[Causes of reoperations in patients with lumbar spinal stenosis treated with instrumentations].

Objective: In present study we analyze the causes leading to reoperation patients treated for lumbar spinal stenosis with laminectomy and lumbar instrumentation.
Material and Methods: 74 patients operated between January of 1996 and December of 2000 with a minimum 4 year follow-up were seleted for the study.
Results: 16 patients (21.1%) underwent a new surgical intervention. The main cause for reoperation was stenosis of the adjacent level superiorly to the instrumentation (in 50%). Other causes were radicular fibrosis, persistence of stenosis after the surgery, neuropatic pain, failure of the instrumentation system, transpedicular screws misplacement and break of screws.
Conclusions: Complications related with the initial surgical procedure are low, as half of the reoperations were due to stenosis of the segment superior to the fixation.