Osteochondrosis and Osteochondritis Dissecans (OCD)
Osteochondrosis is a condition found a dogs shoulders, elbows and knees. The articular cartilage is the covering of the end of the bones within the joint. These protect the bone from bruising with joint movements and also produce synovial fluid within the joint for lubrication. Osteochondrosis is a developmental condition that arises due to a disturbance in the normal growth and development of this cartilage. The area between the end of the bone and the hyaline cartilage covering the area is affected and abnormal, thickened cartilage forms. This is due to lack of blood supply to the bone underneath the cartilage and can lead to pain, lameness and early osteoarthritis.
Sometimes, flaps of diseased cartilage become separated from the cartilage surface. If a piece of cartilage becomes partially or completely detached from the surface of the bone it is called Osteochondritis Dissecans, or OCD.
The loss of blood flow can causes the underlying (or subchondral) bone to die in a process called avascular necrosis. The bone is then reabsorbed by the body, leaving the cartilage it supported prone to damage. The cartilage may still have bone attached and these fragments of cartilage cause pain and further damage to the joint.
Diagnosis can be made by XRay but there may be further investigations to see if there is any further damage to the elbow joint such as an arthroscopy, CT or MRI scan.
In the elbow, the inner side of the end of the upper arm bone (medial humeral condyle) is most commonly affected.