Osteonecrosis of the knee treated with a tissue-engineered cartilage and bone implant - A case report

It is well known that high-dose corticosteroid administration can cause osteonecrosis(1,2). Compared with spontaneous osteonecrosis of the knee(3), corticostetroid-induced osteonecrosis of the knee tends to be more extensive and often occurs in younger patients. Recently, more attention has been given to regenerative tissue-engineering techniques that make use of autologous cells combined with implants to restore lost or dysfunctional tissues or organs(4,5). We have had successful short-term results with use of tissue-engineered cartilage in the treatment of osteochondral defects of the knee(6,5). Tissue-engineering techniques, such as the implantation of calcium hydroxyapatite ceramic together with mesenchymal 2 stem cells(8-12), have also been applied to bone regeneration. Recently, a new type of hydroxyapatite with interconnected pores (IP-CHA) was introduced for use as a scaffold for bone regeneration(13). We present the case of a patient in whom steroid-induced osteonecrosis of the distal part of the femur was treated by implantation of tissue-engineered cartilage together with IP-CHA hybridized with cultured bone-marrow cells. The patient was informed that data concerning the case would be submitted for publication, and she consented.