Surgical treatment of dysplastic spondylolisthesis. Results after in situ fusion.

STUDY DESIGN

Fourteen patients who had symptomatic dysplastic spondylolisthesis with an intact pars interarticularis underwent posterolateral spinal fusion. Patients initially had low back pain, tight hamstrings, and limited forward bending. In addition, four patients had signs of progressive cauda equina or nerve root impingement. In 10 patients (71%), preoperative degree of slippage was more than 50% (mean, 72%).

METHODS

Ten patients underwent in situ posterolateral spinal fusion, and four patients with progressive neurologic symptoms had posterior decompression followed by in situ posterolateral spinal fusion.

RESULTS

All patients had solid fusion at last follow-up. A pseudoarthrosis developed in one patient, which healed after a second operation. Roentgenographic progression of the slip after fusion was rare.

CONCLUSIONS

This study demonstrated that for dysplastic spondylolisthesis in children and adolescents, in situ posterolateral spine fusion yields satisfactory results. In addition, in the presence of progressive cauda equina or nerve root impingement, posterior decompression may be necessary.