Risk Factors for Postoperative Shoulder Imbalance in… : Spine
nd Data. PSI in scoliosis affects patient quality of life. While other correction methods have reported a high correction rate for the main thoracic curve (MTC) in relation to PSI, this correlation has not been confirmed for the VCA technique. Materials and Methods. We studied 176 patients with Lenke types 1 and 2 scoliosis who underwent posterior corrective fusion surgery using the VCA technique at 11 institutions. At 2 years postoperatively, patients were divided into two groups based on radiographic shoulder height (RSH): PSI− (RSH<2 cm) and PSI+ (RSH ≥2 cm) groups. We analyzed the risk factors for PSI. Results. The overall incidence of PSI 2 years postoperatively was 11.4% (20/176), with 9.2% (11/119) and 15.8% (9/57) in patients with Lenke types 1 and 2, respectively. Contrary to a previous study, a high MTC correction rate did not emerge as a risk factor for PSI. Instead, preoperative left shoulder elevation, low postoperative thoracic kyphosis, greater T1 tilt, and high apical v