Pes Anserinus Syndrome

Last updated: February 8, 2026Reviewed date: February 8, 2026Reading time: 3 min read
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Article Summary

Pes anserinus syndrome is the name given to pain occurring on the inside of the lower leg just below the knee joint. There is irritation in the tendon, and the synovial bursa may also be inflamed. Pain worsens under stress, such as when climbing stairs, when crouching, or after walking/running and jumping. Pes anserine bursitis occurs when the bursa — or fluid-filled sac — inside your knee...

Key Takeaways

  • This article explains Other Names in simple medical language.
  • This article explains Differential Diagnosis in simple medical language.
  • This article explains Diagnosis in simple medical language.
  • This article explains Treatment in simple medical language.
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Definition

Pes anserinus is the name given to  occurring on the inside of the lower leg just below the knee joint. There is irritation in the , and the synovial may also be inflamed. Pain worsens under stress, such as when climbing stairs, when crouching, or after walking/running and jumping. Pes anserine occurs when the bursa — or fluid-filled sac — inside your knee joint becomes irritated and produces too much fluid. The bursa then swells, causing knee pain and . This condition is sometimes called pes anserinus pain syndrome (PAPS). The symptoms of pes anserine bursitis include Pain slowly developing on the inside of your knee and/or in the center of the shinbone, approximately 2 to 3 inches below the knee joint. Pain increases with exercise or climbing stairs. Puffiness or tenderness to the touch in this area.

Other Names

  • Pes Anserine Pain Syndrome (PAPS)
  • Anserine bursitis
  • Pes Anserine Pain
  • Pes Anserinus or Bursitis (PATB)

Pathophysiology

  • Mechanical Derangement
    • Thought to cause local to surround tendinous structures
    • Includes Medial , Medial Collateral  which may irritate pes anserine bursa
  • Overuse
    • Thought to be due to repetitive flexion, adduction
  • Other implicated etiologies
    • Direct
    • Obesity

Pathoanatomy

  • Pes Anserine
    • “Pes Anserine” comes from the Latin referring to “goose’s foot”
    • Conjoined tendinous attachment of Semitendinosus, Gracilis, and Sartorius
    • Bursa between proximal medial  and the insertion point of the 3 [1]

Associated Conditions

  • Knee
    • Specifically, the medial joint space
    • Up to 90% of cases
  • Sports]
    • Running
    • Basketball
    • Basketball
    • Racquet Sports
    • Racquet sports
  • Obesity

  • Fractures
    • Distal
    • Patellar Fracture
    • Tibial Plateau Fracture
  • Dislocations & Subluxations
    • Patellar  (and subluxation)
    • Knee Dislocation
    • Proximal Tibiofibular
  • Muscle and Tendon Injuries
    • Quadriceps Contusion
    • Iliotibial Band Syndrome
    • Quadriceps
    • Patellar Tendonitis
    • Popliteus
    • Extensor Mechanism Injury
      • Patellar Tendon Rupture
      • Quadriceps Tendon Rupture
      • Patellar Fracture
  • Ligament Pathology
    • ACL Injury
    • PCL Injury
    • MCL Injury
    • LCL Injury
    • Meniscal Pathology
    • Posterolateral Corner Injury
    • Multiligament Injury
  • Arthropathies
    • Knee Osteoarthritis
  • Bursopathies
    • Prepatellar Bursitis
    • Pes Anserine Bursitis
    • MCL Bursitis
    • Infrapatellar Bursitis
  • Patellofemoral Pain Syndrome (PFPS)/ Anterior Knee Pain)
    • Chondromalacia Patellae
    • Patellofemoral Osteoarthritis
    • Osteochondral Defect Knee
    • Plica Syndrome
    • Infrapatellar Fat Pad Impingement
    • Patellar Instability
  • Neuropathies
    • Saphenous Nerve Entrapment
  • Other
    • Bakers Cyst
    • Patellar Contusion
  • Pediatric Considerations
    • Patellar Apophysitis (Sinding-Larsen-Johansson Disease)
    • Patellar Pole Avulsion Fracture
    • Tibial Tubercle Avulsion Fracture
    • Tibial Tuberosity Apophysitis (Osgood Schalatters Disease)

  • History
    • Medial knee pain
    • Worse withstanding, stairs, crossing leg
    • Subjective , diminished range of motion
  • Physical Exam
    • may or may not be present
    • Tenderness over the pes anserine at the medial, proximal tibia, with the knee at 90°
    • In extension, tenderness may be over the medial joint line
    • Pain with resisted internal rotation and flexion of the knee
    • Location: 3-4 cm medial to the tibial tubercle, 3 cm below anteromedial tibial plateau
  • Special Tests
Pes Anserine bursitis with fluid in the bursa seen in long axis (arrow)

Radiographs

  • Standard Knee Radiographs
  • Findings
    • Underlying osteoarthritis is common

  • Findings
    • Swelling
    • Bursal fluid
    • Thickened pes anserine, especially in patients with knee OA[5]

MRI

  • Not typically indicated
  • Findings[6]
    • Increased bursal fluid
    • Thickened bursal wall
    • Surrounding tissue edema
    • Abnormal wall / surrounding tissue enhancement

Treatment

Nonoperative

  • Indication
    • The vast majority of cases
  • When appropriate, treatment should be directed at the underlying etiology
    • For example, osteoarthritis
  • Relative rest
  • Activity modification
  • NSAIDS
  • Weight Loss
  • Physical Therapy
    • Emphasis on strengthening quadriceps muscles
  • Corticosteroid Injection
    • One small study showed potential benefit[7]
    • Consider an intra-articular injection for knee OA + intra-bursa injection for pes anserine pain

Operative

  • Indications
    • Rarely, failure of conservative treatment
  • Technique
    • Bursal incision and drainage
    • Bursectomy
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A simple rural-patient checklist to help you explain symptoms clearly, ask better questions, and avoid unsafe self-treatment.

Safety note: This is not a prescription or diagnosis. For severe symptoms, pregnancy danger signs, children with serious illness, chest pain, breathing difficulty, stroke-like weakness, or major injury, seek urgent care.

Which doctor may help?

Start with a registered doctor or the nearest qualified health center.

What to tell the doctor

  • Write when the problem started and how it changed.
  • Bring old prescriptions, investigation reports, and current medicines.
  • Write allergies, pregnancy status, diabetes, kidney/liver disease, and major past illnesses.
  • Bring one family member if the patient is weak, elderly, confused, or a child.

Questions to ask

  • What is the most likely cause of my symptoms?
  • Which danger signs mean I should go to hospital quickly?
  • Which tests are necessary now, and which can wait?
  • How should I take medicines safely and what side effects should I watch for?
  • When should I come for follow-up?

Tests to discuss

  • Vital signs: temperature, pulse, blood pressure, oxygen saturation
  • Basic physical examination by a clinician
  • CBC, urine test, blood sugar, or imaging only when clinically needed

Avoid these mistakes

  • Do not use antibiotics, steroid tablets/injections, or strong painkillers without proper medical advice.
  • Do not hide pregnancy, kidney disease, ulcer, allergy, or blood thinner use.
  • Do not delay emergency care when danger signs are present.

Medicine safety and first-aid guide

This section is for patient education only. It does not replace a doctor, pharmacist, or emergency care.

Safe first steps

  • Rest, drink safe water, and observe symptoms carefully.
  • Keep a written note of symptoms, duration, temperature, medicines already taken, and allergy history.
  • Seek medical care quickly if symptoms are severe, worsening, or unusual for the patient.

OTC medicine safety

  • For mild pain or fever, ask a registered pharmacist or doctor before using common over-the-counter pain/fever medicines.
  • Do not combine multiple pain medicines without advice, especially if you have kidney disease, liver disease, stomach ulcer, asthma, pregnancy, or take blood thinners.
  • Do not give adult medicines to children unless a qualified clinician advises it.

Avoid these mistakes

  • Do not start antibiotics without a proper medical decision.
  • Do not use steroid tablets or injections casually for quick relief.
  • Do not delay emergency care because of home remedies.

Get urgent help if

  • Severe symptoms, confusion, fainting, breathing difficulty, chest pain, severe dehydration, or sudden weakness need urgent medical care.
Medicine names, dose, and timing must be decided by a qualified clinician or pharmacist after checking age, pregnancy, allergy, other diseases, and current medicines.

For rural patients and family caregivers

Patient health record and symptom diary

Write your symptoms, medicines already taken, test results, and questions before visiting a doctor. This note stays on your device unless you print or copy it.

Doctor to discuss: Doctor / qualified healthcare provider
Tests to discuss with doctor
  • Basic vital signs: temperature, pulse, blood pressure, oxygen level if needed
  • Relevant blood, urine, imaging, or specialist tests only after clinical assessment
Questions to ask
  • What is the most likely cause of my symptoms?
  • Which warning signs mean I should go to emergency care?
  • Which tests are really needed now?
  • Which medicines are safe for my age, pregnancy status, allergy, kidney/liver/stomach condition, and current medicines?

Emergency warning signs such as chest pain, severe breathing difficulty, sudden weakness, confusion, severe dehydration, major injury, or loss of bladder/bowel control need urgent medical care. Do not wait for online information.

Safe pathway to proper treatment

Care roadmap for: Pes Anserinus Syndrome

Use this simple roadmap to understand the next safe steps. It is educational and does not replace examination by a doctor.

Go to emergency care if you notice:
  • Severe or rapidly worsening symptoms
  • Breathing difficulty, chest pain, fainting, confusion, severe weakness, major injury, or severe dehydration
Doctor / service to discuss: Qualified healthcare provider; specialist depends on symptoms and examination.
  1. Step 1

    Check danger signs first

    If danger signs are present, seek emergency care and do not wait for online information.

  2. Step 2

    Record the symptom story

    Write when symptoms started, severity, medicines already taken, allergies, pregnancy status, and test results.

  3. Step 3

    Visit a qualified clinician

    A doctor, nurse, or qualified healthcare provider can examine you and decide which tests or treatment are needed.

  4. Step 4

    Do only useful tests

    Do tests after clinical assessment. Avoid unnecessary tests, random antibiotics, or repeated medicines without diagnosis.

  5. Step 5

    Follow up and return early if worse

    If symptoms worsen, new warning signs appear, or treatment is not helping, return for review quickly.

Rural patient practical tips
  • Take a written symptom diary and all previous prescriptions/test reports.
  • Do not hide medicines already taken, even herbal or over-the-counter medicines.
  • Ask which warning signs mean urgent referral to hospital.

This roadmap is for education. A real diagnosis and treatment plan requires history, examination, and clinical judgment.