317. Postoperative new shoulder imbalance in severe thoracic scoliosis treated with PVCR: risk factor analysis and countermeasure

BACKGROUND CONTEXT Preoperative shoulder imbalances are more common and significant in severe scoliosis than in AIS patients. Because of the special correction mechanism, a well deformity correction and well trunk balance rebuilding could lead to a new shoulder imbalance in PVCR. There is a lack of analysis of relevant risk factors to help surgeons to reconstruct shoulder balance better. PURPOSE The purpose of this study was to research the shoulder imbalances in patients with severe thoracic scoliosis after PVCR and analyze the associated risk factors. STUDY DESIGN/SETTING A retrospective study. PATIENT SAMPLE The study included 92 severe thoracic scoliosis patients. OUTCOME MEASURES The Cobb angle, correction rate, RSH, trunk drift and coronal plane balance were measured on routine posteroanterior standing radiographs preoperatively and postoperatively. METHODS Patients with severe thoracic scoliosis who received PVCR were retrospectively analyzed. Patients with pelvic obliquity>2 cm, leg length discrepancy (> 2cm) and muscle weakness of lower limbs were excluded. All patients performed routine posteroanterior standing radiographs before and after surgery. All patients were divided into two groups: Group A was the postoperative shoulder balance group (shoulder balance was defined as standing RSH 1cm). The Cobb angle, correction rate, RSH, trunk drift and coronal plane balance were measured preoperatively and postoperatively, and the above data were compared between the two groups. RESULTS The study included 92 severe thoracic scoliosis patients. The mean preoperative major curve of 123±21° was corrected to 43±13° (correction rate: 66±12%). The mean preoperative upper curve of 58±16° was corrected to 29±10° (correction rate: 49±10%). The trunk shift was 2.53±0.63cm before surgery and 1.54±0.33cm after surgery. The mean preoperative SH was 27.2±6.8mm, the mean postoperative SH was 11.7±4.3mm (mean change: 32.4mm) (P CONCLUSIONS Patients with severe thoracic scoliosis are prone to new shoulder imbalances after PVCR. The large angle of the major thoracic curve and the better correction rate of PVCR lead to the elevation of the concave shoulder and the new imbalance. The key to avoid a new shoulder imbalance after PVCR is to avoid excessive major curve correction and to pay attention to the matching of the correction of the major curve and upper curve. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.