Autologous bone is preferred because of its osteoconductive and osteoinducive activity, but it is often not sufficiently available and it repeatedly involves donor site morbidity (Summers and Eisenstein 1989) . Allogenic bone exclusively has osteoconductive activity; it serves as a frame against which newly formed bone gets deposited (Elves and Pratt 1975; Urist 1953) . Allogenic bone is provided by an orthopaedic bone bank.