RESUMO
CASE: Ten days after L3-L5 instrumented posterior lumbar spinal fusion, an 85-year-old woman developed Grade 4 spondylolisthesis at L5-S1 after a minor fall. She underwent posterior open reduction and internal fixation with extension of fusion from L2 to the pelvis. The preexisting hardware at L5 caused partial laceration of the right L5 nerve root. One year after surgery, computed tomography demonstrated maintenance of correction and fusion at L5-S1. CONCLUSION: High-grade lumbosacral spondylolisthesis can occur with minor trauma after short-segment lumbar fusion. Maintenance of correction and fusion is achievable with posterior open reduction and internal fixation to the pelvis alone. Preexisting hardware can damage nerve roots causing permanent neurological deficits.