Reduction of high-grade slips (grades III-V) with VSP instrumentation. Report of a series of 41 cases.

Records of 41 patients were reviewed for early complications resulting from reduction of high-grade spondylolisthesis. Blood loss averaged 1,427 ml. There were no cases of infection, dural tears, or bladder or bowel dysfunction. Two cases of transient foot drop and one case of permanent foot drop developed. A lumbar plexus stretch palsy occurred in one patient. Long-term results were evaluated in 20 patients followed up 2 or more years after surgery. Three of the 20 did not have interbody fusions and lost their reductions. All 20 patients went on to fuse with no pseudoarthrosis. One case of broken plate and two cases of broken screws occurred. Patient satisfaction ranged from good to excellent. Results suggest that reduction of high-grade slips with interbody fusion is a safe and effective procedure.