Hemarthrosis in undisplaced cervical fractures. Tamponade may cause reversible femoral head ischemia.

In eight undisplaced intracapsular fractures of the femoral neck, an intracapsular hematoma was diagnosed by computed tomography. 99mTc-MDP scintimetry revealed markedly reduced or absent blood supply to the head of femur. The intracapsular pressure was 23 (2.7-43) kPa with the hip in neutral position. Following aspiration of 12 (0.5-36) ml of blood, pressure was reduced to zero, and postaspiration scintimetry revealed restitution of blood supply to the femoral head. Hip joint tamponade in these patients has caused femoral head ischemia, reversible by aspiration.