Purpose. The aim of this study is to assess the safety and efficacy of a remote-operated magnetic growth rod in the treatment of 11 patients with progressive early onset scoliosis (EOS). Introduction. The Growth rod technique (GR) has been a viable treatment option for progressive early onset scoliosis (EOS). However, an increased complication rate has been associated with conventional GR due to frequent surgeries required for lengthening. The safety and efficacy of a remote-operated magnetic growth rod (RO-MGR) has been previously reported in a porcine model. We are reporting the preliminary clinical results of this device which obviates the need for repeated surgeries. Methods. Prospective analysis of early clinical and radiographic data of 11 patients, with EOS, undergoing index RO-MGR treatment and at least 3 distractions. The mean age was 8 years (Range 5-12 years). Four patients had single rod (SR) instrumentation and the remaining 7 had a dual rod (DR) construct. Diagnosis was idiopathic 3, neuromuscular 3, congenital 3, syndromic 1 and neurofibromatosis one. In total, 57 rod distractions were performed. Distractions were performed in the clinic without anesthesia or analgesics. The mean preoperative Cobb angle was 68° (range 46°-108°). The mean preoperative T1-S1 length was 304mm (range 243-361mm). Results. Average distraction was 3.2 per patient. The mean lag before the first distraction was 66 days (28-112) and between distractions was 43 days (42-98). Superficial infection occurred in 1 (SR), prominent rod in 1 (DR), hook pull-out in 1(DR), iatrogenic shortening 1(DR) and loss of length in 2 patients (6/57 rod distraction, 11%, all SR), this loss was regained in subsequent distractions. Apart from a case of proximal rod trimming, no further surgery was required in our group of patients. Mean follow-up was 8 months (6-13). Conclusion. Preliminary results indicate that RO-GR appears to be safe and provided a comparable distraction to the standard GR procedure without the need for repeated open surgeries. No major complications were observed in the short follow up period

Between March 2000 and February 2006, we carried out a prospective study of 100 patients with a low-grade isthmic spondylolisthesis (Meyerding grade II or below), who were randomised to receive a single-level and instrumented posterior lumbar interbody fusion with either one or two cages. The minimum follow-up was for two years. At this stage 91 patients were available for review. A total of 47 patients received one cage (group 1) and 44 two cages (group 2). The clinical and radiological outcomes of the two groups were compared.

There were no significant differences between the two groups in terms of post-operative pain, Oswestry Disability Score, clinical results, complication rate, percentage of post-operative slip, anterior fusion rate or posterior fusion rate. On the other hand, the mean operating time was 144 minutes (100 to 240) for patients in group 1 and 167 minutes (110 to 270) for those in group 2 (p = 0.0002). The mean blood loss up to the end of the first post-operative day was 756 ml (510 to 1440) in group 1 and 817 ml (620 to 1730) in group 2 (p < 0.0001).

Our results suggest that an instrumented posterior lumbar interbody fusion performed with either one or two cages in addition to a bone graft around the cage has a low rate of complications and a high fusion rate. The clinical outcomes were good in most cases, regardless of whether one or two cages had been used.