INCREASED FEMORAL NECK-SHAFT ANGLES IN ADOLESCENT IDIOPATHIC SCOLIOSIS

Study Design. Ninety-four females from Southern China, 61 with adolescent idiopathic scoliosis and 33 normal subjects, were evaluated for femoral neck shaft angles an associated asymmetry between the hips. For statistical analysis, the groups were divided into adolescent and adult, and the scoliosis group was further divided into sub-groups according to the type of spinal curvature. Objectives. To evaluate femoral neck-shaft angle and asymmetry between the hips, and their relation to adolescent idiopathic scoliosis. Summary of Background Data. Recently published studies have suggested there is an association between asymmetry of the hip and lower limb and the curvature in AIS. In this study, femoral neck-shaft angle in patients with adolescent idiopathic scoliosis and in normal subjects was evaluated. Methods. Femoral neck-shaft angles of both hips and lateral spinal curvature (using Cobb's method) were measured from standard standing anteroposterior radiographs of the pelvis, including upper femora and spine. Methods of measuring femoral neck-shaft angles were evaluated in an intra- and inter-observer study and were found to be accurate. Results. Patients with scoliosis had highly significantly greater femoral neck-shaft angles of both hips compared with normal subjects. In normal subjects, the femoral neck-shaft angle difference between the hips (asymmetry) was not statistically significant. This asymmetry in the scoliosis group also was not statistically significant when the results were analyzed upon grouping them all together, irrespective of curve pattern. Conclusion. Our new findings show that patients with scoliosis have abnormally increased femoral neck-shaft angles, and the asymmetry is characteristic and significantly different from that of normal subjects. Moreover, increased femoral neck-shaft angle is related to type and side of spinal curvature.