Osteochondritis Dissecans

Osteochondritis dissecans is a joint condition characterised by reduced blood supply to the end of a bone leading to the development of cracks. A piece of cartilage breaks apart along with a thin layer of underlying thin layer of bone. The disease most commonly occurs in young men, usually after an injury to a joint. Though any joints may get affected by osteochondritis dissecans, knee joint tends to be the most commonly affected one.

If the broken fragment does not get jammed between the moving parts of a joint, there may not be any symptoms at all. Surgical repair is required otherwise. Loosened fragments are sometimes referred to as joint mice.

The condition is relatively rare; an estimated incidence is about 15 to 30 cases per 100,000 persons per year. However, it is an important cause of joint pain in physically active adolescents.


Causes

The exact cause of osteochondritis dissecans is often unknown. Mild recurrent injuries, growth disturbances are some of the theories. Though the name “osteochondritis” means inflammation, microscopic studies suggest otherwise. Suggested causes for the condition include:

Repetitive trauma
Restriction or loss of blood flow
Hereditary factors
Endocrine factors
Anomalies in bone growth
Metabolic abnormalities (especially imbalances in calcium and phosphorous levels)
Undernourishment

Repeated trauma (multiple events of minor injuries, often unrecognised) may damage the end of the affected bone compromising its blood supply.

Risk Factors

Sports:

Repeated physical trauma is thought to be a strong risk factor for the development of osteochondritis dissecans. Young athletes exposed to repeated strain injuries are reported to have a higher incidence. Sports like Gymnastics, soccer, basketball, lacrosse, football, tennis, squash, baseball and weight lifting may put participants at higher risk of developing the condition.

Age: People between the ages of 10 and 20 are most commonly affected by osteochondritis dissecans

Sex: Male sex is twice or thrice more likely to develop the condition than female sex.    

Certain case reports also suggest genetic predisposition. Some people may have a greater tendency to develop osteochondritis dissecans by virtue of their genetic makeup.

Complications

Joints affected by osteochondritis are more liable to develop osteoarthritis, a condition in which the cartilage wears off (cartilage is a tough elastic tissue).