Hip dysplasia is a condition which is seen in infants and young children as a result of developmental problems in the hip joint. The femur (thigh bone) partially or completely slips out of the hip socket causing dislocation at the hip joint. It is most common in first born baby with family history of the disorder. The exact cause for hip dysplasia is not known. Genetic factors play an important role in causing this birth defect. The problems caused by an abnormally formed hip joint, even if very minor, can carry through to adulthood.
In normal hip, the head of the femur (thigh bone) fits well into the socket (acetabulum) whereas in hip dysplasia, the socket and femoral head are not congruent because of their abnormal development. Patients with hip dysplasia may have undergone one or more hip operations during their childhood which might have caused considerable skeletal changes and scarring of the soft tissues. Secondary osteoarthritis may develop later in life which may cause pain and stiffness in the hip. Under certain circumstances, the dysplasia may be corrected with a peri-acetabular osteotomy.