Evaluation of related parameters and risk factors of shoulder balance in adolescent idiopathic scoliosis / 中华骨科杂志

ABSTRACT

Adolescent idiopathic scoliosis (AIS) is one of the most common spinal deformities. Postoperative shoulder imbalance (PSI) is one of the issues that doctors and patients focus on, and it is also the focus of current research. At present, there is no unified consensus on the definition of shoulder balance in patients with AIS, which leads to different standards set in some studies, and the final conclusion may be the opposite. Now, most studies define shoulder imbalance as radiographic shoulder height (RSH)>10 mm, coracoid height difference (CHD)>9 mm, clavicle angle (CA)>2°or clavicle tilt angle difference (CTAD)>4.5°. In order to better describe the shoulder balance, scholars have proposed a lot of imaging parameters, in addition, aesthetic parameters have also been introduced into the study of shoulder balance. However, the two parameters have their own limitations, no single parameter can truly and accurately reflect the shoulder balance of patients. Although the evaluation results of aesthetic parameters are more real, they are the most easily obtained in clinic, and imaging parameters are the most widely used. Then, the correlation between imaging parameters and aesthetic parameters is not high, imaging parameters can not be used to completely replace aesthetic parameters. The risk factors of PSI are Risser sign grade, proximal wedge angle (PWA) size, postoperative proximal thoracic curve (PTC)/main thoracic curve (MTC) ratio, preoperative CA size or T1 tilt angle, PTC stiffness, MTC correction rate, upper instrumented vertebrae (UIV) selection and so on, but they are not independent risk factors. Recently, CCAD has been considered as a good predictor, but it has not been reported in other types of AIS except in patients with Lenke type 1 and 5. In the past, the most research on the preventive measures of PSI is the choice of upper fixation of vertebral body (UIV). Recently, it has been found that the degree of correction of deformity has an important effect on shoulder balance after operation. This article reviews the current research status of shoulder balance in adolescent idiopathic scoliosis, in order to provide ideas for further study of shoulder balance in adolescent idiopathic scoliosis.