Posterior Spinal Cord Drift Following C3 to C6 Laminectomy in Patients with CSM at the National Orthopaedic Hospital Dala Kano Nigeria

Abstract

Background: Cervical laminectomy is an indirect decompression technique for cervical spondylotic myelopathy (CSM) that relies on posterior displacement of the spinal cord—commonly referred to as “cord drift.” However, the extent of cord drift and its relationship with functional recovery in African populations has not been characterised. This study aimed to determine the predictors of favourable outcomes following C3–C6 laminectomy with lateral mass screw fixation in patients with CSM at a Nigerian tertiary hospital. Methods: A retrospective cohort study of 167 patients who underwent C3–C6 laminectomy with lateral mass screw fixation (3.5 mm × 14 mm screws) at the National Orthopaedic Hospital Dala, Kano, from January 2019 to December 2025 was conducted. Preoperative and postoperative MRI measurements of spinal cord drift were recorded. Functional outcome was assessed using the modified Japanese Orthopaedic Association (mJOA) score. Multivariate logistic regression identified predictors of favourable outcomes (mJOA recovery rate ≥50%). Results: The mean age was 58.4±10.2 years; 96 patients (57.5%) were male. The mean preoperative mJOA score was 11.2±2.8, improving to 14.6±2.4 postoperatively (p<0.001). The mean spinal cord drift was 2.8±1.2 mm. A cord drift ≥3 mm was achieved in 102 patients (61.1%). Independent predictors of favourable outcome were: cord drift ≥3 mm (adjusted OR = 4.2, 95% CI: 2.1–8.4, p<0.001), preoperative mJOA score ≥12 (OR = 2.8, 95% CI: 1.4–5.6, p=0.004), and symptom duration ≤12 months (OR = 2.3, 95% CI: 1.2–4.4, p=0.01). The complication rate was 7.8%, with C5 palsy occurring in 3.6%. Conclusions: C3–C6 laminectomy with lateral mass screw fixation is an effective treatment for CSM in this Nigerian cohort. Adequate cord fall back (>3 mm), better preoperative neurological status, and shorter symptom duration predict favourable outcomes.