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 suprapatellar bursitis.
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Develop an understanding of the differential diagnosis of suprapatellar bursitis.
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Learn the clinical presentation of suprapatellar 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 suprapatellar bursitis.
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Develop an understanding of the treatment options for suprapatellar bursitis.
Andrew Kelsey
Andrew Kelsey is a 27-year-old carpet layer with the chief complaint of, “My left knee really hurts.” Andrew stated that he just completed laying carpet in the new downtown convention center. “We really got behind on this project so at the end, there was a lot of overtime. At first, by the end of the day, my knee felt a little squishy and it was sore. The Motrin helped the soreness and by morning, the swelling was a little better. By the time we got the job finished, my knee was swollen 24/7 and it hurt whenever I put any weight on it. Whenever I got down on my knees or squatted, the pain went through the roof. Doc, I’ve got to keep working, so I need you to just give me a shot in the knee.”
I asked Andrew about any antecedent knee trauma and he just shook his head no, but went on to say that from time to time, his left knee would bother him a little after a long day of “kicking in carpeting, but usually a couple of Motrin would take care of it,” and he was “good to go.” He also tried to use a heating pad, which he thought made it worse and made the pain go up into the front of his thigh. Andrew said that he felt the knee was kind of swollen and “squishy” and that it felt hot to touch. I asked Andrew what made his pain worse and he said, “Anytime I start to walk or whenever I squat it hurts, and over the last few days I can’t kneel on my left knee. Doc, I have to put all my weight on my right knee, which is really starting to complain. And the crazy thing is, now my back is hurting from the way I’m working. I’m already tired, as my knee is keeping me up at night—or maybe it’s just the worrying about my job.”
I asked Andrew to point with one finger to show me where it hurt the most. He pointed to the area just above the left patella and said, “Doctor, it’s right here!”
On physical examination, Andrew was afebrile. His respirations were 18 and his pulse was 76 and regular. His blood pressure was 138/78. Andrew’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 suprapatellar 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 suprapatellar region. Palpation of this area exacerbated Andrew’s pain. Range of motion of the knee joint, especially resisted extension and passive flexion of the knee joint, caused Andrew to cry out in pain. I performed a resisted extension release test, which was markedly positive on the left and negative on the right ( Fig. 7.1 ). The right knee examination was normal, as was examination of his 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 Andrew to walk down the hall; 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 laying carpeting
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Pain localized to the area of the left suprapatellar 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 kicking in carpeting
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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 suprapatellar 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 resisted extension release test was positive on the left (see Fig. 7.1 )
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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 a fluid density behind the patellar tendon and around the patella tip, and patella tilting due to abundant effusion. No fracture or other bony abnormality was noted ( Fig. 7.2 ). Ultrasound examination of the left knee revealed suprapatellar bursitis and plica formation. Osteophyte and patellofemoral degenerative changes are noted ( Fig. 7.3 ).