Instrumented Fusion in the Management of Post-Laminectomy Lumbar Spinal Stenosis

While the indications for and the effectiveness of decompressive laminectomy have been well documented, there is uncertainty regarding the use of fusion and instrumentation in degenerative spinal disorders. This retrospective review was designed to assess the outcome of repeat decompression and instrumented fusion for post–laminectomy lumbar spinal stenosis.

Methods/Results:

Over a ten–year period, 43 patients with chronic low back and/or leg pain underwent repeat decompressive laminectomy and instrumented fusion for recurrent and/or residual lumbar spinal stenosis. These patients had a total of 51 previous decompressive laminectomies without fusion for lumbar stenosis. The mean interval between the preceding decompressive procedure and subsequent fusion was 2.67 years. The average age of the patients was 66.4 years, and the average number of levels fused was 2.8. Outcome in terms of pain relief and functional improvement was determined by chart review. With a mean follow–up of 1.46 years, an overall improvement was achieved in 77% of patients. Additionally, 35 patients responded to a questionnaire (mean follow–up 3.26 years) in which they graded their outcomes as much improved (51.4%), somewhat improved (37.1%), unchanged (11.4%), somewhat worse (0%), and much worse (0%). Five (11.6%) patients required an additional 7 lumbar spine operations for adjacent level stenosis at a mean interval of 1.93 years after fusion.

Conclusions:

Long–term improvement was attained in approximately 80% of patients who underwent repeat decompression and instrumented fusion for post–laminectomy lumbar spinal stenosis. However, fusion may accelerate degeneration at adjacent levels necessitating additional lumbar spine operations.