Bracing for idiopathic scoliosis: how many patients require treatment to prevent one surgery?

BACKGROUND: Although the efficacy of bracing for adolescent idiopathic scoliosis has been debated, recent evidence indicates a strong dose-response effect with respect to preventing curve progression of ≥6°. The purpose of this study was to investigate whether bracing, prescribed with use of current criteria, prevents surgery and how many patients must be treated with bracing to prevent one surgery. METHODS: Of 126 patients with adolescent idiopathic scoliosis measuring between 25° and 45° and with a Risser sign of ≤2, 100 completed a prospective study in which they were managed with a Boston brace fitted with a heat sensor that measured brace wear. Noncompliant patients were compared both with highly compliant patients and with the entire cohort, with the end point of progression to surgery. The absolute risk reduction (ARR) was calculated and used to calculate the number needed to treat (NNT) to prevent one surgery. RESULTS: Bracing was not effective in preventing surgery unless the patient was highly compliant with brace wear. For patients who were considered to be highly compliant, based on the hours per day that they wore the brace, the NNT was 3 (95% confidence interval [CI], 2 to 7). CONCLUSIONS: Within the limitations of a nonrandomized prospective study design, bracing for adolescent idiopathic scoliosis was found to substantially decrease the risk of curve progression to a range requiring surgery when patients were highly compliant with brace wear. Since many patients avoid surgery without wearing a brace, current indications appear to lead to marked overtreatment. Bracing appears to decrease the risk of curve progression to a magnitude requiring surgery, but current bracing indications include many curves that would not have progressed to a magnitude requiring surgery even if the patient had not worn the brace, and overall compliance with brace wear is low. Identifying these lower-risk patients and improving the compliance of those likely to have curve progression could substantially improve bracing results.

Brace wear control of curve progression in adolescent idiopathic scoliosis.

BACKGROUND: The efficacy of brace treatment for patients with adolescent idiopathic scoliosis remains controversial, and effectiveness remains unproven. We accurately measured the number of hours of brace wear for patients with this condition to determine if increased wear correlated with lack of curve progression. METHODS: Of 126 patients with adolescent idiopathic scoliosis curves measuring between 25 degrees and 45 degrees , 100 completed a prospective study in which they were managed with a Boston brace fitted with a heat sensor that measured the exact number of hours of brace wear. Orthopaedic teams prescribed either sixteen or twenty-three hours of brace wear and were blinded to the wear data. At the completion of treatment, the number of hours of brace wear were compared with the frequency of curve progression of > or =6 degrees and with curve progression requiring surgery. RESULTS: The total number of hours of brace wear correlated with the lack of curve progression. This effect was most significant in patients who were at Risser stage 0 (p = 0.0003) or Risser stage 1 (p = 0.07) at the beginning of treatment and in patients with an open triradiate cartilage at the beginning of treatment. Logistic regression analyses showed a "dose-response" curve in which the greater number of hours of brace wear correlated with lack of curve progression. Brace wear to school and immediately afterward was most successful. Curves did not progress in 82% of patients who wore the brace more than twelve hours per day, compared with only 31% of those who wore the brace fewer than seven hours per day (p = 0.0005). The number of hours of brace wear also correlated inversely with the need for surgical treatment (p = 0.0005). The number of hours of wear were similar for the patients who were advised to wear the brace sixteen or twenty-three hours daily. CONCLUSIONS: The Boston brace is an effective means of controlling curve progression in patients with adolescent idiopathic scoliosis when worn for more than twelve hours per day.

Decreased orthotic effectiveness in overweight patients with adolescent idiopathic scoliosis.

BACKGROUND: Many studies have demonstrated that orthotic treatment is effective for the prevention of curve progression in patients with adolescent idiopathic scoliosis. However, the effect of being overweight on the outcome of orthotic treatment has not been reported. The purpose of the present study was to determine whether orthotic treatment of adolescent idiopathic scoliosis is less successful for patients who are overweight than it is for those who are not overweight. METHODS: A ten-year multicenter retrospective review of patients in whom adolescent idiopathic scoliosis had been treated with a Boston or a custom-molded thoracolumbosacral orthosis was performed. The inclusion criteria were no previous treatment, skeletal immaturity (a Risser sign of 0, 1, or 2), a curve of 25 degrees to 40 degrees at the time of orthotic initiation, and follow-up to skeletal maturity. Patients were divided into two groups according to body habitus, with overweight patients defined as those with a body mass index in the eighty-fifth percentile or greater. Curve progression was compared between the two groups. Successful orthotic treatment was defined as no more than a 5 degrees increase in the primary curve from the start of orthotic wear to skeletal maturity. Absolute curve progression to 45 degrees or greater also was considered to be an adverse outcome. RESULTS: Two hundred and seventy-six consecutive patients from two institutions were analyzed, and thirty-one patients were considered to be overweight. The mean curve progression was 9.6 degrees +/- 7.3 degrees for the patients who were overweight, compared with 3.6 degrees +/- 9.4 degrees for those who were not overweight (p < 0.01). Overweight patients were 3.1 times more likely to have an unsuccessful result than those who were not overweight. Curve progression to 45 degrees or greater occurred in fourteen (45%) of the thirty-one patients who were overweight, compared with sixty-nine (28%) of the 245 patients who were not overweight. CONCLUSIONS: The results of the present study suggest that overweight patients with adolescent idiopathic scoliosis will have greater curve progression and less successful results following orthotic treatment than those who are not overweight. The ability of an orthosis to transmit corrective forces to the spine through the ribs and soft tissue may be compromised in overweight patients. This factor should be taken into consideration when making treatment decisions. Additional study is warranted to determine a threshold effect.