Microdecompression and uninstrumented single-level fusion for spinal canal stenosis with degenerative spondylolisthesis

Study Design. A retrospective review was completed on 21 patients who had a "least invasive" (one or two level) microdecompression and uninstrumented single-segment lumbar fusion for spinal canal stenosis with degenerative spondylolisthesis. Objective. To determine whether a "least invasive" approach to lumbar spinal canal stenosis and degenerative spondylolisthesis would yield acceptable results. Summary of Background Data. The prevailing surgical technique for symptomatic spinal canal stenosis with degenerative spondylolisthesis is a wide midline decompression and instrumented fusion. Methods. On an average of 38 months postoperatively, 21 patients were personally assessed on four scores: 1) their overall satisfaction with the outcome of surgery, 2) an analog back and leg pain scale, 3) a functional evaluation scale, and 4) Ferguson (upshot) anterior-posterior lumbosacral and lateral flexion-extension radiographs. Results. The overall satisfactory outcome on all four scales was 16 (76%) of 21. Twenty of twenty-one patients had their claudicant leg pain; the overall fusion rate was 18 (86%) of 21. Two of three patients with a pseudarthrosis had a successful outcome on the patient-oriented outcome (1, 2, and 3) scales (excluding the radiograph scale), and one was a failure. One patient with a a solid fusion was a failure because of continuing back pain. One patient with a solid fusion was a failure because of continuing leg pain. The overall satisfactory outcome on the nonradiographic scales was 18 of 21, for an 86% patient satisfaction rate. Conclusions. In this retrospective study, a "least invasive" surgical approach to lumbar degenerative spondylolisthesis with spinal canal stenosis causing claudicant leg pain produced acceptable results.