What is the Pes Anserinus?
Pes anserinus (“goose foot”) refers to the fused tendons of three muscles that attach onto the anteromedial (front and inside) surface of the proximal shin bone (tibia). The muscles are the sartorius, gracilis and semitendinosus.
What is the Pes Anserinus Bursa?
Bursae are small, jelly-like sacs that are located throughout the body, including around the shoulder, elbow, hip, knee, and heel. They contain a small amount of fluid, and are positioned between bones and soft tissues, acting as cushions to help reduce friction.
The pes anserinus bursa is located between the proximal shin bone (tibia) and the three tendons of the hamstring muscle (pes anserinus) at the inside of the knee. It lies underneath the pes anserinus.
What is Pes Anserinitis?
Pes anserinitis is inflammation of the pes anserinus bursa. Hence it is a painful condition situated at the insertion of the hamstring tendons to the anteromedial aspect of the proximal shin bone (tibia).
It occurs when the bursa becomes irritated and produces too much fluid, which causes it to swell and put pressure on the adjacent parts of the knee.
Pain and tenderness on the inside of your knee, approximately 2 to 3 inches below the joint, are common symptoms of pes anserine bursitis of the knee.
What causes Pes Anserinitis?
Pes anserinus bursitis usually develops as the result of overuse or constant friction and stress on the bursa.
It is common in athletes, particularly runners.
People with knee osteoarthritis are also susceptible.
Several factors can lead to the development of pes anserine bursitis:
- Incorrect training techniques, such as neglecting to stretch, doing excessive hill running, and sudden increases in mileage
- Tight hamstring muscles
- An out-turning of the knee or lower leg
- Osteoarthritis in the knee
- Medial meniscus tear
What are the Symptoms of Pes Anserinitis?
- Pain in the inner knee with knee bending and/or straightening.
- Inner knee pain when going up or down stairs.
- Weakness or feeling of giving way around the knee.
- Swelling over the inside aspect of the knee.
- Decrease in knee range of motion due to pain.
How to Treat this Condition?
- Rest, avoid climbing stairs, reduce running intensity etc.
- ICE the painful area.
- Take oral anti-inflammatory medications.
- Inject cortisone (steroid).
- Inject Platelet Rich Plasma (PRP).