Pes Anserine Bursitis
Pes Anserine Bursitis
Shanyn Lancaster
Melissa Nayak
Basics
Description
Pes anserine bursitis is an acute or chronic inflammatory condition that affects the medial aspect of the knee at the insertion of the conjoined pes anserine tendon onto the anteromedial proximal tibia. The pes anserine tendon, which is comprised of the tendons of the sartorius, gracilis, and semitendinosus muscles, is superficial to a bursa, which may become inflamed and/or distended. This bursa does not typically communicate with the knee joint.
Epidemiology
The exact incidence is unknown.
Risk Factors
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Incorrect training techniques (ie, sudden increase in mileage, excessive hill running, no stretching routine)
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Tight hamstrings
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Abnormal gait
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Obesity
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Osteoarthritis of the knee (1)[C]
Etiology
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Any abnormal force on the insertion point of the 3 tendons caused by a change in the mechanical relationship between the knee, hip, and pelvis, such as an abnormal gait, can cause pes anserine bursitis, though it may also result from trauma.
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Athletes who perform side-to-side and cutting motions
Commonly Associated Conditions
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Medial collateral ligament (MCL) pathology
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Osteoarthritis
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Obesity
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Pes planus
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Valgus knee deformity
Diagnosis
History
Episodes are typically characterized by:
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Pain, tenderness, and acute swelling within the well-localized area of the tendon and bursa along the medial tibia
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Pain may be exacerbated by rising from a seated position and ascending or descending stairs.
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Pain is generally worse at night.
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Patients may deny pain when walking on level surfaces.
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May be bilateral
Physical Exam
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Tenderness at the insertion of the pes anserine tendon at the proximal medial tibia, ∼2–5 cm below the anteromedial joint line of the knee
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Palpable crepitus of the bursa may be felt, but the bursa is usually not palpable unless effusion and thickening are present.
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Pain occasionally is reproduced with resisted internal rotation and flexion of the knee.
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Pain may also be reproduced when a valgus stress is applied. This may make it difficult to distinguish this problem from an MCL injury; however, MCL injuries are typically superior and posterior to this type of bursitis.
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Hamstring-popliteal angle should be measured to assess hamstring flexibility. This is done by having the patient flex the hip to 90° and then passively extend the leg. The angle is formed by a perpendicular line to the femoral shaft and the tibial shaft.
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Chronic cases are marked by local pain at the site of the bursa.
Diagnostic Tests & Interpretation
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Diagnosis of pes anserine bursitis can be made on clinical grounds, and further workup is not necessarily indicated, although normal radiographs of the knee will rule out bony pathology.
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In refractory cases, workup is dictated based on suggested diagnosis and may include lab work to rule out a rheumatoid disorder or further imaging such as a MRI.
Imaging
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MRI is the preferred imaging study for pes anserine bursitis (2)[C].
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The pes anserine bursa is observed to show a collection of fluid with low signal intensity on T1-weighted images and homogenous increased signal intensity on T2-weighted images.
Diagnostic Procedures/Surgery
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Aspiration of the bursa is typically not required.
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In difficult cases, a local anesthetic block may be used to confirm the diagnosis. Relief of pain with the injection is diagnostic.
Differential Diagnosis
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Medial collateral ligament injury
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Osteoarthritis
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Medial meniscus tear
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Medial plica and discoid medial meniscus
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Medial hamstring strain (semitendinosus) and tendonitis
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Myofascial pain
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Stress fracture
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Fibromyalgia
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Patellofemoral pain syndrome
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Regional tumors, including villonodular synovitis, osteochondromatosis, and synovial sarcoma
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Prepatellar bursitis
P.461
Treatment
The mainstay of treatment for patients with pes anserine bursitis is to reduce pain and inflammation through the following (3)[C]:
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Activity modification (decreased distance)
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Hamstring stretching
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Closed kinetic chain quadriceps strengthening
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Anti-inflammatory medications
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Ice massage
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Use of a protective pad over the affected area
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Addressing gait abnormalities
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Older patients and those with chronic pain should be encouraged to maintain activity levels to prevent disuse atrophy. Obesity counseling should also occur.
Medication
First Line
NSAIDs are recommended, including both nonselective NSAIDs as first line and the selective COX-2 inhibitors if there are tolerance issues.
Second Line
Corticosteroid injections are traditionally utilized as first- or second-line medications, as the blood supply to the bursa is limited.
Complementary and Alternative Medicine
Physical therapy can be beneficial for patients with pes anserine bursitis. Modalities such as US, phonophoresis, ice massage, and stretching can also be helpful in relieving pain and inflammation.
Surgery/Other Procedures
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Injection with local anesthetics and corticosteroids is an option in cases that fail to improve with more conservative measures.
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The patient is placed supine with the leg extended and hip externally rotated.
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The area of maximal tenderness is marked, and ethyl chloride is sprayed on the skin for local anesthesia.
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A smaller-gauge needle is inserted into the skin and directed toward the bursa until the periosteum is contacted.
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The needle should be withdrawn 1/8″ to prevent injection into the medial collateral ligament, and a mixture of corticosteroid and local anesthetic is injected.
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Patients may experience immediate, though not complete, relief.
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The injection should be free flowing with little resistance.
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This injection may be repeated in 6 wks if swelling recurs or persists.
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Surgery is a rare option in chronic cases and includes bursectomy and/or excision of bony exostoses.
Ongoing Care
In general, patients experience success with conservative treatments, including hamstring stretching, quadriceps strengthening, activity modification, and oral NSAIDs. Most patients will experience alleviation of pain within 6–8 wks.
Follow-Up Recommendations
Patients may return to their activities based on their level of pain and function.
Patient Education
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The following recommendations can be made to the patient:
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Minimize the use of stairs and climbing.
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Eliminate squatting.
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Prevent direct pressure on the bursa by using a pillow between the legs at night.
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Avoid crossing the legs.
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Limit repeated bending of the knee.
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Patients and their coaches should be counseled on the gradual increase in activity based on symptoms.
Prognosis
Pes anserine bursitis is usually a self-limiting condition, with few complications if the individual decides to participate through the pain. In general, pain resolves after 6–8 wks of conservative treatment (4)[C].
References
1. Alvarez-Nemegyei J. Risk factors for pes anserinus tendinitis/bursitis syndrome: a case control study. J Clin Rheumatol. 2007;13:63–65.
2. Rennie WJ, Saifuddin A. Pes anserine bursitis: incidence in symptomatic knees and clinical presentation. Skeletal Radiol. 2005;34:395–398.
3. http://utdonline.com/online/content/topic.do?topicKey=st/rheum/6373&selectedTitle=2∼45&source=search/result.
4. http://emedicine.medscape.com/article/90412-overview.
Additional Reading
Nokes SR, Smith T. Acute pes anserine bursitis. J Ark Med Soc. 2007;104:112.
Codes
ICD9
726.60 Enthesopathy of knee, unspecified
Clinical Pearls
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Pes anserine bursitis is a cause of medial-sided knee pain.
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Diagnosis can be made with local tenderness over the bursa, located 2–5 cm distal to the joint line, a negative valgus stress test, and negative radiographs.
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Treat any underlying gait abnormalities; use activity modification, ice, NSAIDs, and steroid injection to decrease pain and inflammation.