Correction of apical axial rotation with pedicular screws in neuromuscular scoliosis

Study Design: A retrospective study to measure the postoperative apical axial derotation with posterior pedicle screw fixation in neuromuscular scoliosis. Objectives: To determine whether the posterior only approach using pedicle screw fixation is able to accomplish apical axial derotation in neuromuscular scoliosis and if there is any difference according to severity of curve or type of disease. Summary of Background Data: Literature search does not reveal anything about the rectification of apical axial rotation in neuromuscular scoliosis with the pedicle screw fixation. Methods: Between January 2005 and December 2006, 24 patients (9 females and 15 males, average age 19 y) with neuromuscular scoliosis (6 cerebral palsy, 9 Duchenne muscular dystrophy, 5 spinal muscular atrophy, and 4 others) underwent posterior pedicle screw construct with correction and fusion for the treatment of progressive, symptomatic spinal deformities. Preoperative, immediate postoperative, and final follow-up radiographs were analyzed according to Cobbs angle and pelvic obliquity, whereas apical axial rotation was measured on preoperative and postoperative computerized tomography scan using Aaro-Dahlborn method from mid-sagittal plane. Twelve (9 females and 3 males) adolescent idiopathic scoliosis patients, who underwent similar operation, comprised our control group for the comparison of results. Results: All the patients exhibited improved sitting balance after surgery. The mean preoperative Cobbs angle, pelvic obliquity, and apical rotation were 74, 14, and 42 degrees, whereas postoperative were 32, 6, and 33 degrees, respectively, showing significant correction in all 3 parameters. Comparison of results based on severity of curve did not reveal any statistically significant difference (P=0.255) in correction of apical axial rotation among group I, group II, and group III. A similar apical rotational correction was recorded in different disease groups (P=0.295). Comparing the results between neuromuscular and idiopathic scoliosis groups, we could not find any statistically significant difference. Conclusions: Our results indicate that apical axial derotation can be well achieved with posterior only pedicle screw fixation in patients with neuromuscular scoliosis without any need for an anterior release procedure.