Deep Pes Anserine Bursa

bursa anserina profunda

The deep pes anserine bursa lies between the medial collateral ligament and the overlying conjoined pes anserine tendons (sartorius, gracilis, semitendinosus) approximately 2-4 cm below the medial joint line. It is distinct from any superficial pes anserine bursa and from the medial joint space. It is commonly inflamed in obese, diabetic women with medial knee OA — the classic pes anserine bursitis demographic.

Region: Knee

Clinical Relevance

Clinical Notes

Pes anserine bursitis is a frequently underdiagnosed cause of medial knee pain, characterised by tenderness 2-4 cm below the medial joint line over the pes anserine insertion rather than at the joint line itself (distinguishing it from medial joint pathology). It is associated with medial knee OA, obesity, and type 2 diabetes, possibly from valgus loading compressing the bursa between the MCL and the pes tendons. Corticosteroid injection into the bursa under ultrasound guidance provides effective relief and confirms the diagnosis.

Pathology

Common Injuries & Conditions

Pes Anserine Bursitis in Obese Diabetic Patients with Knee OA

Medial knee pain located 2-4 cm below the joint line with point tenderness over the pes anserine insertion in an obese diabetic patient with medial OA indicates deep pes anserine bursitis; ultrasound-guided corticosteroid injection into the bursal space provides reliable symptomatic relief distinct from intraarticular OA management.