervical Disc Arthroplasty (CDA). This study compared the biomechanical behavior of Mobi-C and Prestige LP in the operative and adjacent segments during two-level hybrid surgery. A three-dimensional finite element model of C2-C7 was first established and validated. Subsequently, clinical surgery was then simulated to establish a surgical model of anterior cervical fusion at the C4-C5 level. Mobi-C and Prestige-LP artificial disc prostheses were implanted at the C5-C6 level to create two hybrid models. All finite element models were fixed on the lower endplate of the C7 vertebra and subjected to a load of 73.6 N and different directions of 1 Nm torque on the odontoid process of the C2 vertebra to simulate human flexion, extension, lateral bending, and axial rotation. This paper compares the ROM, intervertebral pressure, and facet joint force after hybrid surgery with the intact model. The results show that compared with Prestige LP, Mobi-C can improve ROM of the replacement segment and compensate for the intervertebral pressure of the adjacent segment more effectively, but the facet joint pressure of the replacement segment may be higher.
Collapse
Affiliation(s)
- Wei Jiang
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| | - Fulin Zhao
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| | - Waseem Ur Rahman
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| | - Tianxiang Dong
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| | - Guanghui Yang
- School of Mechanical Engineering, Dalian University of Technology, Dalian, China
| |
Collapse
|
6
|
Nguyen AQ, Credille K, Saifi C. Short-term and Long-term Complications of Cervical Disc Arthroplasty. Clin Spine Surg 2023; 36:404-410. [PMID: 37752635 DOI: 10.1097/bsd.0000000000001541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 08/28/2023] [Indexed: 09/28/2023]
Abstract
STUDY DESIGN A narrative review. OBJECTIVE This review discusses the short and long-term complications associated with cervical disc arthroplasty (CDA). SUMMARY OF BACKGROUND DATA CDA is a safe and effective motion-sparing alternative to fusion for the treatment of cervical disc pathology in patients with cervical radiculopathy or myelopathy. Although CDA offers advantages over fusion within a narrower set of indications, it introduces new technical challenges and potential complications. METHODS A systematic search of several large databases, including Cochrane Central, PubMed, ClinicalTrials.gov, and the World Health Organization International Clinical Trials Registry, was conducted from January 2005 to August 2023 to identify published studies and clinical trials evaluating cervical disc replacement complications and outcomes. RESULTS Short-term complications are primarily related to surgical approach and include dysphagia reported as high as ~70%, laryngeal nerve injury ~0%-1.25%, Horner syndrome ~0.06%, hematoma ~0.01%, gross device extrusion ~0.3%, whereas long-term complications include adjacent segment disease reported at ~3.8%, osteolysis ~44%-64%, heterotopic ossification ~7.3%-69.2%, implant failure ~3.3%-3.7%, and implant wear, which varies depending on design. CONCLUSIONS Approaches for mitigating complications broadly include meticulous dissection, intraoperative techniques, and diligent postoperative follow-up. This review emphasizes the need for a comprehensive understanding and management of complications to enhance the safety, reproducibility, and success of CDA. As CDA continues to evolve, there remains a critical need for ongoing research to delve deeper into evaluating risk for complications and long-term patient outcomes.
Collapse
Affiliation(s)
- Austin Q Nguyen
- Department of Orthopedics and Sports Medicine, Houston Methodist Hospital, Houston, TX
| | | | | |
Collapse
|
7
|
Ratnasamy PP, Rudisill KE, Maloy GC, Grauer JN. Cervical Disc Arthroplasty Usage Has Leveled Out From 2010 to 2021. Spine (Phila Pa 1976) 2023; 48:E342-E348. [PMID: 36728785 PMCID: PMC10300227 DOI: 10.1097/brs.0000000000004560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 12/18/2022] [Indexed: 02/03/2023]
Abstract
STUDY DESIGN Descriptive epidemiologic study. OBJECTIVE To compare trends in utilization and predictive factors for single-level cervical disc arthroplasty (CDA) relative to anterior cervical discectomy and fusion (ACDF) over the years. BACKGROUND CDA is an alternative to ACDF for the treatment of cervical spine pathologies. With both procedures performed for similar indications, controversy on best practices exists. MATERIALS AND METHODS Patients who underwent single-level CDA or ACDF were identified in the 2010 through 2021 PearlDiver M151Ortho data set. The yearly number of CDAs performed and proportionality was assessed. Predictive patient factors for undergoing CDA as opposed to ACDF were determined. Kaplan Meyer survival analysis with an endpoint of cervical spine reoperation compared 5-year outcomes between CDA and ACDF. RESULTS From 2010 to 2021, 19,301 single-level CDAs and 181,476 single-level ACDFs were identified. The proportional utilization of CDA relative to ACDF increased from 4.00% in 2010 to 14.15% in 2018 ( P < 0.0001), after which there was a plateau between 2018 and 2021 where proportional utilization was 14.47% ( P = 0.4654). Multivariate analysis identified several predictors of undergoing CDA rather than ACDF, including: younger age [odds ratio (OR) per decade decrease: 1.72], having surgery performed in the Midwest, Northeast, or West (relative to South, OR: 1.16, 1.13, 2.26, respectively), having Commercial insurance (relative to Medicare, OR: 1.75), and having surgery performed by an orthopedic surgeon (relative to a neurological surgeon, OR: 1.54) ( P < 0.0001 for each). There was no statistically significant difference in 5-year survival to further cervical spine surgery between CDA and ACDF at 5 years (97.6% vs. 97.7%, P = 0.4249). CONCLUSIONS Although the use of CDA relative to ACDF rose from 2010 to 2018, its use has subsequently plateaued between 2018 and 2021 and remained a relatively low percentage of the single-level anterior cervical surgeries performed (14.47% in 2021). The causes for such changes in the trend are unclear.
Collapse
Affiliation(s)
- Philip P Ratnasamy
- Department of Orthopedics and Rehabilitation, Yale School of Medicine, New Haven, CT
| | | | | | | |
Collapse
|
8
|
Pouleau HB, De Witte O, Dhaene B, Jodaïtis A. Restore cervical sagittal alignment by cervical disc arthroplasty and systematic total bilateral uncuscectomy in severe spondylosis: A prospective study. BRAIN & SPINE 2023; 3:101765. [PMID: 38020991 PMCID: PMC10668056 DOI: 10.1016/j.bas.2023.101765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/27/2023] [Accepted: 06/11/2023] [Indexed: 12/01/2023]
Abstract
Introduction Severe spondylosis is common and represents contraindication to achieve cervical disc arthroplasty (CDA). Research question Is it possible to restore cervical sagittal alignment using an adequate prosthetic model and performing systematic bilateral total uncuscectomy (or uncinectomy), even in cases of severe spondylosis ? Material and methods We propose a prospective clinical and radiological study comparing the evolution of preoperative and postoperative cervical sagittal balance 1 year after the interposition of a prosthesis with mobile bearing and systematic total uncuscectomy. VAS for brachialgia and cervicalgia, NDI, Odom's criteria, C2-C7 Cobb angle, C2-C7 SVA, T1 slope, C2 slope, C1-C2 Cobb angle, and segmental Cobb angle were analyzed preoperatively and 1 year postoperatively. Results 73 patients for a total of 129 levels treated were analyzed. Patients showed significant improvements in VASb, VASc, NDI, and Odom's criteria one year after surgery without clinical differences in the severe spondylosis subgroup (41 patients for 77 levels treated). Our results showed an increase in the C2-C7 Cobb angle postoperatively and a better correlation between T1 slope and C2-C7 Cobb angle postoperatively than preoperatively. Postoperative radiological results were similar between the spondylosis and non-spondylosis subgroups. However preoperative C2-C7 Cobb angle and preoperative ROM were lower in the severe spondylosis subgroup. Discussion and conclusion This study showed the possibility of restoring cervical sagittal balance by performing cervical disc arthroplasty with systematic uncuscectomy, even in cases of severe spondylosis. Moreover, we propose a simplified mathematical formula to preoperatively evaluate the lack of angulation to restore sagittal cervical alignment.
Collapse
Affiliation(s)
- Henri-Benjamin Pouleau
- University Hospital Center Tivoli, La Louvière, Department of Neurosurgery, Belgium
- Academic Hospital Center Erasme, Bruxelles, Department of Neurosurgery, Belgium
| | - Olivier De Witte
- Academic Hospital Center Erasme, Bruxelles, Chief of Department of Neurosurgery, Belgium
| | - Benjamin Dhaene
- University Hospital Center Tivoli, La Louvière, Chief of Department of Radiology, Belgium
| | - Alexandre Jodaïtis
- University Hospital Center Tivoli, La Louvière, Chief of Department of Neurosurgery, Belgium
| |
Collapse
|
9
|
Godlewski B, Bebenek A, Dominiak M, Bochniak M, Cieslik P, Pawelczyk T. Adjacent segment mobility after ACDF considering fusion status at the implant insertion site. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2023; 32:1616-1623. [PMID: 36917300 DOI: 10.1007/s00586-023-07634-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/14/2023] [Accepted: 03/03/2023] [Indexed: 03/16/2023]
Abstract
PURPOSE This paper sets out to analyse mobility changes in segments adjacent to the operated segment. Additionally, it investigates the relationship between the degree of fusion in the operated disc space and mobility changes in the adjacent segments. METHODS In total, 170 disc spaces were operated on in 104 consecutive patients qualified for one- or two-level surgery. The degree of mobility of segments directly above and below the implant insertion site was calculated. Measurements were performed the day before the surgery and 12 months post-surgery. Functional (flexion and extension) radiographs of the cervical spine and CT scans obtained 12 months post-surgery were used to evaluate the fusion status. The results were subjected to statistical analysis. RESULTS Statistically significant increase in mobility was recorded for the segments situated immediately below the operative site, with a mean change in mobility of 1.7 mm. Complete fusion was demonstrated in 101 cases (71.1%), and partial fusion in 43 cases (29.9%). In the complete fusion subgroup, the ranges of both flexion and extension in the segments directly below the operative site were significantly greater than those in the partial fusion (pseudoarthrosis) subgroup. CONCLUSION The mobility of the adjacent segment below the implant insertion site was significantly increased at 12 months post-ACDF surgery. The range of this compensatory hypermobility was significantly greater in patients with complete fusion at the ACDF site than in cases of pseudoarthrosis. Implant subsidence was not associated with mobility changes in the segments directly above or directly below the site of ACDF surgery.
Collapse
Affiliation(s)
- Bartosz Godlewski
- Department of Orthopaedics and Traumatology, with Spinal Surgery Ward, Scanmed - St. Raphael Hospital in Cracow, ul. Adama Bochenka 12, 30-693, Cracow, Poland.
| | - Adam Bebenek
- Department of Orthopaedics and Traumatology, with Spinal Surgery Ward, Scanmed - St. Raphael Hospital in Cracow, ul. Adama Bochenka 12, 30-693, Cracow, Poland
| | - Maciej Dominiak
- Department of Orthopaedics and Traumatology, with Spinal Surgery Ward, Scanmed - St. Raphael Hospital in Cracow, ul. Adama Bochenka 12, 30-693, Cracow, Poland
| | - Marcin Bochniak
- Department of Orthopaedics and Traumatology, with Spinal Surgery Ward, Scanmed - St. Raphael Hospital in Cracow, ul. Adama Bochenka 12, 30-693, Cracow, Poland
| | - Piotr Cieslik
- Department of Orthopaedics and Traumatology, Military Institute of Medicine, Warsaw, Poland
| | - Tomasz Pawelczyk
- Department of Affective and Psychotic Disorders, Medical University of Lodz, Lodz, Poland
| |
Collapse
|
10
|
Pouleau HB, De Witte O, Jodaïtis A. Cervical disc arthroplasty with systematic total bilateral uncuscectomy - Adapted technique particularly in severe spondylosis: A prospective study. BRAIN & SPINE 2023; 3:101734. [PMID: 37383473 PMCID: PMC10293310 DOI: 10.1016/j.bas.2023.101734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/12/2023] [Accepted: 03/29/2023] [Indexed: 06/30/2023]
Abstract
Introduction Cervical disc arthroplasty (CDA) is mainly used in young patients with soft herniated discs and seems to have several advantages over anterior cervical discectomy and fusion (ACDF). Severe spondylosis is common and represents a contraindication for performing CDA. Research question Is it possible to expand the indications for the implantation of cervical prostheses by adapting the surgical technique, particularly for severe spondylosis, to benefit from the advantages of prostheses over ACDF ? Materials and methods We propose a prospective two-center study to compare the possible clinical benefit of the placement of a cervical prosthesis with systematic total bilateral uncuscectomy (or uncinectomy) compared to the classical technique of ACDF, particularly for severe spondylosis. Visual analog scales for brachialgia, cervicalgia, and neck disability index were measured before and one year after surgery. Odom's criteria were assessed one year after surgery. Results We compared 81 patients treated with CDA and systematic total bilateral uncuscectomy versus 42 patients treated with ACDF for symptomatic radicular or medullary compression. Patients treated with CDA and uncuscectomy showed greater improvements in VASb, VASc, NDI, and Odom's criteria than those treated with ACDF, with statistically significant results. Moreover, no difference was found between the severe spondylosis subgroup and the non-severe spondylosis subgroup treated with CDA and uncuscectomy. Discussion and conclusion This study assessed the value of systematic total bilateral uncuscectomy for cervical arthroplasty. Our prospective clinical results suggest a surgical technique to reduce cervical pain and improve function one year after surgery, even in cases of severe spondylosis.
Collapse
Affiliation(s)
- Henri-Benjamin Pouleau
- Department of Neurosurgery, University Hospital Center Tivoli, La Louvière, Belgium
- Department of Neurosurgery, Academic Hospital Center Erasme, Bruxelles, Belgium
| | - Olivier De Witte
- Department of Neurosurgery, Academic Hospital Center Erasme, Bruxelles, Belgium
| | - Alexandre Jodaïtis
- Department of Neurosurgery, University Hospital Center Tivoli, La Louvière, Belgium
| |
Collapse
|
11
|
Clohisy JCF, Abjornson C, Bauer TW, Baral E, Albert TJ. Delayed Failure of M6-C Cervical Disc Arthroplasty After Conversion of Adjacent Cervical Disc Arthroplasty to Fusion: A Case Report. JBJS Case Connect 2023; 13:01709767-202306000-00013. [PMID: 37071739 DOI: 10.2106/jbjs.cc.22.00788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
CASE We present a delayed failure of an M6-C cervical disc arthroplasty after conversion of a subjacent failed cervical disc arthroplasty to fusion. The annular component had failed, and the core had been ejected. Histology demonstrated a giant cell reaction to polyethylene debris, and tissue cultures were positive for Cutibacterium acnes. CONCLUSION This is the first report of M6-C failure after conversion of an adjacent arthroplasty to fusion. A growing number of reports surrounding the M6-C failure rate and mechanisms raise concern about the device's durability and underscore the importance of routine clinical and radiographic surveillance for these patients.
Collapse
Affiliation(s)
- John C F Clohisy
- Department of Orthopaedics, Hospital for Special Surgery, New York, New York
| | - Celeste Abjornson
- Integrated Spine Research Program, Hospital for Special Surgery, New York, New York
| | - Thomas W Bauer
- Department of Pathology and Laboratory Medicine, Hospital for Special Surgery, New York, New York
| | - Elexis Baral
- Department of Biomechanics, Hospital for Special Surgery, New York, New York
| | - Todd J Albert
- Department of Orthopaedics, Hospital for Special Surgery, New York, New York
| |
Collapse
|
12
|
Peng J, Li S, Lin X, Zhong D, Zheng R, Huang M, Li P, Song H, Asakawa T. Anterior cervical discectomy and fusion without plate (ACDFWP) versus anterior cervical disc arthroplasty (ACDA) for cervical spondylosis: A meta-analysis and literature review. Intractable Rare Dis Res 2022; 11:105-112. [PMID: 36200026 PMCID: PMC9437997 DOI: 10.5582/irdr.2022.01080] [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: 07/26/2022] [Revised: 08/09/2022] [Accepted: 08/10/2022] [Indexed: 11/05/2022] Open
Abstract
This meta-analysis compared the clinical outcomes between two alternative surgeries for patients with cervical spondylosis, namely anterior cervical discectomy and fusion (ACDF) without plate (ACDFWP) vs. anterior cervical disc arthroplasty (ACDA). We searched databases, including PubMed, EMBASE, Cochrane Library, Google Scholar, and Web of Science (firstly available-2019). A standard meta-analysis was performed with the included studies. A Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool was used for the evaluation of the study quality of nonrandomized-controlled trials (nRCTs), while a Risk of Bias (RoB) battery was used for randomized controlled trials (RCTs). Eight studies involving 640 patients were included. No significant difference was found in the indices of Neck Disability Index (NDI) score, Visual Analog Score (VAS), Japanese Orthopaedic Association (JOA) score, operative time, blood loss, Swallowing Quality of Life Score (SWAL-QL), and complications. Cervical alignment was significantly better in the ACDFWP than in ACDA (mean difference (MD) = -0.67, 95% confidence interval (CI) [-1.11, -0.23], P = 0.003, I 2 = 20%). Although the alternative ACDFWP was slightly superior in terms of the index of cervical alignment, the limited research on this subject present insufficient evidence. Further well-designed studies are warranted in the future.
Collapse
Affiliation(s)
- Jiajie Peng
- Department of Orthopedics, Zhongshan Jishuitan Orthopedic Hospital, Zhongshan, Guangdong, China
| | - Sihan Li
- School of Basic Medical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
- Department of Gastroenterology, The Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Xiangying Lin
- Department of Gastroenterology, The Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Degui Zhong
- Department of Orthopedics, Foshan Hospital of Traditional Chinese Medicine, Foshan, Guangdong, China
| | - Rong Zheng
- Department of Gastroenterology, The Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Minghan Huang
- Department of Gastroenterology, The Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Pengfei Li
- Department of Nephrology, The People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
| | - Hongmei Song
- Department of Gastroenterology, The Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian, China
- Address correspondence to:Hongmei Song, Division of Science and Education, The Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, No. 282 Wusibei Road, Fuzhou 353003, China. E-mail:
| | - Tetsuya Asakawa
- Institute of Neurology, The Third People's Hospital of Shenzhen, Shenzhen, Guangdong, China
- Address correspondence to:Hongmei Song, Division of Science and Education, The Second People's Hospital Affiliated to Fujian University of Traditional Chinese Medicine, No. 282 Wusibei Road, Fuzhou 353003, China. E-mail:
| |
Collapse
|
13
|
Wellington IJ, Kia C, Coskun E, Torre BB, Antonacci CL, Mancini MR, Connors JP, Esmende SM, Makanji HS. Cervical and Lumbar Disc Arthroplasty: A Review of Current Implant Design and Outcomes. Bioengineering (Basel) 2022; 9:bioengineering9050227. [PMID: 35621505 PMCID: PMC9137579 DOI: 10.3390/bioengineering9050227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 05/16/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
While spinal disc pathology has traditionally been treated using fusion-based procedures, recent interest in motion-preserving disc arthroplasties has grown. Traditional spinal fusion is associated with loss of motion, alteration of native spine kinematics, and increased risks of adjacent segment disease. The motion conferred by disc arthroplasty is believed to combat these complications. While the first implant designs resulted in poor patient outcomes, recent advances in implant design and technology have shown promising radiographic and clinical outcomes when compared with traditional fusion. These results have led to a rapid increase in the utilization of disc arthroplasty, with rates of cervical arthroplasty nearly tripling over the course of 7 years. The purpose of this review was to discuss the evolution of implant design, the current implant designs utilized, and their associated outcomes. Although disc arthroplasty shows significant promise in addressing some of the drawbacks associated with fusion, it is not without its own risks. Osteolysis, implant migration, and the development of heterotopic ossification have all been associated with disc arthroplasty. As interest in these procedures grows, so does the interest in developing improved implant designs aimed at decreasing these adverse outcomes. Though they are still relatively new, cervical and lumbar disc arthroplasty are likely to become foundational methodologies for the treatment of disc pathology.
Collapse
Affiliation(s)
- Ian J. Wellington
- Department of Orthopaedics, University of Connecticut, Farmington, CT 06032, USA; (I.J.W.); (E.C.); (B.B.T.); (C.L.A.); (M.R.M.); (J.P.C.)
| | - Cameron Kia
- Department of Orthopaedics, University of Connecticut, Farmington, CT 06032, USA; (I.J.W.); (E.C.); (B.B.T.); (C.L.A.); (M.R.M.); (J.P.C.)
- Correspondence:
| | - Ergin Coskun
- Department of Orthopaedics, University of Connecticut, Farmington, CT 06032, USA; (I.J.W.); (E.C.); (B.B.T.); (C.L.A.); (M.R.M.); (J.P.C.)
| | - Barrett B. Torre
- Department of Orthopaedics, University of Connecticut, Farmington, CT 06032, USA; (I.J.W.); (E.C.); (B.B.T.); (C.L.A.); (M.R.M.); (J.P.C.)
| | - Christopher L. Antonacci
- Department of Orthopaedics, University of Connecticut, Farmington, CT 06032, USA; (I.J.W.); (E.C.); (B.B.T.); (C.L.A.); (M.R.M.); (J.P.C.)
| | - Michael R. Mancini
- Department of Orthopaedics, University of Connecticut, Farmington, CT 06032, USA; (I.J.W.); (E.C.); (B.B.T.); (C.L.A.); (M.R.M.); (J.P.C.)
| | - John P. Connors
- Department of Orthopaedics, University of Connecticut, Farmington, CT 06032, USA; (I.J.W.); (E.C.); (B.B.T.); (C.L.A.); (M.R.M.); (J.P.C.)
| | - Sean M. Esmende
- Department of Orthopedics, Hartford Healthcare, Hartford, CT 06106, USA; (S.M.E.); (H.S.M.)
| | - Heeren S. Makanji
- Department of Orthopedics, Hartford Healthcare, Hartford, CT 06106, USA; (S.M.E.); (H.S.M.)
| |
Collapse
|
14
|
Cervical Disk Arthroplasty Is an Acceptable Treatment Option for Cervical Myelopathy. Clin Spine Surg 2022; 35:95-96. [PMID: 33105159 DOI: 10.1097/bsd.0000000000001103] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 09/30/2020] [Indexed: 11/26/2022]
|
15
|
Prod’homme M, Grasset D, Boscherini D. Posterior intraprosthetic dislocation of cervical arthroplasty: illustrative case. JOURNAL OF NEUROSURGERY: CASE LESSONS 2021; 2:CASE21500. [PMID: 36061081 PMCID: PMC9435578 DOI: 10.3171/case21500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/22/2021] [Indexed: 11/06/2022]
Abstract
BACKGROUND
Cervical disc herniation is a common condition usually treated with anterior cervical discectomy and fusion (ACDF) or, more recently, with cervical disc arthroplasty (CDA). Both treatments offer similar clinical results. However, CDA has been found to offer fewer medium- to long-term complications as well as potential reduction of long-term adjacent disc degeneration.
OBSERVATIONS
A 40-year-old man was treated with cervical discectomy and arthroplasty due to a C6–C7 disc herniation with left C7 radiculopathy. After the treatment, his postoperative follow-up appointments were uneventful for 9 months. However, after 9 months, he reported cervical pain and a right C7 radiculopathy after neck extension. Imaging confirmed a posterior intraprosthetic dislocation, the first case reported to date. The patient was received emergency surgery under neuromonitoring, and the prosthesis was replaced by an ACDF and anterior plate. The insert presented a rupture of the anterior horn. The patient presented no preoperative or postoperative neurological deficit, and his follow-up review revealed no issues.
LESSONS
Posterior intraprosthetic dislocation is an extremely rare complication. It may occur with Mobi-C cervical arthroplasty in the case of rupture and oxidation of the polyethylene insert. Spine surgeons should be aware of this potential major complication.
Collapse
Affiliation(s)
- Marc Prod’homme
- Neuro Orthopedic Center, Clinic La Source, Lausanne, VD, Switzerland
| | - Didier Grasset
- Neuro Orthopedic Center, Clinic La Source, Lausanne, VD, Switzerland
| | - Duccio Boscherini
- Neuro Orthopedic Center, Clinic La Source, Lausanne, VD, Switzerland
| |
Collapse
|
16
|
Wang H, Wang X, Liu H, Meng Y, Guo Y, Hong Y. Risk Factors for High-Grade Heterotopic Ossification After Total Disc Replacement: A Single-Center Experience of 394 Cases. Neurosurgery 2021; 89:852-861. [PMID: 34382657 DOI: 10.1093/neuros/nyab298] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 06/09/2021] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Heterotopic ossification (HO) is a common complication following total disc replacement (TDR). High-grade HO is a clinically relevant complication, however, only a few studies have evaluated risk factors for high-grade HO. OBJECTIVE To evaluate potential risk factors for HO and high-grade HO and their impact on clinical outcomes. METHODS We retrospectively reviewed patients who underwent TDR or hybrid surgery (HS) with Prestige-LP (Medtronic), Discover (Depuy), and Prodisc-C (Synthes). Clinical outcomes were assessed using Japanese Orthopaedic Association, Visual Analogue Scale, and Neck Disability Index scores. Radiological variables, including preoperative ossification, global and segmental range of motion (ROM), HO, and adjacent segment degeneration (ASD) were reviewed. RESULTS A total of 394 patients were evaluated. HO and high-grade HO occurred in 67.77% and 11.17% patients, respectively. Preoperative ossification was significantly associated with the occurrence of HO (P < .001, OR: 3.507, 95%CI: 2.211-5.562) and high-grade HO (P = .019, OR: 2.176, 95%CI: 1.137-4.166). The ROM of replacement levels and C2-7 were significantly lower in the high-grade HO group compared to those without high-grade HO: (3.80° vs 10.18°, P < .001) and (42.81° vs 54.00°, P < .001), respectively. The incidence of ASD was significantly higher in patients with high-grade HO than those without high-grade HO (22.73% vs 11.14%, P = .048). CONCLUSION Preoperative ossification was identified as a potential risk factor for HO and high-grade HO. Patients with high-grade HO had limited ROM of replacement levels and the cervical spine and had a high incidence of ASD compared to those without high-grade HO.
Collapse
Affiliation(s)
- Han Wang
- Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Xiaofei Wang
- Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Hao Liu
- Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Yang Meng
- Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Yingjun Guo
- Department of Orthopaedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Ying Hong
- Department of Anesthesia and Operation Center, West China Hospital, Sichuan University, Chengdu, China.,West China School of Nursing, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
17
|
Virk S, Phillips F, Khan S, Qureshi S. A cross-sectional analysis of 1347 complications for cervical disc replacements from medical device reports maintained by the United States Food and Drug Administration. Spine J 2021; 21:265-272. [PMID: 32966907 DOI: 10.1016/j.spinee.2020.09.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Accepted: 09/14/2020] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Cervical disc replacement (CDR) has increased in popularity over the past decade based on published outcomes from FDA IDE studies with narrowly defined inclusion and exclusion criteria. A low rate of complications was noted in these studies. The broader complication profile for CDR in widespread clinical practice has yet to be described. PURPOSE To outline the complications reported to the FDA regarding commonly used CDR products STUDY DESIGN/SETTING: Retrospective database review PATIENT SAMPLE: Nationwide database of reported complications related to CDR products from patients across the country OUTCOME MEASURES: Complications related to CDR METHODS: We queried the MAUDE database and Alternative Summary Reporting (ASR) data files submitted between January 2005 to March 2020. The complications listed for seven FDA-approved CDR implants were analyzed. The entries in the databases were cataloged for complication type, date of entry, source of report, and whether the investigation was "complete". Reports that had too little information to extract relevant data were excluded. RESULTS There were 1,517 entries identified in the MAUDE database. After removal of duplicate entries and entries without sufficient information, there were 1,347 entries analyzed. The top five complications were (1) migration of implant (338 entries, 25.2%) (2) insertion problem/failure (312 entries, 23.3%) (3) neck pain (203 entries, 15.2%) (4) heterotopic ossification (108 entries, 8.1%) and (5) radiculopathy (90 entries, 8.1%). The number of analyzed implant-related MAUDE entries and most common implant-related complication for each implant was 209 entries for insertion problem/failure for Mobi-C; 158 entries for migration of implant for ProDisc-C; 154 entries for insertion problem/failure for Bryan cervical disc; 130 entries for migration of implant for Prestige cervical disc; 49 entries for migration of implant for PCM cervical disc; 12 entries for migration of implant for M6 and 10 entries for migration of implant for Secure-C. Only 263 entries (19.5%) were deemed "complete". Most entries were from the manufacturer/company representative/distributor (923 entries, 70%). There were no entries related to cervical disc replacement devices within the ASR data. CONCLUSIONS The MAUDE database highlights complications related to CDR implants that may not be emphasized in currently published studies. It is important to understand this broad complication profile for CDR to ensure safe utilization of this new technology.
Collapse
Affiliation(s)
- Sohrab Virk
- Hospital for Special Surgery, Department of Orthopedic Surgery, New York, NY, USA; Northwell Health, Department of Orthopedic Surgery, Great Neck, NY.
| | - Frank Phillips
- Department of Orthopedic Surgery, Rush University, Chicago, IL, USA
| | - Safdar Khan
- Department of Orthopedic Surgery, Ohio State University, Columbus, OH, USA
| | - Sheeraz Qureshi
- Hospital for Special Surgery, Department of Orthopedic Surgery, New York, NY, USA
| |
Collapse
|
18
|
Is There a Relationship Between Bony Fusion After Anterior Cervical Discectomy and Fusion and Heterotopic Ossification After Cervical Disc Arthroplasty in Hybrid Surgery? Spine (Phila Pa 1976) 2020; 45:E1653-E1660. [PMID: 32925690 DOI: 10.1097/brs.0000000000003687] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective analysis. OBJECTIVE The aim of this study was to investigate the relationship between bony fusion after anterior cervical discectomy and fusion (ACDF) and heterotopic ossification (HO) after cervical disc arthroplasty (CDA) in hybrid surgery (HS). SUMMARY OF BACKGROUND DATA The mechanism of postoperative bone formation still remains unknown. It is considered a risk factor in CDA but is essential for a solid union in ACDF. With HS, we could directly study the mechanism and relationship of different forms of postoperative bone formation. METHODS Clinical data of 91 patients who had undergone consecutive two-level HS between January 2011 and January 2018 and with a minimum of 2-year follow-up was analyzed. HO was assessed based on McAfee's classifications, whereas fusion success was evaluated according the Food and Drug Administration approved criteria. Clinical outcomes and radiographic parameters were collected and used for the relevant comparisons. RESULTS HO was identified in 48.4% of patients (44/91). The fusion rates of patients in the HO group and the non-HO group at 3, 6, and 12 months postoperatively, and the final follow-up were 81.8% and 19.1%, 95.4% and 74.5%, 95.4% and 85.1%, and 97.7% and 93.6%, respectively. The fusion rates were significantly higher at 3 and 6 months after operation in the HO group than in the non-HO group (P < 0.05). Patients in both groups had significant improvements across all clinical outcomes at final follow-up. CONCLUSION There was a significant relationship between bony fusion and occurrence of HO after HS, suggesting that both bony fusion and HO are reflections of individual osteogenic capacity. However, a reliable predictor of postoperative bone formation is needed in the future to guarantee a solid bony fusion after ACDF and to further take full advantage of the motion-preserving from CDA. LEVEL OF EVIDENCE 3.
Collapse
|
19
|
Functional Outcomes Associated With Adjacent-level Ossification Disease 10 Years After Cervical Disc Arthroplasty or ACDF. Clin Spine Surg 2020; 33:E420-E425. [PMID: 32149745 DOI: 10.1097/bsd.0000000000000954] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
STUDY DESIGN A retrospective review of a prospective, randomized control Food and Drug Administration (FDA) investigational device exemption trial comparing anterior cervical discectomy and fusion (ACDF) with Bryan cervical disc arthroplasty. OBJECTIVE Determine the clinical significance of adjacent-level ossification disease (ALOD) on long-term functional outcomes after ACDF or arthroplasty. SUMMARY OF BACKGROUND DATA ALOD occurs when the anterior longitudinal ligament and annulus adjacent to the index surgical level calcifies. As previously reported, ALOD happens more commonly after an arthrodesis than an arthroplasty. No investigation has previously examined 10-year clinical outcomes associated with ALOD. MATERIALS AND METHODS Forty patients were included in the 10-year follow-up. The index level was radiographically blinded and the cephalad-adjacent level was evaluated for ALOD. These scores underwent statistical analysis to compare the 2 surgical groups (ACDF and arthroplasty) for differences in the development of ALOD at a decade follow-up. Two investigational groups, on the basis of a high or low ALOD score, then proceeded through statistical analysis to compare the functional outcomes of patients in each group. RESULTS Statistical evaluation of ALOD findings in patients from each surgical group found a significantly higher rate of high-grade ALOD in patients who underwent cervical arthrodesis with plate fixation compared with cervical arthroplasty (68.2% vs. 11.1%, P=0.0003). Functional outcomes of patients were also assessed at the 10-year mark and outcomes in patients with either high-grade or low-grade ALOD were compared. When stratified by high versus low-grade ALOD, no significant difference was found for Neck Disability Index (NDI) (P=0.6431), VAS-arm (P=0.4497), or VAS-neck (P=0.8700) scores between groups. CONCLUSIONS The present study suggests that there are no significant long-term functional outcome differences between patients with and without significant ALOD. Our findings suggest ALOD may be a radiographic finding that does not alter patient-reported outcomes. LEVEL OF EVIDENCE Level III-therapeutic.
Collapse
|
20
|
Kienle A, Graf N, Krais C, Wilke HJ. The MOVE-C Cervical Artificial Disc - Design, Materials, Mechanical Safety. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2020; 13:315-324. [PMID: 33061680 PMCID: PMC7524193 DOI: 10.2147/mder.s270789] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 08/25/2020] [Indexed: 12/16/2022] Open
Abstract
Purpose There are various cervical disc prostheses on the market today. They can be subdivided into implants with a ball-and-socket design and implants with a flexible core, which is captured between the implant endplates and sealed using various sheaths. Implants with an articulating surface are mostly metal-on-metal or metal-on-UHMWPE designs and, thus, do not allow for axial damping. The aim of this study is to provide mechanical safety and performance data of the MOVE-C cervical disc prosthesis which combines both an articulating surface and a flexible core. Materials and Methods MOVE-C consists of a cranial and caudal metal plate made of TiAl6V4. The cranial plate is TiNbN coated on its articulating surface. The caudal plate has a fixed polycarbonate-urethane (PCU) core. The TiNbN coating is meant to optimize the wear behavior of the titanium endplate, whereas the PCU core is meant to allow for a reversible axial deformation, a pre-defined neutral zone and a progressive load-deformation curve in all planes. Results Various standard testing procedures (for example, ISO 18192–1 and ASTM F2364) and non-standard mechanical tests were carried out to prove the implant’s mechanical safety. Due to the new implant design, wear and creep testing was deemed most important. The wear rate for the PCU was in maximum 1.54 mg per million cycles. This value was within the range of the UHMWPE wear rates reported for other cervical disc prostheses (0.53 to 2.59 mg/million cycles). Also in the creep-relaxation test, a qualitatively physiological behavior was shown with a certain amount of remaining deformation but no failure. Conclusion The mechanical safety of the MOVE-C cervical disc prosthesis was shown to be comparable to other cervical disc prostheses. Since PCU wear particles were elsewhere shown to be less bioactive than cross-linked UHMWPE particles, wear-related failure in vivo may be less frequent compared to other prostheses. This, however, will have to be shown in further studies.
Collapse
Affiliation(s)
| | | | | | - Hans-Joachim Wilke
- Institute of Orthopaedic Research and Biomechanics, Ulm University Medical Centre, Ulm 89081, Germany
| |
Collapse
|
21
|
He J, Ding C, Liu H, Wu T, Huang K, Hong Y, Meng Y, Wang B. Does Fusion Affect Anterior Bone Loss in Adjacent Cervical Disc Arthroplasty in Contiguous Two-Level Hybrid Surgery? World Neurosurg 2020; 143:e127-e135. [PMID: 32688043 DOI: 10.1016/j.wneu.2020.07.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/06/2020] [Accepted: 07/09/2020] [Indexed: 02/08/2023]
Abstract
OBJECTIVE To investigate whether anterior bone loss (ABL) in cervical discarthroplasty (CDA) in 2-level hybrid surgery (HS) is affected by adjacent fusion in vivo compared with 1-level CDA alone. METHODS A total of 180 patients undergoing either a 1-level CDA or contiguous 2-level HS were retrospectively reviewed. The clinical and radiographic outcomes were collected preoperatively and at routine postoperative intervals of 1 week, 3, 6, and 12 months, and at the last follow-up. The initial and postoperative radiographs were compared to determine the incidence and degree of ABL. RESULTS ABL was identified in 68.7% of CDA cases (37.9% mild, 34.8% moderate, and 27.3% severe) and 44.0% of HS cases (54.1% mild, 27.0% moderate, and 18.9% severe). Sex, age, bone mineral density, operation time, blood loss, postoperative alignment, and range of movement at the arthroplasty segment were not related to the incidence of ABL. According to the logistic regression analysis results, ABL showed a significant correlation with the surgery type and body mass index. However, there was no significant difference in the incidence and degree of ABL with or without an adjacent fusion level. Compared with preoperative values, clinical outcome scores significantly improved after surgery in both the HS and CDA groups. No definite clinical effect associated with ABL was found. CONCLUSIONS ABL was common in both CDA and HS. Although HS had a lower incidence rate and degree than did CDA, the fusion location in HS did not affect the ABL of adjacent CDA.
Collapse
Affiliation(s)
- Junbo He
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Chen Ding
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Hao Liu
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Tingkui Wu
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Kangkang Huang
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Ying Hong
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Yang Meng
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Beiyu Wang
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, China.
| |
Collapse
|
22
|
Hui N, Phan K, Cheng HMK, Lin YH, Mobbs RJ. Complications of cervical total disc replacement and their associations with heterotopic ossification: a systematic review and meta-analysis. 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 2020; 29:2688-2700. [DOI: 10.1007/s00586-020-06400-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 03/14/2020] [Accepted: 03/27/2020] [Indexed: 12/23/2022]
|
23
|
Harris L, Dyson E, Elliot M, Peterson D, Ulbricht C, Casey A. Delayed periprosthetic collection after cervical disc arthroplasty. J Neurosurg Spine 2019; 32:584-591. [PMID: 31835247 DOI: 10.3171/2019.9.spine19900] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 09/30/2019] [Indexed: 12/12/2022]
Abstract
Cervical disc arthroplasty is a treatment option for symptomatic cervical disc disease. There is a paucity of literature on long-term safety outcomes, durability, and device-related failure rates. The M6-C artificial cervical disc is a device with titanium alloy endplates and a complex polymeric centerpiece. To date, trials have exhibited acceptable safety profiles.This case series describes the presentation, management, and pathological findings of a delayed prevertebral periprosthetic mass anterior to the M6-C disc. Four patients at 3 different institutions underwent cervical disc replacement with the M6-C disc. Two to seven years postoperatively, they presented with dysphagia secondary to a compressive mass anterior to the disc. Case notes were reviewed to collect data on symptoms, management, and outcomes. The patients were systemically well and presented with progressive dysphagia. They had imaging findings of a mass anterior to the disc. They underwent a decompressive procedure, with 2 patients undergoing device removal and fusion. In 2 cases, a soft-tissue mass was seen intraoperatively, with frank pus. In 3 cases, Propionibacterium acnes was identified and antibiotic treatment given. Histopathology demonstrated mixed inflammatory infiltrates with foreign body-type granulomas. Postoperatively, the dysphagia resolved.The development of delayed dysphagia in a patient with an M6-C disc should prompt investigation to identify a mass lesion. To the authors' knowledge, this is the first report of delayed infection, or suspected delayed-type hypersensitivity reaction, following M6-C disc implantation. It is important for this to be added to the device safety concerns. Further prospective studies are needed to establish the incidence and the long-term safety and failure rates of the M6-C disc.
Collapse
Affiliation(s)
- Lauren Harris
- 1Department of Neurosurgery, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, United Kingdom; and
| | - Edward Dyson
- 1Department of Neurosurgery, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, United Kingdom; and
| | - Matthew Elliot
- 1Department of Neurosurgery, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, United Kingdom; and
| | - David Peterson
- 1Department of Neurosurgery, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, United Kingdom; and
| | - Christian Ulbricht
- 1Department of Neurosurgery, Imperial College Healthcare NHS Trust, Charing Cross Hospital, London, United Kingdom; and
| | - Adrian Casey
- 2Department of Neurosurgery, The National Hospital for Neurology and Neurosurgery, Queen Square, London, United Kingdom
| |
Collapse
|
24
|
Abstract
Anterior cervical disc replacement (arthroplasty) has gained momentum over the past 2 decades. The ball-and-socket prosthesis design of arthroplasty has been shown to simulate normal motion in all 3 rotation planes at the level of surgery and replicates physiologic motion. Anterior cervical discectomy and fusion has been shown to be a safe and effective surgery over decades; cervical disc replacement counters some secondary effects owing to its preservation of segmental mobility, the potential to reduce adjacent segment degeneration, and the lack of plating or harvesting bone graft. The literature is growing in support of the success and longevity of arthroplasty.
Collapse
|
25
|
Yang X, Donk R, Arts MP, Arnts H, Walraevens J, Zhai Z, Depreitere B, Bartels RHMA, Vleggeert-Lankamp CLA. Maintaining range of motion after cervical discectomy does not prevent adjacent segment degeneration. Spine J 2019; 19:1816-1823. [PMID: 31326630 DOI: 10.1016/j.spinee.2019.07.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 07/16/2019] [Accepted: 07/17/2019] [Indexed: 02/03/2023]
Abstract
BACKGROUND Motion preservation prostheses were introduced to prevent adjacent disc degeneration (ASD) and to diminish neck disability in the postsurgical follow-up. However, it is still a controversial issue, and the relationship between range of motion (ROM) and ASD has not been studied. PURPOSE To compare the correlation between ROM of the cervical spine and the presence of radiological ASD after anterior discectomy. Clinical outcome was also correlated to ROM and ASD. STUDY DESIGN Retrospective cohort study. METHODS In all, 253 patients who underwent anterior discectomy for cervical radiculopathy due to a herniated disc were analyzed for segmental and global cervical ROM and the presence of ASD both preoperatively, and 12 and 24 months postoperatively. Patients who were included in two randomized, double-blinded trials comparing anterior cervical discectomy with arthroplasty, anterior cervical discectomy with intervertebral cage, or anterior cervical discectomy without intervertebral cage for one level disc herniation were analyzed. ROM was defined by a custom-developed image analysis tool. ASD was defined by decrease in disc height and anterior osteophyte formation on X-rays. Clinical outcome was evaluated by means of the Neck Disability Index (NDI). RESULTS Two years postoperatively, no correlation was demonstrated between ROM and ASD. The incidence of ASD was comparable in the three groups, being 34% at baseline, and 58% at 2-year follow-up. Likewise, ASD progression was comparable in the three treatment arms. No correlation was demonstrated between ROM and NDI or ASD and NDI. CONCLUSIONS Since ROM is not correlated to ASD, and clinical outcome is not correlated to ROM either, the relevance of continued ROM at the target level seems absent.
Collapse
Affiliation(s)
- Xiaoyu Yang
- Department of Neurosurgery, Leiden University Medical Centre, Leiden, the Netherlands.
| | - Roland Donk
- Department of Orthopaedic Surgery, Via Sana Clinics, Mill, the Netherlands
| | - Mark P Arts
- Department of Neurosurgery, Haaglanden Medical Centre, the Hague, the Netherlands
| | - Hisse Arnts
- Department of Neurosurgery, Academic Medical Centre, Amsterdam, the Netherlands
| | - Joris Walraevens
- Division of Biomechanics and Engineering Design, KU Leuven, Heverlee, Belgium
| | - Zhiwei Zhai
- Division of Image processing, Department of Radiology, Leiden University Medical Centre, Leiden, the Netherlands
| | - Bart Depreitere
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium
| | - Ronald H M A Bartels
- Department of Neurosurgery, Radboud University Medical Centre, Nijmegen, the Netherlands
| | | |
Collapse
|
26
|
Samuel AM, Moore HG, Vaishnav AS, McAnany S, Albert T, Iyer S, Katsuura Y, Gang CH, Qureshi SA. Effect of Myelopathy on Early Clinical Improvement After Cervical Disc Replacement: A Study of a Local Patient Cohort and a Large National Cohort. Neurospine 2019; 16:563-573. [PMID: 31607089 PMCID: PMC6790731 DOI: 10.14245/ns.1938220.110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/15/2019] [Indexed: 11/22/2022] Open
Abstract
Objective Cervical disc replacement (CDR) is an effective long-term treatment for both cervical radiculopathy and myelopathy. However, there may be unique differences in the early postoperative clinical improvement for patients with and without myelopathy. In addition, previous studies using CDR to treat cervical myelopathy were underpowered to determine risk factors for relatively postoperative medical complications.
Methods Two different cohorts were studied. A local cohort of patients undergoing CDR by a single surgeon was utilized to study the early postoperative course of clinical improvement. In addition, a national cohort of patients undergoing CDR in the 2015 and 2016 National Surgical Quality Improvement Program database was utilized to study differences in postoperative medical complications after CDR. Patients with a preoperative diagnosis of cervical myelopathy were identified in both cohorts, and perioperative outcomes and complications were compared to patients without myelopathy.
Results A total of 43 patients undergoing CDR were included in the institutional cohort, of those 16 patients (37% of cohort) had a preoperative diagnosis of cervical myelopathy. A total of 3,023 patients undergoing CDR were included in the national cohort, of those 411 (13% of cohort) had a preoperative diagnosis of cervical myelopathy. In the institutional cohort, the nonmyelopathy group had a lower initial Neck Disability Index (NDI) and saw a faster improvement in NDI by 2 weeks postoperative. However, at 24 weeks there was no significant difference between groups in terms of NDI. Interestingly, only the nonmyelopathy cohort had a significant improvement in modified Japanese Orthopaedic Association score by 6 weeks (p<0.05). In the national cohort, myelopathy was associated with longer operative time and length of stay (p<0.05). However, there was no significant difference in perioperative complications (p>0.05) between myelopathy and nonmyelopathy patients.
Conclusion Significant improvements in NDI, visual analogue scale (VAS)-arm pain, and VAS-neck pain are seen in both myelopathy and nonmyelopathy populations undergoing CDR by 6 weeks postoperatively. However, nonmyelopathy populations improve faster by 2 weeks postoperatively. In the national cohort analysis, medical complications were similarly low in both myelopathy and nonmyelopathy groups.
Collapse
Affiliation(s)
| | | | | | - Steven McAnany
- Hospital for Special Surgery, New York, NY, USA.,Weill Cornell Medical College, New York, NY, USA
| | - Todd Albert
- Hospital for Special Surgery, New York, NY, USA.,Weill Cornell Medical College, New York, NY, USA
| | - Sravisht Iyer
- Hospital for Special Surgery, New York, NY, USA.,Weill Cornell Medical College, New York, NY, USA
| | - Yoshihiro Katsuura
- Hospital for Special Surgery, New York, NY, USA.,Weill Cornell Medical College, New York, NY, USA
| | | | - Sheeraz A Qureshi
- Hospital for Special Surgery, New York, NY, USA.,Weill Cornell Medical College, New York, NY, USA
| |
Collapse
|
27
|
Wilson JRF, Badhiwala JH, Moghaddamjou A, Martin AR, Fehlings MG. Degenerative Cervical Myelopathy; A Review of the Latest Advances and Future Directions in Management. Neurospine 2019; 16:494-505. [PMID: 31476852 PMCID: PMC6790745 DOI: 10.14245/ns.1938314.157] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 08/26/2019] [Indexed: 01/23/2023] Open
Abstract
The assessment, diagnosis, operative and nonoperative management of degenerative cervical myelopathy (DCM) have evolved rapidly over the last 20 years. A clearer understanding of the pathobiology of DCM has led to attempts to develop objective measurements of the severity of myelopathy, including technology such as multiparametric magnetic resonance imaging, biomarkers, and ancillary clinical testing. New pharmacological treatments have the potential to alter the course of surgical outcomes, and greater innovation in surgical techniques have made surgery safer, more effective and less invasive. Future developments for the treatment of DCM will seek to improve the diagnostic accuracy of imaging, improve the objectivity of clinical assessment, and increase the use of surgical technology to ensure the best outcome is achieved for each individual patient.
Collapse
Affiliation(s)
- Jamie R F Wilson
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Jetan H Badhiwala
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Ali Moghaddamjou
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Allan R Martin
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| | - Michael G Fehlings
- Division of Neurosurgery, Department of Surgery, University of Toronto, Toronto, ON, Canada.,Spinal Program, Toronto Western Hospital, University Health Network, Toronto, ON, Canada
| |
Collapse
|