The safety and efficacy of a remotely distractible, magnetic controlled growing rod (MCGR) for the treatment of scoliosis in children: a prospective case series with minimum two year follow-up

Abstract

SUMMARY: The growing rod has been the gold standard for the treatment of scoliosis in young children. However, such management requires multiple open surgeries under general anesthesia for rod distraction and is associated with numerous postoperative complications. To avoid such pitfalls, we utilized a magnetically-controlled growing rod (MCGR) implant. Our study found that the MCGR was safe and effective, allowing for distractions on a non-invasive out-patient basis at monthly intervals, eliminating the need for surgeries and their associated complications. Introduction: Traditionally, growing rods are the standard of treatment for young children with severe spinal deformities and significant residual growth potential. However, this requires repeated open distractions under general anesthesia and is associated with numerous post-operative complications. This report addresses the safety and efficacy of the MCGR implant for non-invasive out-patient distractions for scoliosis correction in young children. METHODS: This was a prospective, patient series of the MCGR procedure. From November 2009 to March 2011, five patients (n=3 female; n=2 male) were treated with the MCGR. In this study, we report the first three patients (2 females and 1 male) with minimum 2 years follow-up. All cases were non-invasively distracted using an external magnet on a monthly basis. Pre and post distraction radiographs were carried out to assess the Cobb’s angle, predicted versus achieved rod distraction length and spinal length. Clinical outcome assessment was performed with the pain score (Visual Analogue Scale) and the SRS-30 questionnaire. All procedural or rod related complications were recorded. RESULTS: The main correction of the Cobb’s angle was obtained in the initial surgery and was maintained. The mean monthly increase in T1-T12, T1-S1 and instrumented segment length was 1.6mm, 2.5mm and 1.2mm, respectively. Predicted versus actual length gain per distraction were similar. One case had a superficial wound infection and there was one event of loss of distraction. On last follow-up, no pain was noted and SRS-30 scores remained unchanged to baseline. CONCLUSION: The MCGR is a safe and effective procedure for the surgical treatment of scoliosis in children. The MCGR provides external distractions on an out-patient basis without the need for sedation or anesthesia, and that remote distraction allows more frequent lengthening of the rod that may more closely mimic physiologic growth.