Wiler, Jennifer L. MD, MBA
Dr. Wiler is the assistant chief of clinical operations in the department of emergency medicine and the medical director of the ED Observation Unit at Washington University and Barnes-Jewish Hospital in St. Louis.
A 62-year-old man presents with swelling of the right elbow over three weeks. He denies a history of gout or recent trauma, use of blood thinners, fevers, chills, paresthesias, or weakness in the arm. He claims over the past four days the elbow has been more painful over the area of swelling. He is afebrile, and can fully flex and extend the arm at the elbow with no discomfort.
What is the most likely diagnosis, and how would you manage this condition? See p. 12.
Diagnosis: Olecranon Bursitis
Olecranon bursitis (OB), swelling of the olecranon bursa, is a fairly common condition. The superficial location of the bursa makes it vulnerable to direct trauma, and it is clearly apparent when engorged.
The term OB is a bit of a misnomer because it encompasses a continuum of disease processes, from an acute inflammatory response to a more indolent chronic process. The inflammatory process can be sterile (aseptic or noninfective, usually secondary to acute trauma, overuse, crystal deposition, or systemic disease) or infection (septic [S. aureus in 80% of cases (Clin Rheumatol 2001;20:10)], but rarely fungus or algae). (J Emerg Med 2007 Jul 20; Epub ahead of print.) Approximately two-thirds of OB cases are noninfective inflammation. (J Accid Emerg Med 1996;13:351.)
In general, patients with OB present with pain at the bursa site and localized tenderness and swelling, and are able to move the elbow into full flexion and extension with minimal to no pain. Patients with a simple nonseptic OB do not have an acute inflammatory component. These are generally 50- to 70-year-old men with unilateral painless, walnut-size swelling of the olecranon for days to weeks. (EMN 2002;24: 22.) Patients may have a history of repetitive movement over the bursa or microtrauma or recall a specific traumatic event that led to the rapid accumulation of fluid or blood in the bursal sac. The olecranon bursa when swollen is simple to palpate as the patient holds his arm at a 90-degree angle. Manipulation of the fluid-filled bursa is typically not painful, and clinically there are no signs of diffuse cellulitis.
On the other hand, cases of septic OB typically occur after traumatic violation of the bursa, and less commonly, spread from the local joint or by hematogenous seeding. In these cases, patients have a tender olecranon bursa with more diffuse swelling. The area is typically warm, tender, painful, and red, and it may be associated with systemic symptoms of fevers and rigors. Immunocompromised patients including diabetics are at increased risk of developing septic OB.
The distinction between septic and aseptic bursitis is not always clinically obvious. Peribursal cellulitis is seen in both types (more than 60% of septic cases and 25% of noninfective cases), as is bursal warmth. (J Emerg Med 2007 Jul 20.)
The differential diagnosis of OB is limited. Septic arthritis, inflammatory arthritis (including rheumatoid, gout, or pseudogout), tendonitis, or muscle injury are the most common mimics. Patients with an infected synovial joint classically have pain-limited range of motion, particularly at full extension of the elbow joint, which is not true for OB. Rarely, an olecranon bursa can rupture and leak into dependent areas of the forearm compartment, mimicking venous thrombosis. (Ann Rheum Dis 1981;40:307.)
Diagnosis of OB tends to be clinical but can be confirmed with bursa aspiration. Radiography has no role in the clinical diagnosis of OB unless there is concern for underlying bony injury. It is recommended that olecranon fluid be aspirated in all cases for therapeutic or diagnostic evaluation. (EMN 2002; 24:22.)
Simple nonseptic OB is typically a straightforward clinical diagnosis, but differentiation between septic and gouty inflammation can be difficult without laboratory evaluation and identification of crystals. Fluid aspirate can range from purulent to serosanguinous (more common with trauma) to straw-colored. When there is diagnostic uncertainty, bursal fluid should be sent to the laboratory for cell count, gram stain, culture and sensitivity, and examination for crystals.
WBC counts above 2000/mm3 had a high sensitivity and specificity for bursal infections; the WBC count in nonseptic olecranon bursitis will typically be less than 1000 and usually only a few hundred/mm3. (Brit Med J 1998; 316:1877.) Thirty percent of patients with septic bursitis may have a negative gram stain. (West J Med 1988;149:607.) If there is uncertainty about diagnosing septic OB, it is reasonable to give broad spectrum oral antibiotics for skin flora while awaiting culture and sensitivity results. Close outpatient follow-up is imperative. The duration of antibiotic treatment is unclear and has not been prospectively validated. Oral antibiotics have been shown to have bursal penetration, but may be inadequate with patient's requiring parenteral antibiotics in 32 percent to 67 percent of cases. (J Emerg Med 2007 Jul 20.) Patients who are ill, appear toxic, or are immunocompromised should be considered for inpatient parenteral antibiotic therapy.
After a diagnosis of septic bursitis has been excluded, most authors recommend injection of a long-acting glucocorticoid, with or without local anesthetic, into the bursa. One prospective study demonstrated that injection of 40 mg of methylprednisolone into the olecranon bursal sac appears to be superior to oral NSAIDs alone in decreasing time to recovery and preventing recurrences. (Arch Intern Med 1989;149: 2527.) With injection therapy, most patients have resolution of their symptoms. However, most EPs would not give more than one intrabursal injection for recurrent OB cases, but there are no current data to validate or discount this practice. A compressive ACE wrap can be placed over the elbow for a temporary tamponading effect on the bursa to prevent rapid fluid reaccumulation. Patients should be instructed to prevent local trauma to the olecranon or to eliminate the repetitive motion that precipitated the bursal swelling to prevent fluid reaccumulation.
Chronic persistent OB, often presents with a rubbery thick synovium, and is a candidate for surgical (possibly endoscopic) removal. (Arthroscopy 1990;6: 86; J Shoulder Elbow Surg 1997;6:49.)
This patient had five milliliters of bloody serosanguinous fluid removed from his olecranon bursa, a long-acting glucocorticoid injected, and a compressive ACE wrap placed.
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