Intramedullary pressure patterns.

The insertion of cement and femoral prosthesis in total hip replacement produces biochemical abnormalities. These are thought to be caused by a marked rise in intramedullary pressure. Surgeons aim to reduce these pressures by using different methods of insertion and venting. The present investigation was undertaken to establish if any one method was superior to the others. The greatest modification of acrylic pressure was obtained by means of a drill hole. Thie highest rise in pressure was produced by the insertion of the femoral prosthesis and this was little modified by any of the alternatives of the use of a 3/16 inch drill hole, a 16-gauge catheter, and cement gun.