The most common bursa to be inflamed in the foot is the retrocalcaneal bursa (also referred to as the subtendinous calcaneal bursa). Located between the Achilles tendon and the heel bone (calcaneus), this is a "true" bursa that is present from birth. It acts as a cushion to protect the Achilles tendon from friction against the heel bone. Also commonly affected, the subcutaneous calcaneal bursa (also referred to as the Achilles bursa), located between the Achilles tendon and the skin, sits a little lower down the ankle towards the heel than the retrocalcaneal bursa. This bursa develops as you age, an "adventitious" bursa, to protect the tendon from friction at the back of the heel.
Pain at the posterior heel or ankle is most commonly caused by pathology at either the posterior calcaneus (at the calcaneal insertion site of the Achilles tendon) or at its associated bursae. Two bursae are located just superior to the insertion of the Achilles (calcaneal) tendon. Anterior or deep to the tendon is the retrocalcaneal (subtendinous) bursa, which is located between the Achilles tendon and the calcaneus. Posterior or superficial to the Achilles tendon is the subcutaneous calcaneal bursa, also called the Achilles bursa. This bursa is located between the skin and posterior aspect of the distal Achilles tendon. Inflammation of either or both of these bursa can cause pain at the posterior heel and ankle region.
Symptoms of bursitis usually occur after rest and relaxation. Upon activity there is usually more intense pain in the area of the bursa. The common areas to have a bursitis in the foot are in the bottom of the heel, behind the heel near the attachment of the Achilles Tendon as well as along the side of a bunion. A bursa may also form in multiple areas especially along the metatarsal heads, or "ball" of your foot. You may actually feel the sac like fluid when rubbing the area of pain.
Diagnosis is first by clinical suspicion of symptoms. This can be mistaken for gout or infection especially in the big toe region. A diagnosis of bursitis is usually used in combination of the underlying cause, for instance a bunion deformity, Haglund's deformity, or Heel Spur Syndrome. Many times the cause needs to be addressed to rid the problem of bursitis.
Non Surgical Treatment
Long Term Treatment must be directed towards eliminating the abnormal tilting of the heel, regardless of its cause. If this is delayed, the usual results are the pain and swelling becomes worse, chronic, and debilitating. Eventually, painful calcifications and bone spur formations may occur on the back of the heel, along with tears in the Achilles Tendon. These are serious problems that may require surgical intervention. In order to eliminate abnormal heel tilt, the foot must be re-balanced. Controlling and reducing the biomechanical foot defects that are causing the heel to tilt best accomplish this. The "Gold Standard" of medical care (that treatment most used by doctors and therapists) to help eliminate pain, inflammation, and swelling at the back of the heel is orthotics.
Surgery to remove the damaged bursa may be performed in extreme cases. If the bursitis is caused by an infection, then additional treatment is needed. Septic bursitis is caused by the presence of a pus-forming organism, usually staphylococcus aureus. This is confirmed by examining a sample of the fluid in the bursa and requires treatment with antibiotics taken by mouth, injected into a muscle or into a vein (intravenously). The bursa will also need to be drained by needle two or three times over the first week of treatment. When a patient has such a serious infection, there may be underlying causes. There could be undiscovered diabetes, or an inefficient immune system caused by human immunodeficiency virus infection (HIV).