Relationship between herniated intervertebral disc fragment weight and pain in lumbar microdiscectomy patients

Objective: The relationship between lumbar disc herniation (LDH) size and the severity of preoperative pain and its impact on postoperative recovery is incompletely understood. This study was conducted to investigate the association between herniated disc fragment weight and pain before and after microdiscectomy. Methods: A consecutive series of patients from an ongoing randomised controlled trial (ACTRN12616001360404) were included in this study. Included patients were aged between 18 and 75, had a clinical diagnosis of radiculopathy, and MRI evidence of a concordant single-level lumbar disc herniation. All patients underwent standard microdiscectomy without aggressive discectomy or curettage of the endplates. Disc fragment weight was measured intraoperatively. Results: A total of 122 patients with a mean age of 49.5 ± 12.8 years, were included. The median weight of disc fragment was 0.545 g (95% CI 0.364 – 0.654 g). There was no relationship between disc weight and the duration of symptoms (p = 0.409) severity of preoperative leg pain (p = 0.070) or preoperative back pain (p = 0.884). Disc fragment weight was demonstrated to have no correlation with clinically significant postoperative leg pain improvement (p = 0.535) or back pain (p = 0.991). Additional LDH factors, including radiological percentage of canal compromise (p = 0.714), herniation classification (p = 0.462), and vertebral level (p = 0.788) were also shown to have no effect on leg pain outcomes. Conclusions: Disc fragment weight had no effect on the severity of pain at presentation or after microdiscectomy. Patients benefit from surgery equally, regardless of the size of LDH.