Instrumented posterior lumbar interbody fusion for patients with degenerative lumbar scoliosis

OBJECTIVE: Surgery for degenerative lumbar scoliosis remains challenging for spine surgeons even with the application of pedicle screw instrumentation. This retrospective study assesses the outcomes of instrumented posterior lumbar interbody fusion (PLIF) for degenerative lumbar scoliosis. METHODS: From April 2000 to April 2004, 26 patients with degenerative lumbar scoliosis were treated with instrumented PLIF. Mean age of the 15 females and 11 males was 64.2 years (range, 51 to 77y). Clinical and radiographic outcomes were retrospectively reviewed for each case at a minimum follow-up of 2 years (median follow-up, 3y; range, 2 to 6y). At final follow-up, patients were classified as 'satisfied? or ?dissatisfied? according to self-reported outcomes. RESULTS: At most recent follow-up, the average Oswestry Disability Index score was significantly lower than the preoperative score (25.8 vs. 58.0; P<0.001). Twenty (76.9%) patients reported that they were satisfied with their surgical outcomes. The average lumbar scoliosis angles were significantly less than preoperative angles (7.4 vs. 16.5 degrees; P<0.001), resulting in a reduction in mean scoliosis angles of 55.2%. The average angles of lumbar lordosis were significantly higher than preoperative angles (30.1 vs. 22.2 degrees; P≤0.001), an increase in mean lumbar lordosis angles of 35.6%. No perioperative deaths or major medical complications occurred. Five patients had adjacent segment degeneration and 4 (80%) of 5 reported dissatisfactory outcomes. Further study is required to identify the etiologies of adjacent segment degeneration and methods for avoiding such degeneration. CONCLUSIONS: Analytical results demonstrate that instrumented PLIF after laminectomy in patients with degenerative lumbar scoliosis is an effective and safe procedure.