Arif Abad: A 29-Year-Old Electrical Engineer With Severe Left Knee and Upper Leg Pain and Swelling

Learning Objectives

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Learn the common causes of knee pain.
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Develop an understanding of the unique anatomy of the knee joint.
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Develop an understanding of the bursae of the knee.
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Develop an understanding of the causes of deep infrapatellar bursitis.
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Develop an understanding of the differential diagnosis of deep infrapatellar bursitis.
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Learn the clinical presentation of deep infrapatellar bursitis.
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Learn how to examine the knee and associated bursae.
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Learn how to use physical examination to identify deep infrapatellar bursitis.
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Develop an understanding of the treatment options for deep infrapatellar bursitis.

Arif Abad

Arif Abad is a 29-year-old electrical engineer with the chief complaint of, “My left knee is really bothering me.” Arif stated that over the last few weeks, he began having left knee pain and swelling. “I don’t know whether I injured my knee when I was exercising or I just slept on it wrong. I really notice the pain when I do my morning prayers. I tried to take it easy with the jogging and have been taking Motrin around the clock, but when I kneel during my prayers, it really hurts. By the time I get home from work, my knee is really swollen. The heating pad helps a bit, but the swelling really concerns me.”

I asked Arif about any antecedent knee trauma and he just shook his head no. “I really try to watch what I eat and be sure that my running shoes are in good shape to protect my joints.” “Good to hear, Arif. What kinds of things make your pain and swelling worse?” I asked. “Doctor, any time I put weight on my knee, try to run, or pray, I really feel it.”

I asked Arif to point with one finger to show me where it hurt the most. He pointed to the area just below the left patella and said, “Doctor, it’s right here!”

On physical examination, Arif was afebrile. His respirations were 18 and his pulse was 96 and regular. His blood pressure was 138/98. Arif’s head, eyes, ears, nose, and throat (HEENT) exam was normal, as was his cardiopulmonary examination. His thyroid was normal. His abdominal examination revealed no abnormal mass or organomegaly. There was no costovertebral angle (CVA) tenderness. There was no peripheral edema. His low back examination revealed some tenderness to deep palpation of the paraspinous musculature. Visual inspection of the left lateral knee revealed moderate swelling. The area over the left deep infrapatellar area felt a little warm but did not appear to be infected. The left knee felt “boggy” on palpation, and there was marked tenderness to palpation over the deep infrapatellar region. Palpation of this area exacerbated Arif’s pain. Range of motion of the knee joint, especially with resisted extension and passive flexion of the knee joint, caused Arif to cry out in pain. I performed the active resisted extension release test, which was markedly positive on the left and negative on the right ( Fig. 9.1 ). The right knee examination was normal, as was examination of Arif’s major joints. A careful neurologic examination of the upper and lower extremities revealed there was no evidence of peripheral or entrapment neuropathy, and the deep tendon reflexes were normal. I asked Arif to walk down the hall, where I noted an antalgic gait was present.

Key Clinical Points—What’s Important and What’s Not

The History

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Onset of left knee pain following praying
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Pain localized to the area of the left deep infrapatellar region
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Pain associated with swelling of the affected knee
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Pain made worse by squatting or kneeling on left
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No other specific traumatic event to the area identified
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History of mild, self-limited left knee pain after praying
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No fever or chills
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Sleep disturbance
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Difficulty walking or squatting
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Unable to kneel on left knee

The Physical Examination

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The patient is afebrile
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Point tenderness to palpation of the area over the deep infrapatellar bursa
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Palpation of left knee reveals warmth to touch
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The left lateral knee is swollen, with “bogginess”
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No evidence of infection
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Pain on range of motion, especially resisted extension and passive flexion of the affected left knee
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The active resisted extension release test was positive on the left (see Fig. 9.1 )
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An antalgic gait was present

Other Findings of Note

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Normal HEENT examination
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Normal cardiovascular examination
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Normal pulmonary examination
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Normal abdominal examination
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No tenderness to deep palpation of the lumbar paraspinous muscles
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No peripheral edema
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Normal upper and lower extremity neurologic examination, motor and sensory examination
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Examinations of joints other than the left knee were normal

What Tests Would You Like to Order?

The following tests were ordered:

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Plain radiographs of the left knee
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Ultrasound of the left knee

Test Results

The plain radiographs of the left knee revealed no fracture or bony abnormality. Ultrasound examination of the left knee revealed deep infrapatellar bursitis ( Fig. 9.2 ).