Hip dysplasia associated with abduction contracture of the contralateral hip

Eighteen children with unilateral dysplasia of the hip were found to have asymmetrical gluteal folds and an apparent limb-length inequality secondary to pelvic obliquity caused by an abduction contracture of the contralateral hip. The dysplastic hip was on the left in all but one patient. As a result of the pelvic obliquity, the femoral head on the high side of the pelvis was directed superolaterally, stretching the relaxed capsule still farther. The femoral head was then not concentrically reduced, and the pressure it caused on the superior border of the labrum contributed to the development of the acetabular dysplasia. The eighteen dysplastic hips were treated with abduction splinting and stretching exercises of the contralateral hip to decrease the abduction contracture. All of the dysplastic hips returned to a normal roentgenographic appearance with this treatment. Acetabular dysplasia without dislocation of the hip is not always appreciated by clinical examination, but the asymmetry of the gluteal folds and the apparent limb-length inequality that were seen in all of the children in this series were obvious clinical signs. These findings must be differentiated from the anterior thigh-fold asymmetry that is frequently seen without underlying pathology.