Does decompression adjacent to arthrodesis in the lumbar spine predispose patients to adjacent segment degeneration and disease: A retrospective analysis.

Background: The treatment for multi-level spinal stenosis in the setting of single-level instability is a common operative scenario for surgeons who treat degenerative lumbar spine pathology. However, there is conflicting evidence regarding the inclusion of adjacent "stable" levels in the arthrodesis construct because of the potential for iatrogenic instability placed on those segments with decompressive laminectomy alone. This study aims to determine whether decompression adjacent to arthrodesis in the lumbar spine is a risk factor for adjacent segment disease (AS Disease). Methods: A retrospective analysis identified consecutive patients over a three-year period who underwent single-level posterolateral lumbar fusion (PLF) in the setting of single or multi-level spinal stenosis. Patients were required to have a minimum of two-year follow-up. AS Disease was defined as the development of new radicular symptoms referable to a motion segment adjacent to the lumbar arthrodesis construct. The incidence of AS Disease and reoperation rates were compared between cohorts. Results: 133 patients met the inclusion criteria with an average follow-up of 54 months. Fifty-four patients had a PLF with adjacent segment decompression, and 79 underwent a single-segment decompression and PLF. 24.1% (13/54) of patients who had a PLF with adjacent level decompression developed AS Disease resulting in a 5.5% (3/54) reoperation rate. 15.2% (12/79) of patients who did not receive an adjacent level decompression developed AS Disease resulting in a reoperation rate of 7.5% (6/79). There was neither a significantly higher rate of AS Disease (p = 0.26) nor reoperation (p = 0.74) between the cohorts. Conclusions: Decompression adjacent to single-level PLF was not associated with an increased rate of AS Disease relative to single-level decompression and PLF.