Preliminary Results of Treatment of Early Onset Scoliosis using Magnetic Growing Rods

One of the major disadvantages of traditional growing rod systems is the requirement for multiple surgical procedures to lengthen the rods as the patient grows. This has been avoided by introduction of magnetically controlled growing rod (MCGR). Materials and Methods A prospective uncontrolled, single-center, single-surgeon, clinical and radiological study. Between November 2012 and August 2015, 16 children with EOS were treated using MCGR. Preoperative, postoperative and final follow-up (FFU) whole spine radiographs were reviewed to determine the degree of spinal deformity and correction, measured using Cobb angle. T1–S1 length was calculated. Clinical notes to determine number of rod lengthening procedures using remote control device and to record any complications during surgery or FU period. Mean age was 11.6 years, 3 boys and 13 girls; 11 children had primary correction by MCGR; 7 of them had neuromuscular, three infantile and one congenital scoliosis. All had a dual MCGR implanted. The remaining five patients had previously undergone other growing rod operation before converting to MCGR implant. Results Mean pre-operative Cobb angle of the primary group was 63.2°, postoperative 35.6° (40.5% correction), FFU 39°. Mean initial percentage of the lengthening was 14.8%. Thoracic kyphosis changed from preoperative mean of 49.1° to 34.1° postoperatively. One patient had wound infection, three had pull-out of proximal screws/hooks, one sustained a breakage of a single-rod construct 6 months after surgery and was replaced by a double magnetic-rod construct. A total of 40 distractions have been performed. Mean FU was 15.5 months. Conclusions In our consecutive series of patients treated with MCGR we found that scoliosis was well controlled. Cobb angle was significantly reduced following surgery in patients who had MCGR performed as a primary procedure. Generally, the correction was maintained at FFU. Despite the relatively high complication rate, comparing our results for MCGR and other growing rod techniques, they are comparable, without need to repeated surgery.