Hip Dysplasia, Developmental

Key Features

• Encompasses a spectrum of conditions where an abnormal relationship exists between the proximal femur and the acetabulum

• Dislocatable hip

  • Most severe condition

  • Femoral head is not in contact with the acetabulum

  • Femoral head is within the acetabulum but can be dislocated with a provocative maneuver

• Subluxatable hip

  • Femoral head comes partially out of the joint with a provocative maneuver

• Acetabular dysplasia

  • Denotes insufficient acetabular development

  • Radiographic diagnosis

• Congenital dislocation of the hip

  • More commonly affects the left hip, occurring in approximately 1–3% of newborns

  • At birth, both the acetabulum and femur are underdeveloped

Clinical Findings

• Clinical diagnosis depends on demonstrating the instability of the joint by placing the infant on his or her back and obtaining complete relaxation

• Ortolani sign

  • The examiner's long finger is placed over the greater trochanter and the thumb over the inner side of the thigh

  • Both hips are flexed 90 degrees and then slowly abducted from the midline, one hip at a time

  • With gentle pressure, an attempt is made to lift the greater trochanter forward

  • A feeling of slipping as the head relocates is a sign of instability

• Barlow sign

  • When the joint is more stable, the deformity must be provoked by applying slight pressure with the thumb on the medial side of the thigh as the thigh is adducted

  • As hip slips posteriorly, it elicits a palpable clunk as the hip dislocates

• Limited hip abduction of less than 60 degrees while the knee is in 90 degrees of flexion is believed to be the most sensitive sign for detecting a dysplastic hip

• Galeazzi sign

  • The signs of instability become less evident after the first month of life

  • If the knees are at unequal heights when the hips and knees are flexed, the dislocated hip will be on the side with the lower knee

• Trendelenburg sign

  • When the child stands on the affected leg, a dip of the pelvis is evident on the opposite side due to weakness of the gluteus medius muscle; this accounts for unusual swaying gait

  • If dysplasia of the hip has not been diagnosed before the child begins to walk, there will be a painless limp and/or a lurch to the affected side

• As a child with bilateral dislocation of the hips begins to walk, the gait is waddling

Diagnosis

• Ultrasonography

  • Most useful in newborns

  • Can be helpful for screening high-risk infants, such as those with breech presentation or positive family history

• Radiography

  • More valuable after the first 6 weeks of life, with lateral displacement of the femoral head being the most reliable sign

  • In children with incomplete abduction during the first few months of life, a radiograph of the pelvis is indicated

Treatment

• Early treatment produces better outcome

• Pavlik harness

  • Maintains reduction by placing the hip in a flexed and abducted position

  • Can be easily ...