Optimized scheme for paired transverse corrective forces in S-shaped scoliosis via ultrasound and application in Chêneau brace: a pilot study

BACKGROUND: There is currently no consensus on the optimal positions of the transverse corrective forces (TCFs) for scoliosis braces. OBJECTIVES: This study aimed to explore an optimal scheme of placing paired TCF for S-shaped adolescent idiopathic scoliosis and its feasibility in Chêneau brace (CB) treatment. STUDY DESIGN: Cross-over feasibility pilot trial. METHODS: Ten S-shaped adolescent idiopathic scoliosis participants were invited to receive four tests with different paired TCF positions under ultrasound. The positions of the paired TCF were test 1: thoracic apical vertebra (AV), lumbar AV; test 2: 2 cm inferior to thoracic AV, lumbar AV; test 3: thoracic AV, 2 cm superior to lumbar AV; and test 4: 2 cm inferior to thoracic AV, 2 cm superior to lumbar AV. The test scheme with the highest mean in-force correction rate (IFCR) for the thoracic spinous process angle (SPA) was further applied in the CB fabrication of 4 additional participants. RESULTS: A significant higher mean IFCR of the thoracic SPA of 63.6% was found in test 2 (P < 0.001), which also contributed to its higher overall IFCR of the SPA of 64.6% (P = 0.001). Moreover, the mean in-brace correction rates for the thoracic and overall curves in CB were 46.4% and 51.8%, respectively. No adverse events were reported. CONCLUSIONS: Placing paired TCF at the lumbar AV and 2 cm inferior to the thoracic AV achieved better treatment efficacy than other schemes. The practical application of this scheme on the CB was feasible.