Comparison of anterior and posterior surgery for degenerative cervical myelopathy: An MRI-based propensity-score-matched analysis using data from the prospective multicenter AOSpine CSM North America and international studies

Background: Surgeons often choose between 2 different approaches (anterior and posterior) for surgical treatment of degenerative cervical myelopathy on the basis of imaging features of spinal cord compression, the number of levels affected, and the spinal alignment. However, there is a lack of consensus on which approach is preferable. The objective of the present study was to use magnetic resonance imaging (MRI)-based propensity-score-matched analysis to compare postoperative outcomes between the anterior and posterior surgical approaches for degenerative cervical myelopathy. Methods: A total of 757 patients were enrolled in 2 prospective multicenter AOSpine studies, which involved 26 international sites. Preoperative MRIs were reviewed to characterize the causes of the cord compression, including single-level disc disease, multilevel disc disease, ossification of the posterior longitudinal ligament, enlargement of the ligamentum flavum, vertebral subluxation/spondylolisthesis, congenital fusion, number of compressed levels, or kyphosis. The propensity to choose anterior decompression was calculated using demographic data, preoperative MRI findings, and the modified Japanese Orthopaedic Association (mJOA) scores in a logistic regression model. We then performed 1-to-1 matching of patients who had received anterior decompression with those who had the same propensity score but had received posterior decompression to compare 2-year postoperative outcomes and 30-day perioperative complication rates between the 2 groups after adjustment for background characteristics. Results: A total of 435 cases were included in the propensity score calculation, and 1-to-1 matching resulted in 80 pairs of anterior and posterior surgical cases; 99% of these matched patients had multilevel compression. The anterior and posterior groups did not differ significantly in terms of the postoperative mJOA score (15.1 versus 15.3, p = 0.53), Neck Disability Index (20.5 versus 24.1, p = 0.44), or Short Form-36 (SF-36) Physical Component Summary (PCS) score (41.9 versus 40.9, p = 0.30). The overall rates of perioperative complications were similar between the 2 groups (16% versus 11%, p = 0.48); however, dysphagia/dysphonia was reported only in the anterior group whereas surgical site infection and C5 radiculopathy were reported only in the posterior group. Conclusions: Anterior and posterior decompression for degenerative cervical myelopathy resulted in similar postoperative outcomes and rates of complications. Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.