Overview of Pes Anserine Bursitis

Pes anserine bursitis, also known as intertendinous bursitis, is an inflammation of the bursa located at the conjoined insertion of the sartorius, gracilis, and semitendinosus muscles. This condition manifests at the proximal medial aspect of the knee, approximately two inches below the medial knee joint line, situated between the pes anserine tendons and the tibia. This specific bursa acts as a cushion, reducing friction between the tendons and the underlying bone during movement. However, when subjected to repetitive stress or injury, inflammation of the bursa can occur, leading to pain, swelling, and discomfort along the medial knee. The condition is prevalent in athletes, especially runners and individuals whose activities require frequent knee flexion and extension.

Anatomy of The Pes Anserine

The pes anserine bursa is a fluid-filled sac that secretes synovial fluid to reduce tissue friction, acting as a cushion for bones, tendons, and muscles. Bursitis, the inflammation of this bursa, develops gradually over time rather than suddenly. While bursitis can affect various body parts, such as the shoulder, hip, and elbow, the pes anserine bursa is located at the medial side of the tibia, near the knee. Anatomically, the pes anserine, or “Goose Foot,” refers to the conjoined tendinous insertion of three muscles: the sartorius, gracilis, and semitendinosus. These muscles work together to flex the knee and rotate it internally. Positioned superficially to the medial collateral ligament (MCL), the pes anserine tendons also serve to stabilise the knee joint during movement. The sartorius and gracilis muscles, which are adductors of the leg, help pull the leg toward the body’s median axis, pivotal in stabilising the knee during dynamic movements. The semitendinosus muscle, part of the hamstring group, is responsible for knee flexion and internal rotation, further contributing to the stability and function of the knee.

How Common Is Pes Anserine Bursitis

Research indicates that this condition is more prevalent among overweight middle-aged women. This prevalence can be attributed to the wider pelvis in females, which results in a greater valgus alignment (knees angled inward) and increases pressure at the pes anserine insertion. This biomechanical factor, combined with excess weight, places undue stress on the medial knee structures, predisposing this population to bursitis. Notably, pes anserine bursitis is often secondary to another underlying issue rather than a primary condition. It commonly results from pre-existing biomechanical imbalances, trauma, or degenerative joint diseases. Therefore, managing pes anserine bursitis requires addressing the inflammation and the contributing factors to prevent recurrence.

What Causes Pes Anserine Bursitis

Pes anserine bursitis frequently arises from repetitive stress on the pes anserine bursa, primarily due to repeated knee flexion and adduction. Activities such as running, squatting, or climbing stairs increase friction and pressure on the bursa, leading to inflammation. Trauma, such as a direct blow to the inner knee, can also result in this condition by causing a sudden increase in synovial fluid, which triggers inflammation and pain. An underlying factor in pes anserine bursitis is often knee osteoarthritis. Osteoarthritis contributes to abnormal joint mechanics, increasing stress on the pes anserine region, which can lead to bursitis.

What Are The Symptoms of Pes Anserine Bursitis?

Pes anserine bursitis presents primarily as pain in the inner aspect of the knee, particularly during activities like running or climbing stairs. Patients often report spontaneous anteromedial knee pain, exacerbated by pivoting, kicking, or side-to-side movements. Clinically, tenderness is noted over the pes anserine region, and the area may exhibit swelling or be sensitive to touch. This condition can also lead to reduced muscle strength, altered gait, limited range of motion, and decreased knee function. Postural dysfunction and impaired lower extremity biomechanics are also common. Movements involving knee flexion, internal rotation, and external rotation and adduction aggravate the condition further. These symptoms and physical examination findings are critical indicators in diagnosing pes anserine bursitis and differentiating it from other knee pathologies.

How Is Pes Anserine Bursitis Diagnosed?

The physical assessment of Pes Anserine bursitis involves careful palpation, range of motion testing, and strength assessments to identify characteristic symptoms. The pes anserine bursa can be located approximately 3-4 cm medial to the tibial tubercle. Palpation in this area often elicits tenderness and may reveal localised swelling. Hamstring flexibility should be evaluated with the patient in a supine position, and knee extension should be tested. At the same time, the hip is flexed at 90°. Tight hamstrings may contribute to this condition, particularly in athletes. In sports-related cases, pain may be reproduced with resisted internal rotation or flexion of the knee. However, knee flexion and extension might not provoke significant discomfort in chronic variants commonly seen in older adults. Imaging studies are crucial in differentiating Pes Anserine bursitis from other pathologies. Lateral X-rays of the knee can help rule out fractures or arthritis. At the same time, MRI provides a detailed view of the medial structures and can help avoid unnecessary invasive procedures. Sonography may be an option if other imaging modalities are not feasible. 

• Differential Diagnosis of Pes Anserine Bursitis

Differential diagnosis for Pes Anserine bursitis is critical due to the overlap in symptoms with other medial knee pathologies. Here are some critical differential diagnoses for Pes Anserine bursitis:

• Medial Meniscus Lesions: Pain localised to the medial compartment, different from inferomedial Pes Anserine pain.
• Patellofemoral Syndrome: Anterior knee pain, often worsened by stair climbing.
• Medial Plica Syndrome: Causes medial knee pain and tenderness.
• Stress Fracture of The Proximal Tibia: Pain at the proximal medial tibia.
• L3-L4 Radiculopathy: Knee pain with associated lumbar pain.
• Semimembranosus Tendinitis: Common in runners, presenting pain in the posteromedial knee.
• Extra-articular Cystic Lesions: Including synovial, ganglionic, and parameniscal cysts.

These conditions should be considered and ruled out during the diagnostic process.

How Is Pes Anserine Bursitis Treated?

Pes Anserine bursitis treatment is multifaceted, aiming to control inflammation, relieve pain, and promote tissue repair. The underlying cause of the bursitis and the specific pathological changes in the bursa dictate the course of treatment.

HPL Therapy: High Power Laser (HPL) Therapy is a non-invasive modality that uses focused light energy to penetrate deeply into the tissue. Although clinical evidence specific to bursitis is limited, HPL therapy has effectively reduced pain and inflammation in other musculoskeletal conditions. The treatment works by improving blood circulation, accelerating the removal of inflammatory mediators, enhancing cellular energy production (ATP), and promoting tissue regeneration. HPL therapy can be incorporated into the broader treatment plan for Pes Anserine bursitis, particularly in chronic or severe cases.

Shockwave Therapy (ESWT): Extracorporeal Shockwave Therapy (ESWT) involves the application of high-energy acoustic waves to the affected area. This therapy is commonly used for conditions such as tendinopathy but has also shown promise in treating bursitis. The acoustic waves create microtrauma in the tissue, stimulating the body’s natural healing response, reducing inflammation, promoting tissue regeneration, and alleviating pain. ESWT can be particularly beneficial for patients with chronic Pes Anserine bursitis who have not responded to other treatments.

Medications: Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed to reduce inflammation and provide pain relief. Topical medications, such as creams, gels, sprays, and patches, can be applied directly to the skin over the affected area to offer localised pain relief while minimising the gastrointestinal side effects associated with oral NSAIDs. For cases of septic pes anserine bursitis, antibiotics are necessary to treat the infection. It’s crucial to address the infection promptly to prevent further complications.

Physical Therapy: A comprehensive physical therapy program is essential for restoring function, improving strength, and reducing biomechanical stress on the bursa. Therapeutic exercises focus on stretching and strengthening the surrounding muscles, particularly the quadriceps, hamstrings, and adductors. A well-structured rehabilitation plan can help prevent recurrence and promote long-term recovery.

An individualised treatment plan is essential to ensure optimal recovery and minimise the risk of recurrence. Regular follow-up with a healthcare provider is necessary to monitor progress and adjust the treatment plan as needed.

What’s The Prognosis of Pes Anserine Bursitis?

Pes anserine bursitis generally has a favourable prognosis, as it is typically self-limiting and responds well to conservative, nonoperative treatment. Surgical intervention is rarely required. The prognosis improves significantly when aggravating factors, such as joint overuse, are appropriately managed. Symptom duration can vary, often influenced by co-existing conditions like osteoarthritis, obesity, and physical deconditioning. Prompt recognition and management of underlying conditions, particularly arthritis, can significantly enhance pain relief and restore function.

In sports injury cases, athletes usually recover without long-term issues, even if they continue participating. A targeted rehabilitation program lasting 6 to 8 weeks, focusing on stretching and strengthening exercises for the posterior chain, can effectively alleviate symptoms and facilitate a safe return to activity. Regular follow-up is crucial to ensure complete recovery and prevent recurrence.

How Do You Prevent Pes Anserine Bursitis?

Preventive strategies for pes anserine bursitis centre on mitigating known risk factors and maintaining overall joint health. Key recommendations include:

• Maintaining a Healthy Weight: Reduces stress on the knee joint and surrounding structures.
• Innovative Exercise Practices: Include proper stretching, warm-ups, and avoiding sudden increases in exercise intensity.
• Correct Biomechanical Issues: Addressing improper movement patterns or gait abnormalities.
• Selecting Appropriate Footwear: Ensures adequate support and reduces unnecessary strain.
• Proper Posture and Hydration: Ensures muscle health and flexibility.

Secondary Prevention focuses on avoiding reinjury and educating patients on safe return-to-activity practices. This includes:

• Reinforcing Proper Form During Exercise: Helps prevent reoccurrence.

Targeted Stretching and Strengthening: Specifically, hamstrings and quadriceps, aiding in joint stability.

• Gradual Progression of Activity Levels: Avoids overloading the joint too quickly.
• Rest: Crucial in Acute Phases, balanced with a home-tailored physical therapy program to avoid disuse atrophy.

Education for patients, trainers, and coaches on gradually increasing activity levels is essential in athletic settings. A comprehensive, multifaceted approach to Prevention proves more effective than targeting individual factors alone.