What Is a Bursa and Why Does It Get Inflamed?

A bursa is a small, fluid-filled sac that acts as a cushion between bones, tendons, muscles, and skin. Bursae reduce friction at points where tissues rub against each other during movement, allowing smooth, painless motion. The foot and ankle contain numerous bursae — some anatomically constant, others that develop in response to pressure or irritation (adventitious bursae).

Bursitis refers to inflammation of a bursa, producing pain, swelling, and warmth in the affected area. While bursitis can result from a single traumatic event, it more commonly develops from repetitive friction or pressure — tight shoes, prolonged walking on hard surfaces, or abnormal bony prominences that repeatedly compress the overlying bursa. At Balance Foot & Ankle, Dr. Tom Biernacki DPM and Dr. Daria Gutkin DPM evaluate bursitis throughout Howell and Bloomfield Township, MI, offering both conservative care and advanced interventional options.

Common Locations of Foot and Ankle Bursitis

Retrocalcaneal bursitis is one of the most frequently encountered, affecting the bursa located between the Achilles tendon and the posterior calcaneus (heel bone). It is often associated with Haglund’s deformity — a bony prominence at the back of the heel — and causes pain and swelling directly at the heel-tendon junction. This location is commonly mistaken for Achilles tendinitis, though both conditions can coexist.

Subcalcaneal bursitis occurs at the undersurface of the heel and can mimic plantar fasciitis. The bursa beneath the heel pad becomes inflamed from prolonged standing or walking on hard surfaces. Unlike plantar fasciitis, the tenderness is often more diffuse and may extend medially and laterally rather than being pinpoint at the medial calcaneal tubercle.

Bunion bursitis develops over the medial eminence of the first metatarsophalangeal joint in patients with hallux valgus (bunion). The friction of shoe pressure against the prominent bump creates an adventitious bursa that can become dramatically swollen and painful. Managing the underlying bunion deformity is often necessary to resolve this type of bursitis permanently.

Intermetatarsal bursitis involves bursae located between the metatarsal heads. When enlarged, these bursae can compress the interdigital nerves and mimic Morton’s neuroma — or the two conditions may coexist. The pain is located in the forefoot, worse with tight shoes, and often associated with a sensation of fullness in the ball of the foot.

Lateral fifth metatarsal bursitis (“tailor’s bunion” bursitis) occurs over the bony prominence at the base of the fifth toe. It is particularly common in individuals with a splayed forefoot who wear narrow shoes, and can become chronically inflamed.

Diagnosing Foot Bursitis

Clinical examination usually provides the diagnosis. The characteristic findings are localized swelling directly over a bony prominence, tenderness with palpation or direct pressure, and fluctuance (a fluid-filled, compressible feel) to the swollen area. Range of motion of the adjacent joint may be limited by pain.

X-rays help identify associated bony abnormalities such as Haglund’s deformity, calcifications within the bursa, or underlying arthritic changes. Ultrasound is particularly useful for bursitis, directly visualizing the fluid-filled sac and guiding aspiration or injection procedures. MRI provides more detailed information about the extent of inflammation and any associated tendon or joint pathology.

When bursitis is associated with systemic disease — gout, rheumatoid arthritis, septic bursitis — laboratory testing including uric acid levels, inflammatory markers, and bursal fluid analysis becomes important. Septic bursitis requires urgent treatment with antibiotics and may necessitate surgical drainage.

Non-Surgical Treatment Options

Conservative management is highly effective for most cases of foot and ankle bursitis. Activity modification and footwear changes — eliminating tight shoes, adding cushioned heel cups, or wearing wider toe boxes — remove the mechanical irritant that perpetuates inflammation. Donut-shaped pads placed around (not over) the inflamed bursa reduce direct pressure from shoes.

Ice application for 15–20 minutes several times daily reduces acute inflammation. Oral NSAIDs such as ibuprofen or naproxen provide both analgesic and anti-inflammatory effects. Topical anti-inflammatory gels can be useful for superficial bursae close to the skin surface.

Aspiration of the bursal fluid under sterile technique immediately reduces swelling and pain, and the aspirated fluid can be sent for analysis to rule out infection or gout. Corticosteroid injection into the bursa following aspiration is often performed simultaneously, providing powerful local anti-inflammatory effect. However, injections adjacent to tendons (particularly the Achilles) must be performed carefully to avoid tendon weakening.

Physical therapy addresses contributing biomechanical factors, stretches tight calf muscles (which increase Achilles tendon tension and retrocalcaneal bursa compression), and strengthens intrinsic foot muscles. Custom orthotics may be prescribed to correct abnormal foot mechanics contributing to bursitis.

When Surgery Is Recommended

Surgical intervention becomes appropriate for bursitis that has failed 3–6 months of comprehensive conservative treatment, or when an underlying structural abnormality (such as Haglund’s deformity) makes definitive resolution unlikely without bony correction. Surgical options include bursectomy (excision of the inflamed bursa) and, where relevant, resection of the associated bony prominence.

For retrocalcaneal bursitis with Haglund’s deformity, the combination of bursectomy and calcaneal exostectomy (bone shaving) is standard practice, performed open or endoscopically. Outcomes are generally excellent, with high patient satisfaction and low recurrence rates when the underlying structural cause has been adequately addressed.

Foot or Ankle Pain? We Can Help.

Balance Foot & Ankle — Howell & Bloomfield Township, MI

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Dr. Tom Biernacki, DPM

Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.