Femoral head blood flow in femoral neck fractures. An analysis using intra-osseous pressure measurement.

We studied 50 patients with fractures of the femoral neck, 33 intracapsular and 17 extracapsular. Intraosseous pressure was measured by a transducer within the bone to quantify blood flow, and intracapsular pressure by a needle introduced into the joint space. The mean intracapsular pressure was lower in the extracapsular fractures. In these, the mean intraosseous pressure in the femoral head was unchanged by aspiration of the joint. However in the intracapsular fractures aspiration produced a significant decrease in intra-osseous pressure and an increase in pulse pressure within the femoral head. The results suggest that aspiration of intracapsular haematoma produced an increase in femoral head blood flow by relieving tamponade.