Betsy Roos: A 27-Year-Old Homemaker With Severe Left Knee 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 prepatellar bursitis.
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Develop an understanding of the differential diagnosis of prepatellar bursitis.
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Learn the clinical presentation of prepatellar 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 prepatellar bursitis.
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Develop an understanding of the treatment options for prepatellar bursitis.

Betsy Roos

Betsy Roos is a 27-year-old homemaker with the chief complaint of, “My left knee is bigger than my head.” Betsy stated that over the past several weeks, her left knee started “swelling up like a balloon.” She went on to say, “It is all my mother-in-law’s fault.” I said, “So how is your swollen knee your mother-in-law’s fault”? Betsy laughed and said that her mother-in-law was coming for a visit and she had been scrubbing the house from top to bottom. “Doc, have you ever got down on your hands and knees and used a toothbrush to scrub around the toilets, the baseboards, the corners? I bet you haven’t, and if you do, then your knee will be bigger than your head, too!” I laughed and asked her if she ever had anything like this before and she said, “The mother-in-law or the knee?” I laughed again and said, “The knee, Betsy, the knee.” She just shook her head and said, “No, never, and I don’t want it ever again. It really hurts and it is really hard to walk down the stairs to the basement to throw in a load of laundry. I sure as hell am not letting my husband anywhere near the washing machine. The last time he did laundry, he threw in a brand new red t-shirt with my delicates and now I have a collection of amazing pink unmentionables, so no way. Doc, my knee is so swollen I can’t really see my kneecap anymore. That is really not the look I am going for!”

I asked Betsy what made the pain worse and she said any walking, stairs (going down was worse than going up, but going up still hurt), putting on socks, squatting, and “getting down on my left knee is completely out of the question.” I asked her what made it better and she said Advil seemed to help, but it was upsetting her stomach. She noted that the heating pad felt good, but she thought it made her knee swell more. I asked Betsy about any antecedent knee trauma and she said, “Nothing I can remember.” Betsy volunteered that trying to get to sleep was “a real pain in the keister” because every time she moved her left leg, her knee would really hurt.

I asked Betsy to point with one finger to show me where it hurt the most. She pointed to one of the most swollen knees I had ever seen (she really wasn’t kidding when she said the knee was as big as her head—it literally was no exaggeration) ( Fig. 8.1 ).

On physical examination, Betsy was afebrile. Her respirations were 16 and her pulse was 74 and regular. Her blood pressure was 126/76. Betsy’s head, eyes, ears, nose, and throat (HEENT) exam was normal, as was her cardiopulmonary examination. Her thyroid was normal. Her abdominal examination revealed no abnormal mass or organomegaly. There was no costovertebral angle (CVA) tenderness. There was no peripheral edema. Her low back examination revealed some tenderness to deep palpation of the paraspinous musculature. Visual inspection of the left knee revealed massive swelling. The area over the left prepatellar area felt warm but did not appear to be infected. The left knee felt “boggy” on palpation. There was a positive ballottement test on the left ( Fig. 8.2 ). There was marked tenderness to palpation over the prepatellar region, with palpation of the area exacerbating Betsy’s pain. Range of motion of the knee joint, especially resisted extension and passive flexion of the knee joint, caused Betsy to cry out in pain. The right knee examination was normal, as was examination of her 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 Betsy to walk down the hall, and there, 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 scrubbing floors on her hands and knees
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Pain localized to the area of the left prepatellar 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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No fever or chills
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Sleep disturbance
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Difficulty walking and 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 prepatellar bursa
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Palpation of left knee reveals warmth to touch
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The left 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 ballottement test was positive on the left (see Fig. 8.2 )
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An antalgic gait was present

Oher 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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Examination 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 reveal a large prepatellar fluid collection ( Fig. 8.3 ). Ultrasound examination of the left knee revealed prepatellar bursitis and plica formation. Osteophyte and patellofemoral degenerative changes are noted ( Fig. 8.4 ).