Survival analysis of the first weaned patients treated with the SpineCor brace
Monday, November 2nd, 2009Rivard CH, Coillard C, Zabjek KF Research Centre, Sainte-Justine Hospital, 3175 chemin de la Coˆ te Ste-Catherine, Montreal, Quebec, Canada, H3T 1C5.
Objective: The objective of this study is to assess the success of treatment during the follow-up of a group of consecutively treated Idiopathic Scoliosis (IS) patients treated with the SpineCor brace
Methods: A survival analysis was performed on 68 patients who had terminated treatment from a cohort of 200 consecutively treated patients with the SpineCor since 1994. A survival analysis was performed to estimate the probability of success at 1, 2, 3, 4 years post-treatment without brace. The difference between the initial radiological Cobb angle, and the last available Cobb angle during follow-up without brace was used to define a failure (aggravation of 5 degrees more) or success (stabilization, correction). The patient cohort was categorized as either less than 30 (G1), and greater than 30 (G2).
Results: For the total group of patients (Initial Cobb angle: 30 9) the trend during treatment wasa decrease in spinal curvature at three months with a mean difference of 9 (SD: 6), at termination of treatment (time ¼ 23 months) a mean difference of 5 (SD: 7); and at a follow-up time of 1, 2, 3 and 4 years there was a difference of 2 (SD: 7), 6 (SD: 5), 0 (SD: 8), and 8 (SD: 4) in reference to the initial condition. The survival analysis (G1 and G2) indicated a cumulative probability of success during follow-up without brace as follows. Year 1: probability (p) ¼ 1.00, 57
Abstracts (Confidence Interval (CI): 1.00 to 1.00) for G1, p¼ 1.00 (CI: 1.00 to 1.00) for G2; Year 2: (p) ¼ 0.98 (CI: 0.93 to 1.00) for G1, p¼ 0.92 (CI: 0.82 to 1.00) for G2; Year 3: p ¼0.92 (CI: 0.83 to 1.00) for G1, p¼ 0.92 (CI: 0.83 to 1.00) for G2; Year 4: p¼ 0.88 (CI: 0.76 to 0.99) for G1, p ¼ 0.92 (CI: 0.73 to 1.00) for G2.
Conclusions: This initial cohort of patients demonstrated a general trend of initial decrease in spinal curvature in brace, followed by a stabilization and/or correction at the end of treatment which was maintained through 1, 2, 3, and 4 years follow-up.
