Pes anserinus bursitis refers to symptomatic inflammation of the pes anserinus bursa which is located at the medial aspect of the knee (at the level of the joint space) deep to the pes anserinus tendons.
Classically, symptoms are of pain and swelling along the proximal medial tibia, which may be exacerbated by particular activities such as ascending and descending stairs.
The anatomic location is the key to making the diagnosis. The actual signs are those of bursitis anywhere else in the body 1.
- increased fluid within the bursa
- thickened bursal wall
- surrounding tissue oedema
- abnormal wall / surrounding tissue enhancement
With the correct history of pain, many clinicians will diagnose pes anserinus bursitis based on the presence of increased bursal fluid alone.