The reconstruction of massive bone and joint defect after resection of malignant tumor, severe traumatic loss, osteomylitis or congenital deformity, has used artificial materials. But this procedure has severe problems such as those of endurance, infection, non-union, pathological fracture and joint instability. So the reconstruction procedure made use of biomaterials and many attempts had been tried before. Recently the concept of the vascularized allogeneic joint transplantation was introduced to solve these complications, but the clinial application has not been reported yet and is still in the experimental stages.
We used a genetically inbred rat which was suitable for immunological investigetion and made a model knee joint orthotopical transplantation across a genetically incompatible pair. We particularly paid attention to the vascularity of the grafted joint and investigated its reaction to immunosuppression with cyclosporine in the short and long term.
As the result, after withdrawal of immunosuppression the graft was rapidly rejected and in many cases pathological fractures occurred around the knee joint, losing its skeletal support and joint function.
On the other hand, under continuous immunosuppression the graft was proved to be living without any degenrative changes and its joint function remained.