Electron Microscopic Insights into Degenerating Lumbar Intervertebral Disc: A Prospective, Cohort Study

Abstract Degenerative disc disease is a leading cause of chronic low back pain, yet radiological and histological assessments often fail to explain symptom severity. Existing studies rarely incorporate electron microscopy (EM), leaving a gap in knowledge regarding cellular and extracellular matrix (ECM) alterations at the ultrastructural level and their relationship with clinical outcomes. This study aimed to investigate ultrastructural changes in lumbar intervertebral disc tissue using EM and to correlate these findings with clinical symptoms and radiological features. A prospective observational study was conducted in 50 patients undergoing lumbar discectomy. Disc tissue was analyzed using EM. Clinical parameters (visual analogue scale [VAS] score, symptom duration) and MRI features (Pfirrmann grading, Modic changes) were recorded and statistically correlated with EM findings. Chondrocyte clustering (88%) and intracellular inclusion bodies (56%) were the most common EM findings. Both were significantly associated with higher VAS scores (p = 0.02 and p = 0.009, respectively) and longer symptom duration. Chondrocyte clustering and inclusions increased with higher Pfirrmann grades (p = 0.015 and p = 0.022, respectively). No significant association was found between Modic changes and the study outcomes. EM revealed critical ultrastructural changes in degenerating lumbar discs, with chondrocyte clustering and inclusions emerging as potential morphological markers of disease severity and chronicity.