What Happens to Sagittal Alignment Following Laminoplasty Versus Laminectomy and Fusion?

Abstract

ObjectiveLaminectomy and fusion (LF) and laminoplasty (LP) are two sucessful posterior decompression techniques for cervical myelo-radiuclopathy. There is also a growing body of evidence describing the importance of cervical sagittal alignment (CSA) and its importance in outcomes. We investigated the difference between pre- and postoperative CSA parameters in and between LF or LP. Furthermore, studied predictive variables associated with change in cervical mismatch (CM) MethodsThis is retrospective cohort study of adults with cervical myeloradiculopathy in a single healthcare system. The primary outcomes are intra- and inter-cohort comparison of LF vs. LP radiographic parameters at pre- and postoperative time points. A secondary multivariable analysis of predictive factors was performed evaluating factors predicting postoperative CM. Results89 patients were included; 38 (43%) had LF and 51 (57%) underwent LP. Both groups decreased in lordosis (LF 11.4° vs 4.9°, p = 0.01; LP 15.2° vs 9.1°, p < 0.001), increased in cSVA (LF 3.4 vs 4.2cm, p = 0.01; LP 3.2 vs 4.2cm, p < 0.001), and increased in CM (LF 22.0° vs 28.5°, p = 0.02; LP 16.8° vs 22.3°, p = 0.002). There were no significant differences in the post operative CSA between groups. No significant predictors of change in pre- and postoperative CM were found ConslusionsThere were no significant pre-or post-operative differences following the two procedures, suggesting radiographic equipoise in well indicated patients. Across all groups, lordosis decreased, cSVA increased, and cervical mismatch increased. There were no predictive factors that led to change in cervical mismatch.