Supine correction index as a predictor for brace outcome in adolescent idiopathic scoliosis

Abstract

Aims The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment. Methods Patients with AIS to be treated by bracing were prospectively recruited between December 2016 and 2018, and were followed until brace removal. In all, 207 patients with a mean age at recruitment of 12.8 years (SD 1.2) were enrolled. Cobb angles, supine flexibility, and the rate of in-brace correction were measured and used to predict curve progression at the end of follow-up. The SCI was defined as the ratio between correction rate and flexibility. Receiver operating characteristic (ROC) curve analysis was carried out to assess the optimal thresholds for flexibility, correction rate, and SCI in predicting a higher risk of progression, defined by a change in Cobb angle of ≥ 5° or the need for surgery. Results The baseline Cobb angles were similar (p = 0.374) in patients whose curves progressed (32.7° (SD 10.7)) and in those whose curves remained stable (31.4° (SD 6.1)). High supine flexibility (odds ratio (OR) 0.947 (95% CI 0.910 to 0.984); p = 0.006) and correction rate (OR 0.926 (95% CI 0.890 to 0.964); p < 0.001) predicted a lower incidence of progression after adjusting for Cobb angle, Risser sign, curve type, menarche status, distal radius and ulna grading, and brace compliance. ROC curve analysis identified a cut-off of 18.1% for flexibility (sensitivity 0.682, specificity 0.704) and a cut-off of 28.8% for correction rate (sensitivity 0.773, specificity 0.691) in predicting a lower risk of curve progression. A SCI of greater than 1.21 predicted a lower risk of progression (OR 0.4 (95% CI 0.251 to 0.955); sensitivity 0.583, specificity 0.591; p = 0.036). Conclusion A higher supine flexibility (18.1%) and correction rate (28.8%), and a SCI of greater than 1.21 predicted a lower risk of progression. These novel parameters can be used as a guide to optimize the outcome of bracing. Cite this article: Bone Joint J 2022;104-B(4):495–503.

Contribution of coronal vertebral and IVD wedging to Cobb angle changes in Adolescent Idiopathic Scoliosis during growth

“…Spinal exibility and in-brace correction have been used to predict curve progression (24,25). Our ndings suggest that a gradual increase in wedging along the curve and a relatively larger change in IVD wedging than vertebral wedging represent a higher possibility of curve progression.…”

Associations between spinal flexibility and bracing outcomes in adolescent idiopathic scoliosis: a literature review

“…Table 2 shows the results of the QUIPS appraisal. Of the 14 articles included, five (59.4%) had a low risk of bias [ 6 , 14 , 15 , 28 , 29 ], three (21.4%) had a moderate risk [ 30 – 32 ], and the remaining six studies (42.9%) had a high risk of bias [ 16 , 17 , 33 – 36 ].…”

“…The Chêneau brace was used in one study [ 17 ], and the Osaka Medical College (OMC) brace was prescribed in two studies [ 34 , 35 ]. In addition, one study used the Boston or Milwaukee brace [ 28 ].…”

Contribution of coronal vertebral and IVD wedging to Cobb angle changes in adolescent idiopathic scoliosis during growth

“…Spinal flexibility and in-brace correction have been used to predict curve progression [ 25 , 26 ]. Our findings suggest that a gradual increase in wedging along the curve and a relatively larger change in IVD wedging than vertebral wedging represent a higher possibility of curve progression.…”