title: Analysis of adjacent segment degeneration with laminectomy above a fused lumbar segment.
abstract: Although recent data suggests that lumbar fusion with decompression contributes to some marginal acceleration of adjacent segment degeneration (ASD), few studies have evaluated whether it is safe to perform a laminectomy above a fused segment. This study investigates the hypothesis that laminectomy above a fused lumbar segment does not increase the incidence of ASD, and assesses the benefits and risks of performing a laminectomy above a lumbar fusion. A retrospective review of 171 patients who underwent decompression and instrumented fusion of the lumbar spine was performed to analyze the association between ASD and laminectomy above the fused lumbar segment. Patients were divided into two groups - one group with instrumented fusion alone and the other group with instrumented fusion plus laminectomy above the fused segment. Of the 171 patients, 34 underwent additional decompressive laminectomy above the fused segment. There was a significant increase in ASD incidence as well as progression of ASD grade in both groups. There was no significant increase in ASD in patients with decompressive laminectomy above the fused lumbar segment compared to patients with laminectomy limited to the fused segment. This retrospective review of 171 patients who underwent decompression and instrumented fusion with follow-up radiographs demonstrates that laminectomy decompression above a fused segment does not significantly increase radiographic ASD. There is, however, a significant increase in ASD over time, which was observed throughout the entire cohort likely representing a natural progression of lumbar spondylosis above the fusion segment.
authors.affiliation: Division of Neurosurgery, Department of Surgery, University of Nebraska Medical Center, 982035 Nebraska Medical Center, Omaha, NE 68198-2035, USA. Electronic address: apgard@unmc.edu.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Gard
authors.forename: Hendrik B
authors.initials: HB
authors.lastname: Klopper
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Doran
authors.forename: Leslie C
authors.initials: LC
authors.lastname: Hellbusch
mesh_terms: D000368:Aged; D019299:Decompression, Surgical; D005260:Female; D006801:Humans; D015994:Incidence; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000453:epidemiology*; D007796:Laminectomy; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology*; D011859:Radiography; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects*
keywords: Adjacent segment degeneration; Adjacent segment instability; Instrumented fusion; Laminectomy