The Ortolani test has a high positive predictive value in clinical hip screening for developmental dysplasia of the hip.

Abstract

Previous studies have not described separate positive predictive values for Ortolani and Barlow tests in clinical hip screening. We aimed to determine the positive predictive values at discharge following birth, in predicting dysplasia or instability in the subsequent hip ultrasound examinations. We included all infants with suspected or diagnosed DDH at the study hospital from 2015 to 2017 in this retrospective study. Infants with positive Ortolani or Barlow test after birth were referred for a hip ultrasound, without treatment being started. The positive predictive value of the tests to predict Graf type ≥ IIC morphology, ≥5 mm displacement in a dynamic ultrasound, or either one or both findings at the hip ultrasound examination was calculated. There were 33 Ortolani-positive hips and 103 Barlow-positive hips in 105 referred infants (30% male) at the screening. They received ultrasound examination at mean 21.7 days of age (SD 4.8, range 11-35). The positive predictive value was 39-61% for the Ortolani test and 4%-16% for the Barlow test depending on the true positive definition. The Ortolani test, performed by a specialist at the maternity ward, has a high positive predictive value for developmental dysplasia of the hip.