Kitty Lee: A 24-Year-Old Optician With Severe Left Anteriomedial Knee Pain

Learning Objectives

  • Learn the common causes of knee pain.

  • Develop an understanding of the unique anatomy of the knee joint.

  • Develop an understanding of the bursae of the knee.

  • Develop an understanding of the causes of pes anserine bursitis.

  • Develop an understanding of the differential diagnosis of pes anserine bursitis.

  • Learn the clinical presentation of pes anserine bursitis.

  • Learn how to examine the knee and associated bursae.

  • Learn how to use physical examination to identify pes anserine bursitis.

  • Develop an understanding of the treatment options for pes anserine bursitis.

Kitty Lee

Kitty Lee is a 24-year-old female optician with the chief complaint of, “The inside of my knee hurts.” Kitty stated that over the past several weeks, the inside of her left knee really started hurting. She went on to say that the knee pain has really been “messing with my workout.” I asked Kitty if she had ever had anything like this before and she said, “My knees were fine until I missed that step. Doctor, do you know that trail in Griffith Park that takes you up to the Hollywood sign?” I told her I did and she went on to tell me that she likes to run up that trail every morning as part of her workout. “So, I was trying to beat my best time and I was really trucking up the hill when I accidently missed a step. I didn’t actually fall, but as I caught my balance, I came down funny on my left knee and kind of twisted it.”

I asked Kitty what made the pain worse and she said that any walking, going down stairs, putting on her jogging shoes, squatting, or getting on and off the commode all made the pain much worse, and “jogging was completely out of the question.” I asked her what made it better and she reported that Advil helped, but it was upsetting her stomach. She noted that icing the knee felt good, but the pain came back as soon as she took off the ice. I asked Kitty about any antecedent knee trauma and she could not remember any. Kitty volunteered that she has having a real hard time getting a good night’s sleep. “Doctor, my serious sleeping position is on my left side and even with a pillow between my legs, whenever my right knee puts pressure on my left knee, it wakes me up.”

I asked Kitty to point with one finger where it hurt the most. She pointed to her anteriomedial knee just below the joint space on the left ( Fig. 10.1 ).

Fig. 10.1

Ultrasound image demonstrating pes anserine bursitis.

On physical examination, Kitty was afebrile. Her respirations were 16 and her pulse was 64 and regular. Her blood pressure was 126/80. Kitty’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 medial knee revealed no obvious ecchymosis, but the area appeared a little swollen. The area over the left pes anserine bursa felt warm but did not appear to be infected. The left medial knee felt “boggy” on palpation. There was marked tenderness to palpation over the pes anserine region, with palpation of the area exacerbating Kitty’s pain. Range of motion of the knee joint, especially active resisted flexion of the knee joint, caused Kitty 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 Kitty 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

  • Onset of left knee pain following a jogging injury to the left knee

  • Pain localized to the area of the left pes anserine bursa

  • Pain made worse by walking, going down stairs, and squatting

  • No other specific traumatic events to the knees

  • No fever or chills

  • Sleep disturbance

  • Unable to jog due to persistent left knee pain

The Physical Examination

  • The patient is afebrile

  • Point tenderness to palpation of the area over the pes anserine bursa

  • Palpation of left knee reveals warmth to touch

  • The left medial knee is swollen, with “bogginess” over the pes anserine bursa

  • No evidence of infection

  • Pain on range of motion, especially active resisted flexion of the affected left knee

  • An antalgic gait was present

Other Findings of Note

  • Normal HEENT examination

  • Normal cardiovascular examination

  • Normal pulmonary examination

  • Normal abdominal examination

  • Tenderness to deep palpation of the lumbar paraspinous muscles

  • No peripheral edema

  • Normal upper and lower extremity neurologic examination, motor and sensory examination

  • Examinations of joints other than the left knee were normal

What Tests Would You Like to Order?

The following tests were ordered:

  • Plain radiographs of the left knee

  • Ultrasound of the left knee

Test Results

The plain radiographs of the left knee reveal mild soft tissue swelling over the medial knee. Ultrasound examination of the left knee revealed pes anserine bursitis (see Fig. 10.1 ).

Clinical Correlation—Putting It All Together

What is the diagnosis?

  • Pes anserine bursitis

The Science Behind the Diagnosis


The pes anserine bursa lies beneath the pes anserinus (Latin for “goose foot”), which is the insertional conjoined tendons of the sartorius, gracilis, and semitendinous muscles on the medial side of the tibia ( Fig. 10.2 ). This bursa may exist as a single bursal sac or, in some patients, as a multisegmented series of loculated sacs. The pes anserine bursa is susceptible to the development of inflammation from overuse, misuse, or direct trauma. If inflammation of the pes anserine bursa becomes chronic, calcification may occur. Rarely, the pes anserine bursa becomes infected.

Aug 9, 2021 | Posted by in PAIN MEDICINE | Comments Off on Kitty Lee: A 24-Year-Old Optician With Severe Left Anteriomedial Knee Pain
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