Spontaneous osteonecrosis of the knee

Spontaneous osteonecrosis of the Knee, is the result of vascular arterial insufficiency to the medial femoral condyle of the knee resulting in necrosis and destruction of bone. It is often unilateral and can be associated with a meniscal tear.The condition is usually characterized by a sudden onset of knee pain, worse at night. Examination reveals tenderness of the medial femoral condyle, joint effusion, and occasional locking of the knee joint.It is more common in females over the age of 50 with possible risk factors of corticosteroid use, Lupus, alcoholism, pancreatitis, sickle cell anemia, and rheumatoid arthritis.