Understanding Pes Anserine (Goosefoot) Bursitis

The pes anserine bursa is a small, fluid-filled sac located on the inner side of the knee, just below the joint line. It lies between the pes anserinus tendons—a conjoined insertion of the sartorius, gracilis, and semitendinosus muscles—and the upper part of the shinbone (tibia). Its primary role is to act as a cushion, minimizing friction between these tendons and the bone during knee movement.

When this bursa becomes inflamed, the condition is known as pes anserine bursitis. Inflammation can result from repetitive strain, friction, or direct trauma, leading to pain, tenderness, and restricted movement on the inner side of the knee.

Anatomy and Biomechanics

The term “pes anserinus” means “goose’s foot” in Latin, reflecting the webbed pattern of the three tendons where they attach to the tibia. Each of these muscles supports both hip and knee stability:

  • Sartorius: assists in hip flexion, abduction, and external rotation

  • Gracilis: helps with hip adduction and knee flexion

  • Semitendinosus: aids in hip extension and knee flexion

Because these muscles cross two joints, they are frequently activated during running, squatting, and quick directional movements. Overuse, poor posture, or misalignment can cause excessive friction at their attachment site, irritating the underlying bursa.

Common Causes and Risk Factors

Pes anserine bursitis typically develops due to a combination of mechanical stress, muscle imbalance, and underlying knee conditions. Common contributors include:

  • Repetitive stress from running, cycling, or climbing stairs

  • Poor lower limb alignment (flat feet or knock knees)

  • Tight hamstrings or weak quadriceps

  • Excess body weight increasing knee load

  • Inadequate warm-up or improper training form

  • Coexisting conditions like arthritis, meniscal tears, or ligament injuries

  • Post-surgical changes following ACL reconstruction or total knee replacement

Treatment and Management

In most cases, non-surgical treatments effectively relieve pain and restore knee function. These include:

  • Rest, ice, and anti-inflammatory medication

  • Physical therapy to improve strength and flexibility

  • Custom orthotics or knee braces for alignment and support

  • Corticosteroid or biologic injections (PRP or IRAP) for persistent inflammation

Surgery is rarely necessary but may be considered for chronic cases that do not respond to conservative management.

Recovery and Prevention

With proper treatment, most patients notice improvement within 6 to 8 weeks. Maintaining flexibility, wearing supportive footwear, and strengthening surrounding muscles can help prevent recurrence.

Expert Orthopedic Care in Frisco, TX

Dr. Andrew Dold, MD, a double board-certified orthopedic surgeon, specializes in sports injuries and knee disorders. His comprehensive, patient-focused approach integrates advanced diagnostics, cutting-edge non-surgical therapies, and personalized rehabilitation to help you recover quickly and return to an active lifestyle.

Book an appointment today to learn more about pes anserine bursitis treatment in Frisco, TX.