Approach Considerations
Pes anserine bursitis is primarily a self-limiting condition. [3] Patients generally are treated successfully with conservative measures and typically should receive outpatient physical therapy. For preventive purposes, every athlete should participate in a regular stretching program for the hamstring tendons.
Intrabursal injection of local anesthetics, corticosteroids, or both constitutes a second line of treatment. Surgical therapy is indicated only in very rare cases.
In patients whose symptoms last more than several months, consideration may be given to referring the patient to a specialist to confirm the diagnosis and rule out other potential causes of the patient’s pain (eg, proximal tibial plateau fracture). Cases that do not respond to a program of activity modification and exercise may be referred to a specialty-trained, sports medicine physician, primary care physician, or orthopedic surgeon for evaluation.
Rest, NSAIDs, PRP, and Physical Therapy
Rest, including cutting back or eliminating the offending activities, is essential to treatment. Along with the use of nonsteroidal anti-inflammatory drugs (NSAIDs), it represents first-line treatment.
Physical therapy is beneficial and often is indicated for patients with pes anserine bursitis. Rehabilitative exercise for persons with significant medial knee stress follows general physiatric principles for knee disorders and includes the following:
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Stretching and strengthening of the adductor, abductor, and quadriceps groups (especially the last 30° of knee extension using the vastus medialis)
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Stretching of the hamstrings
Thus, patients with pes anserine bursitis need to work on both a hamstring stretching program and a concurrent closed-chain quadriceps and pelvifemoral strengthening program. Such programs can usually be taught to the patient by an athletic trainer or physical therapist. Patients should understand that to gain the maximum benefit from this program, they must stretch their hamstrings frequently during the day, sometimes hourly. The quadriceps strengthening program is recommended in most patients because of other concurrent pathology in the knee.
A regular program of hamstring stretching and quadriceps strengthening usually results in alleviation of the pain from pes anserine bursitis in approximately 6-8 weeks. Addition of a nonsteroidal anti-inflammatory drug (NSAID) may help to alleviate some of the pain at this time. In addition, and an ice massage may help to reduce inflammation. Ice in foam cups can be applied and rubbed directly on the patient’s skin (ice massage) for up to 10 minutes at a time; other forms of cryotherapy (eg, cold packs) also may be used.
During the rehabilitation program, the patient should incorporate the following measures:
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Continue with activity modification as necessary
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Begin a gradual resumption of activities
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Continue alternative training for cardiovascular fitness
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After regaining full, pain-free motion with good isometric strength, work on improving strength and endurance
Advise older patients and those with chronic pain to avoid muscle atrophy from disuse. Address obesity in cases in which it is a contributing factor.
A small cushion placed between the thighs before sleeping is useful in managing medial knee bursitis.
If resective surgery is performed, the knee remains in extension or slight flexion within an immobilizer for 1-2 weeks after surgery. Pursue active range-of-motion (AROM) exercises until 3 weeks after surgery, then begin progressive resistive exercises (PREs).
Other appropriate means of and ideas for treating pes anserine bursitis include the following:
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Ultrasound – This is reportedly effective in reducing inflammation associated with pes anserine bursitis
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Electrical stimulation – This has been used in other forms of bursitis, although its use has not been documented specifically in pes anserine bursitis
A study by Khosrawi et al indicated that pes anserine bursitis can be effectively treated with extracorporeal shock wave therapy (ESWT). The visual analog scale and the McGill Pain Questionnaire total pain index were used to assess mean pain scores before and immediately after therapy, as well as 8 weeks after the treatment’s conclusion. The investigators found the follow-up scores to be significantly lower in patients who received ESWT than they were in patients who received sham ESWT. [36]
A study by Homayouni et al reported that in patients with pes anserine tendinobursitis, pain and swelling can be better reduced with kinesiotaping than with a combination of the nonsteroidal anti-inflammatory drug (NSAID) naproxen and physical therapy. The study compared kinesiotaping with treatment consisting of 250 mg of naproxen three times per day for 10 days plus 10 daily physical therapy sessions, with pain and swelling measured with the visual analog scale (VAS) and ultrasonography, respectively. [37]
In a study of 33 patients with chronic pes anserinus pain, Rowicki et al found that, following autologous platelet-rich plasma (PRP) injection, 84.8% of the cohort had achieved total or near-total pain relief by 6 months. [38]
Injection of Local Anesthetics or Corticosteroids
Intrabursal injection of local anesthetics, corticosteroids, or both represents a second-line treatment option. It should be considered only for refractory cases that have not responded to physical therapy, rest, ice, and NSAIDs. A study found no difference in short-term pain relief between 3-5 mL of 1% lidocaine with methylprednisolone and the same amount of lidocaine without the corticosteroid.
Injection can be directed to the point of maximal tenderness. Care should be taken to avoid injecting any of the 3 tendons converging at the pes anserinus; injection within the tendons themselves can weaken these structures and intensify the patient’s pain. Ultrasound guidance has demonstrated effectiveness in cadaveric studies, increasing accuracy from 17% (unguided) to 92%. [39]
Occasionally, an area 0.5-1 cm higher than the tendons is injected in order to include the medial collateral ligament (MCL) bursa, which also may be a pain generator. Injection of the knee joint itself may be beneficial in recalcitrant cases.
Generally, use a 22-gauge or 23-gauge needle to inject 1-3 mL of 1% lidocaine and corticosteroid (20-40 mg of triamcinolone, 20-40 mg of methylprednisolone, or 6 mg of betamethasone). If infection—which is rarer here than in the bursae of the anterior knee—is suggested, use a larger, 19- or 20-gauge needle and a 20-30 mL syringe for aspiration. Relief is usually immediate but may not be complete.
Repeated lidocaine injections or the use of corticosteroids may result in longer-lasting relief (from 1 to several months). No more than 3 injections should be used over a 1-year period, with intervals of at least 1 month between injections. It should be kept in mind, however, that patients who do not respond to the initial injection rarely respond to repeat treatments. [20] Patients who do not respond to initial injection rarely respond to repeated bursal injections.
A study by Sarifakioglu et al indicated that physical therapy and corticosteroid injection are similarly effective in the treatment of pes anserine tendinobursitis. In the study, 60 patients with a combination of knee osteoarthritis and pes anserine tendinobursitis were divided into physical therapy and corticosteroid injection treatment groups, with significant improvement seen in functional capacity and pain scores in both groups after 8 weeks. [40]
Surgical Decompression and Resection
Surgical management of pes anserine bursitis is very rarely warranted. Surgery is usually indicated when an immunocompromised patient has a localized infection that does not resolve with standard antibiotic treatment. Surgical decompression of the bursa may be performed in such cases.
Clinically, pes anserine bursitis can mimic distal anteromedial knee disorders or internal derangement of the knee, sometimes leading to unnecessary surgery. In an investigation of 509 magnetic resonance imaging (MRI) studies done on patients thought to have an internal knee derangement, the prevalence of pes anserine bursitis was found to be 2.5%. [18]
In cases of disability, such as those causing 6-8 weeks of limitation in athletes, some surgeons advocate resection, especially if mature exostosis is present and causing irritation. The operation includes excision of the bursa and any bony exostosis.
Activity
In patients with generalized anterior knee pain, activity modification may be necessary to allow the joint to quiet down and to allow the hamstring tightness to resolve. In most patients, this modification involves minimizing the use of stairs, climbing, or other activities that cause irritation of the joint.
Athletes and active patients may return to play or activities as their symptoms permit. In more severe cases, restrictions on activities may be necessary. Athletes who play contact sports may benefit from the use of a protective pad over the affected area.
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Location of pes anserinus bursa on medial knee. MCL = medial collateral ligament.
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Pes anserinus bursa is located on proximomedial aspect of tibia between superficial medial (tibial) collateral ligament and hamstring tendons (ie, sartorius, gracilis, and semitendinosus). This bursa serves as space where motion occurs between these hamstring tendons and underlying superficial tibial collateral ligament.
