Correction of severe pelvic obliquity using maximum-width segmental sacropelvic screw fixation: an analysis of 20 neuromuscular scoliosis patients.

STUDY DESIGN: The present study was a retrospective analysis.

OBJECTIVE: The purpose of the study was to evaluate the safety and efficacy of the maximum-width (M-W) segmental sacropelvic fixation technique, comprising iliac screws and/or iliosacral pedicle screws, to correct severe pelvic obliquity. Classic spinal fixation using the Luque-Galveston procedure for the correction of neuromuscular scoliosis may be inadequate to manage severe pelvic obliquities.

METHODS: A series of 20 consecutive patients with severe neuromuscular spinopelvic deformities was reviewed by an independent observer. Coronal and sagittal Cobb angle, frontal pelvic obliquity, and trunk shift were measured preoperatively, immediately postoperatively and at final follow-up.

RESULTS: All 20 patients underwent spinal fusion with instrumentation extending to the pelvis. Fourteen cases had primary operations, and six patients had undergone previous spinal fusion above the pelvis, requiring extension to the pelvis. The mean age of the patients at surgery was 13 years, and the mean duration of the follow-up period was 36 months. The mean preoperative Cobb angle was 84° (range 56°-135°), which was corrected to a mean of 41° (range 8°-75°) postoperatively. At the final follow-up, the mean spinal curve remained at 42° (range 10°-75°). The mean preoperative pelvic obliquity was 42° (range 15°-105°), which was corrected by 78 % to 9° (range 0°-49°) postoperatively, with a pelvic obliquity of 10° (range 2°-49°) at final follow-up. Comparing the results of the present study with results in the literature describing the Luque-Galveston or unit rod techniques, despite patients in the present study having a greater mean pelvic obliquity (42° compared with 21° in the literature), a 78 % correction was still achieved, which is similar and, in certain instances, superior to the results of other published case series (78 % compared with 53 %).

CONCLUSIONS: Maximum-width (M-W) segmental sacropelvic fixation, comprising iliosacral screws and/or iliac screws, enables a superior correction of severe pelvic obliquity in patients with neuromuscular scoliosis.