Correction effects of the ScoliOlogiC(® )„Chêneau light" brace in patients with scoliosis

BACKGROUND: Different bracing concepts are used today for the treatment of scoliosis. The plaster cast method worldwide seems to be the most practiced technique at the moment. CAD (Computer Aided Design) systems are on the market which allow brace adjustments without plaster. The latest development however, is the use of the ScoliOlogiC™ off the shelf system enabling the orthopaedic technician to construct a light brace for scoliosis correction from a variety of pattern specific shells to be connected to an anterior and a posterior upright. This „Chêneau light" brace, developed according to the Chêneau principle, promises a reduced impediment of quality of life in the brace. However, material reduction should not result in reduced effectiveness. Therefore the primary correction effect in the „Chêneau light" brace has been evaluated and compared with that of other braces used today. METHODS: The correction effects of the first 81 patients (main diagnosis Adolescent Idiopathic Scoliosis (AIS) [n = 64] or Early Onset Scoliosis (EOS) [n = 15]), treated according to the principle of the „Chêneau light" brace were evaluated after an average treatment time of 6 weeks by a full-body X-ray made in the standing position whilst wearing the brace and compared with the last X-ray before bracing. The average curvature angle of the whole group was 35,6°, the average age was 12,9 years (SD 1,9), average Risser sign was 1,3 (SD 1,5), average Tanner rating 2,75 (SD 0,7). RESULTS: The Cobb angle in the whole group was reduced by an average of 16,4°, which corresponds to a correction effect of 51%. The differences were highly significant in the T-test (T = 17,4; p < 0,001). The best correction effects reported in literature so far are about 40% in two different studies. The correction effect was highest in lumbar and thoracolumbar curve pattern (62 %; n = 18). In thoracic scoliosis the correction effect was 36 % (n = 41) and in double major curve pattern 50 % (n = 22). The correction effect correlated slightly negative with age (r = -0,24; p = 0,014), negatively with the Risser stage (-0,29; p = 0,0096) and correlated negatively with the Cobb angle measured before treatment (r = -0,43; p < 0,0001). CONCLUSION: The use of the „Chêneau light" brace leads to correction effects above average when compared to the correction effects of other braces described in literature. The reduction of material seems to affect the desired correction in a positive way

Hydrocarbon molar water solubility predicts NMDA vs. GABAA receptor modulation

BACKGROUND: Many anesthetics modulate 3-transmembrane (such as NMDA) and 4-transmembrane (such as GABA(A)) receptors. Clinical and experimental anesthetics exhibiting receptor family specificity often have low water solubility. We hypothesized that the molar water solubility of a hydrocarbon could be used to predict receptor modulation in vitro. METHODS: GABA(A) (α(1)β(2)γ(2s)) or NMDA (NR1/NR2A) receptors were expressed in oocytes and studied using standard two-electrode voltage clamp techniques. Hydrocarbons from 14 different organic functional groups were studied at saturated concentrations, and compounds within each group differed only by the carbon number at the ω-position or within a saturated ring. An effect on GABA(A) or NMDA receptors was defined as a 10% or greater reversible current change from baseline that was statistically different from zero. RESULTS: Hydrocarbon moieties potentiated GABA(A) and inhibited NMDA receptor currents with at least some members from each functional group modulating both receptor types. A water solubility cut-off for NMDA receptors occurred at 1.1 mM with a 95% CI = 0.45 to 2.8 mM. NMDA receptor cut-off effects were not well correlated with hydrocarbon chain length or molecular volume. No cut-off was observed for GABA(A) receptors within the solubility range of hydrocarbons studied. CONCLUSIONS: Hydrocarbon modulation of NMDA receptor function exhibits a molar water solubility cut-off. Differences between unrelated receptor cut-off values suggest that the number, affinity, or efficacy of protein-hydrocarbon interactions at these sites likely differ