Objective: Assessment of the clinical outcome of pedicle screw fixation and posterior lumbar interbody fusion using Oswestry Disability Score comparing preoperative scores with postoperative (1 month, three months, six months and 1 year) scores, evaluate clinical improvement in terms of pain relief, mobility and radiological outcome in patients with spondylolisthesis.

Materials and Methods: Study was performed in the orthopedic department of Katuri medical college and hospital, Chinakondrupadu, Guntur from October 2016 to September 2018. Patients diagnosed with spondylolisthesis who underwent PLIF with pedicle screw fixation are included in our study.

Results: The average preoperative ODI score was 57. The ODI score at most recent follow up (1yr) was 12.53. The result was excellent in all cases improving from severe disability to minimal disability. Mean ODI at each follow-up visit was compared with preoperative using Paired T-test, and p values were calculated. P-value was found to be significant with each comparison. Radiological evidence did not reveal any signs of cage subsidence or disc space narrowing or migration of the cage. 28 (93.3%) patients showed radiological signs of fusion, and 2 (6.6%) patients had no signs of fusion.

Conclusion: PLIF technique supplemented with posterolateral fusion is an ideal technique in spondylolisthesis for achievement of reduction, maintenance of lordosis, direct decompression of nerve roots, interbody fusion and provides good biomechanical support by pedicular screw instrumentation and cage.