Subchondral bone cysts (SBCs), also known as subchondral cystic lesions, are a form of developmental orthopedic disease. SBCs are a significant cause of performance-limiting lameness in young horses.

SBCs are signs of osteochondrosis and consist of round cavities in the bone that may or may not involve the joint surfaces. When it does involve the joint, it occurs near the surface of the stifle, fetlock, pastern, shoulder, elbow, coffin, and/or carpus joints. There are many predictions on the cause--which include trauma to the cartilage or subchondral bone, chronic osteoarthritis and inflammation, or leakage of synovial fluid through an articular defect.

There are many different treatments available for SBCs, however recurrence and treatment failure rates are unacceptably high.