SUMMARY
PurposeTo apply statistical shape modelling to perform an evaluation of femoral deformity in developmental hip dysplasia and to describe its relation to the amount of acetabular coverage.Methods An observational case-control study consisting of 40 right dysplastic cases compared to 43 normal hips, was designed. The femurs were scanned, followed by 3D reconstruction for statistical shape modelling. Inter-shape correspondences of the femoral shape were used to portray changes in femoral morphology to the amount of acetabular coverage. Partial least-squares regression was applied to establish a direct connection between acetabular coverage and the geometry of the femoral shape.ResultsAcetabular coverage accounted for 7.1% of variation in the overall femur shape. Significant changes in femoral morphology were observed with decreasing acetabular coverage. Conclusion Anatomic abnormalities inherent to the dysplastic hip are limited to the very proximal part of the femur and significantly increase when the acetabular coverage decreases. Flattening of the femur head is most pronounced at the peripheral part of the head.