The Repair of Experimental Defects in Rabbit Skulls; Observations after Implantation with Decalcified, Deproteinised and Deep Frozen Homogenous Whole Bone.

Implants of homogenous and especially heterogenous bone are more slowly incorporated than autografts and may be rejected. Bone has been treated in various ways in attempts to reduce the incidence of implant rejection while still retaining such osteogenetic properties as it may have, thereby improving its rate and degree of incorporation. Usually pieces of bone have been either decalcified or macerated to remove the protein but there are conflicting reports about the relative efficacy of these implants. In 1957 Ray and Holloway published the results of experiments on the repair of defects in rat skulls using homo-implants of frozen whole bone, decalcified bone and deproteinised bone. They found the best substitute for fresh autogenous bone implants to be decalcified bone, whereas none of twelve defects implanted with deproteinised bone showed more than slight healing. Other authors, however, have reported the success of deproteinised implants. Maatz, Lentz and Graf (1954) obtained successful incorporation of deproteinised implants in bone defects in dogs. Hancox, Owen and Singleton (1961) found deproteinised heterogenous implants to be well incorporated into experimental bone defects in sheep. Because there might be a species variation in the response to implants of deproteinised bone, the experiments of Ray and Holloway have been repeated, but using the rabbit. The healing of standard bone defects without any implant has also been studied as a control.