Clinical Outcomes of Posterior Lumbar Interbody Fusion for the Management of Clinical and Radiological Instability: A Six-Month Retrospective Analysis at a Tertiary Care Hospital

Abstract

Background:
Lumbar instability is a common and debilitating condition, which is associated with chronic low back pain and significant functional impairment. Posterior lumbar interbody fusion (PLIF) is an invasive surgical procedure that involves simultaneous nerve decompression and spinal stabilization.

Objectives:
To assess clinical and radiological outcomes of PLIF in the management of lumbar instability at a six-month follow-up.

Methods:
A retrospective observational study at the Department of Neurosurgery was performed in adult patients undergoing PLIF between November 2025 and April 2026. Pain intensity was assessed using the Visual Analogue Scale (VAS), disability with the Oswestry Disability Index (ODI) and quality of life with the SF-36 Health Survey. Radiological outcomes were assessed using plain CT scan and MRI at baseline, and at three and six months postoperatively.

Results:
Forty-two patients met the inclusion criteria (mean age 44.3 ±13.6 years; 54.8% male), and degenerative disc disease was the diagnosis of choice (57%). Significant improvements were observed in VAS (7.6 ±1.3 to 2.1 ± 0.9; p <0.001), ODI scores (57.8 ±10.5% to 21.9 ±6.8%; p<0.001), and SF-36 Physical Component Summary (33.2 ±7.8 to 49.5 ± 7.3; p < 0.001). Satisfactory spinal fusion was confirmed in 92.9% of patients at six months, and the overall complication rate was 9.5%, with no significant neurological deficits or implant failures.

Conclusion:

PLIF is a safe, effective and reproducible surgical approach for lumbar instability with noticeable improvement in pain, function, and quality of life as well as high radiological fusion rates and a favorable risk of complications.