Background: Prolapsed intervertebral disc (PIVD) in lumbar disc herniation is a leading cause of low back pain and radiculopathy, frequently necessitating surgery after failed conservative treatment. This study assesses functional outcomes following surgical management in patients at a tertiary center in eastern Nepal.

Methods: A retrospective review was conducted of 335 patients surgically treated for lumbar PIVD at Nobel Medical College Teaching Hospital from January 2016 to December 2023. Inclusion criteria required single-level herniation (documented on MRI), failure of structured conservative treatment (physiotherapy, analgesics, and lifestyle modification for a minimum of 3 months), and/or neurological deterioration. Patients with multi-level disease (n=49, 14.6%) underwent surgery based on clinical-radiological concordance and are reported descriptively. Functional outcomes were evaluated using Visual Analog Scale (VAS) for leg and back pain, Oswestry Disability Index (ODI), and Modified Macnab Criteria at baseline, 1 month, and 3 months postoperatively.

Results: Mean age was 44.34 ± 13.60 years; 58.2% were male. L4-L5 herniation predominated (54.3%). Microdiscectomy was performed in 70.0% of cases. VAS leg pain decreased from 7.5 ± 1.2 preoperatively to 2.0 ± 0.9 at 3 months (p<0.001); ODI improved from 55 ± 12% to 20 ± 9% (p<0.001). Excellent or good Macnab outcomes were achieved in 90.2%; recurrence occurred in 3.0%.

Conclusions: Surgical intervention for lumbar PIVD provides substantial pain relief and functional improvement at short-term follow-up. Limitations include retrospective design, short follow-up duration (3 months), absence of imaging confirmation at follow-up, and single-center data. Long-term prospective studies with extended follow-up are warranted.

Keywords: Discectomy; Intervertebral Disc Displacement; Lumbar Vertebrae; Nepal; Treatment Outcome; Microdiscectomy