Bursitis can principally be divided into three groups: aseptic, septic and chronic. Differential diagnosis between the groups is not always easy.
Prepatellar and olecranon bursae that are located in the subcutaneous space are most commonly injured.
If septic bursitis is suspected, antimicrobial treatment should be started as soon as possible.
General
Bursae facilitate the movement of joints by reducing friction from tendons and structures beneath muscles.
If bursae are irritated, they are filled with fluid secreted by the synovial membrane and become swollen.
Septic bursitis
Bacterial infection of the bursa, most commonly caused by Staphylococcus aureus (> 80%). Patients with impaired immune response or rheumatoid arthritis are also at risk of septic bursitis.
Septic bursitis should be suspected if the bursa region has rapidly become painful, swollen and red. There may be slight fever. Predisposing factors are often adjacent injuries, such as a scratch on the skin, but the infection may also spread from cellulitis. Septic bursitis is rarely haematogenous.
If septic bursitis is suspected, before antimicrobial treatment is started the bursa should be punctured to take a sample of bursa fluid for culture (video Septic Bursitis of the Elbow - Aspiration for Bacterial Culture) in a blood culture bottle (one aerobic culture bottle suffices), or a bacterial culture test tube can be used.
The sample is often cloudy, sometimes bloody, and the cells in the fluid are mostly granulocytes (> 50% polymorphonuclear) with a leukocyte count over 2 000 × 106 /l .
Aspiration is the primary treatment of septic bursitis. If fluid reaccumulates, aspiration should be repeated as often as daily, as necessary. The limb should be kept at rest and a light compression bandage applied. Non-steroidal anti-inflammatory drugs (NSAIDs) can be used for pain.
Antimicrobial treatment should be started immediately after taking the aspiration sample.
If there are no general symptoms and infection parameters are not markedly elevated, oral antimicrobial treatment can be started with, for example, 500 mg cephalexin 3 times daily for two weeks.
If there are general symptoms (fever, high CRP levels) and in patients with impaired immune response, intravenous antimicrobial treatment with 1 500 mg cefuroxime 3 times daily, for instance, should be started in hospital.
Aseptic acute and chronic bursitis
Acute aseptic bursitis is usually caused by a sudden contusion injury and is significantly more common than septic bursitis. The bursa is filled with blood, there is swelling in the subcutaneous space over the joint, and active joint movements are painful. Treatment consists of rest, application of cold, and NSAIDs.
The bursa should be aspirated even if there is only mild swelling. Aspiration samples should be taken as necessary. Aspiration can be repeated as often as once a week, as necessary.
Chronic bursitis is a consequence of repeated injury in association with exercise or in certain jobs (carpet layers, gardeners). The bursa is filled with fluid, its walls are thick, and the bursal cavity is often multilocular.
Treatment consists of drainage of the bursa and injection of a long-acting glucocorticoid (methylprednisolone or triamcinolone in depot form; video Aseptic Bursitis of the Elbow). The injection may be repeated after 2-4 weeks if the result of the first injection is not satisfactory.
In prolonged cases, and if the bursa is clearly disturbing, it may be surgically removed.
Brown OS, Smith TO, Parsons T et al. Management of septic and aseptic prepatellar bursitis: a systematic review. Arch Orthop Trauma Surg 2021.[PubMed]
Charret L, Bart G, Hoppe E et al. Clinical characteristics and management of olecranon and prepatellar septic bursitis in a multicentre study. J Antimicrob Chemother 2021;76(11):3029-3032.[PubMed]