Definition

Bursae are closed sacs lined by a synovium-like membrane; they contain synovial fluid and are usually located in areas that are subject to friction. Their purpose is to mitigate friction and thus to facilitate the motion that occurs between bones and tendons, bones and skin, or tendons and ligaments [1].

Bursae are classified according to their location, as shown in Table 86.1 [1,2].

Symptomatic malleolar bursae most likely result from abnormal contact pressures. They may also be secondary to shear forces that arise between the bony malleoli and the patient s footwear, particularly boots or athletic shoes that surround the ankle. These may occur either medially or laterally. However, medial bursae are more common [1]. The bone prominences of the malleoli have little inherent soft tissue to protect them from these excessive pressures. The body responds to this abnormal stress by developing an adventitious bursa at this site. The skin and subcutaneous tissues are then able to glide over the bone prominences and thus dissipate these excessive forces. Sometimes, these bursae may become inflamed, resulting in bursitis.

The posterior heel includes the retrocalcaneal bursa, which is located between the calcaneus and the Achilles tendon insertion site, and the retroachilles bursa, which is located between the Achilles tendon and the skin. Each bursa is a potential site of inflammation. The most common cause of posterior heel bursitis is ill-fitting footwear with a stiff posterior edge that abrades the area of the Achilles tendon insertion. Retrocalcaneal inflammation may also be associated with a prominence of the posterosuperior lateral aspect of the calcaneus, causing irritation of the bursa, called a Haglund deformity or pump bump. This entity often goes hand-in-hand with retrocalcaneal bursitis, and frequently there is an element of insertional tendinitis as well.

Although Haglund deformity is more commonly found in women who wear high-heeled shoes, it is sometimes found in hockey players who wear a rigid heel counter that causes irritation. The population of patients that has this superolateral bone prominence tends to be younger than the patients with retrocalcaneal bursitis [3]. Numerous biomechanical risk factors have been associated with Haglund deformity. These include a high-arch cavus foot, rearfoot varus, rearfoot equinus, and trauma to the apophysis in childhood [4–6] (Fig. 86.1).

Bursitis can also occur in the forefoot and may involve the intermetatarsal bursae or the adventitial bursae beneath the metatarsal heads [2].

Risk factors for foot and ankle bursitis are outlined in Table 86.2. Runners, especially those who train uphill, sustain repeated ankle dorsiflexion. Repetitive stress through this motion can lead to bursitis. Also, runners and recreational walkers with sudden increase in mileage are at risk for acquiring symptoms of tenderness, swelling, redness, and pain near the insertion of the Achilles tendon. The most common cause of ankle bursitis is tight-fitting shoes with a firm heel counter. Women wearing high-heeled shoes, runners with improper shoe fit or overworn footwear, skaters, and patients with lower extremity edema are susceptible to development of ankle bursitis. Other important causes of bursitis, in general, are trauma, infection, rheumatoid arthritis, and gout.

Symptoms

With malleolar bursitis, there may be exquisite tenderness surrounding the inflamed bursa, a fluctuant mass over the medial malleolus, and decreased range of motion of the ankle.

Retrocalcaneal bursitis is hallmarked by pain that is anterior to the Achilles tendon and just superior to its insertion on the os calcis. Compression of the bursa between the calcaneus and the Achilles tendon occurs every time the ankle is dorsiflexed; in a runner, the repetitions are countless, particularly with uphill running, when ankle dorsiflexion is increased. Patients often develop a limp, and wearing of shoes may eventually become increasingly painful. Thus, it is not surprising that long-distance runners who use uphill running as a training method frequently develop retrocalcaneal bursitis.

Patients with retroachilles bursitis are often asymptomatic. However, when symptoms occur, the patient usually presents with a painful, tender subcutaneous swelling overlying the Achilles tendon, usually at the level of the shoe counter. The overlying skin may be hyperkeratotic or reddened.

Patients with metatarsal bursitis usually have exquisite tenderness surrounding the inflamed bursa, swelling over the metatarsal head, and decreased range of motion of the metatarsophalangeal joint.

Physical Examination

The physical examination findings in bursitis are described in Table 86.3.