Development and growth of immature hips.
The authors investigated the development of the bony acetabulum in type IIa+ immature hips using ultrasound follow-up evaluation of the alpha and beta angle. The study comprised 900 hips in one-month old infants. In the initial ultrasound examination the alpha angle measured less than 60 degrees and the beta angle more than 55 degrees. In the second ultrasound examination at the age of two months a discrepancy between the bony and cartilaginous acetabular component was found in 15% of the hips, which means that the type IIa+ hips were transformed into the type IIa-. The infants with type IIa- hips had more than two risk factors for developmental dysplasia of the hip. The statistical relative risk was 17. These hips were treated with the Pavlik harness during two months on average. After treatment all hips had normal values the alpha and beta angles (more than 60 degrees and less than 55 degrees respectively). This study showed that each newborn and infant with a sonographically confirmed hip development disorder has to be included in the follow-up evaluation of acetabular development, which makes it possible to choose the most adequate therapeutic and prophylactic measures.
Vrdoljak
J
J
Children's Hospital Zagreb, Croatia.
Irha
E
E
D000077:Acetabulum / Q000000981:diagnostic imaging*; D005500:Follow-Up Studies; D006615:Hip / Q000254:growth & development*; D006617:Hip Dislocation / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D014463:Ultrasonography