Further Observations on the Use of Radioactive Phosphorus (P32) to Determine the Viability of the Head of the Femur

Abstract

1. Since avascular necrosis inevitably develops in a certain percentage of patients with fractures of the neck of the femur because the blood supply of the head of the femur has been diminished as a result of the fracture, theoretically one should be able to predict shortly after fracture whether a given patient will have clinical evidence of avascular necrosis. 2. If the circulation of the head of the femur is interrupted, in vivo uptake studies reveal no uptake of P32 ninety minutes or more after injection. 3. Studies of uptake of P32 appear to be of prognostic value in two-thirds of patients with displaced fractures of the neck of the femur. In the group reported here, had these data been used as the deciding factor as to whether a prosthesis should be inserted primarily, an actual or irreversible error would have been made in approximately 10 per cent. 4. In a given patient, the experimental uptake study may not predict the clinical end result accurately either because of failure to obtain data from the weight-bearing area, or because of the presumably insurmountable obstacle presented by irregular isotope uptake in the head of the femur caused by partial interruption of the circulation.