Pes anserine complex (bursitis)

Cause, clinical and ultrasound findings

• Reasons for the injection include overuse and diseases such as rheumatoid arthritis and diabetes.

• Pain is experienced mainly over the medial aspect of the tibia, distal to the joint line of the knee. Ganglion cysts also can arise in this region, but they are often painless, thickened and hard due to their viscoid nature.

• Pain may be elicited with resisted knee flexion.

• Under ultrasound, the bursa can be recognized by its haphazard and anechoic appearance above the pes anserinus (not to be confused with the genicular artery which lies close to the tibial metaphysis).