Anorganic bone grafting: Clinical experiences with heterografts processed by ethylenediamine extraction

Abstract

This report presents a preliminary account of experience with anorganic bone in surgical procedures on 149 patients whose progress was followed up from five months to two years. When properly handled, anorganic bone has been well tolerated by the host and rapidly incorporated in reparative callus at an early stage. With one exception, no untoward responses occurred in this series of cases. If the material is too fine, a non-specific inflammatory response may be anticipated. In the presence of infection, necrosis of tissue or avascularity, anorganic bone is poorly tolerated, and becomes extruded or walled-off as would other alloplastic materials. Studies of the radiologic evolution of anorganic bone grafts, compared with homogenous grafts from bone banks, has revealed a slower rate of removal of the anorganic bone implant. Grafting with anorganic bone should not be used when fixation is required, because of the extreme fragility of the material. It serves best as an implant or filling material in bone defects when it acts to prevent the invasion of fibrous connective tissue and to supply an absorbable trellis through which new bone from the host may develop. As a basic criterion for clinical use, anorganic bone should be employed only in osseous defects which would reconstitute themselves, provided fibrous tissue were prevented from entering the empty space, and then only in situations in which first and third grade grafts are not available. These preliminary findings indicate that further experimental and clinical evaluation must be undertaken before this material can be recommended for general use. The real significance of this study may be in its application to our understanding of the basic nature of bone as a tissue.