[Effectiveness analysis of Lenke type 1 adolescent idiopathic scoliosis with different proximal fixation vertebra]

Objective: To investigate the short-term effectiveness of proximal fixation of one vertebra above to the upper end vertebra and the upper end vertebra in the treatment of Lenke type 1 adolescent idiopathic scoliosis (AIS) patients with preoperative right higher shoulder.

Methods: The clinical data of 37 Lenke type 1 AIS patients treated with posterior correction between January 2010 and December 2015 were retrospectively analysed. According to proximal fixation vertebra, the patients were divided into 2 groups: group A ( n=17), proximal fixation of one vertebra above to the upper end vertebra; group B ( n=20), proximal fixation of the upper end vertebra. There was no significant difference in gender, age, Risser stage, radiographic shoulder height (RSH), flexibility of proximal thoracic curve, flexibility of main thoracic curve, flexibility of thoracolumbar/lumbar curve between 2 groups ( P>0.05). The main thoracic curve Cobb angle, proximal thoracic curve Cobb angle, thoracolumbar/lumbar curve Cobb angle, apical vertebral translation (AVT), clavicle angle (CA), RSH, coronal trunk shift, sagittal trunk shift, thoracic kyphosis (TK), and lumbar lordosis (LL) were measured by X-ray film before operation, and at 1 month, 1 year, and 2 years after operation. The correction indexes of main thoracic curve were evaluated, including the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation.

Results: The operation time and intraoperation blood loss in group A were significantly greater than those in group B ( P<0.05). All the patients were followed up, and the follow-up time was 2-4 years (mean, 2.8 years) in group A and 2-3.5 years (mean, 2.6 years) in group B. No serious complication such as nerve damage occurred during perioperative period and follow-up period. No complication such as failure of fusion, loosening and rupture of internal fixator, adjacent segment degeneration, and proximal junctional kyphosis occurred. There was no significant difference between 2 groups in the correction degree and correction rate of main thoracic curve and AVT correction at 1 month after operation, the loss degree and the loss rate of the correction of main thoracic curve at 2 years after operation ( P>0.05). Comparison within the two groups: except for LL had no significant difference between pre- and post-operation ( P>0.05), the other indicators were significantly improved after operation ( P<0.05) in the two groups. There were significant differences in RSH, CA, proximal thoracic curve Cobb angle, and thoracolumbar/lumbar curve Cobb angle at each time point after operation ( P<0.05), and there were spontaneous correction during follow-up; however, there was no significant difference in main thoracic curve Cobb angle, AVT, TK, LL, trunk shift at each time point after operation ( P>0.05), and there was no significant loss during follow-up. Comparison between the two groups: there was no significant difference in all the radiographic indexes at pre- and post-operation ( P>0.05).

Conclusion: For Lenke type 1 AIS patients with preoperative right high shoulder, proximal fixation vertebra be fixed to the upper end vertebral can obtain satisfactory short-term orthopedic effectiveness and reduce blood loss and operation time.