The Impact of Cervical Multifidus Sarcopenia on Outcomes After Laminoplasty for Cervical Ossification of the Posterior Longitudinal Ligament

Background: The associations between spine-specific muscle sarcopenia and clinical outcomes after cervical and lumbar spinal surgery have been investigated. However, no study has investigated the associations between cervical multifidus sarcopenia (CMS) and outcomes after laminoplasty for cervical ossification of the posterior longitudinal ligament (OPLL). The aim of the present study was to investigate whether CMS affects cervical sagittal alignment (CSA) and patient-reported outcomes (PROs) in patients with cervical OPLL who underwent laminoplasty. Methods: A retrospective review of prospectively collected data on patients with cervical OPLL who underwent laminoplasty was conducted from 2015 to 2020. CMS was evaluated on T2-weighted magnetic resonance imaging sequences at the C5-C6 level and graded according to the Goutallier classification. CSA parameters, including the C2-C7 lordosis angle, C2-C7 sagittal vertical axis (SVA), C2 slope, and T1 slope, were measured. PROs, including visual analog scale (VAS) neck and arm pain, Japanese Orthopaedic Association (JOA), and Neck Disability Index (NDI) scores, were recorded. Patients were grouped according to the Goutallier classification of CMS, and their preoperative demographic and OPLL characteristics, preoperative and latest follow-up PROs, and preoperative, immediate postoperative, and latest follow-up CSA parameters were analyzed. Results: A total of 134 patients with cervical OPLL were enrolled, including 36 patients with mild CMS (Goutallier grade >0 to 1.0), 47 patients with moderate CMS (grade 1.5 to 2.0), and 38 patients with severe CMS (grade 2.5 to 4.0). All patients were Han Chinese. The mean age differed significantly among the groups (p = 0.004), whereas the other demographic characteristics were comparable among the groups. CMS severity was significantly associated with the OPLL occupancy ratio. Significant differences were found in the postoperative changes in C2-C7 lordosis angle, C2-C7 SVA, C2 slope, and T1 slope among the groups. Greater CMS severity was associated with worse NDI and VAS neck pain scores at the latest follow-up. Conclusions: In a uniform cohort of patients who underwent laminoplasty for cervical OPLL, CMS had a negative impact on CSA and PROs. These findings highlight the potential value of preoperative assessment of CMS in this patient population. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.