[The principle of autogeneic rib perichondrial transplantation in the treatment of deep articular cartilage defects].

The purpose of this study was to examine the fate of autologous perichondrial grafts after transplantation into cartilage lesions in weight-bearing joints. Results were evaluated depending on the age of the animals and on the weight-bearing conditions. Osteochondral lesions were drilled in the articular surface of knee joints in 36 adolescent sheep. The defects were filled with autologous rib perichondrial grafts which were secured by either collagen sponges (n = 12) or fibrin glue (n = 12). Twelve animals served as controls. Following one week of immobilisation the animals were allowed to move freely. Animals were sacrificed after 4, 8, 12, and 16 weeks. The same procedure was performed in three adult animals in order to achieve hints regarding the age-dependent ingrowth of the transplants. In two of them the transplantation was done using fibrin glue for fixation; one animal served as control. Grafts were removed corresponding to the time intervals and investigated histologically. In adolescent animals grafts from weight-bearing areas and control defects did not show a regular cartilagenous differentiation. In contrast to that, hyaline-like cartilage formation could be noted in non-weight-bearing areas even after 4 weeks. In principle, the same results were found in adult sheep but a delay of cartilagenous differentiation of four weeks was observed. Depending on these results we use the procedure of perichondrial transplantation clinically for treatment of circumscript deep lesions of articular cartilage provided no osteoarthritis or any other overlying general diseases are evident. By means of the Lysholm- and Ranawat-score all six patients demonstrated postoperative improvement. Furthermore, in two patients arthroscopic controls exhibited sufficient filling of the defects and ingrowth to the surrounding cartilage. Thus, autogeneic perichondrial transplantation can be recommended for treatment of circumscript deep cartilagenous lesions of articular cartilage.