Knee
Pes Anserine Bursitis
거위발 점액낭염
Inflammation of the bursa under the pes anserinus tendon insertion on the medial knee
- How common
- Common
- Typical age
- Women, middle-aged, obese
What is it?
The bursa between sartorius/gracilis/semitendinosus tendons (pes anserinus) and the tibia inflames from repetitive friction.
Commonly affected: 2–5 cm below medial joint line on the tibia
How it develops
- Normal BursaBursa cushions friction between tendon and bone
- Repetitive Load/ObesityWalking, obesity, and varus knee increase medial load
- Bursal InflammationBursa swells, producing pain
- ChronicityUntreated cases relapse repeatedly
Symptoms
- Medial Knee PainLocalized tenderness 2–5 cm below joint line
- Stair/Rising PainPain with stairs and sit-to-stand
- Night PainKnee-on-knee contact disturbs sleep
- Local SwellingMild swelling over medial tibia
How it is examined
- Pes Anserinus TendernessTenderness 3 cm below medial joint line over tendon insertion
- Joint Line NegativeMedial joint line itself non-tender (differentiates from OA)
- Resisted Flexion PainPain with resisted knee flexion
Imaging
X-ray usually normal — rules out OA.
- Normal joint space
- Rules out concurrent OA
MRI or US confirms bursal effusion.
- Pes anserine bursa swelling
- Fluid accumulation
- Peri-bursal edema
Non-surgical care
- Activity Mod + Weight LossReduce load; target BMI <25
- NSAIDs + IceNSAIDs with ice during flare
- Hamstring StretchImprove medial hamstring flexibility
- US-guided Steroid InjectionUS-guided bursal injection for rapid relief
Conservative options are generally tried first. Medications listed here can have side effects — discuss them with your prescriber.
When surgery is considered
Rare — chronic recurrent, failed 6-month conservative
Procedures that may be discussed
- Bursectomy (rarely indicated)
Outlook
Most cases resolve in 4–6 weeks with conservative care.