Posterior pedicular screw instrumentation and anterior interbody fusion in adult lumbar spondylolysis or grade I spondylolisthesis with segmental instability.

Between 1988 and 1993, we treated 21 adults with symptomatic lumbar spondylolysis by a combined surgery of posterior stabilization and anterior interbody fusion. Our indication for this combined surgery was persistent pain that was unresponsive to conservative measures and segmental instability on flexion-extension roentgenogram. The patients' mean age at the time of surgery was 34 years (range 24-42 years). All patients showed degenerated disks on preoperative magnetic resonance imaging. The mean follow-up period was 30.4 months. The clinical result was excellent or good in 95%, and the radiographic fusion was successful in 95%. Prolonged pain at the donor site was the most common complication, which usually disappeared by 3 months after the operation. We recommend the combined surgery of posterior instrumentation and anterior fusion to stabilize symptomatic adult lumbar spondylolysis.