Developmental Dysplasia of the Hip Diagnosis in Newborns and Infants

Introduction to Diagnostic Techniques

The Ortolani and Barlow procedures are essential clinical examination techniques used to detect developmental dysplasia of the hip (DDH) in newborns and infants, with the Ortolani test identifying an already dislocated hip that can be reduced, and the Barlow test identifying a hip that is in place but can be dislocated with gentle manipulation 1, 2

The Ortolani test detects an already dislocated hip by causing the femoral head to slip back into the acetabulum when the examiner abducts and gently lifts the flexed thigh while pushing the greater trochanter anteriorly, producing a palpable or audible "clunk" 2, 3
The Barlow test identifies unstable hips missed by the Ortolani test by attempting to dislocate a reduced but unstable hip through a two-step process: 1) gently adducting the thigh to dislocate the femoral head posteriorly, and 2) lifting the thigh upward while abducting the leg to relocate the femoral head 4, 5

Both tests are designed to detect instability between the femoral head and acetabulum, indicating ligamentous or capsular laxity that may lead to developmental dysplasia of the hip 1, 3
These tests are most reliable in the first 2-3 months of life, as the hip capsule tightens with age, making the tests less sensitive after 3 months 5, 6

The American Academy of Pediatrics recommends performing these tests at every well-baby visit, particularly at 1-2 weeks and at 2, 4, 6, 9, and 12 months of age 2, 6
It is important to differentiate between a true positive Ortolani or Barlow test and a benign "clicking" hip, which has no laxity but produces a click during examination 3, 7

In children older than 3 months, the Ortolani and Barlow tests become less reliable due to increased tightening of the hip capsule 5, 6
For children older than 3 months, limitation of hip abduction and asymmetric thigh folds become more useful clinical signs of DDH 3, 6
When Ortolani or Barlow tests are positive, further imaging evaluation is indicated 5
Ultrasound is the preferred imaging modality for infants under 4-6 months of age, as the femoral heads are primarily cartilaginous 6
After 4-6 months of age, radiographs become more reliable as ossification progresses 3, 7

Early detection and treatment of DDH through these procedures can prevent early degenerative joint disease and impaired function 1, 6
Untreated subluxed and dislocated hips can lead to lifelong disability and early arthritis 8, 6
The most serious complication of treatment is avascular necrosis, which is a predictor of poor prognosis 5