Diagnosis. Every newborn should be screened for DDH, and subsequent screenings should be performed at each visit.11 The two major tests for signs of hip instability include the Ortolani sign and the Barlow sign.12 In addition, a trained clinician can use the Galeazzi sign, which will indicate whether the femoral lengths are equal. This is accomplished with the infant supine and buttocks flat to the table with hips and knees flexed, then visually inspecting the comparative lengths of the femurs.5 All exams must be performed with the infant unclothed and placed in a supine, warm, comfortable position.12
The Ortolani maneuver can help show hips that are dislocated when the infant is in a resting position. In this test, the trained examiner attempts to reduce an already dislocated hip. The infant’s hips and knees need to be flexed at 90 degrees. The examiner will grasp the infant’s thigh between the thumb and index finger, and will use the fourth and fifth fingers to lift the greater trochanter while abducting the hip. When the infant has a positive Ortolani, the femoral head will slip or slide into the socket with a gentle “clunk.”5 This sensation is often palpable but not always audible. Like other maneuvers for the hips, the Ortolani maneuver takes practice.
The Barlow test detects hips that are dislocatable.13 It is often referred to as a provocative test, as the examiner is attempting to dislocate the femoral head. However, when in a resting position, the hips are typically reduced. To execute the test, begin with the hips and knee in 90 degrees of flexion and abduction, stabilize the contralateral hip, and bring the hip to the midline with gentle posterior pressure. If the Barlow is positive, the examiner will feel the femoral head come out of the acetabulum posteriorly.13 As the examiner relaxes the proximal push, the hip should slide back into position in the acetabulum. The Ortolani and Barlow tests become less reliable as infants grow older.11
As an adjunct to the clinical examination, infants younger than age 4 months with suspected DDH should undergo a hip ultrasound, performed by a pediatric ultrasonographer and read by a pediatric radiologist.11 Ultrasound should not be performed until the infant is more than 30 days old; a test performed any sooner often leads to inaccurate diagnosis because maternal hormones can contribute to hip laxity.11
After age 4 months, an anterior/posterior radiograph of the pelvis can be useful, as that is when the ossific nuclei (beginning appearance of the femoral heads) begin to develop and the acetabular index can be measured.11
Hips should be examined at each well-child check.11
Treatment. If examination reveals a positive Ortolani, Barlow, or Galeazzi or sign, the clinician should refer the infant to a pediatric orthopedist for potential treatment. In some cases ultrasonographer confirmation is obtained to demonstrate laxity, subluxation, or dysplasia. When the decision is made to initiate therapy, the treatment of choice is a Pavlik harness,5 to be worn by the infant 24 hours a day. Ultrasound scans are obtained every two to three weeks with stress views in the harness. Within the first several weeks, the ultrasound should normalize. If the hips continue to be subluxated or dislocated, Pavlik harness treatment can be discontinued and the child can be braced instead. If this is ineffective, the hips may require an evaluation under general anesthesia with a hip arthrogram and spica (full body) casting to maintain position of the hip. Should these treatment methods fail, open reduction and internal fixation will be necessary (also done under general anesthesia).5,14
Follow-up. Children with DDH must be followed until they are approximately age 10 years. Once the child is weaned from the Pavlik harness after six to 12 weeks of treatment and normal hip ultrasounds, obtain an anterior/posterior view of the pelvis (after 4 months of age). The acetabular index is measured to ensure that it falls within the normal range for the child’s age. (This is typically done by a pediatric radiologist or pediatric orthopedic surgeon.)
Initially, radiographs will be obtained every three months, then every six months, then yearly as long as they are normal. Keep in mind that someone with normal radiographs can still develop dysplasia in the future, hence the need for long-term follow-up.
Slipped capital femoral epiphysis
Slipped capital femoral epiphysis (SCFE) (Figure 2) is the most common adolescent hip disorder,6 affecting, on average, five to six of every 100,000 children and adolescents. SCFE is a displacement (slip) of the capital femoral epiphysis from the rest of the femur through the pliable cartilaginous growth plate known as the proximal femoral physis. In general, patients diagnosed with SCFE do not have significant disability, but the condition does require proactive surgical measures because if left untreated, SCFE can develop into severe hip arthritis.
The mechanism behind the development of SCFE is fairly variable; the factors triggering this mechanism remain largely unknown. Specific risk factors increase a child’s risk of developing SCFE. These include:
Obesity. More than 90% of patients who develop SCFE are obese or significantly overweight. The more obese a child, the greater the likelihood that he or she will develop SCFE at a younger age.15
Male gender. More than 60% of SCFE patients are male.16
African-American heritage. SCFE is roughly twice as common in African-American children as in white children.16
Pacific Islander heritage. This group has the highest rate of SCFE of any population.15
Endocrinology disorders. SCFE is known to occur in association with hypothyroidism, panhypopituitarism, gonadal conditions, and renal osteodystrophy, and during growth hormone therapy. Endocrine abnormalities should certainly be considered when a child presents with bilateral SCFE.17