Pes Anserine: Anatomy and Function

The pes anserine, often referred to as the "goose's foot," is formed by the conjoined tendons of the sartorius, gracilis, and semitendinosus muscles. These tendons insert into the anteromedial proximal tibia, just below the medial joint line of the knee. Nestled between these tendons and the shinbone is the pes anserine bursa, a fluid-filled sac that acts as a cushion, minimizing friction as the tendons glide over the bone during movement.

This anatomical arrangement allows the pes anserine to play a vital role in knee flexion, internal rotation, and overall stabilization of the knee joint. By supporting smooth, pain-free motion, the anserine bursa and pes anserine tendons are essential for maintaining healthy knee function, especially during activities that involve bending or rotating the leg.

What Is Pes Anserine Bursitis?

The pes anserine bursa is a fluid sac situated between the shinbone and the hamstrings on the inner side of the knee. More specifically, the pes anserinus bursa lies beneath the pes anserinus, which is formed by the conjoined tendons of the sartorius, gracilis, and semitendinosus muscles. When working properly, the pes anserine bursa cushions the joint and reduces friction around the knee.

Pes anserine bursitis, or knee bursitis, occurs when the bursa becomes inflamed. Inflammation causes pain and limits mobility in the knee. Pes anserinus bursitis and pes anserinus tendinobursitis syndrome are related conditions involving inflammation of the bursa and adjacent tendons.

Clinical diagnosis often relies on identifying tenderness in the pes anserine bursal region during a physical examination. Differentiating pes anserine bursitis from other knee conditions, such as meniscal tears or ligament injuries, may require diagnostic imaging (MRI) for confirmation.

If you're struggling with pain from knee bursitis, get moving again by booking an appointment with a Resurgens knee expert.

What Causes Pes Anserine Bursitis?

Pes anserine bursitis is most often caused by overuse and degenerative disorders such as knee osteoarthritis, since constant friction in the joint can lead to inflammation. It may also occur from direct injury to the knee. Acute pes anserine bursitis can develop suddenly due to trauma or infection, while pes anserinus Tendinobursitis involves both the bursa and tendons.

Knee bursitis commonly occurs among athletes and people with active lifestyles. Running, basketball, racquetball, and other sports may make one prone to pes anserine bursitis. The condition is also more common in people with knee osteoarthritis or chronic arthritis. Individuals who kneel frequently for work are also at higher risk. Stress fractures, obscure knee injuries, and asymptomatic meniscal tears should be considered in the differential diagnosis of medial knee pain. Rare causes or complications include infected total knee arthroplasty and tibial collateral ligament bursitis.

Pes Anserine Bursitis Symptoms and Medial Knee Pain

Knee bursitis symptoms can vary depending on which bursae are affected. Common pes anserine bursitis symptoms include:

• Pain developing on the inside of the knee or center of the shinbone

• Pain and tenderness while the knee is in motion

• Inflammation or puffiness around the affected area

• Warmth or heat radiating from the knee

• Limited range of motion

Pain severity can vary depending on the degree of inflammation and involvement of the affected bursa. Some patients may experience anterior knee pain or persistent discomfort. Chronic bursitis may require additional strategies for reducing ongoing pain and swelling.

How Is Pes Anserine Bursitis Diagnosed?

To diagnose knee bursitis, your Resurgens knee physician will first discuss your medical history and how the condition developed. Then, they will perform a physical examination to evaluate pain levels and range of motion in the knee.

MRI imaging is often used to differentiate pes anserine bursitis from other conditions such as meniscal tears, bone abnormalities, or juxta-articular bone cysts. It is important to note that lumbar pain and saphenous nerve entrapment can mimic pes anserine bursitis symptoms.

Using imaging results, your physician will create a customized treatment plan based on your specific needs.

Knee Bursitis Treatment

No two cases of knee bursitis are the same, and treatment varies depending on severity. Fortunately, most cases are non-surgical and respond well to conservative measures. Pes anserine bursitis treatment options may include:

• Rest and immobilization of the joint

• Ice therapy

• NSAIDs for pain management

• Corticosteroid injections for severe pain

• Extracorporeal shock wave therapy for refractory cases

Treatment may also focus on preserving cartilage in osteoarthritis and reducing chronic pain in patients with degenerative joint disease. Comparing the affected knee to the opposite knee can help assess recovery progress.

Prevention and Management of Pes Anserine Bursitis

Preventing anserine bursitis starts with protecting the knee from excessive stress and repetitive strain. Maintaining a healthy weight and engaging in regular, low-impact exercise can help reduce pressure on the pes anserine and surrounding structures.

Incorporating proper training techniques, thorough warm-ups, and cool-down stretches, especially for the hamstrings and inner thigh muscles, can further lower the risk of developing pes anserine bursitis.

If symptoms arise, early management is key. Conservative measures such as rest, ice, compression, and elevation (RICE) are often effective in reducing inflammation. Physical therapy can help restore strength and flexibility, while pain management medications may provide relief during flare-ups. In some cases, corticosteroid injections or ultrasound treatments may be recommended to target persistent inflammation.

Addressing underlying issues such as osteoarthritis or meniscal injuries is crucial in preventing recurrence and maintaining long-term knee health.

Complications and Outcomes

When anserine bursitis is left untreated, it can progress to chronic pain and significantly limit mobility, impacting daily activities and overall quality of life. Persistent inflammation may contribute to other knee disorders, such as osteoarthritis or meniscal tears, and in rare cases can complicate recovery after total knee arthroplasty if infection occurs.

Fortunately, with timely and appropriate treatment, most individuals experience a good prognosis and can return to normal routines. Addressing risk factors such as obesity, tight hamstrings, and improper training techniques helps prevent recurrence and long-term complications.

Conclusion

Anserine bursitis is a common cause of medial knee pain, often resulting in swelling and restricted movement. Understanding the anatomy and function of the pes anserine, as well as recognizing risk factors and implementing prevention strategies, is essential for maintaining knee health.

By addressing underlying conditions and adopting healthy habits, individuals can reduce their risk of developing pes anserine bursitis and other knee disorders. Early diagnosis and intervention are crucial for optimal outcomes, so seeking medical attention for persistent symptoms is highly recommended. With the right approach, anserine bursitis can be effectively managed to preserve long-term knee function and quality of life.

Schedule an appointment with our knee specialists today to begin your recovery.