Osteonecrosis of the Knee Treated with a Tissue-Engineered Cartilage and Bone Implant

Abstract

It is well known that high-dose corticosteroid administration can cause osteonecrosis1,2. Compared with spontaneous osteonecrosis of the knee3, corticosteroid-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 organs4,5. We have had successful short-term results with use of tissue-engineered cartilage in the treatment of osteochondral defects of the knee6,7. Tissue-engineering techniques, such as the implantation of calcium hydroxyapatite ceramic together with mesenchymal stem cells8-12, 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 regeneration13. 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. A thirty-six-year-old female office worker had received corticosteroid therapy for the treatment of a connective-tissue disease since 1988. Oral prednisolone had been administered at an initial dosage of 60 mg per day and then gradually reduced. In 1991, the patient began to feel piercing pain in her left knee while walking. In 1993, osteonecrosis of the medial and lateral femoral condyles of the left knee was diagnosed. The knee pain gradually increased despite several nonoperative treatments, and in January 2004 she presented with severe pain in the left knee. In addition, she reported having a clicking sensation in the same knee, which was especially noticeable while walking. …