musculoskeletal and connective tissue disorders
Bursitis
Diagnosis of Bursitis
Clinical evaluation Ultrasonography or MRI for deep bursitis Aspiration for suspected infection, hemorrhage (due to trauma or anticoagulants), or crystal-induced bursitis Superficial bursitis should be suspected in patients with swelling or signs of inflammation over bursae. Deep bursitis is suspected in patients with unexplained pain worsened by motion in a location compatible with bursitis. Usually, bursitis can be diagnosed clinically. Ultrasonography or MRI can help confirm the diagnosis when deep bursae are not readily accessible for inspection, palpation, or aspiration. These tests are done to confirm a suspected diagnosis or exclude other possibilities. These imaging techniques increase the accuracy of identifying the involved structures. If bursal swelling is particularly painful, red, or warm or if the olecranon or prepatellar bursa is affected, infection and Overview of Crystal-Induced Arthritides should be excluded by bursal aspiration. After a local anesthetic is injected, fluid is withdrawn from the bursa using sterile techniques; analysis includes cell count, Gram stain and culture, and microscopic search for crystals. Gram stain, although helpful if positive, may not be specific, and white blood cell counts in infected bursae are usually lower than those in septic joints. Urate crystals are easily seen with polarized light microscopy, but the apatite crystals typical of calcific tendinitis appear only as shiny chunks that are not birefringent. Cholesterol plate crystals can be seen in chronic rheumatoid bursitis. develops acute bursitis. Hemorrhagic bursitis can cause similar manifestations because blood is inflammatory. Fluid in traumatic bursitis is usually serosanguinous. Cellulitis can cause signs of inflammation but does not normally cause bursal effusion; cellulitis overlying the bursa is a relative contraindication to bursal puncture through the cellulitis, but if septic bursitis is strongly suspected, aspiration must be done. 