VASCULARITY OF THE NEONATAL FEMORAL-HEAD - IN-VIVO DEMONSTRATION WITHPOWER DOPPLER US

PURPOSE: To detect the intrinsic blood supply of the unossified neonat al femoral head in vivo by using power Doppler ultrasound (US) and to ascertain whether a reduction in blood flow could be demonstrated with hip abduction. MATERIALS AND METHODS: One hip of 13 neonates was exam ined with power Doppler sonography. After vessels within the femoral h ead were identified, the thigh was slowly abducted and the angle at wh ich now became undetectable was recorded. Spectral Doppler tracings we re obtained in all subjects. RESULTS: Intrinsic blood flow of the femo ral head was demonstrated in all subjects. Flow became undetectable du ring hip abduction in 11 of 13 neonates and reappeared during adductio n. The angle at which now became undetectable varied from 60 degrees t o 85 degrees. Spectral Doppler signals demonstrated a mixed arterial a nd venous trace. CONCLUSION: Power Doppler US provides a simple real-t ime assessment of the femoral head blood supply. This may prove helpfu l in identifying neonates at risk of avascular necrosis, a complicatio n of treatment of hip dysplasia with abduction hip restraints.