Multiaxial high-modularity spinopelvis (HMSP) fixation device in neuromuscular scoliosis: a comparative study.

Purpose: To compare radiological and clinical results in patients operated for neuromuscular scoliosis with pelvic fixation using high-modularity spinopelvic screw (HMSP) designed by authors.

Methods: Of 54 patients with neuromuscular scoliosis, group 1 comprised of 27 patients with conventional pelvic fixation; and group 2 comprised of 27 patients using HMSP. Results were evaluated radiologically and functionally. We compared preoperative and postoperative complications, especially the loosening or breakage of spinopelvis fixation device, failure of fixation, and the change of shadow around the spinopelvis fixation device.

Results: There was no difference of correctional power, preoperative average Cobb's angle of each group was 79.8 and 75 to postoperative 30.2 and 28.3 (P < 0.05). Pelvic obliquity improved from average 18.3°-8.9° in group I and average 24.3°-12.5° in group II (P < 0.05). However, there was no difference between two groups (P > 0.05). Average blood loss was 2,698 ml in group 1 and 2,414.8 ml in group 2 (P > 0.05). Average operative time was 360 min in group 1 and 332 min in group 2 (P = 0.30). There was no difference found between two groups regarding gait and functional evaluation. On the all cases of group 1 and 2, the change of shadow around the spinopelvis fixation device was observed. There was one case of the fracture of spinopelvis fixation device in group I.

Conclusion: There was no difference of Cobb's angle and correctional power between the groups using HMSP when compared with the group using standard spinopelvis fixation device. Therefore, HMSP can be used more effectively in case of neuromuscular scoliosis.