CONVEX SPINAL EPIPHYSIODESIS IN THE MANAGEMENT OF PROGRESSIVE INFANTILE IDIOPATHIC SCOLIOSIS

Study Design. Retrospective review of patient records with current cli nical and radiographic assessment. Objective. To evaluate the long-ter m result of anterior and posterior convex spinal growth arrest, with o r without instrumentation, in managing infantile idiopathic scoliosis. Summary of Background Data. There were 12 male male patients studied, With a mean follow-up period of 10 years, 9 months. The mean Cobb ang le before surgery was 65 degrees. All had a rib vertebral angle differ ence more than 20 degrees. The mean age at surgery was 6 years. Nine p atients had epiphysiodesis alone; nine patients also underwent Harring ton instrumentation simultaneously, and four underwent Harrington inst rumentation 2-4 years later. Method. Clinical evaluation and sequentia l measurements of Cobb angle were done. Results. The epiphysiodesis-on ly group had a mean preoperative Cobb angle of 72 degrees, mean progre ssion of curves of +12 degrees, and mean rate of progression of +2.5 d egrees per year; the group's postoperative figures were 92 degrees, +1 5 degrees, and +3 degrees per year, respectively. The epiphysiodesis a nd late Harrington rod group had a mean preoperative Cobb angle of 56 degrees, mean progression of +12 degrees, and a mean rate of progressi on of +5 degrees per year; the group's postoperative Cobb angle averag ed 62 degrees, progression +6 degrees, and rate of progression +1 degr ees per year. The epiphysiodesis with simultaneous Harrington rod grou p had a preoperative mean Cobb angle of 60 degrees, mean progression o f +18 degrees, and mean rate of progression of +6 degrees per year. Af ter surgery, these improved to 58 degrees, correction of 2 degrees, an d rate of correction of 0.5 degrees per year. Conclusion. Combined ant erior and posterior convex spinal growth arrest alone does not prevent progression of deformity in infantile idiopathic scoliosis. The addit ion of posterior instrumentation can slow or arrest deformity progress ion but not reverse it.