Association of C7 Laminoplasty and Decompression Construct Length With Postoperative Axial Symptoms After Cervical Expansive Unilateral Open-door Laminoplasty

Study Design. Retrospective cohort study. Objective. To evaluate whether C7 laminoplasty and decompression construct length were associated with postoperative axial symptoms after expansive unilateral open-door laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM). Summary of Background Data. Postoperative axial symptoms remain a common source of dissatisfaction after cervical laminoplasty. Although prior studies have examined patient-related risk factors, the association between observed operative patterns and postoperative pain burden remains clinically relevant. Methods. Adults undergoing ELAP for CSM between April 2016 and April 2024 were retrospectively reviewed. Patients with preoperative axial symptoms, cervical deformity, trauma-related cervical spinal cord injury, neurologic disorders affecting outcome assessment, incomplete data, or follow-up shorter than 1 year were excluded. The primary outcome was new-onset postoperative axial symptoms at 12 months. The main operative variables were C7 laminoplasty versus C7 preservation and longer- versus shorter-segment ELAP. Multivariable logistic regression, descriptive joint operative-pattern analyses, longitudinal mixed-effects models, and sensitivity analyses were performed. Results. Among 865 patients, crude axial symptom rates differed across the four joint operative-pattern groups: 1.4%, 27.6%, 22.7%, and 69.4%. Exploratory logistic-regression, Firth-penalized, and propensity score analyses were directionally consistent with these absolute event-rate patterns, but the OR magnitudes should be interpreted cautiously because of nonrandom operative selection, clinical coupling between operative variables, residual confounding, and sparse reference-group events. VAS trajectories differed across groups, whereas JOA trajectories and complication rates were broadly similar. Conclusion. C7 laminoplasty and longer-segment ELAP were associated with greater postoperative axial symptom burden, and the C7-preserving/shorter-segment group had the lowest observed pain burden. These findings should be considered hypothesis-generating and should not be interpreted as evidence of operative superiority or causal surgical effects because of the observational design, nonrandom operative selection, clinical coupling between operative variables, and residual confounding.