Treatment of cervical adjacent segment pathology: A systematic review

Study Design. Systematic review. Objective. To critically review and summarize evidence on the treatment of cervical adjacent segment pathology (ASP). Summary of Background Data. Clinical ASP (CASP) refers to clinically significant symptoms and signs (radiculopathy, myelopathy, mechanical pain) that correlate with imaging evidence of degeneration at motion segments adjacent to a previous intervention. Despite growing awareness of the long-term risks of ASP, fusion is the most commonly performed type of cervical spine surgery. There are little data regarding the optimal treatment for cervical CASP. Methods. A systematic search of PubMed, the Cochrane Library, and Google Scholar for literature published through March 2, 2012, was conducted to answer 2 key questions: (1) What is the comparative effectiveness and safety of operative versus nonoperative treatments for cervical CASP?; and (2) Describe the outcomes of surgical treatment of cervical CASP. Results. A total of 5 studies were selected for inclusion. No comparative studies were found to answer question 1. We found 1 comparative study and 4 case series of more than 10 patients that addressed question 2: 2 studies described fusion (1 comparing discectomy with corpectomy), 2 evaluated laminoplasty, and 1 reported on use of artificial discs. No studies on use of laminectomy, foraminotomy, or posterior decompression and fusion were found. Two poor-quality (level of evidence III) retrospective cohort studies compared anterior cervical discectomy and fusion with corpectomy for the treatment of CASP, but 1 study was too small to draw meaningful comparisons and was considered a case series. The other reported a 37.5% risk difference favoring corpectomy; however, most patients in both treatment groups had excellent or good clinical results, and the study had significant methodological limitations that limit comparison of anterior cervical discectomy and fusion with corpectomy (nonrandomized allocation to treatment groups, limited follow-up, small numbers of patients). No studies describing subsequent development or advancement of ASP after reconstructive surgery were found. Conclusion. Surgical options to treat cervical CASP include fusion, laminoplasty, and disc arthroplasty. There are no comparative data to guide operative versus nonoperative management. Favorable results are reported for each of these operative strategies, but small patient numbers and largely retrospective methodology limit definitive conclusions. There were conflicting data regarding the risk of single- versus multilevel fusion with respect to arthrodesis rates, and very low evidence that fusions at spinal levels caudal to ASP have a higher pseudoarthrosis risk compared with rostral levels. Consensus Statement: 1. Arthroplasty, laminoplasty, and fusion for treatment of cervical CASP were described in the studies found. These seem to be effective for treatment of cervical CASP. No studies on foraminotomy, laminectomy, and posterior decompression and fusion were found. Level of Evidence: Insuffi cient Strength of Statement: Strong Recommendation no.1: Despite the importance of this topic, a dearth of literature was found. We recommend further studies on this topic. Level of Evidence: Insuffi cient Strength of Statement: Strong.