The causes and risk factors of retrocalcaneal bursitis are listed below. Identifying the underlying reason the bursa is inflamed will help set a course for treatment.
Repetitive use of the ankle. Retrocalcaneal bursitis is often caused by frequent "mini-traumas." These mini-traumas are often due to excessive walking, jumping, or running. Running uphill, which causes the foot to flex considerably, can be especially irritating to the retrocalcaneal bursae. People who suddenly intensify their exercise programs without adequate stretching and muscle conditioning may get retrocalcaneal bursitis. In general, it is often associated with over use of the Achilles attachment, the area where the Achilles tendon fibers attach to the heel.
Ill-fitting footwear. Wearing poorly fitting or constrictive footwear can cause the heel to become irritated and inflamed. Shoes that dig into the back of the heel are the primary cause of retroachilles bursitis.
Foot or ankle deformity. A foot or ankle deformity can make it more likely to develop retrocalcaneal bursitis. For example, some people can have an abnormal, prominent shape of the top of their heel, known as a Haglund's deformity. This condition increases the chances of irritating the bursa.
Previous injury. A trauma to the affected heel, such as inadvertently striking the back of the heel against a hard object, can cause the bursa to fill with fluid, which in turn can irritate and inflame the bursa's synovial membrane. Even though the body usually reabsorbs the fluid, the membrane may stay inflamed, causing bursitis symptoms.
Another underlying condition. The retrocalcaneal bursa can become inflamed as the result of another condition, such as damage to the Achilles tendon, osteoarthritis, rheumatoid arthritis, gout, and pseudogout. In these instances, the treatment for bursitis must accompany treatment for the underlying condition.
Infection. Septic retrocalcaneal bursitis, which is caused by an infection, is uncommon. Infection can reach the bursa through a cut, puncture, a blister, or even an insect bite. It is possible to have septic bursitis without an obvious opening. In these cases the superficial wound may have healed quickly, but still allowed bacteria into the bursa.
See Septic Bursitis
Certain medical conditions and medications suppress people's immune systems and make them more susceptible to septic bursitis. For example, people with cancer, HIV/AIDS, lupus, alcoholism, chronic obstructive pulmonary disease (COPD), and diabetes may be more likely to get septic bursitis.
History of inflammation of the bursa. Patients who have had bursitis in the past have an increased chance of getting it again.
There may be more than one reason why the retrocalcaneal bursa is inflamed. In these cases, treatment should address all of the causes.