Two-level total disc replacement with Mobi-C(r) over 3-years

Evidence-based use of arthroplasty in cervical degenerative disc disease

INTRODUCTION

Cervical disc arthroplasty (CDA) was developed to decrease the rate of symptomatic adjacent-level disease while preserving motion in the cervical spine.

METHODS

The objectives of this paper are to provide criteria for proper patient selection as well as to present a comprehensive literature review of the current evidence for CDA, including randomized studies, the most recent meta-analysis findings, and long-term follow-up clinical trials as well.

RESULTS

Currently, there are several prospective randomized controlled studies of level I of evidence attesting to the safety and efficacy of CDA in the management of cervical spondylotic disease (CSD) for one- or two-level degenerative diseases. These as well as recent meta-analyses suggest that CDA is potentially similar or even superior to anterior cervical discectomy and fusion (ACDF) when considering several outcomes, including dysphagia and re-operation rate over medium-term follow-up. Less robust studies have also reported satisfactory clinical and radiological outcomes of CDA for hybrid procedures (ACDF combined with CDA), non-contiguous disease, and even for multilevel disease (more than 2 levels).

CONCLUSIONS

Based on this evidence we conclude that CDA is a safe and effective alternative to ACDF in properly selected patients for one- or two-level diseases. Defining superiority of specific implants and detailing optimal surgical indications will require further well-designed long-term studies.

Adverse Events Following Cervical Disc Arthroplasty: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

Cervical arthroplasty is an increasingly popular treatment of cervical radiculopathy and myelopathy. An understanding of the potential adverse events (AEs) is important to help both clinicians and patients. We sought to provide a comprehensive systematic review of the AEs reported in all randomized controlled trials (RCTs) of cervical disc arthroplasty in an attempt to characterize the quality of reporting.

METHODS

We conducted a systematic review of MEDLINE and Web of Science for RCTs of cervical disc arthroplasty reporting AEs. We reported the most frequently mentioned AEs, including dysphagia/dysphonia, vascular compromise, dural injury, and infections. We recorded the presence of industry funding and scored the quality of collection methods and reporting of AEs.

RESULTS

Of the 3734 identified articles, 29 articles met full inclusion criteria. The quality of AE reporting varied significantly between studies, and a combined meta-analysis was not feasible. The 29 articles covered separate 19 RCTs. Eight studies were US Food and Drug Administration (FDA) investigational device exemption (IDE) trials. Rates were recorded for the following AEs: dysphagia/dysphonia (range = 1.3% to 27.2%), vascular compromise (range = 1.1% to 2.4%), cervical wound infection (range = 1.2% to 22.5%), and cerebrospinal fluid leak (range = 0.8% to 7.1%).

CONCLUSIONS

There is a lack of consistency in reporting of AEs among RCTs of cervical arthroplasty. FDA IDE trials scored better in AE event reporting compared to other studies. Standardized definitions for AEs and standardized data collection methodology are needed to improve future studies.

Adjacent segment degeneration and disease following cervical arthroplasty: a systematic review and meta-analysis

BACKGROUND CONTEXT

Cervical arthroplasty is an increasingly popular alternative for the treatment of cervical radiculopathy and myelopathy. This technique preserves motion at the index and adjacent disc levels, avoiding the restraints of fusion and potentially minimizing adjacent segment pathology onset during the postoperative period.

PURPOSE

This study aimed to identify all prospective studies reporting adjacent segment pathology rates for cervical arthroplasty.

STUDY DESIGN/SETTING

Systematic review and meta-analysis were carried out.

PATIENT SAMPLE

Studies reporting adjacent segment degeneration (ASDegeneration) and adjacent segment disease (ASDisease) rates in patients who underwent cervical arthroplasty comprised the patient sample.

OUTCOME MEASURES

Outcomes of interest included reported ASDegeneration and ASDisease events after cervical arthroplasty.

METHODS

We conducted a MEDLINE, SCOPUS, and Web of Science search for studies reporting ASDegeneration or ASDisease following cervical arthroplasty. A meta-analysis was performed to calculate effect summary values, 95% confidence intervals (CIs), Q values, and I(2) values. Forest plots were constructed for each analysis group.

RESULTS

Of the 1,891 retrieved articles, 32 met inclusion criteria. The patient incidence of ASDegeneration and ASDisease was 8.3% (95% CI 3.8%-12.7%) and 0.9% (95% CI 0.1%-1.7%), respectively. The rate of ASDegeneration and ASDisease at individual levels was 10.5% (95% CI 6.1%-14.9%) and 0.2% (95% CI -0.1% to 0.5%), respectively. Studies following patients for 12-24 months reported a 5.1% (95% CI 2.1%-8.1%) incidence of ASDegeneration and 0.2% (95% CI 0.1%-0.2%) incidence of ASDisease. Conversely, studies following patients for greater than 24 months reported a 16.6% (5.8%-27.4%) incidence of ASDegeneration and 2.6% (95% CI 1.0%-4.2%) of ASDisease. This identified a statistically significant increase in ASDisease diagnosis with lengthier follow-up. Additionally, 1- and 2-level procedures resulted in a 7.4% (95% CI 3.3%-11.4%) and15.6% (95 CI-9.2% to 40.4%) incidence of ASDegeneration, respectively. Although there was an 8.2% increase in ASDegeneration following 2-level operations (relative to 1-level), it did not reach statistical significance. We were unable to analyze ASDisease incidence following 2-level arthroplasty (too few cases), but 1-level operations resulted in an ASDisease incidence of 0.8% (95% CI 0.1%-1.5%).

CONCLUSIONS

This review represents a comprehensive estimation of the actual incidence of ASDegeneration and ASDisease across a heterogeneous group of surgeons, patients, and arthroplasty techniques. Our investigation should serve as a framework for individual surgeons to understand the impact of various cervical arthroplasty techniques, follow-up duration, and surgical levels on the incidence of ASDegeneration and ASDisease during the postoperative period.