Iatrogenic Spondylolisthesis Following Open Lumbar Laminectomy: Case Series and Review of the Literature.

OBJECTIVE: To present diagnosis and surgical management of postlaminectomy spondylolisthesis in patients without preoperative instability and a review of relevant literature.

METHODS: Medical records and radiographic studies of 105 patients who underwent first-time bilateral 1- to 4-level open laminectomies for degenerative lumbar disease at a single academic institution were reviewed. Patients who initially presented with listhesis and had additional discectomy or fusion procedures were excluded.

RESULTS: Of 105 patients with laminectomies across 1-4 levels, 10 patients (9.5%; 5 men and 5 women with average age of 63.0 ± 11.2 years) developed subsequent iatrogenic spondylolisthesis at the same operative levels that required reoperation. New or worsening low back pain and lower extremity pain were reported over an average period of 19.0 ± 17.5 months postoperatively. Imaging studies showed new spondylolisthesis that was not present before the index surgery, most commonly at L4-L5 level. All patients were treated surgically with posterior instrumented fusion. The average period between the first and second surgery was 32.6 ± 19.9 months. Surgical reduction of spondylolisthesis resulted in significant clinical improvement of patients' symptoms.

CONCLUSIONS: In patients without overt pre-existing instability, laminectomy for lumbar stenosis can disrupt spinal stability and result in iatrogenic spondylolisthesis. The extent of decompression of the facet joints, number of levels decompressed, and preoperative disc space height can help assess the risk of postoperative spondylolisthesis. Patients who develop recurrent radiculopathy after decompressive lumbar laminectomy should be evaluated for potential iatrogenic spondylolisthesis.