Ultrasonographic evaluation of the coxofemoral joint region in young foals

The purpose of this study was to map the coxofemoral region in foals to obtain ultrasonographic reference values for the interpretation of potentially pathological findings in hip joints. Using a 7.5 MHz linear transducer, 38 examinations were carried out: 10 (20 joints) on cadavers and 28 (55 joints) on live healthy foals up to 8 weeks of age. The chosen plane of examination was caudolateral–craniomedial oblique on an imaginary line connecting the greater trochanter and the cranial edge of the tuber sacrale.The relatively thin muscular layer covering the coxofemoral joint allowed good image quality. The evaluated structures included the bone surface of the ilium and acetabulum, the subchondral bone on the femoral head and greater trochanter, the joint cartilage on the femoral head, the fibrocartilaginous acetabular labrum, the femoral capital physis, the cartilaginous layer covering the greater trochanter, the joint capsule and the presence of visible synovial fluid and the gluteal muscles. A bilateral anatomical frozen section in the plane of examination was made in one cadaver. A good correlation was found between ultrasonographic and corresponding anatomical measurements on the frozen section. This study indicated that ultrasound is a valuable diagnostic tool which can provide good image quality in neonates.