Bilateral Lower-Extremity Edema Caused by Iliopsoas Bursal Distention after Hip Arthroplasty

In July 2015, an 86-year-old woman presented for evaluation of sudden worsening of her left LE swelling and pain. She had been dealing with swelling in both of her ankles for the past 8 years. Up to this point, it had been controlled with escalating doses of a diuretic.

Her physical examination was negative for chest pain and shortness of breath. Her medical and surgical histories were significant for hypertension, atrial fibrillation (on aspirin for stroke prevention), obesity, bilateral total knee replacements, and bilateral total hip replacements. She had never had a venous thromboembolism.

Her vital signs were unexceptional. Her physical examination revealed nonpitting bilateral LE edema (the left worse than the right) and varicosity of her saphenous veins. Her venous clinical severity score was 2 (moderate), and a positive Stemmer sign was present on both sides. She had normal peripheral pulses, no jugular venous distention, and lungs clear to auscultation.

Laboratory investigations revealed intact kidney and liver function. An echocardiogram showed a preserved ejection fraction and a normal diastolic function. Results of bilateral LE Doppler ultrasonography showed no evidence of acute thrombosis but did reveal nonvascular masses in both groins. A computed tomographic venogram showed bilateral iliopsoas bursal distention (Fig. 1), which was believed to have been caused by her hip prostheses. This abnormality was not visible on a plain radiograph of the left hip. After identification of the lesion, the patient underwent drainage of the fluid collection, guided by ultrasonography. A follow-up visit several weeks later indicated clinical improvement, and radiographic improvement (via computed tomographic venography) was also noted.

Lower-extremity swelling is a common patient complaint. Bilateral LE edema is usually due to cardiac, hepatic, or renal disease. It can also be caused by the impingement of venous outflow by a pelvic or abdominal mass. Distention of the iliopsoas bursa has also been known to cause LE edema, usually in the presence of underlying hip disease.³  The bursa lies between the iliopsoas muscle and the anterior portion of the hip joint. In one report, authors described bursal distention secondary to an underlying hip prosthesis.⁴  This infrequently recognized (and often clinically silent) chronic process occurs when the polyethylene component of a hip prosthesis breaks down, leading to a communication between the artificial joint and the iliopsoas bursa.⁵  Venous compression caused by chronic bursal distention can also lead to the formation of a deep vein thrombosis, a sequela that our patient did not have.⁶  Although some authors have described an enlarged iliopsoas bursa causing extravascular compression leading to leg swelling,^4,7,8  we think that this is the first report of an enlarged iliopsoas bursa's causing clinically significant edema bilaterally. In common with an iliopsoas abscess, a distended bursa can be drained to provide relief of symptoms.⁹ 

This challenging case serves as an example of the meticulous diagnostic examination necessary to identify the exact, but uncommon, cause of the patient's symptom. A thorough history and physical examination, supplemented by advanced imaging, led to the appropriate diagnosis. The case also serves to highlight the initial clinical inertia that can lead to the use of substantial doses of diuretics to treat a symptom without first identifying a cause.

We thank Stephanie Stebens, MLIS, AHIP, for assistance with preparing and editing the manuscript.