1
|
Zheng B, Xu S, Lu T, Wu Y, Li H, Guo C, Haiying L. Sagittal sequence and clinical efficacy of cervical disc replacement and hybrid surgery in the treatment of cervical spondylotic myelopathy: a retrospective study. Front Surg 2024; 10:1265349. [PMID: 38249309 PMCID: PMC10797051 DOI: 10.3389/fsurg.2023.1265349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 11/13/2023] [Indexed: 01/23/2024] Open
Abstract
Background Hybrid surgery (HS) combines anterior cervical discectomy and fusion (ACDF) with cervical disc replacement (CDR) is gradually being more frequently implemented, but there are few studies reporting the safety and effectiveness of hybrid surgery in three levels cervical spondylotic myelopathy. Methods The clinical and radiographic data of patients with three-segment cervical spondylosis, who underwent CDR, ACDF and HS in our hospital from February 2007 to February 2013 were analyzed. The Visual Analog Scale (VAS), Japanese Orthopedic Association (JOA) and Neck Disability Index (NDI) were used to evaluate the clinical efficacy post surgery. Cervical spine x-rays were conducted to assess ROM, CL, T1S and relevant outcomes. Results A total of 94 patients were included in the study: 26 in the CDR group, 13 in the HS1 group, 31 in the HS2 group, and 24 in the ACDF group. Most patients in the CDR group were younger. There was no difference in the follow-up duration, blood loss volume or surgery time (P > 0.05). Four groups reported improvements in JOA and NDI scores compared to baseline. There was no significant difference in the final JOA, final NDI or recovery rate among the 4 groups. The final ROM was smaller in the ACDF group than in the other 3 groups. There was no difference among the four groups in the final UROM, final LROM or their changes. There was no difference in the final T1S, final SVA or their change among the four groups. All groups showed similar changes in CL and T1S-CL. Conclusions There was no difference in the clinical outcomes of ACDF, CDR, or hybrid surgery. CDR can better preserve the mobility of the cervical spine. Neither CDR nor hybrid surgery was significantly advantageous over ACDF in restoring the sagittal sequence in patients with three-level CSM.
Collapse
Affiliation(s)
- Bin Zheng
- Spine Surgery Department, Peking University People's Hospital, Beijing, China
| | - Shuai Xu
- Spine Surgery Department, Peking University People's Hospital, Beijing, China
| | - Tianliang Lu
- Orthopedics Department, The Coal Central Hospital of Shanxi Province, Taiyuan, Shanxi, China
| | - Yonghao Wu
- Spine Surgery Department, Peking University People's Hospital, Beijing, China
| | - Haoyuan Li
- Spine Surgery Department, Peking University People's Hospital, Beijing, China
| | - Chen Guo
- Spine Surgery Department, Peking University People's Hospital, Beijing, China
| | - Liu Haiying
- Spine Surgery Department, Peking University People's Hospital, Beijing, China
| |
Collapse
|
2
|
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
|
3
|
Divi SN, Plantz MA, Tegethoff J, Su BW. Current and Expanded Indications for Cervical Disc Arthroplasty: Beyond the FDA IDE Studies. Clin Spine Surg 2023; 36:375-385. [PMID: 37691166 DOI: 10.1097/bsd.0000000000001525] [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: 06/16/2023] [Accepted: 08/10/2023] [Indexed: 09/12/2023]
Abstract
The widespread success of cervical disc arthroplasty (CDA) has led to an interest in expanding indications beyond those outlined in the initial Food and Drug Administration investigational device exemption studies. Some of these off-label indications currently include 3-level and 4-level CDA, hybrid constructs with adjacent segment anterior cervical discectomy and fusion or corpectomy constructs, pre-existing kyphosis, revision of a failed anterior cervical discectomy and fusion to a CDA, CDA in the setting of significant degenerative disc disease and/or facet joint arthropathy, CDA for congenital cervical stenosis, and CDA in the presence of ossification of the posterior longitudinal ligament. This review article will summarize the current literature pertaining to the aforementioned indications.
Collapse
Affiliation(s)
- Srikanth N Divi
- Department of Orthopaedic Surgery, Northwestern University, Chicago IL
| | - Mark A Plantz
- Department of Orthopaedic Surgery, Northwestern University, Chicago IL
| | - Jason Tegethoff
- Department of Orthopaedic Surgery, Northwestern University, Chicago IL
| | - Brian W Su
- California Orthopedics & Spine, Novato, CA
| |
Collapse
|
4
|
Foley D, Hardacker P, McCarthy M. Emerging Technologies within Spine Surgery. Life (Basel) 2023; 13:2028. [PMID: 37895410 PMCID: PMC10608700 DOI: 10.3390/life13102028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 10/02/2023] [Accepted: 10/07/2023] [Indexed: 10/29/2023] Open
Abstract
New innovations within spine surgery continue to propel the field forward. These technologies improve surgeons' understanding of their patients and allow them to optimize treatment planning both in the operating room and clinic. Additionally, changes in the implants and surgeon practice habits continue to evolve secondary to emerging biomaterials and device design. With ongoing advancements, patients can expect enhanced preoperative decision-making, improved patient outcomes, and better intraoperative execution. Additionally, these changes may decrease many of the most common complications following spine surgery in order to reduce morbidity, mortality, and the need for reoperation. This article reviews some of these technological advancements and how they are projected to impact the field. As the field continues to advance, it is vital that practitioners remain knowledgeable of these changes in order to provide the most effective treatment possible.
Collapse
Affiliation(s)
- David Foley
- Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Pierce Hardacker
- Indiana University School of Medicine, Indianapolis, IN 46202, USA;
| | | |
Collapse
|
5
|
Goh BC, Lightsey HM, Lopez WY, Tobert DG, Fogel HA, Cha TD, Schwab JH, Bono CM, Hershman SH. Magnetic Resonance Imaging Is Inadequate to Assess Cervical Sagittal Alignment Parameters. Clin Spine Surg 2023; 36:E70-E74. [PMID: 35969678 DOI: 10.1097/bsd.0000000000001382] [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: 02/18/2021] [Accepted: 06/29/2022] [Indexed: 11/25/2022]
Abstract
STUDY DESIGN Retrospective radiographic study. OBJECTIVE To evaluate cervical sagittal alignment measurement reliability and correlation between upright radiographs and magnetic resonance imaging (MRI). SUMMARY OF BACKGROUND DATA Cervical sagittal alignment (CSA) helps determine the surgical technique employed to treat cervical spondylotic myelopathy. Traditionally, upright lateral radiographs are used to measure CSA, but obtaining adequate imaging can be challenging. Utilizing MRI to evaluate sagittal parameters has been explored; however, the impact of positional change on these parameters has not been determined. METHODS One hundred seventeen adult patients were identified who underwent laminoplasty or laminectomy and fusion for cervical spondylotic myelopathy from 2017 to 2019. Two clinicians independently measured the C2-C7 sagittal angle, C2-C7 sagittal vertical axis (SVA), and the T1 tilt. Interobserver and intraobserver reliability were assessed by intraclass correlation coefficient. RESULTS Intraobserver and interobserver reliabilities were highly correlated, with correlations greater than 0.85 across all permutations; intraclass correlation coefficients were highest with MRI measurements. The C2-C7 sagittal angle was highly correlated between x-ray and MRI at 0.76 with no significant difference ( P =0.46). There was a weaker correlation with regard to C2-C7 SVA (0.48) and T1 tilt (0.62) with significant differences observed in the mean values between the 2 modalities ( P <0.01). CONCLUSIONS The C2-C7 sagittal angle is highly correlated and not significantly different between upright x-ray and supine MRIs. However, cervical SVA and T1 tilt change with patient position. Since MRI does not accurately reflect the CSA in the upright position, upright lateral radiographs should be obtained to assess global sagittal alignment when planning a posterior-based cervical procedure.
Collapse
Affiliation(s)
- Brian C Goh
- Harvard Combined Orthopaedic Residency Program
| | | | | | - Daniel G Tobert
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Harold A Fogel
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Thomas D Cha
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Joseph H Schwab
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Christopher M Bono
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| | - Stuart H Hershman
- Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA
| |
Collapse
|
6
|
Lang A, Lener S, Grassner L, Abramovic A, Thomé C, Päsler D, Lehmberg J, Schär R, Hartmann S. Clinical and radiological outcome 1-year after cervical total disc replacement using the Signus ROTAIO - Prosthesis. 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 2022; 31:3477-3483. [PMID: 36219329 DOI: 10.1007/s00586-022-07416-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/13/2022] [Accepted: 09/29/2022] [Indexed: 12/13/2022]
Abstract
INTRODUCTION The instantaneous center of rotation (iCOR) of a motion segment has been shown to correlate with its total range of motion (ROM). Importantly, a correlation of the correct placement of cervical total disc replacement (cTDR) to preserve a physiological iCOR has been previously identified. However, changes of these parameters and the corresponding clinical relevance have hardly been analyzed. This study assesses the radiological and clinical correlation of iCOR and ROM following cTDR. MATERIALS/METHODS A retrospective multi-center observational study was conducted and radiological as well as clinical parameters were evaluated preoperatively and 1 year after cTDR with an unconstrained device. Radiographic parameters including flexion/extension X-rays (flex/ex), ROM, iCOR and the implant position in anterior-posterior direction (IP ap), as well as corresponding clinical parameters [(Neck Disability Index (NDI) and the visual analogue scale (VAS)] were assessed. RESULTS 57 index segments of 53 patients treated with cTDR were analyzed. Pre- and post-operative ROM showed no significant changes (8.0° vs. 10.9°; p > 0.05). Significant correlations between iCOR and IP (Pearson's R: 0.6; p < 0.01) as well as between ROM and IP ap (Pearson's R: - 0.3; p = 0.04) were identified. NDI and VAS improved significantly (p < 0.01). A significant correlation between NDI and IP ap after 12 months (Pearson's R: - 0.39; p < 0.01) was found. CONCLUSION Implantation of the tested prosthesis maintains the ROM and results in a physiological iCOR. The exact position of the device correlates with the clinical outcome and emphasize the importance of implant design and precise implant positioning.
Collapse
Affiliation(s)
- Anna Lang
- Department of Neurosurgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria.
| | - Sara Lener
- Department of Neurosurgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - Lukas Grassner
- Department of Neurosurgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - Anto Abramovic
- Department of Neurosurgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - Claudius Thomé
- Department of Neurosurgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| | - Dennis Päsler
- Department of Neurosurgery, University of Greifswald, Greifswald, Germany
| | - Jens Lehmberg
- Department of Neurosurgery, Academic Hospital Bogenhausen Munich, Munich, Germany
| | - Ralph Schär
- Department of Neurosurgery, University of Bern, Bern, Switzerland
| | - Sebastian Hartmann
- Department of Neurosurgery, Medical University of Innsbruck, Anichstrasse 35, 6020, Innsbruck, Austria
| |
Collapse
|
7
|
Muth-Seng C, Huneidi M, Heidsieck C, Laporte S, Le Coz JY, Gille O, Skalli W. Personalised gravitational loading of the cervical spine from biplanar X-rays for asymptomatic and clinical subjects in neutral standing position. Clin Biomech (Bristol, Avon) 2022; 92:105577. [PMID: 35042094 DOI: 10.1016/j.clinbiomech.2022.105577] [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: 09/08/2021] [Revised: 01/07/2022] [Accepted: 01/09/2022] [Indexed: 02/07/2023]
Abstract
BACKGROUND As a leading cause of disability with a high societal and economic cost, it is crucial to better understand risk factors of neck pain and surgical complications. Getting subject-specific external loading is essential for quantifying muscle forces and joint loads but it requires exertion trials and load cells which are uncommon in clinical settings. METHODS This paper presents a method to compute the gravitational loading at four levels of the cervical spine (C3C4, C4C5, C5C6, C6C7) in neutral standing position from biplanar radiographs exclusively. The resulting load was decomposed in local disc frames and its components were used to compare different populations: 118 asymptomatic subjects and 46 patients before and after surgery (anterior cervical discectomy and fusion or total disc replacement). Comparisons were performed at C6C7 and the upper level adjacent to surgery. FINDINGS Significant changes in gravitational loading were observed with age in healthy subjects as well as in patients after surgery and have been associated with changes in posture. INTERPRETATION This approach quantifies the influence of postural changes on gravitational loading on the cervical spine. It represents a simple way to obtain necessary input for muscle force quantification models in clinical routine and to use them for patient evaluation. The study of the subsequent subject-specific spinal loading could help further the understanding of cervical spine biomechanics, degeneration mechanisms and complications following surgery.
Collapse
Affiliation(s)
- Christophe Muth-Seng
- Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, IBHGC - Institut de Biomécanique Humaine Georges Charpak, HESAM Université, F-75013, Paris, France.
| | - Maxime Huneidi
- Service de chirurgie orthopédique et traumatologique, Groupe Hospitalier Pellegrin, CHU de Bordeaux, Bordeaux 33076, France
| | - Cécile Heidsieck
- Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, IBHGC - Institut de Biomécanique Humaine Georges Charpak, HESAM Université, F-75013, Paris, France
| | - Sébastien Laporte
- Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, IBHGC - Institut de Biomécanique Humaine Georges Charpak, HESAM Université, F-75013, Paris, France
| | - Jean-Yves Le Coz
- Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, IBHGC - Institut de Biomécanique Humaine Georges Charpak, HESAM Université, F-75013, Paris, France
| | - Olivier Gille
- Service de chirurgie orthopédique et traumatologique, Groupe Hospitalier Pellegrin, CHU de Bordeaux, Bordeaux 33076, France
| | - Wafa Skalli
- Arts et Métiers Institute of Technology, Université Sorbonne Paris Nord, IBHGC - Institut de Biomécanique Humaine Georges Charpak, HESAM Université, F-75013, Paris, France
| |
Collapse
|
8
|
Comparison of Radiographic Reconstruction and Clinical Improvement between Artificial Cervical Disc Replacement and Anterior Cervical Discectomy and Fusion. Pain Res Manag 2022; 2022:3353810. [PMID: 35140830 PMCID: PMC8820923 DOI: 10.1155/2022/3353810] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 12/22/2021] [Indexed: 12/14/2022]
Abstract
Background The surgical management of cervical degenerative disc degeneration (CDDD) has not reached a consensus. Artificial cervical disc replacement (ACDR) has been shown to be efficient in reducing symptoms after CDDD, although the topic remains highly controversial in this field. This study aimed to evaluate the effectiveness of ACDR on the treatment of CDDD on the aspect of radiographic reconstruction and clinical improvement compared with anterior cervical discectomy and fusion (ACDF). Methods This was a retrospective comparative study with 47 patients who underwent single-level ACDR and 46 patients who underwent single-level ACDF. The radiographic reconstruction was assessed by the cervical sagittal alignment parameters, consisting of two aspects, distance and angle, such as cervical sagittal vertical axis (cSVA), cervical lordosis (CL), T1 slope (T1s), and intervertebral space height (ISH). The clinical improvement was assessed by patient-related outcomes (PROs), consisting of two aspects, relief of axial neck pain and recovery of cervical dysfunction, measured through the Visual Analogue Scale (VAS), Neck Disability Index (NDI), and Japanese Orthopedic Association (JOA). Results Significant variations were achieved on aspects of radiographic reconstruction and clinical improvement after ACDR (P < 0.05), which were similar to that of the ACDF group (P < 0.05). A significantly larger postoperative range of motion (ROM) was found in patients less than 45 years of age in the ACDR group (P < 0.05). In addition, a significantly better postoperative JOA was found in patients with a preoperative ISH less than 4 mm in the ACDF group than that in the ACDR group (P < 0.05). Other than that mentioned above, no significant variations in radiographic and clinical outcomes were found between the two groups (P > 0.05). Conclusions Overall, this study showed that a similar capability in terms of radiographic reconstruction and clinical improvement was found between the two methods. Specific concerns should be analyzed while choosing between an ACDR and an ACDF. It should be pointed out that, based on our experience, if the patient is younger, ACDR is recommended; for patients with preoperative ISH less than 4 mm, ACDF is more recommended.
Collapse
|
9
|
Goel V, Mumtaz M, Mendoza J, Tripathi S, Kelkar A, Nishida N, Sahai A. Total disc replacement alters the biomechanics of cervical spine based on sagittal cervical alignment: A finite element study. JOURNAL OF CRANIOVERTEBRAL JUNCTION AND SPINE 2022; 13:278-287. [PMID: 36263350 PMCID: PMC9574107 DOI: 10.4103/jcvjs.jcvjs_21_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/08/2022] [Indexed: 11/04/2022] Open
|
10
|
Hui N, Phan K, Lee MY, Kerferd J, Singh T, Mobbs RJ. The Changes in Cervical Biomechanics After CTDR and Its Association With Heterotopic Ossification: A Systematic Review and Meta-analysis. Global Spine J 2021; 11:565-574. [PMID: 32677512 PMCID: PMC8119929 DOI: 10.1177/2192568220922949] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
STUDY DESIGN A systematic review and meta-analysis. OBJECTIVES Cervical total disc replacement (CTDR) can preserve range of motion (ROM) of the operated spinal segment in cadaver studies. Evidence is less clear in clinical trials. The present study aims to investigate the differences in cervical biomechanics before and after CTDR and its association with heterotopic ossification (HO) development. METHOD Articles that reported the rate of HO and ≥1 difference in cervical biomechanics were included in quantitative analyses. We pooled the mean difference (MD) of cervical biomechanics before and after CTDR. Subgroup analyses and metaregression analyses were conducted to identify potential contributors to heterogeneity. RESULTS Of the 599 studies screened, 35 studies were included in the final analysis. In comparison with preoperative values, ROM of the spinal segment inferior (MD: 0.38; 95% CI: 0.02 to 0.74) and superior (MD: 0.43; 95% CI: 0.12 to 0.75) to the surgical spinal segment, functional spinal unit (FSU) angle (MD: 2.23; 95% CI: 1.11 to 3.35), and C2/C7 Cobb angle (MD: 3.49; 95% CI: 1.73 to 5.25) significantly increased after CTDR. In contrast, FSU and cervical ROM at baseline were no different from follow-up. On multivariable meta-regression analyses, HO and ROM-limiting HO were not associated with changes in cervical biomechanics. Single-level CTDR and duration of follow-up were associated with changes in cervical biomechanics. CONCLUSION Our study reported the pooled mean of biomechanics at baseline and final follow-up and their differences. The changes in biomechanics were not associated with the rates of HO and ROM-limiting HO.
Collapse
Affiliation(s)
- Nicholas Hui
- NeuroSpine Surgery Research Group, Sydney, Australia,7800University of New South
Wales, Sydney, Australia
| | - Kevin Phan
- NeuroSpine Surgery Research Group, Sydney, Australia,7800University of New South
Wales, Sydney, Australia
| | - Mei-Yi Lee
- NeuroSpine Surgery Research Group, Sydney, Australia,85120Hong Kong Polytechnic
University, Hong Kong
| | - Jack Kerferd
- NeuroSpine Surgery Research Group, Sydney, Australia,7800University of New South
Wales, Sydney, Australia
| | - Telvinderjit Singh
- NeuroSpine Surgery Research Group, Sydney, Australia,7800University of New South
Wales, Sydney, Australia
| | - Ralph J. Mobbs
- NeuroSpine Surgery Research Group, Sydney, Australia,7800University of New South
Wales, Sydney, Australia,NeuroSpineClinic, Sydney, Australia,Ralph J. Mobbs, NeuroSpineClinic, Suite 7,
Level 7, Prince of Wales Private Hospital, Randwick, New South Wales 2031,
Australia.
| |
Collapse
|
11
|
Jacobs CAM, Siepe CJ, Ito K. Viscoelastic cervical total disc replacement devices: Design concepts. Spine J 2020; 20:1911-1924. [PMID: 32810609 DOI: 10.1016/j.spinee.2020.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 08/12/2020] [Accepted: 08/12/2020] [Indexed: 02/03/2023]
Abstract
Cervical disc replacement (CDR) is a motion-preserving surgical procedure for treating patients with degenerative disorders. Numerous reports of first generation CDR "ball-and-socket" articulating devices have shown satisfactory clinical results. As a result, CDR devices have been safely implemented in the surgeon's armamentarium on a global scale. However, only minor design improvements have been made over the last few years, as first generation CDRs devices were based on traditional synovial joint arthroplasty designs. As a consequence, these articulating designs have limited resemblance to the complex kinematic behavior of a natural disc. This has driven the development of deformable viscoelastic CDR devices to better mimic the biomechanical behavior of a natural disc. As a result, several viscoelastic CDR devices have been developed in recent years that vary in terms of materials, design and clinical outcomes. Since these viscoelastic CDR devices are fairly new, their weaknesses and strengths, which are related to their design characteristics, have not been well described. Therefore, this literature review discusses design related advantages and disadvantages of deformable viscoelastic CDR devices. As such, this paper can provide insight for surgeons and engineers on specific design characteristics of several viscoelastic devices and could potentially help to develop and design future implants. Eleven viscoelastic CDR devices were identified. An extensive database search on the devices' tradenames in Medline and PubMed was performed next. The devices were categorized based on common design characteristics to give an overview of both category and device specific complications and advantages. Overall, literature shows that most of these viscoelastic CDR devices can provide motion in all six degrees-of-freedom and have a variable center of rotation. Nevertheless, the viscoelastic materials used do not have an extensive history in orthopedics, so the long-term material behavior in vivo is still unknown. Although the viscoelastic devices have common benefits and risks, each specific design and category also has its own design related advantages and drawbacks that are described in this review. Altogether, viscoelastic total disc replacements seem to be a promising option for the future of cervical arthroplasty, but long-term clinical outcome is needed to confirm the advantages of mimicking the viscoelasticity of a natural disc.
Collapse
Affiliation(s)
- Celien A M Jacobs
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, De Rondom 70, 5612 AP Eindhoven, the Netherlands.
| | - Christoph J Siepe
- Schoen Clinic Munich Harlaching, Spine Center, Harlachinger Str. 51, D-81547 Munich, Germany; Spine Research Institute and Academic Teaching Hospital of the Paracelsus University Salzburg (PMU), Strubergasse 21, A-5020 Salzburg, Austria
| | - Keita Ito
- Orthopaedic Biomechanics, Department of Biomedical Engineering, Eindhoven University of Technology, De Rondom 70, 5612 AP Eindhoven, the Netherlands
| |
Collapse
|
12
|
Lee SH, Hyun SJ, Jain A. Cervical Sagittal Alignment: Literature Review and Future Directions. Neurospine 2020; 17:478-496. [PMID: 33022153 PMCID: PMC7538362 DOI: 10.14245/ns.2040392.196] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 08/13/2020] [Indexed: 12/26/2022] Open
Abstract
Cervical alignment as a concept has come to the forefront for spine deformity research in the last decade. Studies on cervical sagittal alignment started from normative data, and expanded into correlation with global sagittal balance, prognosis of various conditions, outcomes of surgery, definition and classification of cervical deformity, and prediction of targets for ideal cervical reconstruction. Despite the recent robust research efforts, the definition of normal cervical sagittal alignment and cervical spine deformity continues to elude us. Further, many studies continue to view cervical alignment as a continuation of thoracolumbar deformity and do not take into account biomechanical features unique to the cervical spine that may influence cervical alignment, such as the importance of musculature connecting cranium-cervical-thoracic spine and upper extremities. In this article, we aim to summarize the relevant literature on cervical sagittal alignment, discuss key results, and list potential future direction for research using the '5W1H' framework; "WHO" are related?, "WHY" important?, "WHAT" to evaluate and "WHAT" is normal?, "HOW" to evaluate?, "WHEN" to apply sagittal balance?, and "WHERE" to go in the future?
Collapse
Affiliation(s)
- Sang Hun Lee
- Department of Orthopaedic Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Seung-Jae Hyun
- Department of Neurological Surgery, Seoul National University College of Medicine, Seoul, Korea
| | - Amit Jain
- Department of Orthopaedic Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| |
Collapse
|
13
|
Hui N, Phan K, Kerferd J, Lee M, Mobbs RJ. Prevalence of and Risk Factors for Heterotopic Ossification After Cervical Total Disc Replacement: A Systematic Review and Meta-Analysis. Global Spine J 2020; 10:790-804. [PMID: 32707022 PMCID: PMC7383784 DOI: 10.1177/2192568219881163] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
STUDY DESIGN A systematic review and meta-analysis. OBJECTIVES The results from previous meta-analyses are limited by the small number of included studies. Moreover, the risk factors of heterotopic ossification (HO) have not been well studied. Therefore, this study aims to estimate the prevalence of HO after cervical total disc replacement (CTDR) at different follow-up time points and explore potential risk factors for HO. METHODS We searched databases to identify eligible studies that reported the rate of HO after CTDR. The pooled prevalence of HO, according to different grades of HO, length of follow-up and types of prosthesis, and 95% confidence intervals (CIs) were calculated. Multivariable meta-regression analyses were performed to identify factors that may contribute to the heterogeneity between estimates. RESULTS Of the 94 studies included, 82 studies reported an overall rate of HO, encompassing a total of 5861 cervical spinal levels that underwent CTDR. The overall pooled prevalence of HO was 32.5% (95% CI 26.7% to 38.4%). Single-level CTDR was associated with a higher overall rate of HO. When the rate of HO was stratified by McAfee/Mehren classification, the pooled prevalence of range of motion (ROM)-limiting HO was 11.0% (95% CI 9.2% to 12.8%). Latest publication, single-level CTDR, longer follow-up period, and studies published outside were associated with a higher rate of ROM-limiting HO. CONCLUSIONS We provide a comprehensive overview of the prevalence of different grades of HO. This meta-analysis also identifies and rules out some risk factors for HO after CTDR.
Collapse
Affiliation(s)
- Nicholas Hui
- NeuroSpine Surgery Research Group, Sydney, New South Wales, Australia,University of New South Wales, Sydney, New South Wales, Australia
| | - Kevin Phan
- NeuroSpine Surgery Research Group, Sydney, New South Wales, Australia,University of New South Wales, Sydney, New South Wales, Australia
| | - Jack Kerferd
- NeuroSpine Surgery Research Group, Sydney, New South Wales, Australia,University of New South Wales, Sydney, New South Wales, Australia
| | - Meiyi Lee
- NeuroSpine Surgery Research Group, Sydney, New South Wales, Australia,The Hong Kong Polytechnic University, Hong Kong SAR
| | - Ralph J. Mobbs
- NeuroSpine Surgery Research Group, Sydney, New South Wales, Australia,University of New South Wales, Sydney, New South Wales, Australia,NeuroSpineClinic, Sydney, New South Wales, Australia,Ralph J. Mobbs, NeuroSpineClinic, Suite 7, Level 7, Prince of Wales Private Hospital, Randwick, New South Wales, Australia 2031.
| |
Collapse
|
14
|
Hui N, Phan K, Kerferd J, Lee M, Mobbs RJ. Cervical Total Disc Replacement and Heterotopic Ossification: A Review of Literature Outcomes and Biomechanics. Asian Spine J 2020; 15:127-137. [PMID: 32050310 PMCID: PMC7904491 DOI: 10.31616/asj.2019.0234] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 09/11/2019] [Indexed: 12/30/2022] Open
Abstract
Anterior cervical discectomy and fusion (ACDF) immobilizes surgical segments and can lead to the development of adjacent segment degeneration and adjacent segment disease. Thus, cervical total disc replacement (CTDR) has been developed with the aim to preserve the biomechanics of spine. However, heterotopic ossification (HO), a complication following CTDR, can reduce the segmental range of motion (ROM) and defects the motion-preservation benefit of CTDR. The pathological process of HO in CTDR remains unknown. HO has been suggested to be a self-defense mechanism in response to the non-physiological biomechanics of the cervical spine following CTDR. The current literature review is concerned with the association between the biomechanical factors and HO formation and the clinical significance of HO in CTDR. Endplate coverage, disc height, segmental angle, and center of rotation may be associated with the development of HO. The longer the follow-up, the higher the rate of ROM-limiting HO. Regardless of the loss of motion-preservation benefit of CTDR in patients with HO, CTDR confers patients with a motion-preservation period before the development of ROM-limiting HO. This may delay the development of adjacent segment degeneration compared with ACDF. Future clinical studies should explore the association between HO and changes in biomechanical factors of the cervical spine.
Collapse
Affiliation(s)
- Nicholas Hui
- NeuroSpine Surgery Research Group, Sydney, Australia.,Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Kevin Phan
- NeuroSpine Surgery Research Group, Sydney, Australia.,Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Jack Kerferd
- NeuroSpine Surgery Research Group, Sydney, Australia.,Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Meiyi Lee
- NeuroSpine Surgery Research Group, Sydney, Australia.,Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong
| | - Ralph Jasper Mobbs
- NeuroSpine Surgery Research Group, Sydney, Australia.,Faculty of Medicine, University of New South Wales, Sydney, Australia.,NeuroSpineClinic, Sydney, Australia
| |
Collapse
|
15
|
Wang X, Meng Y, Liu H, Hong Y, Wang B. Is Anterior Bone Loss the Opposite of Anterior Heterotopic Ossification in Prestige-LP Cervical Disc Replacement? World Neurosurg 2020; 136:e407-e418. [PMID: 31931240 DOI: 10.1016/j.wneu.2020.01.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/03/2020] [Accepted: 01/04/2020] [Indexed: 02/08/2023]
Abstract
BACKGROUND Heterotopic ossification (HO) and anterior bone loss (ABL) are 2 complications in cervical disc replacement (CDR), which have impacts on the clinical outcomes. Physiologically, bone formation (HO) and bone loss are 2 sides of bone remodeling. However, clinically, some patients experienced anterior HO (AHO) after CDR, whereas other patients experienced ABL. Is there any factor in determining the fate of the vertebral bone in the anterior region? Is ABL the opposite of AHO? This study aims to answer these questions. METHODS Seventy patients with 1-level Prestige-LP CDR were retrospectively reviewed and were divided into an AHO group or ABL group. Radiologic outcomes, including cervical lordosis, sagittal vertical axis, functional spine unit angle, disc angle, range of motion, implant migration, subsidence, and adjacent segment degeneration were evaluated. Patient-reported clinical outcomes were also evaluated. RESULTS AHO group showed significantly lower disc angle after surgery (0.9° ± 4.2°), compared with ABL group (6.7° ± 4.7°) (P < 0.001). The preoperative segmental range of motion was significantly higher in the AHO group (10.2° ± 3.3°) than in the ABL group (8.2° ± 3.7°) (P = 0.042). No correlation was observed between clinical outcomes and the presence of anterior bone remodeling. Both groups maintained cervical alignment and functional spine unit angle during long-term follow-up. No significant difference was found in the end plate preparation, implant subsidence, migration, or adjacent segment degeneration rate between the 2 groups. CONCLUSIONS The differences in the disc angle showed the role of mechanical load in the anterior bone remodeling. Combined the results with the basic concepts of bone remodeling, ABL may be the opposite of AHO.
Collapse
Affiliation(s)
- Xiaofei Wang
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yang Meng
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Hao Liu
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| | - Ying Hong
- Department of Operation Room, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Beiyu Wang
- Department of Orthopedic Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| |
Collapse
|
16
|
Sagittal Reconstruction and Clinical Outcome Using Traditional ACDF, Versus Stand-alone ACDF Versus TDR: A Systematic Review and Quantitative Analysis. Spine (Phila Pa 1976) 2019; 44:E1151-E1158. [PMID: 31261280 DOI: 10.1097/brs.0000000000003077] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Systematic review. OBJECTIVE To determine the difference in postoperative sagittal alignment when single level cervical radiculopathy or myelopathy is treated with an anterior cervical discectomy and fusion (ACDF) using a structural graft and plate, a stand-alone ACDF, or a total disc arthroplasty (TDR). We also wanted to determine if postoperative sagittal alignment impacted clinical outcomes in this patient population. SUMMARY OF BACKGROUND DATA Although there are several accepted techniques for interbody reconstruction during single level anterior cervical surgery, little is known on the impact of any of them on segmental and regional sagittal alignment. METHODS A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines of the PubMed, Embase, and Cochrane databases. Only studies which contained pre and postoperative C2-7 Cobb angles as well as Neck Disability Index (NDI) scores following single level traditional ACDF with plate and cage, stand-alone ACDF, or TDR with at least 1 year follow up were included. RESULTS There were 12 publications that fulfilled the inclusion criteria with a total of 658 patients. Cluster regression analysis showed no difference between treatment arms at each respective time-point or in the overall change in NDI from preoperative to postoperative (P = 0.88). Cluster regression analysis showed no difference between treatment arms at each respective time point or in the overall change in lordosis from pre-op to post-op (P = 0.93). CONCLUSION This review provides evidence that while NDI scores improved across all devices, there was no significant difference in NDI improvement or C2-7 Cobb angle change between single level traditional ACDF, stand-alone ACDF, or TDR. Although TDR has not been considered a lordosis producing operation, our investigation shows it does not differ significantly in sagittal profile from other cervical fusion techniques. Moreover, we show that the NDI score improved, regardless of device implanted. LEVEL OF EVIDENCE 1.
Collapse
|
17
|
Snowden R, Miller J, Saidon T, Smucker JD, Riew KD, Sasso R. Does index level sagittal alignment determine adjacent level disc height loss? J Neurosurg Spine 2019; 31:579-586. [PMID: 31226683 DOI: 10.3171/2019.4.spine181468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/05/2019] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The authors sought to compare the effect of index level sagittal alignment on cephalad radiographic adjacent segment pathology (RASP) in patients undergoing cervical total disc arthroplasty (TDA) or anterior cervical discectomy and fusion (ACDF). METHODS This was a retrospective study of prospectively collected radiographic data from 79 patients who underwent TDA or ACDF and were enrolled and followed prospectively at two centers in a multicenter FDA investigational device exemption trial of the Bryan cervical disc prosthesis used for arthroplasty. Neutral lateral radiographs were obtained pre- and postoperatively and at 1, 2, 4, and up to 7 years following surgery. The index level Cobb angle was measured both pre- and postoperatively. Cephalad disc degeneration was determined by a previously described measurement of the disc height/anteroposterior (AP) distance ratio. RESULTS Sixty-eight patients (n = 33 ACDF; n = 35 TDA) had complete radiographs and were included for analysis. Preoperatively, there was no difference in the index level Cobb angle between the ACDF and TDA patients. Postoperatively, the ACDF patients had a larger segment lordosis compared to the TDA patients (p = 0.002). Patients who had a postoperative kyphotic Cobb angle were more likely to have undergone TDA (p = 0.01). A significant decrease in the disc height/AP distance ratio occurred over time (p = 0.035), by an average of 0.01818 at 84 months. However, this decrease was not influenced by preoperative alignment, postoperative alignment, or type of surgery. CONCLUSIONS In this cohort of patients undergoing TDA and ACDF, the authors found that preoperative and postoperative sagittal alignment have no effect on RASP at follow-up of at least 7 years. They identified time as the only significant factor affecting RASP.
Collapse
Affiliation(s)
- Ryan Snowden
- 1Indiana Spine Group, Carmel (Indianapolis), Indiana; and
| | - Justin Miller
- 1Indiana Spine Group, Carmel (Indianapolis), Indiana; and
| | - Tome Saidon
- 2NewYork-Presbyterian Och Spine Hospital, Columbia University, New York, New York
| | | | - K Daniel Riew
- 2NewYork-Presbyterian Och Spine Hospital, Columbia University, New York, New York
| | - Rick Sasso
- 1Indiana Spine Group, Carmel (Indianapolis), Indiana; and
| |
Collapse
|
18
|
Yu Y, Li JS, Guo T, Lang Z, Kang JD, Cheng L, Li G, Cha TD. Normal intervertebral segment rotation of the subaxial cervical spine: An in vivo study of dynamic neck motions. J Orthop Translat 2019; 18:32-39. [PMID: 31508305 PMCID: PMC6718920 DOI: 10.1016/j.jot.2018.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 12/05/2018] [Accepted: 12/11/2018] [Indexed: 12/03/2022] Open
Abstract
Background Accurate knowledge of the intervertebral center of rotation (COR) and its corresponding range of motion (ROM) can help understand development of cervical pathology and guide surgical treatment. Methods Ten asymptomatic subjects were imaged using MRI and dual fluoroscopic imaging techniques during dynamic extension-flexion-extension (EFE) and axial left-right-left (LRL) rotation. The intervertebral segment CORs and ROMs were measured from C34 to C67, as the correlations between two variables were analyzed as well. Results During the EFE motion, the CORs were located at 32.4 ± 20.6%, -2.4 ± 11.7%, 21.8 ± 12.5% and 32.3 ± 25.5% posteriorly, and the corresponding ROMs were 13.8 ± 4.3°, 15.1 ± 5.1°, 14.4 ± 7.0° and 9.2 ± 4.3° from C34 to C67. The ROM of C67 was significantly smaller than other segments. The ROMs were not shown to significantly correlate to COR locations (r = −0.243, p = 0.132). During the LRL rotation cycle, the average CORs were at 85.6 ± 18.2%, 32.3 ± 25.3%, 15.7 ± 12.3% and 82.4 ± 31.3% posteriorly, and the corresponding ROMs were 3.5 ± 1.7°, 6.9 ± 3.8°, 9.6 ± 4.1° and 2.6 ± 2.5° from C34 to C67. The ROMs of C34 and C67 was significantly smaller than those of C45 and C56. A more posterior COR was associated with a less ROM during the neck rotation (r = −0.583, p < 0.001). The ROMs during EFE were significantly larger than those during LRL in each intervertebral level. Conclusion The CORs and ROMs of the subaxial cervical intervertebral segments were segment level- and neck motion-dependent during the in-vivo neck motions. The translational potential of this article Our study indicates that the subaxial cervical intervertebral CORs and ROMs were segment level- and neck motion-dependent. This may help to improve the artificial disc design as well as surgical technique by which the neck functional motion is restored following the cervical arthroplasty.
Collapse
Affiliation(s)
- Yan Yu
- Orthopaedic Bioengineering Research Center, Department of Orthopedic Surgery, Newton-Wellesley Hospital/Harvard Medical School, Wellesley, MA, USA
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, PR China
| | - Jing-Sheng Li
- College of Health and Rehabilitation Sciences: Sargent College, Boston University, Boston, MA, USA
| | - Tao Guo
- Orthopaedic Bioengineering Research Center, Department of Orthopedic Surgery, Newton-Wellesley Hospital/Harvard Medical School, Wellesley, MA, USA
| | - Zhao Lang
- Orthopaedic Bioengineering Research Center, Department of Orthopedic Surgery, Newton-Wellesley Hospital/Harvard Medical School, Wellesley, MA, USA
| | - James D. Kang
- Department of Orthopaedic Surgery, Brigham and Women's Hospital/Harvard Medical School, Boston, MA, USA
| | - Liming Cheng
- Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, PR China
- Corresponding author. Department of Spine Surgery, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
| | - Guoan Li
- Orthopaedic Bioengineering Research Center, Department of Orthopedic Surgery, Newton-Wellesley Hospital/Harvard Medical School, Wellesley, MA, USA
- Corresponding author. Orthopaedic Bioengineering Research Center, Department of Orthopaedic Surgery, Newton-Wellesley Hospital and Harvard Medical School, Newton, MA, USA.
| | - Thomas D. Cha
- Department of Orthopaedic Surgery, Massachusetts General Hospital/Harvard Medical School, Boston, MA, USA
| |
Collapse
|
19
|
Chen WM, Jin J, Park T, Ryu KS, Lee SJ. Strain behavior of malaligned cervical spine implanted with metal-on-polyethylene, metal-on-metal, and elastomeric artificial disc prostheses - A finite element analysis. Clin Biomech (Bristol, Avon) 2018; 59:19-26. [PMID: 30119037 DOI: 10.1016/j.clinbiomech.2018.08.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/25/2018] [Accepted: 08/09/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Postoperative alterations in cervical spine curvature (i.e. loss of lordotic angle) are frequently observed following total disc replacement surgery. However, it remains unclear whether such changes in lordotic angle are due to preoperative spinal deformities and/or prostheses design limitations. The objective of the study is to investigate strain and segmental biomechanics of the malaligned cervical spine following total disc replacement. METHODS Three disc prostheses were chosen, namely a metal-on-polyethylene, a metal-on-metal, and an elastomeric prosthesis, which feature different geometrical and material design characteristics. All discs were modelled and implanted into multi-segmental cervical spine finite element model (C3-C7) with normal, straight and kyphotic alignments. Comparative analyses were performed by using a hybrid protocol. FINDINGS The results indicated that as the spine loses lordotic alignment, the prosthesis with elastomeric core tends to produce significantly larger flexion range of motion (difference up to 6.1°) than metal-on-polyethylene and metal-on-metal prostheses. In contrast, when the treated spine had normal lordotic alignment, the range of motion behaviors of different prostheses are rather similar (difference within 1.9°). Large localized strains up to 84.8% were found with the elastomeric prosthesis, causing a collapsed anterior disc space under flexion loads. INTERPRETATION Changes in cervical spinal alignments could significantly affect the surgical-level range of motion behaviors following disc arthroplasty; the in situ performance was largely dependent on the designs of the artificial disc devices in particular to the material properties.
Collapse
Affiliation(s)
- Wen-Ming Chen
- Department of Biomedical Engineering, University of Shanghai for Science and Technology, 516 JunGong Road, Shanghai, China.
| | - Jie Jin
- Department of Orthopedic Surgery, YanBian University Hospital, China
| | - Taehyung Park
- Department of Biomedical Engineering, College of Biomedical Science & Engineering, Inje University, 607 O-bang, Gyongnam, Republic of Korea
| | - Kyeong-Sik Ryu
- Department of Neurosurgery, College of medicine, The Catholic University of Korea, 222 Banpo-Daero, Seoul, Republic of Korea
| | - Sung-Jae Lee
- Department of Biomedical Engineering, College of Biomedical Science & Engineering, Inje University, 607 O-bang, Gyongnam, Republic of Korea.
| |
Collapse
|
20
|
Siasios I, Winograd E, Khan A, Vakharia K, Dimopoulos VG, Pollina J. Cervical sagittal balance parameters after single-level anterior cervical discectomy and fusion: Correlations with clinical and functional outcomes. JOURNAL OF CRANIOVERTEBRAL JUNCTION AND SPINE 2018; 9:56-62. [PMID: 29755238 PMCID: PMC5934966 DOI: 10.4103/jcvjs.jcvjs_9_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Background: Normal sagittal cervical alignment has been associated with improved outcome after anterior cervical discectomy and fusion (ACDF). Objective: The aim of this study is to identify alterations of cervical sagittal balance parameters after single-level ACDF and assess correlations with postoperative functionality. Methods: A retrospective chart review was performed between January 2010 and January 2014 to identify adult patients with no previous cervical spine surgery who underwent ACDF at any one level between C2 and C7 for the single-level degenerative disease. Tumor, infection, and trauma cases were excluded from the study. For the included cases, the following data were recorded preoperatively and 6 months–1 year after surgery: sagittal balance-marker measurements of the C1–C2 angle, C2–C7 angle, C7 slope, segmental angle at the operated level, and sagittal vertical axis (SVA) distance between C2 and C7, as well as the neck disability index and visual analog scale of pain. Results: The present study included 47 patients (average age: 51.2 years; range: 28–86 years). A moderate negative correlation between a smaller C2–C7 angle and the presence of right arm pain before treatment was found (P = 0.0281). Postoperatively, functionality scores significantly improved in all patients. C1–C2 angle increased with statistical significance (P = 0.0255). C2–C7 angle, segmental angle, C7 slope, and SVA C2–C7 distance did not change with statistical significance after surgery. C7 slope significantly correlated with overall cervical sagittal balance (P < 0.05). Conclusions: Single-level ACDF significantly increases upper cervical lordosis (C1–C2) without significantly changing lower cervical lordosis (C2–C7). The C7 slope is a significant marker of overall cervical sagittal alignment (P < 0.05).
Collapse
Affiliation(s)
- Ioannis Siasios
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, USA.,Department of Neurosurgery, Kaleida Health, Buffalo, New York, USA
| | - Evan Winograd
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, USA.,Department of Neurosurgery, Kaleida Health, Buffalo, New York, USA
| | - Asham Khan
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, USA.,Department of Neurosurgery, Kaleida Health, Buffalo, New York, USA
| | - Kunal Vakharia
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, USA.,Department of Neurosurgery, Kaleida Health, Buffalo, New York, USA
| | - Vassilios G Dimopoulos
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, USA.,Department of Neurosurgery, Kaleida Health, Buffalo, New York, USA
| | - John Pollina
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, USA.,Department of Neurosurgery, Kaleida Health, Buffalo, New York, USA
| |
Collapse
|
21
|
McAnany SJ, Merrill RK, Brochin RL, Overley SC, Kim JS, Qureshi SA. Comparing the 5-Year Health State Utility Value of Cervical Disc Replacement and Anterior Cervical Discectomy and Fusion. Global Spine J 2018; 8:6-10. [PMID: 29456909 PMCID: PMC5810897 DOI: 10.1177/2192568217721893] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
STUDY DESIGN Health utility analysis. OBJECTIVES To determine the health state utility (HSU) of 1- and 2-level anterior cervical discectomy and fusion (ACDF) and cervical disc replacement (CDR). METHODS Data from the Medtronic Prestige Cervical Disc investigational device exemption studies was used. Four groups were defined: 1-level ACDF, 1-level CDR, 2-level ACDF, and 2-level CDR. The 36-item Short Form Health Survey (SF-36) was collected at baseline, 12 months, 24 months, 36 months, and 60 months postoperatively and converted into utility scores for each time point. A repeated-measures 1-way analysis of variance (ANOVA) was used to detect differences among groups. Tukey's method for multiple comparisons was used to determine which means within the groups were statistically different (P < .05). RESULTS We found a statistically significant difference in HSU among groups as determined by repeated-measures 1-way ANOVA (P = .0008). Post hoc analysis indicated that 1-level ACDF had a statistically lower utility score compared with 1- and 2-level CDR (P = .04 and P = .02, respectively). Similarly, 2-level ACDF had lower utility values compared with 2-level CDR (P = .010). One-level ACDF utility values were not different from 2-level ACDF values (P = .55). Similarly, 1-level CDR and 2-level CDR did not have different utility values (P = .67). CONCLUSIONS Overall, CDR had higher health state utility scores for 1- and 2-level procedures at every time point. This study indicates that CDR results in a higher postoperative health utility state than ACDF, and may therefore be an effective alternative to ACDF for treating degenerative conditions of the cervical spine.
Collapse
Affiliation(s)
| | | | | | | | - Jun S. Kim
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sheeraz A. Qureshi
- Icahn School of Medicine at Mount Sinai, New York, NY, USA,Sheeraz A. Qureshi, Department of Orthopaedic Surgery, Icahn School of Medicine at Mount Sinai, 5 East 98th Street, 4th Floor, New York, NY, USA.
| |
Collapse
|
22
|
Pointillart V, Castelain JE, Coudert P, Cawley DT, Gille O, Vital JM. Outcomes of the Bryan cervical disc replacement: fifteen year follow-up. INTERNATIONAL ORTHOPAEDICS 2017; 42:851-857. [DOI: 10.1007/s00264-017-3745-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 12/18/2017] [Indexed: 10/18/2022]
|
23
|
Cervical sagittal alignment after different anterior discectomy procedures for single-level cervical degenerative disc disease: randomized controlled trial. Acta Neurochir (Wien) 2017; 159:2359-2365. [PMID: 28887690 PMCID: PMC5686251 DOI: 10.1007/s00701-017-3312-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 08/22/2017] [Indexed: 12/14/2022]
Abstract
Background The effect of anterior cervical discectomy without fusion (ACD), ACD with fusion by stand-alone cage (ACDF) or with arthroplasty (ACDA) on cervical sagittal alignment is not known and is the subject of this study. Methods A total of 142 adult patients with single-level cervical disease were at random allocated to different procedures: ACD (45), ACDF (47) and ACDA (50). Upright cervical spine radiographs were obtained. Angles of the involved angle and the angle between C2 and C7 were determined. Results After a mean follow-up of 25.4 ± 18.4 months, the angles of the involved level comparing ACD with ACDA and ACD with ACDF were different, reaching statistical significance. However, the angle between C2 and C7 did not differ between groups or between preoperative values and at follow-up. Conclusions Irrespective of the technique used for anterior cervical discectomy for single-level degenerative disc disease, the alignment of the cervical spine is unaltered.
Collapse
|
24
|
Zhou X, Cai P, Li Y, Wang H, Xia S, Wang X. Posterior or Single-stage Combined Anterior and Posterior Approach Decompression for Treating Complex Cervical Spondylotic Myelopathy Coincident Multilevel Anterior and Posterior Compression. Clin Spine Surg 2017; 30:E1343-E1351. [PMID: 27681535 PMCID: PMC5704650 DOI: 10.1097/bsd.0000000000000437] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STUDY DESIGN A single-center, retrospective, longitudinal matched cohort clinical study of prospectively collected outcomes. OBJECTIVE To compare retrospectively the clinical outcomes and complications of the posterior approach laminoplasty and single-stage anterior approach laminoplasty combined with anterior cervical corpectomy and fusion and anterior cervical discectomy and fusion for treating patients with cervical spondylotic myelopathy coincident multilevel anterior and posterior compression, known as complex cervical spondylotic myelopathy (cCSM) here. SUMMARY OF BACKGROUND DATA The optimal surgical management of this type of cCSM remains controversial. METHODS Sixty-seven patients with multilevel cCSM underwent decompression surgery from 1996 to 2007. Among these patients, 31 underwent a single-stage combined approach with decompression (combined approach group) and 36 underwent laminoplasty for posterior approach (posterior approach group). Average operative duration, operative estimated blood loss, surgical costs, and cervical alignment were measured. RESULTS Average operative duration, operative estimated blood loss, and surgical costs were significantly lower in the posterior approach group than those in the combined approach group (P<0.001). Visual analog scale and modified Japanese Orthopedic Association scale were insignificantly different at each data collection period (P>0.05). No statistical difference was observed in the preoperative Cobb angle (P>0.05), whereas a significant statistical difference was observed for the postoperative Cobb angle (P<0.05) and variation of Cobb angle (P<0.05) between the 2 groups. The surgical incidences of complications were 22.2% and 48.4% in the posterior and combined approach groups (P<0.05), respectively. CONCLUSIONS For treating multilevel cCSM, both the posterior approach laminoplasty and single-stage combined approach led to significant neurological improvement and pain reduction in the majority of patients. Both approaches showed similar results in terms of decompression and neurological improvement. The posterior approach was superior to the combined approach in terms of surgical costs, surgical time, blood loss, and complication rate.
Collapse
Affiliation(s)
- Xiaoxiao Zhou
- Department of Orthopedics, Zhoupu Hospital of Pudong District, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Pan Cai
- Department of Orthopedics, Zhoupu Hospital of Pudong District, Shanghai University of Medicine & Health Sciences, Shanghai, China
| | - Yuwei Li
- Spineosurgery Department, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan Province
| | - Haijiao Wang
- Spineosurgery Department, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan Province
| | - Shengli Xia
- Spineosurgery Department, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan Province
| | - Xiuhui Wang
- Spineosurgery Department, Luohe Central Hospital, The First Affiliated Hospital of Luohe Medical College, Luohe, Henan Province
| |
Collapse
|
25
|
Analysis of the Factors That Could Predict Segmental Range of Motion After Cervical Artificial Disk Replacement: A 7-Year Follow-up Study. Clin Spine Surg 2017; 30:E603-E608. [PMID: 28525485 DOI: 10.1097/bsd.0000000000000201] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
STUDY DESIGN A retrospective cohort study. OBJECTIVE To identify the potential preoperative factors and surgical technique factors that are associated with long-term range of motion (ROM) after surgery. Further, this article aimed to guide selection of patients with cervical artificial disk replacement and a fine surgical technique. SUMMARY OF BACKGROUND DATA Segmental ROM is the most important parameter concerning cervical kinematics after a cervical artificial disk replacement. There are few researches regarding the influencing factors on postoperative ROM, and consistent results have not yet been reported. METHODS The cohort comprised a total of 68 disks implanted into 57 patients who were retrospectively analyzed. The mean follow-up period was 84.1 months. Segmental ROM and other useful parameters were measured using lateral neutral, extension, and flexion radiographs, which were obtained preoperatively, 3 months after surgery, and at last follow-up. Preoperative CT and clinical assessment were also used. To find out associated factors, the patients were divided into 2 groups according to the segmental ROM at last follow-up. RESULTS After surgery, the clinical outcomes were satisfactory. The segmental ROM at last follow-up (7.8±4.3 degrees) was preserved without significant change from preoperative ROM (8.8±3.8 degrees). The patients who had a better segmental ROM after surgery were found to have a higher preoperative segmental ROM, a younger age, a better disk insertion angle, and disk insertion depth. These 4 factors were identified as independent risk factors (P=0.027, 0.017, 0.036, and 0.046, respectively) for long-term ROM. CONCLUSIONS The postoperative long-term, segmental ROM was well preserved and found to be affected by the preoperative segmental ROM, patient's age, disk insertion angle, and disk insertion depth.
Collapse
|
26
|
Cervical Disk Replacement With Discover Versus Fusion in a Single-Level Cervical Disk Disease: A Prospective Single-Center Randomized Trial With a Minimum 2-Year Follow-up. Clin Spine Surg 2017; 30:E515-E522. [PMID: 28525471 DOI: 10.1097/bsd.0000000000000170] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STUDY DESIGN Prospective randomized study. OBJECTIVE To compare the clinical outcome after Discover arthroplasty versus anterior cervical discectomy and fusion (ACDF) in patients treated for symptomatic single-level cervical disk disease. SUMMARY OF BACKGROUND DATA ACDF is still the gold standard for surgical treatment of cervical spine degenerative disk disease. However, results of many studies suggest that it may cause degenerative changes at levels immediately above and below the fusion, known as adjacent segment degenerative disease. Cervical arthroplasty has recently been introduced as an alternative to standard procedure of ACDF. It showed decreased surgical morbidity, decreased complications from postoperative immobilization, and an earlier return to previous level of function. MATERIALS AND METHODS A total of 105 consecutive patients with single-level cervical disk disease, producing radiculopathy and/or myelopathy were randomly divided into groups to undergo ACDF or Discover arthroplasty. All patients were evaluated with preoperative and postoperative serial radiographic studies and clinically, using Neck Disability Index, Visual Analog Scale and neurological status at 3, 6, 12, and 24 months. RESULTS The results of our study indicate that cervical arthroplasty using Discover Artificial Cervical Disc provides favorable clinical and radiologic outcomes in a follow-up period of 24 months. There has been significant improvement in clinical parameters, Visual Analog Scale and Neck Disability Index, at 3, 6, 12, and 24 months in arthroplasty group comparing to control group. CONCLUSION The Discover artificial cervical disc replacement offers favorable outcome compared with ACDF for a single-level cervical disk disease at short-term and long-term follow-up.
Collapse
|
27
|
Dejaegher J, Walraevens J, van Loon J, Van Calenbergh F, Demaerel P, Goffin J. 10-year follow-up after implantation of the Bryan Cervical Disc Prosthesis. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2016; 26:1191-1198. [PMID: 27904963 DOI: 10.1007/s00586-016-4897-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Revised: 11/02/2016] [Accepted: 11/23/2016] [Indexed: 12/30/2022]
Abstract
PURPOSE Cervical arthroplasty is being used as an alternative for cervical fusion, but long-term follow-up results have rarely been reported. In this paper, we present 10-year follow-up results after implantation of the Bryan Cervical Disc Prosthesis in a single center. METHODS 89 patients underwent implantation of a single-level Bryan Cervical Disc Prosthesis to treat radiculopathy and/or myelopathy. Clinical (Neurological Success, Neck Disability Index (NDI), Neck- and Arm-Pain, and SF-36) and radiological follow-up was prospectively organized up to 10 years after surgery. Adverse events and second surgeries were recorded and evaluated. RESULTS Ten-year follow-up data were available for 72 (81%) patients. Maintenance or improvement of the neurological state was seen in 89% of patients after 10-year follow-up. SF-36 PCS scores improved significantly at all follow-up points. SF-36 MCS improvement was significant at 4 and 6 year, but not at 8- and 10-year follow-up. Significant improvement for NDI, and Neck- and Arm-Pain scores was found for the subgroup of patients in whom these data were available. Mean angular motion of the prosthesis at 10-year follow-up was 8.6°. Mobility of the device, defined as >2° of angular motion, was reached in 81% of patients. During the study period, 21 patients (24%) developed new or recurrent radiculopathy or myelopathy, the majority of these being treated conservatively. Seven patients (8%) required 8 additional spine surgeries to treat persistent or recurrent symptoms. Of these, 2 patients (2%) were reoperated at the index level and at 5 (6%) an adjacent level. CONCLUSION In this study, favorable long-term clinical outcome after implantation of the Bryan Cervical Disc Prosthesis was seen, with the majority of prostheses remaining mobile after 10-year follow-up. However, still 6% of patients required adjacent level surgery.
Collapse
Affiliation(s)
- Joost Dejaegher
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium.
| | | | - Johannes van Loon
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium
| | | | - Philippe Demaerel
- Department of Radiology, University Hospitals Leuven, Leuven, Belgium
| | - Jan Goffin
- Department of Neurosurgery, University Hospitals Leuven, Leuven, Belgium
| |
Collapse
|
28
|
Staudt MD, Das K, Duggal N. Does design matter? Cervical disc replacements under review. Neurosurg Rev 2016; 41:399-407. [PMID: 27465393 DOI: 10.1007/s10143-016-0765-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/30/2016] [Accepted: 06/23/2016] [Indexed: 01/11/2023]
Abstract
The present article reviews the design rationale of currently available cervical disc replacements. Recent prospective randomized control trials comparing cervical disc replacement and anterior fusion have demonstrated safety as well as equal or superior clinical results. Increasingly, more devices are becoming available on the market. Understanding design rationale will provide context for the surgeon to optimize decision making for the most appropriate prosthesis. Cervical arthroplasty is a technique that is undergoing rapid design refinement and development. Further improvements in device design will enable patient-specific device selection. Understanding the design rationale and complication profile of each device will improve clinical and radiographic outcomes.
Collapse
Affiliation(s)
- Michael D Staudt
- Department of Clinical Neurological Sciences, Division of Neurosurgery, Western University, London, Ontario, Canada
| | - Kaushik Das
- Department of Neurosurgery, New York Medical College, Valhalla, NY, USA
| | - Neil Duggal
- Department of Clinical Neurological Sciences, Division of Neurosurgery, Western University, London, Ontario, Canada.
| |
Collapse
|
29
|
X-Ray-based Kinematic Analysis of Cervical Spine According to Prosthesis Designs: Analysis of the Mobi C, Bryan, PCM, and Prestige LP. ACTA ACUST UNITED AC 2016; 28:E291-7. [PMID: 23429318 DOI: 10.1097/bsd.0b013e318288a923] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
STUDY DESIGN A retrospective study. OBJECTIVE To identify significant kinematic changes in the cervical spine after cervical artificial disk replacement (ADR) using prostheses with diverse designs. SUMMARY OF BACKGROUND DATA Various types of artificial disks are used for cervical ADR. However, few clinical studies with a follow-up of 2 or more years have reported on the change in the curvatures and range of motion (ROM) of the cervical spine after cervical ADR in relation to different designs. METHODS The cohort comprised 58 patients who underwent single-level cervical ADR for radiculopathy. The patients were divided into 4 groups according to the device they received: Mobi-C, Bryan, PCM, and Prestige LP. The radiographs of the cervical spine were obtained preoperatively and at 12, 24, and 36 months after surgery. Several kinematic parameters, including lordotic angles and ROM of the cervical spine, index level, and superior and inferior adjacent disk levels, were assessed preoperatively and at predefined follow-up time points. RESULTS Cervical sagittal lordosis in patients who received Bryan and PCM prostheses increased at the last follow-up period. The 4 patient groups showed a trend toward an increase of lordosis in the superior adjacent segment with time. The patients who received the Bryan device lost their preoperative lordotic angle at the inferior adjacent level. The ROM of the cervical spine in patients who received Bryan and PCM prostheses increased at the last follow-up compared with preoperative values. The incidence of adjacent segment degeneration in the Mobi-C, Bryan, Prestige LP, and PCM groups were 14.2%, 25%, 9.0%, and 7.6%, respectively. CONCLUSIONS These results suggest preservation of sagittal ROM and increased superior adjacent segment kinematics, regardless of prosthesis design. Devices with an unconstrained design may not be beneficial to adjacent segment kinematics compared with semiconstrained prostheses.
Collapse
|
30
|
Cervical Footprint Anthropometry in Indian Population: Implications on Design of Artificial Disc Replacement Devices. Asian Spine J 2016; 10:20-6. [PMID: 26949454 PMCID: PMC4764536 DOI: 10.4184/asj.2016.10.1.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/14/2015] [Accepted: 06/17/2015] [Indexed: 11/08/2022] Open
|
31
|
Cervical spine alignment in disc arthroplasty: should we change our perspective? 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 2015; 24 Suppl 7:810-25. [PMID: 26441258 DOI: 10.1007/s00586-015-4258-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Revised: 09/24/2015] [Accepted: 09/24/2015] [Indexed: 01/06/2023]
Abstract
PURPOSE The alignment at the cervical spine has been considered a determinant of degeneration at the adjacent disc, but this issue in cervical disc replacement surgery is poorly explored and discussed in this patient population. The aim of this systematic review is to compare anterior cervical fusion and total disc replacement (TDR) in terms of preservation of the overall cervical alignment and complications. METHODS A systematic review of the current literature was performed, together with the evaluation of the methodological quality of all the retrieved studies. RESULTS In most of the retrieved studies, a tendency towards a more postoperative kyphotic alignment in TDR was reported. The reported mean complication rate was of 12.5 % (0-66.2 %). Complications associated with cervical prosthesis included heterotopic ossification, device migration, mechanical instability, failure, implant removal, reoperations and revision. CONCLUSIONS Even though cervical disc arthroplasty leads to similar outcomes compared to arthrodesis in the middle term follow-up, no evidence of superiority of cervical TDR is available up to date. We understand that the overall cervical alignment after TDR tends towards the loss of lordosis, but only longer follow-up can determine its influence on the clinical results.
Collapse
|
32
|
Lazennec JY, Aaron A, Ricart O, Rakover JP. The innovative viscoelastic CP ESP cervical disk prosthesis with six degrees of freedom: biomechanical concepts, development program and preliminary clinical experience. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY 2015; 26:9-19. [PMID: 26341803 PMCID: PMC4705139 DOI: 10.1007/s00590-015-1695-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 08/21/2015] [Indexed: 12/20/2022]
Abstract
The viscoelastic cervical disk prosthesis ESP is an innovative one-piece deformable but cohesive interbody spacer. It is an evolution of the LP ESP lumbar disk implanted since 2006. CP ESP provides six full degrees of freedom about the three axes including shock absorbtion. The prosthesis geometry allows limited rotation and translation with resistance to motion (elastic return property) aimed at avoiding overload of the posterior facets. The rotation center can vary freely during motion. The concept of the ESP prosthesis is fundamentally different from that of the devices currently used in the cervical spine. The originality of the concept of the ESP® prosthesis led to innovative and intense testing to validate the adhesion of the viscoelastic component of the disk on the titanium endplates and to assess the mechanical properties of the PCU cushion. The preliminary clinical and radiological results with 2-year follow-up are encouraging for pain, function and kinematic behavior (range of motion and evolution of the mean centers of rotation). In this series, we did not observe device-related specific complications, misalignment, instability or ossifications. Additional studies and longer patient follow-up are needed to assess long-term reliability of this innovative implant.
Collapse
|
33
|
Lee SE, Jahng TA, Kim HJ. Correlation between cervical lordosis and adjacent segment pathology after anterior cervical spinal surgery. 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 2015. [PMID: 26198705 DOI: 10.1007/s00586-015-4132-6] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the incidence and risk factors for adjacent segment pathology (ASP) after anterior cervical spinal surgery. METHODS Fourteen patients (12 male, mean age 47.1 years) who underwent single-level cervical disk arthroplasty (CDA group) and 28 case-matched patients (24 male, mean age 53.6 years) who underwent single-level anterior cervical discectomy and fusion (ACDF group) were included. Presence of radiologic ASP (RASP) was based on observed changes in anterior osteophytes, disks, and calcification of the anterior longitudinal ligament on lateral radiographs. RESULTS The mean follow-up period was 43.4 months in the CDA group and 44.6 months in the ACDF group. At final follow-up, ASP was observed in 5 (35.7%) CDA patients and 16 (57.1%) ACDF patients (p = 0.272). The interval between surgery and ASP development was 33.8 months in the CDA group and 16.3 months in the ACDF group (p = 0.046). The ASP risk factor analysis indicated postoperative cervical angle at C3-7 being more lordotic in non-ASP patients in both groups. Restoration of lordosis occurred in the CDA group regardless of the presence of ASP, but heterotopic ossification development was associated with the presence of ASP in the CDA group. And the CDA group had significantly greater clinical improvements than those in the ACDF group when ASP was present. CONCLUSION In both CDA and ACDF patients, RASP developed, but CDA was associated with a delay in ASP development. A good clinical outcome was expected in CDA group, even when ASP developed. Restoration of cervical lordosis was an important factor in anterior cervical spine surgery.
Collapse
Affiliation(s)
- Soo Eon Lee
- Department of Neurosurgery, Seoul National University Hospital, Seoul, Republic of Korea
| | - Tae-Ahn Jahng
- Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 173-82 Gumi-Ro, Bundang-Gu, Seongnam, Gyeonggi-Do, 463-707, Republic of Korea.
| | - Hyun Jib Kim
- Department of Neurosurgery, Seoul National University Bundang Hospital, Seoul National University College of Medicine, 173-82 Gumi-Ro, Bundang-Gu, Seongnam, Gyeonggi-Do, 463-707, Republic of Korea
| |
Collapse
|
34
|
Liu B, Zeng Z, Hoof TV, Kalala JP, Liu Z, Wu B. Comparison of hybrid constructs with 2-level artificial disc replacement and 2-level anterior cervical discectomy and fusion for surgical reconstruction of the cervical spine: a kinematic study in whole cadavers. Med Sci Monit 2015; 21:1031-7. [PMID: 25853772 PMCID: PMC4403376 DOI: 10.12659/msm.892712] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Multi-level cervical degeneration of the spine is a common clinical pathology that is often repaired by anterior cervical discectomy and fusion (ACDF). The aim of this study was to investigate the kinematics of the cervical spine after hybrid surgery compared with 2-level ACDF. MATERIAL AND METHODS Five freshly frozen, unembalmed whole human cadavers were used including 3 males and 2 females with a mean age of 51 ± 8 years. After evaluating the intact spine for range of motion (ROM), sagittal alignment and instantaneous center of rotation (ICR), each cadaver underwent 4 consecutive surgeries: 2-level artificial disc replacement (ADR) from C4 to C6 (ADR surgery); 2-level ACDF from C4 to C6 (ACDF surgery); hybrid C4-5 ACDF and C5-6 ADR (ACDF+ADR surgery); and hybrid C4-5 ADR and C5-6 ACDF (ADR+ACDF surgery). The ROM and ICR of adjacent intact segments (C3-4; C6-7), and whole sagittal alignment were revaluated. RESULTS Two-level ACDF resulted in increased ROM at C3-4 and C6-7 compared with intact spine. ROM was significantly different to intact spine using ACDF surgery at C3-C4 and C6-C7 and ROM was increased with ACDF+ADR surgery at C6-C7 (all P<0.05). No improvement in sagittal alignment was observed with any approach. The localization of the ICR shifted upwards and anteriorly at C3-C4 after reconstruction. ICR changes at C3-C4 were greatest for ADR+ACDF surgery and were significantly different to ACDF surgery (P<0.05), but not between ADR surgery and ACDF+ADR surgery. At C6-C7, the ICR was more posterior and superior than in the intact condition. The greatest change in ICR was observed in ACDF surgery at the C6-C7 level, significantly different from the other groups (P<0.05). CONCLUSIONS For 2-level reconstruction, hybrid surgery and ADR did not alter ROM and minimally changed ICR at the adjacent-level. The type of surgery had a significant impact on the ICR location. This suggests that hybrid surgery may be a viable option for 2-level cervical surgery.
Collapse
Affiliation(s)
- Baoge Liu
- Department of Orthopaedic Surgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland)
| | - Zheng Zeng
- Department of Orthopaedic Surgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland)
| | - Tom Van Hoof
- Department of Anatomy, Ghent University, Ghent, Belgium
| | | | - Zhenyu Liu
- Department of Orthopaedic Surgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland)
| | - Bingxuan Wu
- Department of Orthopaedic Surgery, Beijing Tian Tan Hospital, Capital Medical University, Beijing, China (mainland)
| |
Collapse
|
35
|
Ling JM, Tiruchelvarayan R. Early clinical and radiographical results of keel-less and shallow keel cervical disc replacement. Asian J Neurosurg 2015; 10:5-9. [PMID: 25767568 PMCID: PMC4352635 DOI: 10.4103/1793-5482.151501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Background: Cervical disc replacements has been shown to be as effective as fusions in the treatment of radiculopathy or myelopathy due to disc prolapse. Newer implants were designed to reduce the difficulty of end-plate preparation. Since 2010, the authors have started using Discocerv (Alphatec Spine, Carlsbad, USA) a keel-less implant and Activ-C (B. Braun, Sheffield, UK), a shallow keel implant. Aim: The aim of this study was to compare the duration of surgery between cervical disc replacement and anterior cervical discectomy and fusion, and also to evaluate the functional outcome, complications, and radiographic outcome of cervical disc replacement. Results: Fifty patients were included (20 disc replacement and 30 fusion). This was a single surgeon retrospective study, with all surgery performed by the senior author (RT). The mean operation duration for single-level disc replacement was 2.6 h, and for single-level fusion was 2.4 h (P = 0.4684). For 2-levels surgery, the result was 3.5 h for 2-level hybrid surgery (one level disc replacement and one level fusion) and 3.4 h for fusion (P = 0.4489). Disc replacement resulted in preservation of an average of 67% of the angle of motion at the sagittal plane (FFflexion-extension). The average range of motion after disc replacement was 6.1°. The median clinical follow-up duration was 2 years (average 1.8 years). There was no incidence of major complications or significant neurovascular injury in this series of patients. A significant improvement in short form-36 scores was seen as early as 3 months postoperative (from 58 preoperative to 92 at 3 months). The improvement was sustained up to the fourth year of follow-up. Conclusion: Cervical arthroplasty with keel-less and shallow keel implants are safe and relatively easy to perform. The surgical time for disc replacement is not significantly longer than standard fusion surgery. There is reasonably good preservation of motion. The short-term functional improvement is good, and we await further long-term outcome results. The authors felt that cervical disc replacement will have an important role in the treatment of cervical degenerative disc disease in the future.
Collapse
Affiliation(s)
- Ji Min Ling
- Department of Neurosurgery, National Neuroscience Institute, 11 Jalan Tan Tock Seng, 308433 Singapore
| | - Rajendra Tiruchelvarayan
- Department of Neurosurgery, National Neuroscience Institute, 11 Jalan Tan Tock Seng, 308433 Singapore ; Department of Neurosurgery, Singapore General Hospital, Academia, Level 5, 169865 Singapore ; Spine Neuro Specialist Centre, Gleneagles Medical Centre, 258499 Singapore
| |
Collapse
|
36
|
Zang L, Fan N, Hai Y, Lu SB, Su QJ, Yang JC, Du P, Gao YJ. Using the modified Delphi method to establish a new Chinese clinical consensus of the treatments for cervical radiculopathy. 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 2015; 24:1116-26. [PMID: 25753006 DOI: 10.1007/s00586-015-3856-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 03/03/2015] [Indexed: 11/28/2022]
Abstract
PURPOSE Although cervical radiculopathy is very common, there is no standard treatment for this condition, with little high-level evidence available to guide the treatment choice. Thus, this study aimed to review the current data on the management of cervical radiculopathy; and, further, to establish a new Chinese clinical consensus of the treatments for cervical radiculopathy using the Delphi method. METHODS First, a systematic review of the previously established treatment guidelines and of articles related to cervical radiculopathy was conducted to establish a protocol for the clinical consensus of the treatment for cervical radiculopathy. Second, from February 2012 to June 2014, we performed a modified Delphi survey in which the current professional opinions from 30 experienced experts, representing almost all of the Chinese provinces, were gathered. Three rounds were performed, and consensus was defined as ≥70% agreement. RESULTS Consensus of the treatments for cervical radiculopathy was reached on seven aspects, including the proportion of patients requiring only non-surgical therapies; the effectiveness of neck immobilization, physiotherapy, pharmacologic treatment; surgical indications; contraindications; surgery. CONCLUSIONS The modified Delphi study conducted herein reached a consensus concerning several treatment issues for cervical radiculopathy. In the absence of high-level evidence, at present, these expert opinion findings will help guide health care providers to define the appropriate treatment in their regions. Items with no consensus provide excellent areas for future research.
Collapse
Affiliation(s)
- Lei Zang
- Department of Orthopedics, Beijing Chaoyang Hospital, Capital Medical University, GongTiNanLu 8#, Chaoyang district, 100020, Beijing, China
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Zhang Z, Jiao L, Zhu W, Du Y, Zhang W. Comparison of Bryan versus ProDisc-C total disk replacement as treatment for single-level cervical symptomatic degenerative disk disease. Arch Orthop Trauma Surg 2015; 135:305-11. [PMID: 25555380 DOI: 10.1007/s00402-014-2149-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2014] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this retrospective trial was to compare the role of the Bryan with ProDisc-C total disk replacement (TDR). MATERIALS AND METHODS Data were collected before surgery and 1, 3, 6, 12, and 24 months after surgery. Disability and pain were assessed using the Neck Disability Index (NDI) and the Visual Analog Scale of the neck and of the arm pain. SF-36 outcome measures were obtained including the physical component score as well as the mental component score. Functional spinal unit (FSU) was examined on lateral radiographs at 24-month follow-up. Occurrences of heterotopic ossification (HO) were detected from 24-month follow-up X-rays. RESULTS The mean NDI, mean VAS, and mean SF-36 scores were not statistically different between groups before surgery and at 24-month follow-up. At 24 months: Bryan 49 and ProDisc-C 53 (P > 0.05). The FSU angle increased slightly for the Bryan group (from 0.7 to 0.8°, P > 0.05), while for the ProDisc-C group, it increased significantly (from 0.5 to 2.3°, P < 0.05). There were 2 additional operations in this series: 1 in the Bryan group and 1 in the ProDisc-C group. There were no intraoperative complications, no vascular or neurologic complications, no spontaneous fusions, and no device failures or explantation. No significant difference was noted in terms of HO formation. CONCLUSION Both the Bryan and the ProDisc-C TDR resulted in satisfactory clinical outcome. Moreover, Bryan TDR can maintain the lordosis of FSU, whereas ProDisc-C TDR can restore the lordosis of FSU, whether or not this radiographic evidence leads to more favorable clinical outcome for ProDisc-C TDR requires further investigation.
Collapse
Affiliation(s)
- Zhenxiang Zhang
- Orthopedic Department, The Affiliated Taizhou People's Hospital of Nantong University, Taizhou, 225300, Jiangsu, People's Republic of China
| | | | | | | | | |
Collapse
|
38
|
Alvin MD, Abbott EE, Lubelski D, Kuhns B, Nowacki AS, Steinmetz MP, Benzel EC, Mroz TE. Cervical arthroplasty: a critical review of the literature. Spine J 2014; 14:2231-45. [PMID: 24704679 DOI: 10.1016/j.spinee.2014.03.047] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/10/2014] [Accepted: 03/26/2014] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Cervical disc arthroplasty (CDA) is a motion-preserving procedure that is an alternative to fusion. Proponents of arthroplasty assert that it will maintain cervical motion and prevent or reduce adjacent segment degeneration. Accordingly, CDA, compared with fusion, would have the potential to improve clinical outcomes. Published studies have varying conclusions on whether CDA reduces complications and/or improves outcomes. As many of these previous studies have been funded by CDA manufacturers, we wanted to ascertain whether there was a greater likelihood for these studies to report positive results. PURPOSE To critically assess the available literature on cervical arthroplasty with a focus on the time of publication and conflict of interest (COI). STUDY DESIGN/SETTING Review of the literature. METHODS All clinical articles about CDA published in English through August 1, 2013 were identified on Medline. Any article that presented CDA clinical results was included. Study design, sample size, type of disc, length of follow-up, use of statistical analysis, quality-of-life (QOL) outcome scores, COI, and complications were recorded. A meta-analysis was conducted stratifying studies by COI and publication date to identify differences in complication rates reported. RESULTS Seventy-four studies were included that investigated 8 types of disc prosthesis and 22 met the criteria for a randomized controlled trial (RCT). All Level Ib RCTs reported superior quality-of-life outcomes for CDA versus anterior cervical discectomy and fusion (ACDF) at 24 months. Fifty of the 74 articles (68%) had a disclosure section, including all Level Ib RCTs, which had significant COIs related to the respective studies. Those studies without a COI reported mean weighted average adjacent segment disease rates of 6.3% with CDA and 6.2% with ACDF. In contrast, the reverse was reported by studies with a COI, for which the averages were 2.5% with CDA and 6.3% with ACDF. Those studies with a COI (n=31) had an overall weighted average heterotopic ossification rate of 22%, whereas those studies with no COI (n=43) had a rate of 46%. CONCLUSIONS Associated COIs did not influence QOL outcomes. Conflicts of interest were more likely to be present in studies published after 2008, and those with a COI reported greater adjacent segment disease rates for ACDF than CDA. In addition, heterotopic ossification rates were much lower in studies with COI versus those without COI. Thus, COIs did not affect QOL outcomes but were associated with lower complication rates.
Collapse
Affiliation(s)
- Matthew D Alvin
- Neurological Institute, Center for Spine Health, Department of Orthopaedic and Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Case Western Reserve University School of Medicine, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - E Emily Abbott
- Neurological Institute, Center for Spine Health, Department of Orthopaedic and Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA
| | - Daniel Lubelski
- Neurological Institute, Center for Spine Health, Department of Orthopaedic and Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Cleveland Clinic Lerner College of Medicine, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA
| | - Benjamin Kuhns
- Neurological Institute, Center for Spine Health, Department of Orthopaedic and Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Case Western Reserve University School of Medicine, 10900 Euclid Ave, Cleveland, OH 44106, USA
| | - Amy S Nowacki
- Cleveland Clinic Lerner College of Medicine, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Quantitative Health Sciences, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA
| | - Michael P Steinmetz
- Neurological Institute, Center for Spine Health, Department of Orthopaedic and Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Neurosciences, MetroHealth Medical Center, 2500 Metrohealth Dr., Cleveland, OH 44109, USA
| | - Edward C Benzel
- Neurological Institute, Center for Spine Health, Department of Orthopaedic and Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Cleveland Clinic Lerner College of Medicine, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA
| | - Thomas E Mroz
- Neurological Institute, Center for Spine Health, Department of Orthopaedic and Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Department of Neurological Surgery, Cleveland Clinic, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA; Cleveland Clinic Lerner College of Medicine, 9500 Euclid Ave., S-80, Cleveland, OH 44195, USA.
| |
Collapse
|
39
|
Liu B, Liu Z, VanHoof T, Kalala J, Zeng Z, Lin X. Kinematic study of the relation between the instantaneous center of rotation and degenerative changes in the cervical intervertebral disc. EUROPEAN SPINE JOURNAL : OFFICIAL PUBLICATION OF THE EUROPEAN SPINE SOCIETY, THE EUROPEAN SPINAL DEFORMITY SOCIETY, AND THE EUROPEAN SECTION OF THE CERVICAL SPINE RESEARCH SOCIETY 2014; 23:2307-13. [PMID: 24972979 DOI: 10.1007/s00586-014-3431-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2013] [Revised: 06/20/2014] [Accepted: 06/21/2014] [Indexed: 11/29/2022]
Abstract
PURPOSE We located the instantaneous center of rotation (ICR) for the cervical spine at various ages and investigated age-related changes. We evaluated the impact of cervical disc degeneration on the ICR using a scoring system based on plain radiographs. METHODS Flexion, extension, and neutral lateral radiographs were obtained from 680 asymptomatic subjects (363 men, 317 women; ages 20-79 years) divided into six 10-year-age groups. The ICRs from C3/C4 to C6/C7 were determined from the radiographs using MIMICS software. A scoring system determined from lateral radiographs quantitatively assessed degeneration of cervical intervertebral discs. ICRs were compared among groups to analyze age-related changes and the relation between degenerative changes and ICR location. RESULTS In asymptomatic subjects, the ICR was located approximately at the superior half of the lower vertebral body height and the posterior half of its width. The ICR at the C5/C6 level was located more anterior and higher in patients >50 years than in younger subgroups (P < 0.05). Degenerative changes produced more anterosuperior translation of the ICR, which was significantly correlated with height loss (P < 0.05). In moderately or severely degenerated segments, the ICR location change reached statistical significance (P < 0.05). CONCLUSIONS Baseline data for Chinese cervical spine ICRs were established for the third through eighth decade of life, including age-related changes and the kinematic effects of degenerative change on the ICR in the functional spine unit. These findings should be considered in clinical practice and when designing disc prostheses.
Collapse
Affiliation(s)
- Baoge Liu
- Department of Orthopaedic surgery, Beijing TianTan Hospital, Capital Medical University, TianTan Xili No.6, Dongcheng District, Beijing, 100050, China,
| | | | | | | | | | | |
Collapse
|
40
|
Abstract
Cervical arthroplasty was developed in an attempt to maintain cervical motion and potentially to avoid or minimize adjacent-segment degeneration. If cervical arthroplasty is successful, the long-term results of surgery for cervical disc disease should improve. However, problems associated with cervical arthroplasty have been reported: these include kyphosis, heterotopic ossification-induced motion limitation, no motion preservation even at the index level, and a higher revision rate in a limited number of cases compared with anterior cervical discectomy and fusion (ACDF). In addition, for degenerative cervical disc disorders, the risk of developing adjacent segment degeneration more than 2 years after surgery is reportedly similar for ACDF and cervical arthroplasty. Cervical disc arthroplasty is an emerging motion-sparing technology and is currently undergoing evaluation in many countries as an alternative to arthrodesis for the treatment of cervical radiculopathy and myelopathy. The decision whether to use arthrodesis or arthroplasty is a difficult one. The achievement of good prosthetic performance demands exacting implantation techniques to ensure correct placement. This fact underlines the increasing importance of special instrumentation and surgical skills that involve an understanding of prosthetic lubrication, wear, and biologic effects and familiarity with currently available information regarding kinematics, basic science, testing, and early clinical results. Fortunately, a number of devices are at the late preclinical study stage or at the early clinical trial stage, and results in many cases are promising. In the near future, it is likely that new designs will be produced to replace spinal discs totally or partially in a pathologic entity-specific manner.
Collapse
|
41
|
Li Z, Yu S, Zhao Y, Hou S, Fu Q, Li F, Hou T, Zhong H. Clinical and radiologic comparison of dynamic cervical implant arthroplasty versus anterior cervical discectomy and fusion for the treatment of cervical degenerative disc disease. J Clin Neurosci 2013; 21:942-8. [PMID: 24411326 DOI: 10.1016/j.jocn.2013.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Revised: 09/05/2013] [Accepted: 09/12/2013] [Indexed: 11/30/2022]
Abstract
This study compared the clinical and radiological outcomes of dynamic cervical implant (DCI; Scient'x, Villers-Bretonneux, France) arthroplasty versus anterior cervical discectomy and fusion (ACDF) for the treatment of cervical degenerative disc disease. This prospective cohort study enrolled patients with single-level cervical degenerative disc disease who underwent DCI arthroplasty or ACDF between September 2009 and June 2011. Patients were followed up for more than 2years. Clinical evaluation included the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), Neck Disability Index (NDI), Japan Orthopedic Association (JOA) score, and visual analog scale (VAS) scores for neck and arm pain. Radiological assessments included segmental range of motion (ROM), overall ROM (C2-C7), disc height (DHI), and changes in adjacent disc spaces. The VAS, SF-36, JOA, and NDI scores improved significantly after surgery in both the DCI and ACDF groups. The VAS, JOA, and SF-36 scores were not significantly different between the DCI and ACDF groups at the final follow-up. The segmental ROM at the treated level and overall ROM increased significantly after surgery in the DCI group, but the ROM in the adjacent cephalad and caudal segments did not change significantly. The mean DHI at the treated level was significantly restored after surgery in both groups. Five patients (12.8%) in the DCI group showed new signs of adjacent segment degeneration. These results indicate that DCI is an effective, reliable, and safe procedure for the treatment of cervical degenerative disc disease. However, there is no definitive evidence that DCI arthroplasty has better intermediate-term results than ACDF.
Collapse
Affiliation(s)
- Zhonghai Li
- Department of Orthopaedics, First Affiliated Hospital of PLA General Hospital, 51 Fucheng Road, Beijing 100048, China
| | - Shunzhi Yu
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yantao Zhao
- Department of Orthopaedics, First Affiliated Hospital of PLA General Hospital, 51 Fucheng Road, Beijing 100048, China
| | - Shuxun Hou
- Department of Orthopaedics, First Affiliated Hospital of PLA General Hospital, 51 Fucheng Road, Beijing 100048, China.
| | - Qiang Fu
- Department of Orthopaedics, First Affiliated Hospital of PLA Second Military Medical University, Shanghai, China
| | - Fengning Li
- Department of Orthopaedics, First Affiliated Hospital of PLA Second Military Medical University, Shanghai, China
| | - Tiesheng Hou
- Department of Orthopaedics, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Hongbin Zhong
- Department of Orthopaedics, First Affiliated Hospital of PLA General Hospital, 51 Fucheng Road, Beijing 100048, China
| |
Collapse
|
42
|
Clinical and radiographic results of Bryan cervical total disc replacement: 4-year outcomes in a prospective study. Arch Orthop Trauma Surg 2013; 133:1061-6. [PMID: 23681469 DOI: 10.1007/s00402-013-1772-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Early results have indicated that the Bryan cervical total disc replacement (TDR) favorably compares to anterior cervical decompression and fusion, while it is associated with fewer complications and higher levels of satisfaction. In this study, we sought to prospectively report the midterm outcomes of the Bryan TDR. PATIENTS AND METHODS A total of 20 patients had performed their 4-year follow-up visit and had been assessed clinically and radiologically. Clinical outcomes (JOA, VAS, NDI, SF-36) and ROM measurements were investigated preoperatively and at 1 and 6 months, and 1, 2 and 4 years after operation. Complications were also investigated. Occurrences of heterotopic ossifications (HOs) and adjacent-level degeneration (ALD) radiographic changes were detected from 4-year follow-up X-rays. RESULTS The mean JOA score, VAS score for arm and neck, NDI score and SF-36 score for PCS and MCS were reduced significantly at each postoperative time point when compared with the preoperative condition. The range of movement of the cervical spine, functional spinal unit, treated segment and the adjacent segment temporarily decreased at the early assessment, but all recovered to preoperative levels over a 6-month to 4-year time period. HO was evident in 6 of the 23 operated segments, which did not restrict the movement of the prosthesis. No obvious ALD was found on MRI. There were no cases of prosthesis migration, subsidence, loosening or wear. CONCLUSION The midterm outcomes demonstrated that the Bryan TDR maintains favorable clinical and radiological results, with preservation of movement and satisfactory clinical outcome. There were no serious complications or cases of prosthetic wear or failure. The long-term benefits are yet to be examined.
Collapse
|
43
|
Reversal of anterior cervical discectomy and fusion with cervical artificial disc replacement: regain motion after 9 years fusion. ACTA ACUST UNITED AC 2013; 26:55-9. [PMID: 21964454 DOI: 10.1097/bsd.0b013e3182337275] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
STUDY DESIGN Case report and review of the literature. OBJECTIVE To present a conversion of an anterior cervical discectomy and fusion (ACDF) with a cervical artificial disc replacement in a 39-year-old woman and to review the relevant literature. SUMMARY OF BACKGROUND DATA Return of functional spinal unit motion 9 years after attempted fusion is extremely rare. METHODS The patient underwent an attempted anterior cervical discectomy and fusion 9 years earlier for bilateral hand numbness and leg weakness. Most of her neurological deficits had resolved after the index operation, but returned 2 months before the second operation and were unresponsive to nonoperative treatment. Computed tomography (CT) myelography showed recurrence of cervical disc herniation at the cephalad adjacent segment, which compressed the spinal cord. There was still some osteophyte at the C5/6 level that was also causing compression to the spinal cord. A solid fusion was suspected at this level. Surgery was performed to take down the grafted region and replace both levels with artificial disks. RESULTS The range of motion (ROM) of the revised level at the 6-month follow-up was well preserved, there was no sign of instability at either operated level. The 6-month follow-up CT scan shows that, there was no obvious compression in the spinal canal. The remobilized facet joints of C5/6 segment have not demonstrated further degeneration. The patient's neck symptom and neurological function were significantly recovered. CONCLUSIONS This case demonstrates application of a cervical artificial disc replacement to restore motion at a level that was previously grafted and fused. In select cases, cervical artificial disc replacement may represent a reasonable alternative to a repeated attempt at fusion. It is imperative that preoperatively lack of fusion of the facet joints be demonstrated on reconstructed CT scanning.
Collapse
|
44
|
Chen Y, Wang X, Lu X, Yang H, Chen D. Cervical disk arthroplasty versus ACDF for preoperative reducible kyphosis. Orthopedics 2013; 36:e958-65. [PMID: 23823056 DOI: 10.3928/01477447-20130624-29] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Cervical total disk arthroplasty has proven to be an effective and safe alternative for anterior cervical diskectomy and fusion (ACDF) for the treatment of cervical disk degenerative disease. However, whether and when cervical disk arthroplasty is indicated for preoperative cervical spine kyphosis is unclear. In the authors' clinical experiences, preoperative kyphosis can generally be divided into reducible and irreducible forms according to the results of dynamic flexion-extension lateral radiographs. Reducible kyphosis is mostly related to local disk prolapse, clinical symptoms, and musculature weakness, but irreducible kyphosis is always associated with significant cervical degeneration or congenital bone malformation. In this study, 32 patients with preoperative reducible kyphosis were randomized in a 1:1 ratio to either single-level total cervical arthroplasty with the Discover cervical disk prosthesis (DePuy Spine, Raynham, Massachusetts) (arthroplasty group) or single-level ACDF with a polyetheretherketone cage and plate (ACDF group). No significant differences existed in clinical and radiological results at 2-year follow-up between the arthroplasty and ACDF groups. The global and functional spinal unit angles of the arthroplasty group were significantly lower than those of the ACDF group 6 months postoperatively, which was consistent with the result of the comparison in Neck Disability Index score. However, the sagittal alignment of the overall cervical spine and the treated segment and the Neck Disability Index score significantly improved after 6 months in the arthroplasty group but not in the ACDF group. Therefore, preoperative reducible kyphosis is not a contraindication for cervical total disk arthroplasty. However, neck strength-building exercises should be emphasized for the postoperative rehabilitation after cervical total disk arthroplasty.
Collapse
Affiliation(s)
- Yu Chen
- Department of Spine Surgery, Orthopedics Research Institute of the Chinese People’s Liberation Army, Changzheng Hospital, Second Military Medical University, Shanghai, China.
| | | | | | | | | |
Collapse
|
45
|
Vorsic M, Bunc G. ProDisc-C versus fusion with Cervios chronOS prosthesis in cervical degenerative disc disease: Is there a difference at 12 months? EVIDENCE-BASED SPINE-CARE JOURNAL 2013; 1:51-6. [PMID: 23544025 PMCID: PMC3609006 DOI: 10.1055/s-0028-1100894] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Study design: Prospective cohort study. Objective: The aim of the study was to compare clinical results and to determine differences in outcomes between anterior cervical discectomy and fusion (ACDF) and disc arthroplasty in patients treated for symptomatic cervical degenerative disc disease. Methods: Forty patients with cervical degenerative disc disease were treated with ProDisc-C disc arthroplasty and 40 patients with fusion using an intervetebral spacer with integrated fixation (Cervios chronoOS) implants without additional anterior fixation. Fifty disc prostheses were placed in the first group and 52 intervertebral spacers were implanted in the second group. Clinical outcomes were assessed before and 12 months following the procedure using the neck disability index (NDI) and visual analog scale (VAS) for neck and arm pain, with 15% improvement in NDI and 20% in VAS defined as a clinically significant. Results: Eighty patients with cervical degenerative disc disease with a mean age of 49.7 years were included in the study with a minimum follow-up of 12 months. The groups were similar at baseline both clinically and statistically (P > .05) except for age and VAS for arm pain. Both groups had a statistically significant improvement in NDI and VAS for neck and arm pain (P < .05) and the arthroplasty group had a better improvement according to NDI (74.3% of patients in the arthroplasty group achieved ≥15% improvement in NDI versus 65.7% of patients in ACDF group). Conclusions: Both ProDisc C and Cervios chronoOS prostheses resulted in significant pain reduction and functional outcome for the patients with slightly better results in the group treated with disc arthroplasty 12 months after the surgery.
Collapse
Affiliation(s)
- Matjaz Vorsic
- University Hospital Maribor, Department of Neurosurgery; Maribor, Slovenia
| | | |
Collapse
|
46
|
Clinical and radiological follow-up of single-level Prestige LP cervical disc replacement. Arch Orthop Trauma Surg 2013; 133:473-80. [PMID: 23392650 DOI: 10.1007/s00402-013-1689-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Indexed: 02/09/2023]
Abstract
OBJECTIVE To evaluate the clinical outcomes and radiographic results of patients who underwent single-level cervical arthroplasty using the Prestige LP. METHOD Thirty-one patients with single-level cervical disc disease received the Prestige LP disc replacement from June 2008 to December 2009. The neck disability index (NDI), Japanese Orthopedic Association score (JOA) and visual analogue scale (VAS) were used to assessed clinical outcomes pre-operatively and post-operatively at 24 months. The overall cervical alignment (C2-7 Cobb angle), the functional segmental unit (FSU) curvature, the range of motion (ROM) of treated and adjacent levels were measured, and the evidence of heterotopic ossification (HO) was observed from static and dynamic radiographs. RESULTS There was a statistically significant improvement in the NDI from 20.2 ± 7.5 to 6.4 ± 3.5 (P < 0.000), JOA from 12.8 ± 2.2 to 16.6 ± 0.6 (P < 0.000), the neck VAS score from 4.1 ± 2.5 to 1.4 ± 1.1 (P < 0.000), the arm VAS score from 4.6 ± 2.5 to 0.7 ± 1.1 (P < 0.000). The post-operative overall cervical alignment (9.3° ± 7.2°), ROM of treated level (7.6°) and adjacent level (upper level 9.4° ± 3.1°, lower level 9.1° ± 3.5°) are well maintained. The FSU were 0.2° ± 5.4° and 1.9° ± 5.5° at pre-operation and final follow-up with statistical significance (P = 0.011). Heterotopic ossification was evidenced in five operated segment (16 %). CONCLUSIONS The Prestige LP disc arthroplasty maintains favorable clinical outcomes, preserves the overall cervical alignment, FSU curvature, ROM of treated level and adjacent levels.
Collapse
|
47
|
Heary RF, Choudhry OJ, Jalan D, Agarwal N. Analysis of cervical sagittal alignment after screw-rod fixation. Neurosurgery 2013; 72:983-91; discussion 991-2. [PMID: 23442516 DOI: 10.1227/neu.0b013e31828e20ff] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND The use of posterior instrumentation constructs is well established for subaxial cervical stabilizations/fusions. The importance of global and regional sagittal alignment has become increasingly recognized. OBJECTIVE To perform an analysis using computed tomography scans to determine the effect of posterior instrumentation on postoperative cervical sagittal alignment at long-term follow-up. METHODS Over a period of 6 years, 56 consecutive patients (38 male and 18 female patients; mean age, 47 years) underwent cervical screw-rod fixation. Plain radiographs, computed tomography scans, and magnetic resonance images were analyzed preoperatively to assess sagittal alignment (C2-C7). Postoperatively, computed tomography scans and serial radiographs were obtained in all patients. With the use of independent observers, changes in sagittal alignment were determined by comparing the preoperative and postoperative imaging studies. RESULTS In total, 390 screws were placed in the cervical spines of 56 patients. Definitive radiographic fusion was detected in all 56 patients (100%). There were no incidences of instrumentation failures or lucencies surrounding any screws. Patients with preoperative kyphosis (n = 19; mean, +9.9°) improved their sagittal alignment by 6.5° (final mean, +3.4°), whereas patients with preoperative lordosis (n = 37; mean -15.44°) maintained their lordosis (final mean, -15.3°). Mean duration of follow-up was 32.5 months. CONCLUSION Radiographic analysis showed lateral mass fixation to be safe and effective. Certain operative techniques allowed substantial deformity correction and maintenance of long-term correction of deformity. Screw-rod fixation may be an effective method for maintaining lordotic cervical alignment in previously lordotic patients and for significantly correcting kyphotic deformity in patients with a preoperative kyphosis.
Collapse
Affiliation(s)
- Robert F Heary
- Department of Neurological Surgery, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 17101-1709, USA.
| | | | | | | |
Collapse
|
48
|
Footprint mismatch in total cervical disc arthroplasty. 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 2012. [PMID: 23184184 DOI: 10.1007/s00586-012-2594-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE Cervical disc arthroplasty has become a commonplace surgery for the treatment of cervical radiculopathy and myelopathy. Most manufacturers derive their implant dimensions from early published cadaver studies. Ideal footprint match of the prosthesis is essential for good surgical outcome. METHODS We measured the dimensions of cervical vertebrae from computed tomography (CT) scans and to assess the accuracy of match achieved with the most common cervical disc prostheses [Bryan (Medtronic), Prestige LP (Medtronic), Discover (DePuy) Prodisc-C (Synthes)]. A total of 192 endplates in 24 patients (56.3 years) were assessed. The anterior-posterior and mediolateral diameters of the superior and inferior endplates were measured with a digital measuring system. RESULTS Overall, 53.5 % of the largest device footprints were smaller in the anterior-posterior diameter and 51.1 % in the mediolateral diameter were smaller than cervical endplate diameters. For levels C5/C6 and C6/C7 an inappropriate size match was noted in 61.9 % as calculated from the anteroposterior diameter. Mismatch at the center mediolateral diameter was noted in 56.8 %. Of the endplates in the current study up to 58.1 % of C5/C6 and C6/C7, and up to 45.3 % of C3/C4 and C4/C5 were larger than the most frequently implanted cervical disc devices. CONCLUSION Surgeons and manufacturers should be aware of the size mismatch in currently available cervical disc prostheses, which may endanger the safety and efficacy of the procedure. Undersizing the prosthetic device may lead to subsidence, loosening, heterotopic ossification and biomechanical failure caused by an incorrect center of rotation and load distribution, affecting the facet joints.
Collapse
|
49
|
Tu TH, Wu JC, Huang WC, Wu CL, Ko CC, Cheng H. The effects of carpentry on heterotopic ossification and mobility in cervical arthroplasty: determination by computed tomography with a minimum 2-year follow-up. J Neurosurg Spine 2012; 16:601-9. [DOI: 10.3171/2012.3.spine11436] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Heterotopic ossification (HO) after cervical arthroplasty can limit the mobility of an artificial disc. In this study the authors used CT scanning to assess the formation of HO with the goal of investigating the correlation between the carpentry of arthroplasty, formation of HO, mobility, and clinical outcomes.
Methods
A retrospective review of medical records, radiological studies, and clinical evaluations was conducted for consecutive patients who underwent 1- or 2-level cervical arthroplasty with the Bryan disc. The patients underwent follow-up for more than 24 months. The formation of HO was assessed using CT scanning as the final determination. The perfectness of carpentry for each arthroplasty level was scrutinized using criteria composed of 2 parameters (postoperative shell kyphosis and inadequate endplate coverage). Levels were divided into the optimal carpentry group and the suboptimal carpentry group. Radiographic and clinical outcomes, including the visual analog scale and neck disability index, were compared between the groups.
Results
A total of 107 levels of Bryan discs were placed in 75 patients (mean age 46.71 ± 9.94 years) and were analyzed. There was a male predominance of 68.0% (51 men), and the mean follow-up duration was 38.56 ± 9.66 months. Heterotopic ossification was identified in 60 levels (56.1%) by CT scanning. Most cases of HO were low grade and did not correlate with the limitation in the segmental motion of the arthroplasty device. There were no significant differences in terms of age, sex, and number of arthroplasty levels between the optimal and the suboptimal carpentry groups. However, the suboptimal carpentry group had significantly more high-grade HO (≥ Grade 2) than the optimal carpentry group (13 levels [12.1%] vs 7 levels [6.5%], p = 0.027). There were also more immobile (range of motion < 3°) artificial discs in the suboptimal carpentry group than the optimal carpentry group (11 levels [10.3%] vs 4 levels [3.7%], p = 0.010). The clinical outcomes (neck and arm visual analog scale scores and Neck Disability Index) in both groups were similarly good.
Conclusions
Shell kyphosis and inadequate endplate coverage have adverse effects on the formation of HO and segmental mobility after cervical arthroplasty with the Bryan artificial disc. Appropriate carpentry is the more important factor in determining the maintenance of segmental motion. Although the midterm clinical outcome remained similarly good regardless of HO, the carpentry of cervical arthroplasty should not be overlooked. Further studies are needed to clarify the etiology of HO.
Collapse
Affiliation(s)
- Tsung-Hsi Tu
- 1Department of Neurosurgery, Neurological Institute, and
- 2School of Medicine and
- 3Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Jau-Ching Wu
- 1Department of Neurosurgery, Neurological Institute, and
- 2School of Medicine and
- 3Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| | - Wen-Cheng Huang
- 1Department of Neurosurgery, Neurological Institute, and
- 2School of Medicine and
| | - Ching-Lan Wu
- 2School of Medicine and
- 4Department of Radiology, Taipei Veterans General Hospital; and
| | - Chin-Chu Ko
- 1Department of Neurosurgery, Neurological Institute, and
- 2School of Medicine and
| | - Henrich Cheng
- 1Department of Neurosurgery, Neurological Institute, and
- 2School of Medicine and
- 3Institute of Pharmacology, National Yang-Ming University, Taipei, Taiwan
| |
Collapse
|
50
|
Goel VK, Faizan A, Palepu V, Bhattacharya S. Parameters that effect spine biomechanics following cervical disc replacement. 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 2012; 21 Suppl 5:S688-99. [PMID: 21598118 PMCID: PMC3377804 DOI: 10.1007/s00586-011-1816-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 04/11/2011] [Accepted: 04/13/2011] [Indexed: 10/18/2022]
Abstract
Total disc replacement (TDR) is expected to provide a more physiologic alternative to fusion. However, long-term clinical data proving the efficacy of the implants is lacking. Limited clinical data suggest somewhat of a disagreement between the in vitro biomechanical studies and in vivo assessments. This conceptual paper presents the potential biomechanical challenges affecting the TDR that should be addressed with a hope to improve the clinical outcomes and our understanding of the devices. Appropriate literature and our own research findings comparing the biomechanics of different disc designs are presented to highlight the need for additional investigations. The biomechanical effects of various surgical procedures are analyzed, reiterating the importance of parameters like preserving uncinate processes, disc placement and its orientation within the cervical spine. Moreover, the need for a 360° dynamic system for disc recipients who may experience whiplash injuries is explored. Probabilistic studies as performed already in the lumbar spine may explore high risk combinations of different parameters and explain the differences between "standard" biomechanical investigations and clinical studies. Development of a patient specific optimized finite element model that takes muscle forces into consideration may help resolve the discrepancies between biomechanics of TDR and the clinical studies. Factors affecting long-term performance such as bone remodeling, subsidence, and wear are elaborated. In vivo assessment of segmental spine motion has been, and continues to be, a challenge. In general, clinical studies while reporting the data have placed lesser emphasis on kinematics following intervertebral disc replacements. Evaluation of in vivo kinematics following TDR to analyze the quality and quantity of motion using stereoradiogrammetric technique may be needed.
Collapse
Affiliation(s)
- Vijay K Goel
- Departments of Bioengineering and Orthopaedic Surgery, 5046 NI, MS 303, Colleges of Engineering and Medicine, Engineering Center for Orthopaedic Research Excellence, University of Toledo, Toledo, OH 43606, USA.
| | | | | | | |
Collapse
|