High-grade lumbosacral spondylolisthesis reduction and fusion in children using transsacral rod fixation.

PURPOSE

There is no consensus on how to treat surgically high-dysplastic developmental spondylolisthesis in children and adolescents. Although reducing spinal deformity seems mandatory, the issue of surgical reduction versus in situ fusion remains controversial.

METHODS

The files of 12 consecutive patients surgically treated for a grade 3 or 4 spondylolisthesis were reviewed. The treatment consisted in L4 to sacrum reduction and fusion by posterior approach. The reduction of lumbopelvic imbalance was made intraoperatively using a trans-sacral rod fixation technique.

RESULTS

Mean preoperative L5 anterior slippage was 72.3 % (60 to 95 %). The mean preoperative lumbosacral tilt angle was 70.5° (43 to 92°). Mean final lumbosacral tilt angle was 102° (91 to 114°). Mean final L5 anterior slippage was 19 % (7 to 63 %). Neurological complications (radicular L5 or S1 deficits) were noted in five patients. At final follow-up L4 to S1 fusion was achieved in all patients. No patient had persistent deficit or radicular pain.

CONCLUSIONS

The fusion rate in our series proved to be optimal. Thanks to the trans-sacral rod fixation, lumbosacral kyphosis correction was very good. The intrasacral positioning of the screws reduces the risk of implant prominence especially in such pediatric patients. We stress the importance to avoid complete slip reduction in such patients to minimize stretching on L5 and S1 roots. No additional immobilization is needed due to solid posterior instrumentation. Doing such procedure only by posterior approach avoids anterior approach-related complications.