The Preoperative Cross-sectional Area of the Deep Cervical Extensor Muscles Does Not Predict Loss of Lordosis After Cervical Laminoplasty.

Study design This was a retrospective, single center. Objectives The objective of this study was to investigate the association between the cross-sectional area (CSA) of the deep extensor muscles (DEM) and postlaminoplasty alignment. Summary of background data The preoperative CSA of the semispinalis cervicis (SC) has been reported to correlate with loss of lordosis (LL) after laminoplasty, with a CSA Methods Laminoplasty patients at the University of California San Francisco between 2009 and 2018 by 2 spine surgeons were retrospectively studied. Patients with previous cervical surgery or nondegenerative diagnoses were excluded. Measurements included the C2-C7 Cobb, T1 slope, and cervical sagittal vertical axis. Preoperative DEM CSA was measured on magnetic resonance imaging. Variables associated with lordosis were analyzed with univariate analysis and multivariate logistic regression, and association between postoperative cervical alignment and the musculature was evaluated. Results Seventy-six patients with a mean age of 64 years were included. The average follow-up was 22.53 months. The overall average CSA of the DEM was 2274.55 mm2 and that of the SC was 275.64 mm2. Means of both CSAs were higher in men (P 0.05). Conclusions Preoperative CSA of the deep cervical extensor muscles may not predict LL after cervical laminoplasty. The correlation between the preoperative SC CSA and postoperative cervical alignment may not be as strong as previously reported.