Brace treatment of Idiopathic Scoliosis is effective for a curve over 40 degrees, but is the evaluation of Cobb angle the only parameter for the indication of treatment?

Abstract

The recent literature showed positive results for bracing of patients with idiopathic scoliosis above 45° who refused surgery. However, no one has investigated whether other parameters can affect the results. The aim of this study was to evaluate the effectiveness of bracing in idiopathic scoliosis with curves above 40° and to verify the mechanical and biological parameters which go beyond the simple bend value expressed in Cobb degrees. This is an observational controlled cohort study nested in a prospective clinical on-going database including 1,238 patients with idiopathic scoliosis. Inpatients and outpatients in Rome. The study enrolled 160 patients with idiopathic scoliosis with curves above 40°. This is a prospective study based on an ongoing database including 1,238 patients with idiopathic scoliosis. The patients studied had idiopathic scoliosis with curves of 40° or more, Risser grade 0-4, and had refused any surgical treatment. 160 patients met the inclusion criteria. Of these, 104 patients had a definite outcome, 28 abandoned treatment and 28 are currently under treatment. The minimum duration of follow-up was 24 months. X-rays were used to obtain Cobb degrees and torsion of the apical vertebrae (Perdriolle's method). Three outcomes were distinguished according to SRS-SOSORT criteria: correction, stabilization and progression. To achieve the second aim, we divided the sample into subgroups according to Cobb degrees (<45°; ≥45°), Risser (0-2; 3-4) and rotation (<20; ≥20). Furthermore, logistic regression was applied by Stepwise Regression. The results of our study showed that in 104 patients with a definite outcome the Cobb mean value was initially 47±5.25 SD and 34.19 ±8.45 SD at follow-up. Perdriolle was initially 20.04±5.53 SD and 16.76±7.04 at follow-up. Overall, 81 patients (78%) obtained a curve correction, and stabilization was achieved in 14 cases (13%). Nine patients experienced curve progression (9%), 16 patients were recommended for surgery because the curve at follow up was over 45°. The analysis of subgroups shows that with Cobb <45° at baseline, the average reduction was 11.46° Cobb, while in cases with Cobb ≥45 at baseline, the mean correction was 13.74° Cobb. In subgroups with Perdriolle <20° at baseline, the average reduction was 16.02° Cobb, while in cases with Perdriolle ≥20° at baseline, the mean correction was 8.4° Cobb. In subgroups with Risser 0-2 at baseline, the average reduction was 14.7° Cobb, while in cases with Risser 3-4 at baseline, the mean correction was 6.7° Cobb. The logistic regression model shows significance for the initial value of Perdriolle and Risser. Our results indicate that an adequate conservative treatment must definitely be considered for patients with scoliotic curves who refuse surgery; the results will be better particularly if the rotation is lower than 20 and Risser is between 0-2. With the simultaneous evaluation of the Cobb angle, the vertebral rotation and the potential vertebral growth, it was possible to predict the final results at the start of treatment.