Risk Factors for Multiple Implant-Related Complications (MIRC) with Growing-Rod for Early-Onset Scoliosis

Study design: A retrospective single center study.Objective：To identify risk factors for multiple implant-related complications with growing-rod for early-onset scoliosis.Background: High incidence of implant-related complications in the treatment of early-onset scoliosis with traditional growing rod. The risk factors for multiple implant-related complications (MIRC) have not been adequately studied.Methods: Data of 59 early-onset scoliosis patients who had been underwent growing rod surgery at Beijing Chao-yang Hospital from September 2007 to December 2017 were reviewed. All patients had complete clinical and radiographic data. Patients were divided into groups with or without MIRC. The univariate and multivariate logistic regression analysis were performed to identify the risk factors associated MIRC.Results: The average age of insertion was 8.9 years and mean follow-up was 51.91 months. 234 implantation or expansion surgeries were performed and the average operation interval was 11.4 months. A total of 60 implant-related complications occurred. Ultimately, MIRC developed in 20 (33.9%) of 59 patients. Number of surgery procedure > 3 times , follow-up time ³50 months , preoperative thoracic kyphosis > 50°, postoperative thoracic kyphosis >50°, postoperative lumbar lordosis >50°, postoperative sagittal vertical axial >40mm are potential risk factors for MIRC (P<0.1). Multivariate logistic regression analysis showed that Number of surgery procedure > 3 times, postoperative thoracic kyphosis >50°, postoperative lumbar lordosis >50°are independent risk factors for MIFRC (P<0.05), Among them, patients with postoperative thoracic kyphosis >50°had an 18.647 times higher risk of MIFRC than postoperative thoracic kyphosis angle <50°.Conclusions: Traditional growing rod in the setting of EOS has excellent clinical and radiographic outcomes but a high multiple implant-related complications. Number of surgery procedure > 3 times, postoperative thoracic kyphosis >50°, postoperative lumbar lordosis >50° are independent risk factors for MIRC.