Anserine bursa lies under the conjoined tendon of the Sartorius, Gracilus and Semitendinosus muscles at their insertion into the medial aspect of the tibia, approximately 5 cm below the medial joint line.7
In the same study 91.6% of the patients who received a local injection of methylprednisolone plus lidocaine at the anserine bursa had relief of pain.11
The epicenter was deep to the traversing pes anserine tendons and superficial to the MCL and tibia in the expected location of the pes anserine bursa. The pes anserine tendons (sartorius, gracilis, and semitendinosus) were all intact and without evidence of any acute tear.
There are three bursae medial to the knee: the pes anserine bursa, the MCL bursa, and the semimembranosus MCL bursa.
[Editor's note: The pes anserine bursa is a small lubricating sac located between the shinbone (tibia) and three tendons of the hamstring muscle at the inside of the knee.] Symptoms include medial proximal tibial tenderness and tight hamstrings.