Radiological Outcome in Adolescent Idiopathic Scoliosis Patients 20 Years after Treatment

Abstract

Introduction The purpose of this study was to evaluate the long-term radiological outcome, curve progression, and adjacent level degeneration 20 years after idiopathic scoliosis treatment with Boston brace or Harrington rods. Materials and Methods A total of 219 patients treated with Boston brace or posterior spinal fusion a.m. Harrington were invited to participate in a long-term evaluation with clinical examination and X-ray evaluation. The old medical charts and X-ray descriptions were available. Standing X-ray was examined, the Cobb angle measured and compared with the patient's previous X-ray and the adjacent levels were evaluated for any signs of adjacent level disease or local kyphosis. Results A total of 159 patients (78%) participated. Of them, 66 patients were treated with Boston brace and 92 patients were treated with posterior spinal fusion a.m. Harrington. In the brace group, the Cobb angle before treatment was 37.5 degrees (35.1–40.0 degrees) and after treatment was 34.7 degrees (31.9–37.5 degrees). Cobb angle after 20 years was 40.2 degrees (36.7–43.6 degrees). In the surgical group, the Cobb angle before treatment was 54.5 degrees (50.4–58.8 degrees), 1-year postoperatively was 29.5 degrees (25.7–33.9 degrees). Cobb angle after 20 years was 32.35 degrees (27.9–39.5 degrees). A total of 26 patients had distal segment degeneration in X-ray (16.5%), 4 patients were treated with brace and 22 patients with posterior spinal fusion. A total of 8 patients had proximal segment degeneration (5%), 2 patients were treated with brace and 6 patients with posterior spinal fusion. A total of 4 patients were treated with posterior fusion of the distal adjacent segment (2.6%), 1 was treated with brace and 3 were treated with posterior spinal fusion. Conclusion The average follow-up was 24.5 years (range, 15–35 years). The brace group had a small reduction in the spinal deformity during the treatment period, and X-rays show a small progression of the deformity, with the Cobb angle increasing by 5.5 degrees within 20 years. The surgically treated patients had a large correction during surgery and there is no statistical significant progression or loss of correction over a 20-year period. Only 4 patients in the brace group have distal segment degeneration and only 1 patient was treated with a one-level spinal fusion. The surgically treated groups had a significant deformity correction during surgery and have maintained the correction after 20 years. A total of 22 patients have distal degeneration and 3 patients were treated with distal adding on surgery.