Long-term results after brace treatment with Progressive Action Short Brace in adolescent idiopathic scoliosis

Background: In the literature, there are few papers on long-term results after brace treatment and there is no consensus on whether scoliotic curves stop progressing at skeletal maturity. To date the factors that could influence curve behaviour following bracing have not been fully determined. Aim: The aim of this study was to evaluate the results and the loss of the scoliotic curve correction in a cohort of patients treated with Progressive Action Short Brace (PASB) brace during adolescence and to compare patient outcomes of under and over 30 Cobb degrees 10 years after brace removal. Design: This is an observational controlled cohort study nested in a prospective clinical on-going database including 1536 patients with idiopathic scoliosis. Setting: Inpatients and outpatients in Rome. Population: The study enrolled 163 patients with idiopathic adolescent scoliosis who had been treated with the PASB brace at a 10 years minimum long-term follow-up examination. Methods: One hundred sixty-three (female) patients with adolescent idiopathic scoliosis (AIS) treated with the Progressive Action Short Brace (PASB) at a mean age of 13.4 years (range 10-34) had accepted to undergo long-term follow-up examination. All patients had clinical and radiological examinations, but only 62 replied to some simple questions (including work status, pregnancy and pain) the population was divided into two groups based on Cobb degrees (< 30° and ≥ 30°). Statistical analysis was applied to test the efficacy of our hypothesis. Results: The patients underwent a long-term follow-up after brace removal at a mean age of 13.46 years (±3.4). The prebrace mean curve was 28.98° (±7.918); after treatment, the mean was 13.88° and increased to a minimum of 15.35° in the 10 years following brace removal. However, there was no significant difference between the mean Cobb angle at the end of weaning and the mean Cobb angle at long-term follow-up. The curve angle at baseline of patients who were treated with a brace was reduced by 15° during the treatment, but at follow-up the curve size was found to have lost 2°. The over 30° group showed a prebrace scoliotic mean curve of 37.26°; at the end of weaning, the mean curve angle was 22.98° which increased to a mean of 25.07° at follow-up. The <30° group showed a prebrace scoliotic mean curve of 24.40° which, at the end of weaning, had reduced to a mean of 8.69°, increasing to 9.98° at follow-up. There was no significant difference in the mean progression of curve magnitude between the ˂ 30° and ≥ 30° groups at the long-term follow-up. Work status was 62% full-time and 11% part-time. 24% had given birth. Three percent presented back pain related to instability of the spine. No patients underwent surgery after maturity but one patient had indication to surgical treatment. Conclusions: The PASB brace is effective for the treatment of lumbar and thoracolumbar scoliosis and is characterized by positive long-term outcomes, including in patients demonstrating moderate curves. In both groups, at 10-years minimum follow-up after bracing, scoliotic curves did not deteriorate beyond their original curve size after bracing in both groups at the 10-years minimum follow-ups. Clinical rehabilitation impact: At 10 years follow-up after bracing, scoliotic curves had not deteriorated beyond their original curve size.