The magnetically controlled growing rod (MCGR) system allows growth maintenance without the risk of anaesthesia, implant and wound complications associated with repeated surgeries. This is a medium-term report of the complications of MCGR from a multicentre study.

Twenty-six patients from 6 spine institutes that are part of a multicentre study with prospectively collected data of minimum 24 months follow-up were assessed. Pre-operative, immediate post-operative and most recent spine radiographs were reviewed to measure the Cobb angle and the rod lengthening distance. The causes and any associated risk factors for re-operations were examined.

Eleven patients required re-operation within the follow-up period, with a mean time to re-operation of 17 months after the initial surgery. Five were due to failure of rod distractions; 3 were due to failure of proximal foundation implants; 2 were due to rod breakage; and one case of superficial wound infection with failure of proximal fixation. Proximal junctional kyphosis occurred in 5 patients. Three had proximal anchor dislodgement and all five constructs were revised.

This is the largest series with the longest follow-up to date. Our series show that the perception that using MCGR may reduce the frequency of re-operations may not be entirely true. This is the first report to examine the need for re-operation after MCGR implantation, and highlights the inherent risks of any surgical treatment in this group of patients despite the advantages of this new implant. Longer-term studies and comparisons with traditional growing rods are required.

Introduction

We prospectively examined the effect of pedicle screw placement at a young age (<5 years) for early-onset spinal deformity on the growth and development of pedicles and the spinal canal.