Symptom Duration of 1 Year or More Is Associated With Worse Absolute Outcomes but Similar Clinically Meaningful Improvement After ACDF for Cervical Myelopathy

Study Design. Retrospective Cohort Study Objective. To evaluate the association between preoperative symptom duration and neurologic and patient-reported outcomes following anterior cervical discectomy and fusion (ACDF) for degenerative cervical myelopathy (DCM). Summary of Background Data. Prior studies suggest longer duration of preoperative myelopathic symptoms may impair neurologic recovery after surgery, but its relationship with patient-reported outcome measures (PROMs) and clinically meaningful improvement remains unclear. Methods. Adult patients undergoing primary ACDF for myelopathy at a single academic institution (2017–2023) were identified. Patients were stratified by symptom duration (<1 y versus ≥1 y). Demographic, surgical, and clinical outcomes were collected. PROMs included Short Form-12 mental and physical component scores (MCS, PCS), Visual Analog Scale (VAS) Neck and Arm, Neck Disability Index (NDI), and modified Japanese Orthopaedic Association (mJOA) scores collected preoperatively and at 3, 6, and 12 months postoperatively. Achievement of minimal clinically important difference (MCID) was assessed. Results. A total of 139 patients met inclusion criteria, including 75 (54.0%) with symptom duration <1 year. Patients with <1 year of symptoms were older, less likely to have commercial insurance, less likely to undergo inpatient surgery, and underwent fusion of fewer levels. Six-month MCS (55.1 versus 50.2, P =0.038) and 3-month PCS (38.5 versus 34.3, P =0.030) were greater in the <1 year cohort. VAS Neck and NDI scores were lower at select postoperative time points in the <1 year cohort. The ≥1 year cohort demonstrated higher rates of MCID achievement for VAS Neck at 6 and 12 months. No differences were observed in mJOA scores or MCID achievement for other outcomes. Conclusion. Longer preoperative symptom duration was associated with worse absolute postoperative pain and disability but not neurologic recovery, with largely comparable rates of MCID achievement following ACDF. These findings suggest that delayed presentation does not preclude meaningful postoperative improvement for cervical myelopathy. Level of Evidence. III