A three day old female was brought to her pediatrician for a routine newborn evaluation. Prenatally, the infant was noted by ultrasound to be in the frank breech position, and was born via Cesarean section at 40 weeks of gestation. She is the mother’s first child. At this visit, the pediatrician noted that the infant’s left thigh segment was shorter than the right, and a palpable “clunk” was felt when pressure was applied to lift the greater trochanter and the left hip was abducted (Figure 87-1). The pediatrician ordered an ultrasound of the left hip joint, which revealed a dislocated femoral head. The patient was subsequently placed in a Pavlik harness. After three months, the hip was completely reduced and stable on exam, and the harness was discontinued. Her standing x-ray of the hips at one year was normal.

Developmental Dysplasia of the Hip (DDH) is a disorder of acetabular development leading to a shallow acetabulum (acetabular dysplasia), which may or may not be associated with an unstable or dislocated hip joint.¹

Hip dysplasia, Congenitally dislocated hip.

• Most common in females, especially those of Native American descent.

• Incidence of DDH is approximately 1 in 100 live births, but only 1 in 1000 requires treatment.

• Can be discovered in neonates, infancy, or later in childhood.

• Intrauterine positioning is crucial for proper development of the acetabulum.

• Intrauterine crowding can result in excessive hip flexion and adduction, which leads to acetabular flattening, stretching of the labrum, and ultimately hip joint instability.

• Frank breech positioning and oligohydramnios are the most common causes of intrauterine crowding.

• Breech positioning (especially frank breech, 20 percent risk).

• Positive family history of DDH.

• First born.

• Female (6:1).

• Disorders associated with ligamentous laxity (i.e., Ehlers-Danlos).

• Oligohydramnios.

• Postnatal positioning with hips held in extension.

• Infrequently associated with torticollis and metatarsus adductus.

Clinical Features

• Galeazzi sign—Shortened thigh segment with the hip and knee flexed to 90 degrees compared to the unaffected side (Figure 87-1A). One may also see asymmetric skin folds, with excessive folds over the affected side due to superior/posterior dislocation of the femur.

• Barlow sign—Palpable “clunk” with hip adduction and posterior pressure applied on the femur, with the hip and knee flexed to 90 degrees (Figure 87-1A). Indicates subluxation of the femoral head out of the acetabulum.

• Ortolani sign—Palpable “clunk” with abduction and anterior pressure applied over the greater trochanter (Figure 87-1B). Indicates reduction of a dislocated femoral head.

• In children older than 3 months with DDH, the femur becomes fixed in a dislocated position, and the Barlow and Ortolani tests are no longer helpful. Instead, the prominent physical exam finding is limited abduction on the affected side due to tightening of the adductor muscles (Figure 87-2). However, if the DDH is bilateral, the limited abduction is difficult to appreciate. If the child is of walking age, he or she may have a waddling gait, with the unaffected side of the pelvis “dropping” as the child bears weight on the affected side, as well as lumbar hyperlordosis. This is due to weakened abductor muscles on the affected hip.