Spontaneous Osteonecrosis of the Knee Treated with

pontaneous osteonecrosis of the knee is a disease whose primary etiology remains unknown. First described by Ahlbäck et al.1 in 1968, it is now categorized as either primary (spontaneous) or secondary osteonecrosis2. Primary osteonecrosis usually presents in people over the age of fifty years, with sudden onset of pain, most frequently in the medial femoral condyle. Secondary osteonecrosis is associated with certain risk factors, such as corticosteroid therapy and alcohol use, and is usually encountered in younger people. In patients with advanced disease or for whom nonopera-tive treatment has failed, surgery is recommended, typically partial or total joint replacement3-5. Reports of non-arthroplasty proce-dures are limited. Debridement, curettage, microfracture surgery, osteochondral allograft, bone-grafting, and isolated high tibial osteotomy (HTO) have been proposed6-12, but none have dem