Abstract
Objectives : Since the system of screening students for scoliosis was established some 15 years ago, a large number of patients with mild or moderate idiopathic scoliosis have been referred to orthopedic surgeons for adequate treatment. When the patient is considered a candidate for treatment, a brace is usually applied, but this treatment modality is not well accepted by the patients. Determining whether a particular patient requires a brace, has not yet been standardized. The present study developed an equation to predict scoliosis progression in idiopathic scoliosis before skeletal maturity of the patient and utilized this equation to select candidates for treatment.
Materials and methods : Female patients with idiopathic scoliosis who had been periodically observed without treatment or who had shown poor compliance with brace therapy were selected for the study. There were 112 patients with 122 spinal curves (102 single curves and 10 double curves) treated at the Scoliosis Clinic of Juntendo University Hospital who met these criteria. The magnitude of Cobb angle at the time of initial examination ranged from 20 to 45 degrees (aver. 28.6 degrees). Twelve roentgenological parameters, most of which were reported as “risk factors” by various authors, were selected for the study. These parameters were used to evaluate spinalfilms obtained at the initial consultation. Correlation between the parameters and the actual progression of the curves of the patients were analyzed, and their relative weights were studied by a multivariate analysis method.
Results : Through the analysis of 12 parameters, five heavily weighted factors were selected : 1) Cobb angle, 2) rotation of the apical vertebra, 3) deviation of the apical vertebra, 4) Risser's expected correction angle : (standing Cobb-supine Cobb) ×3 (degrees) and5) maturation index of the iliac apophysis (Risser sign). Then, using a multiple regression analysis, the first equation was established to correlate the actual progression and the predicted progression, the multiple correlation coefficient being 0.739 (Fig. 5). This equation was then tested using 17 other curves from another scoliosis clinic and 34 additional curves from the author's clinic. The test demonstrated the adequacy of the equation in predicting curve progression. By including data from these 51 curves, the equation slightly modified, and the second equation was produced and proposed for a wider clinical trial.
Conclusion : To predict scoliosis progression, an equation was established. This equation is easily applicable to female patients with moderate idiopathic scoliosis and will help physicians determine whether the patient needs treatment.
