Analysis Of Related Factors Of Postoperative Of Shoulder Imbalance In Lenke1A/B Adolescent Idiopathic Scoliosis

Objective:To explore the risk factors of postoperative shoulder imbalance in Lenke 1A/B Adolescents Idiopathic Scoliosis(AIS),and detect the factors’effect on Postoperative Shoulder Imbalance(PSI).Methods:A total of 58 patients with Lenke1A/B adolescent idiopathic scoliosis who received surgical treatment in the Department of Spine Surgery,Xiangya Hospital,Central South University from 2012 to2018 were included and retrospectively studied.Risser sign and curves flexibility were measured before surgery,the number of vertebral body(EV-UIV)between Upper Instrumentation Vertebra(UIV)and End Vertebra(EV)were recorded after surgery.Radiographic Shoulder Height(RSH),Clavicle Angle(CA),Main Thoracic Curve(MTC)Cobb angle and correction rate,Proximal Thoracic Curve(PTC)and Lumbar Curve(LC)Cobb Angle and correction rate and other parameters were measured before surgery,in 3 months after surgery and the last follow-up.All 58patients were divided into the shoulder balance group(RSH at last follow-up<10mm)and the shoulder imbalance group(RSH at last follow-up≥10mm).The differences of various indicators between the two groups were compared,and the correlation analysis of indicators with significant differences was conducted to evaluate their relationship with PSI.Results:All 58 patients with Lenke1A/B AIS achieved satisfactory surgical corrective result.At the last follow-up,the correction rate of MTC was 75.16%±10.36%,the correction rate of PTC was42.66%±20.91%,and the correction rate of LC was 74.02%±21.23%.Through the comparison of various indicators and correlation analysis between the two groups,the factors related to PSI are as follows:preoperative Risser sign(r=-0.312,P=0.017),EV-UIV vertebral body number(R=-0.367,P=0.005),PTC correction rate at last follow-up(r=-0.768,P=0.010),LC Cobb Angle at last follow-up(r=-0.361,P=0.005),the correction rate of LC at the last follow-up(r=0.273,P=0.038),CA at the last follow-up(r=0.894,P<0.001),and the occurrence of Adding-on phenomenon(X~2=5.560,P=0.018).Conclusions:In patients with Lenke1A/B AIS,the choice of instrument and fusion segment,the correction rate of PTC at the last follow-up,Risser sign,the postoperative Adding-on phenomenon,the LC Cobb angle and the correction rate of LC at the last follow-up are related to the occurrence of PSI.The choice of instrument and fusion segment is related to the occurrence of postoperative shoulder imbalance.PTC correction rate is negatively correlated with PSI,and excessive PTC correction may increase the probability of PSI.Adding-on phenomenon is positively correlated with PSI.The incidence of PSI could be reduced by preventing the occurrence of Adding-on phenomenon after surgery.Risser sign is negatively correlated with PSI,and it is possible to predict PSI according to Risser sign before surgery.The Cobb Angle of LC is negatively correlated with PSI at the last follow-up,and the correction rate of LC is positively correlated with PSI.If the flexibility of LC is adequate,the instrumentation of LC can be shortened appropriately to reduce the incidence of PSI.