Osteochondrosis Dissecans, frequently called "OCD", is a condition that occurs as a result from osteocondrosis (OC). Osteocondrosis is a condition of abnormal cartilage development. OCD describes a flap that forms as a result of this abnormal articular cartilage development. This loose piece or flap of cartilage causes secondary joint osteoarthritis. These problems generally occur early in the dog's life, as opposed to the "wear and tear" arthritis that people manifest later in life.

Cartilage is the tissue, normally at the ends of long bones, which contributes to pain-free motion. OC is a congenital defect in normal joint cartilage development that results in either a loose piece or flap of cartilage.

OCD occurs more in males than females, and some breeds are genetically predisposed including Great Danes, Newfoundlands, Rottweilers, Bernese mountain dogs, Old English sheepdogs, Labrador retrievers and Irish setters.

Osteochondritis dissecans can occur in the shoulder, stifle (knee), hock (joint below the knee) and elbow. OCD of the shoulder was once the most commonly recognized form of OC; however, a different complication of OC, Fragmented coronoid process (FCP), is now more commonly diagnosed. OCD of the shoulder occurs when there is abnormal ossification or development of the joint cartilage of the upper portion of the humerus. A layer of thicker cartilage results from the osteochondrosis. This thicker cartilage can crack, cause a fissure and dissect (hence the name dissecans) a cartilage flap. This causes secondary joint inflammation and lameness. OCD affects young, large-breed dogs. This condition also frequently affects both front legs.

The amount of secondary arthritis present when the condition is diagnosed is "there to stay"; however, most surgeons feel that if the condition is dealt with in a timely manner, further development of degneration could be lessened.

Diagnosis

Diagnostic tests are needed to recognize OCD and exclude other diseases that may cause lameness in young dogs. Many times, the veterinarian will suspect OCD based on signalment (age, sex and breed), history and clinical examination. In addition to obtaining a medical history and performing a thorough general physical examination, other tests that your veterinarian may wish to perform include:

A thorough orthopedic examination. This usually shows lameness and joint pain or swelling.

Radiographs (X-rays) of the affected joint. These can illustrate the primary OCD problem or show the secondary DJD that results from it.

Joint contrast studies (arthrogram). Occasionally injecting dye into the joint and taking a radiograph may be helpful in establishing a definitive diagnosis of OCD.

Blood tests. These can be done to determine your pet's general health, particularly if surgery is being considered. They are also done to assess the risks to your pet in undergoing anesthesia.

Magnetic resonance imaging (MRI) or computed tomography (CT).
These are specialized tests that are sometimes performed at large referral centers.

Treatment

Treatment for OCD may include the following:

Surgical treatment is usually recommended for dogs suffering from OC, but the exact type of surgery performed depends on the joint involved.

The goal of the surgical procedure is to remove any loose pieces of cartilage from the joint surface and curette (scrape) the cartilage defect to stimulate filling of the defect.

At some centers, arthroscopic surgery is used to treat lameness associated with OCD.

Chondroprotective nutraceutical agents such as chondroitin sulfate and glucosamine (Cosequin®) are probably beneficial, especially during the time of cartilage healing.

Home Care and Prevention

After your pet has joint surgery, you will need to limit exercise for three to four weeks after surgery. Follow your veterinarian's instructions regarding physical therapy and medications.

Since many of these animals have experienced rapid growth, some veterinarians feel that feeding lower protein diets without supplements may be helpful in decreasing the incidence of the disease. Discuss this issue with your veterinarian.