Coronal and sagittal plane correction in adolescent idiopathic scoliosis - A comparison between all pedicle screw versus hybrid thoracic hook lumbar screw constructs

Study Design. This was a retrospective cohort study using a previously matched convenience sample of 34 patients. Objective. This study sought to determine the relative corrective benefits of these 2 types of constructs in the correction of coronal and sagittal curves in patients with adolescent idiopathic scoliosis (AIS). In addition, the 2 constructs were compared for coronal and sagittal balance. Summary of Background Information. Recent clinical research suggests that thoracic pedicle screw constructs (all-screw constructs) are more effective than hybrid lumbar screw thoracic hook constructs ( hybrid constructs) in correcting spine deformity. Methods. The sample consisted of patients with AIS who underwent isolated posterior spinal fusion and instrumentation. Seventeen patients underwent fusion using all-screw constructs, and 17 underwent fusion with hybrid constructs; preoperative and postoperative radiographs and measurements were compared. Results. There was no significant difference observed when comparing the 2 groups, although there was a trend toward better correction of the main thoracic curve in the all-screw construct group (P = 0.089). In the all- screw group, mean thoracic kyphosis decreased from 29.6 to 19.4 (P = 0.012). Sagittal balance changed in the hybrid group from -21.2mmto 8.2 mm, and in the all- screw group changed from -28.8 mm to 1.5 mm. The major curve in the hybrid group improved from 54.06 to 20.25 and improved from 54.88 to 15.06 in the all- screw group. Conclusions. There was no statistically significant difference comparing the 2 groups, although a trend was observed toward better correction of the main thoracic curve in the all- screw construct group. The all-screw group demonstrated a significant decrease in kyphosis, which was not seen in the hybrid group. Hybrid constructs were comparable to all-screw constructs in the correction of coronal plane deformity and sagittal balance.