MRI and Histopathology-Based Predictors of Postoperative Functional Recovery in Patients with Lumbar Disc Herniation: A Retrospective Cohort Study

Abstract

Background: Functional recovery after lumbar microdiscectomy varies despite adequate decompression. Magnetic resonance imaging (MRI) and histopathological characteristics of excised disc tissue may provide complementary prognostic information.

Objective: To identify MRI- and histopathology-based predictors of postoperative functional recovery in patients with lumbar disc herniation.

Methods: This retrospective cohort study included 100 patients undergoing primary lumbar microdiscectomy at District Headquarters Hospital, Nankana Sahib, and Neurosurgery Unit III, Punjab Institute of Neurosciences, Lahore General Hospital, from March 2025 to March 2026. Preoperative MRI assessed disc morphology, Pfirrmann grade, Modic changes, nerve-root compression, canal compromise, and foraminal stenosis. Histopathology evaluated degeneration, inflammation, neovascularization, fibrosis, and cartilaginous endplate fragments. Functional recovery was assessed using the Oswestry Disability Index (ODI) at 6 months. Poor recovery was defined as <30% improvement in ODI.

Results: Successful recovery occurred in 74% of patients. Poor recovery was independently associated with symptom duration ≥6 months (aOR 2.74), Modic type 1 changes (aOR 3.12), severe nerve-root compression (aOR 2.89), and substantial cartilaginous endplate involvement (aOR 3.46). Advanced disc degeneration and foraminal stenosis were associated with poor recovery on univariable analysis but lost significance after multivariable adjustment in the final model. The combined clinical-MRI-histopathological model demonstrated the highest predictive accuracy (AUC 0.87; 95% CI 0.79–0.94), with 84.6% sensitivity and 81.1% specificity.

Conclusion: MRI and histopathological features provide complementary prognostic information after lumbar microdiscectomy. Their combined assessment may improve risk stratification and postoperative management.