immunology allergic disorders
Tissue Transplantation
Bone Transplantation
Bone transplantation is used for reconstruction of large bony defects (eg, after massive resection of bone cancer). No viable donor bone cells survive in the recipient, but dead matrix from allografts can stimulate recipient osteoblasts to recolonize the matrix and lay down new bone. This matrix acts as scaffolding for bridging and stabilizing defects until new bone is formed. Cadaveric allografts are preserved by freezing to decrease immunogenicity of the bone (which is dead at the time of implantation) and by glycerolization to maintain chondrocyte viability. No postimplantation immunosuppressive therapy is used. Although patients develop anti-human leukocyte antigen (HLA) antibodies, early follow-up detects no evidence of cartilage degradation. 