The immunology of bone and cartilage transplantation.

Bone tissue was one of the earliest human transplanted tissues, yet little is known about its transplant biology. For many years, bone and cartilage tissues were though to be immunoprivileged tissues because of the absence of acute rejection phenomenon. Advances in the understanding of transplant immunology of vascularized tissue grafts (kidney, heart, liver, etc) have led to a renewed interest in the immunobiology of bone and cartilage allograft transplantation. Since prosthetic materials used in orthopedic reconstructive surgery have a limited lifespan, there is great interest in the transplantation of bone and cartilage tissue. The first half of the article discusses transplant terminology, basic principles of immunology, and experimental studies on the immunogenicity of bone and cartilage tissue. The second half of the article discusses how allotransplanted bone and cartilage behaves in human transplants, storage and preservation techniques, and future directions in bone and cartilage transplantation.