Verification of hip reduction using anterior ultrasound scanning during Pavlik harness treatment of developmental dysplasia of the hip.

Ultrasound scanning (USS) is used for diagnosis and surveillance in developmental dysplasia of the hip (DDH). Lateral coronal scanning is performed with the hip flexed, in neutral adduction. In this position an unstable hip may dislocate, failing to demonstrate a reducible hip, leading to abandonment of harness treatment. Anterior ultrasound permits imaging of the flexed abducted hip in harness. This study evaluates the role of anterior & lateral USS in determining duration of treatment and reduction in DDH.Between 1997 & 2010, 233 patients requiring harness treatment received lateral USS, with dislocated & dysplastic hips re-imaged fortnightly. From 2005, anterior USS was used additionally to assess reduction in harness.One-hundred and eighteen patients (167 hips) received lateral USS, 115 (160 hips) received both. In the lateral cohort, 103 (140 hips) were treated successfully, mean duration 66.2 days (95% CI 60.2-72.1), with 15 (26 hips) failures (15.5%), mean 30 (CI 95% 19.3-40.6). In the anterior cohort, 107 (150 hips) were treated successfully, mean 53.3 (95% CI 49.8-56.7), with 8 (10 hips) failures (6.25%), mean 35.3 (CI 95% 25.5-44.9). Children receiving an anterior USS had a shorter duration of treatment (p = 0.011) and no difference in failures (p = 0.21).A reduced duration of treatment for Graf 3 hips was observed. Anterior ultrasound allows earlier recognition of hips that fail to stabilize, via two observed modes of failure; failure of hip reduction and failure to stabilize after reduction.