(Purpose) We treated four patients with avascular bone necrosis (two in the talus, one in the capitulum of the humerus and one in the scaphoid) using a free vascularized osteoperiosteal graft based on the descending genicular artery, which was taken from the medial epicondyle of the femur. (Patients) There were four patients. Two of them had been suffered from avascular necrosis of the talus (one from the fracture of the talus and the other from idiopathic talus necrosis), another from avascular necrosis of the capitulum of the humerus after the fracture of the elbow joint and the other from avascular necrosis of the proximal scaphoid after the scaphoid fracture. The age of the patients at the time of the surgery was 20-72 years. The follow-up period was 19-39 months (mean; 27 months). (Surgery) The descending genicular artery originating from the femoral artery about 15 cm proximal to the knee joint bifurcates the articular branch nourishing the bone and periosteum around the medial epicondyle of the femur, and the saphenous branch nourishing the skin around the medial knee. An osteoperiosteal graft (supplied by the articular branch) with a monitor cutaneous flap (supplied by the saphenous branch) was simultaneously harvested based on the descending genicular artery. The osteoperiosteal graft was transplanted to the space created after removel of the portion with avascular necrosis, and microvascular anastomosis was performed. (Results) In all patients, the monitor flaps survived and the transplanted bones fused with surrounding bones. One patient with a talus nercosis was relieved from the ankle pain completely, however, the low signal area was still observed in T1 and T2 MRI examinations two years after surgery, although an X-ray showed bone union between the transplanted bone and the surrounding talus. (Conclusions) A small osteoperiosteal graft with a long vascular pedicle (descending genicular vessels or sometimes superior medial popliteal vessels) can be easily harvested from the medial epicondyle of the femur. It is also easy to trim the grafted bone into the shape of a recipient site. A vascular necrosis often occurs in bones covered by articular cartilage. A long pedicle of the graft guarantees the postoperative joint movement and easy trimming enables the grafted bone to fit a recipient site that is often adjacent to a joint.