Location of Bursa

Subcutaneous

The subcutaneous bursae can be classified as adventitious when they become abnormal and develop a distinct wall. These bursae appear between the subcutaneous tissue and deep fasciae junction, or bony prominences. 

Submuscular 

The submuscular bursae exist between adjacent muscles or muscles and bony prominences.

Bursa naming is according to the location within the human body: bursae of the upper body include subacromial, subscapular, and olecranon;  bursae of the hip include ischiogluteal, iliopsoas, and trochanteric; bursae of the knee include medial collateral ligament, pes anserinus, prepatellar, infrapatellar, popliteal bursa; and the ankle bursa is Retrocalcaneal. 

Upper Body Bursae

The subacromial bursa lies between the acromion and the rotator cuff. This bursa protrudes laterally from below the acromion when the arm is at rest and moves medially below the bone when the person lifts their arm away from the center of the body. 

The subscapular bursa lies between the frontward facing scapula surface and the backward-facing chest wall. 

There are two olecranon bursae with the first bursa lying between the tricep tendons, the posterior elbow ligament, and the olecranon, while the second bursa lies more superficially between where the triceps attaches to the olecranon and the skin.

Hip Bursae

The ischiogluteal bursa lies deep within the gluteus maximus and surfaces the ischial tuberosity.

The iliopsoas bursa is known for being the largest bursa in the human body, which extends into the iliac fossa and lies between the lesser trochanter and the iliopsoas tendon. 

The trochanteric bursa extends superficially between the tensor fascia latae and the skin while also lying deeply between the tensor fasciae latae and the greater trochanter.

Knee Bursae

The medial collateral ligament bursa lies between the superficial and deep medial collateral ligament in the knee.

The pes anserinus bursa lies between the hamstring tendons and superficial collateral ligament.

The prepatellar bursa is located anteriorly over the knee’s patella and below the skin.

The infrapatellar bursa contains a superficial component, as well as a deep component. The superficial bursa is between the patellar ligament and the skin, while the deep bursa is between the patellar ligament and the proximal aspect of the anterior tibia. 

The popliteal bursae are known as baker cysts and lie in the posterior joint capsule of the knee.

Ankle Bursae

The retrocalcaneal bursa is at the back of the heel and lies deep to the Achilles tendon and above the calcaneus bone. Occasionally you can see bursa over the medial malleolus, the subcutaneous medial bursa, and a bursa behind the heel called the subcutaneous calcaneal bursa.

Inflamed Bursae

Irritation to any part of the body can cause inflammation. Any inflammation of the bursa is called bursitis. This inflammatory response can result from a minor, repetitive impact on the surrounding bursa area, or can occur from sudden and more urgent injuries.[6] Other factors that affect bursitis formation include age, a body’s elasticity and ability to tolerate stress, and diseases, such as rheumatoid arthritis or thyroid disease, or infection. Additionally, any overuse or impairment to the bursa or surrounding body parts- joint, bone, tendon, muscle, or ligament- can increase the risk of developing bursitis. Common symptoms of bursitis may include discomfort, tenderness, redness, or swelling in the affected area, difficulty or loss of movement, and fever.[7]

Septic Bursitis and Surgical Considerations

Patients can also present with sudden onset of redness and pain in a previously inflamed bursa. That could be as a result of infection, which can be due to poor host immune response or a direct inoculation with penetrating trauma or an insect bite.[8] When the conservative measures to treat the painful and infected bursa have failed, surgical inversion may be required to drain the collection.[9]

In certain scenarios, the clinical findings might not be adequate to differentiate septic bursitis from friction, crystal deposition, or inflammatory conditions. Aspiration under aseptic precautions and, if required with ultrasound guidance, followed by oral antibiotics, is the recommendation.[10] Aspirate should have microbiology and biochemistry assessments. Antibiotics should be changed depending on the culture and sensitivity results.

Surgical treatment for recurrent bursitis is not standardized with supporting evidence. There is a considerable variation in treatment modalities across the globe. The patient should be made aware of the potential risks associated with surgical excision, including infection, delayed healing, sinus formation, the persistence of pain, and recurrence.[11]

Bursitis can be treated through many interventions including rest, stretching and physical therapy, Non-steroidal anti-inflammatory drugs such as ibuprofen, aspirin, naproxen, COX-2 inhibitors, topical medications such as lidocaine patches, NSAIDs, or analgesics, aspiration to drain the excess fluid to relieve bursa pressure, corticosteroid injections, antibiotics, RICE: rest, ice, compression, elevation, and in some cases- surgery.[12] The required treatment for bursitis depends on the location of the inflamed sac, the severity of the inflammatory response, and the duration of the condition.

Sub-acromial bursitis is a common diagnosis in patients presenting with shoulder pain, particularly in a young and active population. Often their symptoms are exaggerated with over-head activities. A thorough clinical examination supported with appropriate imaging is vital in confirming the diagnosis and drawing up a treatment plan. The vast majority of patients notice improvement with activity modifications, rest, analgesics, and appropriate physiotherapy. Referral to specialists for surgical intervention is the recommended next step when these modalities fail.

Clinicians can adequately manage trochanteric bursitis with anti-inflammatory medications, rest, and physiotherapy. Ultrasound-guided steroid injections are proven to provide good relief in a few patients while there is increasing evidence for injecting platelet-rich plasma.[7][13][14]