Impact of the Free-Pelvis Innovation in Very Rigid Braces for Adolescents with Idiopathic Scoliosis: Short-Term Results of a Matched Case-Control Study

Abstract

We introduced pelvis semi-rigid material (ethylene vinyl acetate) (Free-Pelvis) to improve the comfort and adaptability of very rigid braces (VRBs) for adolescents with idiopathic scoliosis (AIS), but this can also negatively impact the corrective forces on the trunk. Study Design: This was a matched retrospective cohort study. The inclusion criteria were AIS, age 10–16, VRB 23 h/day, X-rays available, primary curve 36°–65°, and angle of trunk rotation 7–23°. The cases were Sforzesco VRB with Free-Pelvis (FPB). The controls included classical Sforzesco VRB matched for Risser (range 0/4), menarche age (10/15), weight (33.5/83 kg), height (140/180 cm), BMI (13.5/29 kg/sqm), aesthetics (TRACE 4/12), plumbline distances (S1: −60/35; C7 + L3: −10/115 mm), and referred brace use (22/24 h/day). Statistics: predictors of the results have been tested with linear and logistic regression according to the outcome variable type. We performed logistic regression for improved vs. worsened. The explanatory variable was brace type. We included 777 VRB and 25 FPB, age 13 ± 1, 47° ± 8° Cobb, and 11% men. The few baseline statistical differences were not clinically relevant. We achieved in-brace corrections of 15.2° ± 7.7° and 17.4° ± 6.5° for VRB and FPB, respectively (p = 0.21); out-of-brace corrections at 5 ± 2 months were 7.8° ± 0.2° for VRB and 8.1° ± 1.3° for FPB (p = 0.83). The type of brace did not influence the Cobb angle at either time interval or affect the odds of improvement. Free-Pelvis innovation, introduced to improve comfort and adaptability, does not change the in-brace or short-term results of classical VRB and consequently can be safely applied.

The New Modular Sforzesco Brace (Modular Italian Brace) Is as Effective as the Classical One: A Retrospective Controlled Study from a Prospective Cohort

“…It could have reduced stability because the APB is not fixed like the hinges of the SfB and due to the FP. The latter has already been tested and does not negatively impact the short-term clinical results [15].…”

“…Brace efficacy is strongly related to dosage [12,13], but brace-wearing hours are also considered inversely correlated to demand on patients [1,4,14]. Materials, production methods, and personalization of the brace have all evolved in the last decades to improve efficacy and patient comfort [7,[15][16][17][18][19][20][21]. It can be postulated that increased comfort could also improve compliance, which is one of the main factors of brace efficacy [15].…”

“…Materials, production methods, and personalization of the brace have all evolved in the last decades to improve efficacy and patient comfort [7,[15][16][17][18][19][20][21]. It can be postulated that increased comfort could also improve compliance, which is one of the main factors of brace efficacy [15].…”

“…It was introduced in the first decade of this millennium, and its effectiveness has been proven, especially in severe curves [10]. Recently, the "Free Pelvis" (FP) innovation has been introduced into the SfB [15]. The FP consists of semi-rigid material (ethylene vinyl acetate) on the pelvis connected to the main very rigid body of the brace (high-density polyethylene) on the trunk.…”

“…The FP consists of semi-rigid material (ethylene vinyl acetate) on the pelvis connected to the main very rigid body of the brace (high-density polyethylene) on the trunk. It was found that this innovation, introduced to improve patient comfort and brace adaptability, does not change the in-brace and short-term results of classical very rigid braces and, consequently, can be safely applied [15].…”