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 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.