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 degrees to 19.4 degrees (P = 0.012). Sagittal balance changed in the hybrid group from -21.2 mm to 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 degrees to 20.25 degrees and improved from 54.88 degrees to 15.06 degrees 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.