Study of the pressures applied by a Chêneau brace for correction of adolescent idiopathic scoliosis

We performed a study on 32 idiopathic scoliotic patients (30 females, 2 males) treated with a Chêneau brace. Eighteen patients had a single right thoracic curve and 14 had a single right thoracolumbar curve. We used the TekScan system (ClinSeat Type 5315 Sensor, TekScan, Boston MA, USA) to measure pressures at the skin-brace interface, assess the effect of strap tension and analyze the variation of these pressures with position and activity. The TekScan device enabled identification of the pressure areas corresponding to the brace's three loading points. The pressure under the main pad had a greater mean value than the pressure under the two counter-pads. Tightening the straps led to a significant increase in the pressures, whatever the position studied or the curve pattern. Compared with the standing (reference) position, we observed significantly higher pressures during maximal inspiration (p < 0.001) and lower pressures during maximal expiration, in the prone position and after having risen from a lying position, for both thoracic curves (p < 0.001) and thoracolumbar curves (p < 0.01). The pressures for thoracolumbar curves were lower than those for thoracic curves, whatever the position studied and both before and after strap adjustment. For lying positions, lying on the right side produced the greatest increase pressure. Even though the TekScan system does not provide direct information on the correction of spinal curvature, it appears to be a useful tool in the treatment of scoliotic patients. Strap adjustment clearly influences the applied pressures - particularly those on the rib cage. During activity, there is a natural tendency to decrease the pressure; this justifies efforts to maintain strap tensions in general and during day wear in particular.