EMReports | The Inflamed Goose's Foot

The Inflamed Goose's Foot

Larry Mellick, MD, MS, FAAP, FACEP
Professor of Emergency Medicine
Medical College of Georgia

Pearl: Pes anserine bursitis should be included in your differential of possible conditions causing medial knee pain.

Presentation: A late middle-aged, overweight female presented to the emergency department with medial knee pain that began two weeks ago. The pain reportedly began after a flurry of house-cleaning activities. The pain was worse with walking, climbing steps, and crossing her legs. She localized the pain to medial proximal tibia. On examination, the patient had a visible swelling that was extremely tender to palpation. The skin over the area of visible swelling was neither red nor distinctly warm to touch. There was no evidence of knee ligament instability, effusion, or range of motion. Radiographs of the knee demonstrated changes consistent with osteoarthritis of the joint.

Discussion: In addition to osteoarthritis, medial collateral ligament injuries, and medial meniscus problems, the differential diagnosis of medial knee pain should include pes anserine bursitis. This bursa lies medial to the attachment of the conjoined hamstring tendon formed by the sartorius, gracilis, and semitendinosus muscles and is slightly distal and medial (3-4 cm) to the tibial tubercle. (See Figure 1.) It is sandwiched between the hamstring tendons and the medial collateral ligament. This tendon and bursa have a strange Latin derived name that is translated "goose's foot," a webbed foot-like structure. (See http://www.flickr.com/photos/45913260@N00/137028353) When this potential space becomes irritated and inflamed, fluid collects and swelling develops. In older patients, this bursitis may be associated with osteoarthritis of the knee. In younger, athletic patients, it is commonly seen in sports requiring frequent side to side movements. The condition most commonly is associated with tight hamstring muscles. It also can occur following direct trauma to the area. If additional imaging is indicated, an inflamed bursa will be demonstrated with magnetic resonance imaging (MRI).^1,2,3 Treatment typically includes hamstring stretching and quadriceps strengthening exercises. Non-steroidal anti-inflammatory drugs or a tapering course of steroids also can be used. On occasion, the bursa inflammation can be treated with an injectable steroid.⁴

References:

Forbes JR, Helms CA, Janzen DL. Acute pes anserine bursitis: MR imaging. Radiology 1995;194:525-527.
Tschirch FTC, Schmid MR, Pfirrmann CWA., et al. Prevalence and size of meniscal cysts, ganglionic cysts, synovial cysts of the popliteal space, fluid-filled bursae, and other fluid collections in asymptomatic knees on MR imaging. Am J Roentgenol 2003;180:1431-1436.
3. Beaman FD, Peterson JJ. MR imaging of cysts, ganglia, and bursae about the knee. Radiol Clin North Am 2007;45:969-82, vi.
http://www.fpnotebook.com/Ortho/Procedure/PsAnsrnBrsInjctn.htm

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