Comparison of traditional growth rods and magnetically controlled growing rods in early-onset scoliosis: a case-matched mid term follow-up study.

PURPOSE: Early-onset scoliosis (EOS) has always been a challenging situation for spine surgeons. The aim of treatment is to control the direction of curve progression to allow for the complete development of lungs. Among all the growth constructs available, traditional growth rods (TGR) and magnetically controlled growth rods (MCGR) are most widely used. The MCGR has been introduced a few years back and there is a dearth of long-term follow-up studies. The purpose of this study is to compare the effectiveness of TGR and MCGR for the treatment of EOS. METHODS: All patients of EOS managed with either TGR or MCGR were included in the study. The patients managed with other methods or having follow-up < 2-years were excluded from the study. A total of 20 patients were recruited in the MCGR group and 28 patients were recruited in the TGR group. Both groups were matched by etiology, gender, pre-operative radiological parameters, and complications including unplanned surgeries. RESULTS: The mean age in our study was 7.90 years in the MCGR group and 7.46 years in the TGR group. The mean duration of follow-up in the MCGR group was 50.89 months and in the TGR group 94.2 months. Pre-operative cobb's angle in the coronal plane and T1-S1 were comparable in both groups with a mean cobb's angle of 65.4 in MCGR and 70.5 in TGR. The mean T1-S1 length in the MCGR group was 36.1cms and in the TGR group was 35.2 cms (p = 0.18). The average increase in T1-S1 length was 1.3 cm/year in the TGR group and 1.1 cm/year in the MCGR group (p > 0.05). The TGR patients underwent 186 open lengthening surgeries and 11 unplanned surgeries for various complications. The MCGR group has 180 non-invasive lengthening with only 4 unplanned returns to OT for various causes. CONCLUSION: The curve correction was similar in both TGR and MCGR groups. The average T1-S1 length achieved on final follow-up was similar in both groups. The MCGR patients have attained similar correction with fewer invasive procedures and lesser complications compared to the TGR group.

Quantitative Characteristics of Consecutive Lengthening Episodes in Early-onset Scoliosis (EOS) Patients With Dual Growth Rods.

STUDY DESIGN: A prospective single-center study. OBJECTIVE: The aim of this study was to record the characteristic forces and lengths observed during distraction episodes in early-onset scoliosis (EOS), and analyze their interdependencies on the key variability among the patients. SUMMARY OF BACKGROUND DATA: The goal of the growing-rod technique is to achieve deformity correction alongside maintaining growth of the spine. The deformity correction is achieved during the initial surgery, but follow-up distraction episodes are necessary to maintain the growth. The key variables, under the control of a surgeon, that affect the growth are the applied distraction forces and the distraction lengths. Since the advent of dual growth rod technique, there have been many studies exploring the relationship between these and the actual growth. However, there is sparse evidence on the actual magnitude of distraction forces, and none on its association with patient's parameters such as sex, age, and deformity. METHODS: In a consecutive series of 47 patients implanted with dual growth rods, the distraction forces (in N) and the lengths (in mm) achieved during each distraction episode and compared against the episode-specific demographics. The values obtained from each side, that is, concave and convex sides, were averaged to calculate the mean. Statistical analysis was performed using t-distribution because for each normalized time points (distraction episode). RESULTS: In cumulative, the distraction force increased by an amount of 268%, with 120% increase in the early stages (distractions episodes 1-6) and 68% increase in the later stages (distractions episodes 6-11), whereas the cumulative decrease in the length over 11 distractions episodes was 47%, with 34% and 20% in the early and later stages, respectively. The study does not identify any significant trend with respect to sex, age, and deformity. CONCLUSION: The distraction force and the length increased and decreased respectively with every consecutive distraction episode, with no correlation to sex, age, extent of deformity, or the extent of correction. LEVEL OF EVIDENCE: 5.

Severe Rigid Scoliosis: Review of Management Strategies and Role of Spinal Osteotomies.

Severe rigid curves pose a considerable challenge to the treating spine surgeon. In our practice, approximately 30%-40% of patients with scoliosis present late with severe rigid scoliosis (>90° and <30% correction on bending films). Controversy still exists with regard to the ideal surgical strategy for correcting these rigid curves. Rigid scoliosis often presents in the form of either sharp angular or rounded deformities. Rounded deformities can be effectively managed with an anterior release to loosen the apex and posterior instrumentation (with osteotomies, if required). In contrast, severe rigid scoliosis, which is a sharp angular deformity, is not very amenable to anterior release and is best managed by posterior-only vertebral column resection and posterior instrumentation.