Clinical Outcome of Magnetically Controlled Growing Rod in Early-onset Scoliosis: A Systematic Review.

Study Design: This was a systematic literature review. Objective: To evaluate the efficacy and safety of magnetically controlled growing rod (MCGR) in treating early-onset scoliosis. Summary of Background Data: Preliminary studies reported the promising potential of MCGR in deformity correction and spine growth preservation with noninvasive distraction. This study was conducted on the basis of data from published literatures. Materials and Methods: A systematic search from multimedical database was conducted for studies of MCGR. Involved studies should provide at least one of the followings: deformity correction, spine growth, and complication. During treatment period, improvement or progression of scoliosis/kyphosis, annual T1-S1/T1-T12 extension, incidence of complication, and unplanned surgery were summarized and the correlations with term of follow-up were investigated. Results: In total, 13 studies (n=249) were involved, with an average of 22.2-month follow-up. Scoliosis correction was well maintained, improving from 36.4 degrees at postinitial to 37.1 degrees at last follow-up (P=0.794). Kyphosis progressed from 28.8 degrees at postinitial to 34.4 degrees at last follow-up (P=0.024). Annual T1-S1 and T1-T12 longitudinal extensions were 8.7 and 4.7 mm/year, respectively. As follow-up went on, no significant decline was observed in annual extension of T1-S1 (P=0.4680) or T1-T12 (P=0.8053). The incidences of alignment-related, implant-related, and wound-related complication were 3.5%, 30.1%, and 6.9%, respectively. No significant correlation was observed between occurrence of complication and term of follow-up. The rate of receiving unplanned surgery was 24.3%. Conclusions: MCGR is efficient in the maintenance of coronal correction and preservation of spine growth, with loss of sagittal correction and a 24.3% unplanned revision rate.