Long-Term Functional Results and Predictors of Clinical-Functional Outcomes After Unilateral Open-Door Laminoplasty in Patients With Cervical Spondylotic Myelopathy

Study Design: Single-center retrospective study. Objective: To evaluate the long-term functional impact and independent predictors of neurological and functional outcomes following open-door laminoplasty (ODL). Summary of background data: Open-door laminoplasty is widely used for multilevel degenerative cervical myelopathy. While neurological recovery is well documented, comprehensive long-term functional evaluation and identification of independent predictors remain limited. Methods: Fifty-nine patients undergoing ODL at a single Institution between 2010 and 2024 were retrospectively analyzed. Neurological and functional outcomes were assessed using the Japanese Orthopedic Association (JOA) score and Oswestry Disability Index (ODI). Sagittal alignment parameters and radiologic findings were recorded. Prespecified multivariable linear regression models, adjusted for baseline score, were constructed to identify independent predictors of postoperative outcome. Results: Median follow-up was 65 months. Radiologic myelomalacia was present in 59% of patients, and the median minimum canal diameter was 7 mm. Median preoperative JOA and ODI scores were 13 and 36, respectively. At final follow-up, both neurological and functional outcomes improved significantly ( P <0.001). Fifty-eight patients (98%) improved their ODI functional class. Preoperative hypolordosis (<10 degrees) did not adversely affect long-term outcomes. Multivariable analysis identified baseline JOA and ODI scores as the primary independent predictors of postoperative neurological and functional recovery, respectively. The number of involved segments demonstrated a modest independent association with functional outcome. Conclusions: ODL provides sustained neurological and functional improvement in patients with multilevel degenerative cervical myelopathy. Baseline clinical severity is the principal determinant of recovery, while mild preoperative hypolordosis does not appear to compromise long-term outcome in appropriately selected patients.