The influence of acrylic cement on the femur of the dog. A histological study.

Using dogs as experimental animals, polymerizing methylmethacrylate was inserted into the marrow cavity of the femur. The influence on bone over a period of 21 months was studied by means of histological techniques and microradiography. To distinguish the effect of the methacrylate proper from the circulatory disturbance resulting from the operation, control experiments were performed in which the marrow cavity was emptied, but no acrylic cement was inserted. Polymerization of the methacrylate in vivo resulted in a local rise in temperature to about 58 degrees C. In the femurs containing the acrylic cement a consistent picture developed, consisting of: a) necrosis and removal of the central part of the cortex and b) apposition of a thick layer of bone on the outer surface of the cortex, c) deposition of a cylindrical bone sleeve in contact with the methacrylate. In the control experiments only a minimal resorption at the inside surface of the cortex and the deposition of a thin layer of bone at the outside of the cortex were observed. It is concluded inter al. that circulatory distrubance contributes only slightly to the total reaction of bone to the insertion of methacrylate.