What are the limits of pes anserine (pes anserinus) bursa steroid injections?

From the Guidelines

Steroid injections for pes anserine bursitis should be limited to no more than 3-4 injections per year at the same site, with at least 3 months between injections, as recommended by the European League Against Rheumatism (EULAR) 1.

Key Considerations

• The EULAR recommendations suggest that local injections of glucocorticoids should be considered as adjunctive therapy in psoriatic arthritis, with systemic glucocorticoids used with caution at the lowest effective dose 1.
• The limitations on steroid injections exist to prevent local tissue atrophy, tendon weakening or rupture, skin depigmentation, and systemic effects if administered too frequently.
• A typical injection consists of 40mg methylprednisolone (Depo-Medrol) or equivalent mixed with 1-2ml of lidocaine 1%, inserted at the medial aspect of the proximal tibia, about 2-3cm below the joint line where the pes anserine tendons (sartorius, gracilis, and semitendinosus) insert.

Rationale

• The EULAR recommendations are based on the best available evidence and expert opinion, with a focus on maximizing long-term health-related quality of life for patients with psoriatic arthritis 1.
• The use of steroid injections should be carefully considered, taking into account the potential benefits and risks, as well as alternative treatment options such as physical therapy, activity modification, or addressing biomechanical issues.

Important Notes

• If a patient requires more than 3-4 injections per year, this suggests that the diagnosis should be reconsidered or that alternative treatments may be more appropriate for long-term management.
• The injection provides anti-inflammatory effects by inhibiting phospholipase A2 and reducing production of inflammatory mediators, which helps decrease pain and swelling in the bursa.

From the Research

Pes Anserine Steroid Injection Limits

• The efficacy of local corticosteroid injection in treating pes anserine bursitis has been evaluated in several studies 2, 3, 4, 5.
• A randomized multicenter clinical trial compared the efficacy of corticosteroid injection, oxygen-ozone injection, and prolotherapy in patients with pes anserine bursitis, and found that all three treatment options are effective, but the effects of oxygen-ozone injection and prolotherapy last longer than those of corticosteroid injection 2.
• Another study compared the efficacy of local corticosteroid injection, platelet-rich plasma injection, and extracorporeal shockwave therapy in patients with pes anserine bursitis, and found that local corticosteroid injection is more efficient than platelet-rich plasma injection and extracorporeal shockwave therapy for reducing pain and enhancing function 3.
• A study comparing the efficacy of physical therapy and corticosteroid injection in the treatment of pes anserine tendino-bursitis found that both treatments resulted in significant improvements in all measured parameters, but no significant difference was detected between the two groups 4.
• An open-label randomized clinical trial compared the effectiveness of local corticosteroid injection and extracorporeal shockwave therapy in patients with pes anserine bursitis, and found that both treatments are safe and effective, but local corticosteroid injection resulted in greater reduction in pes anserine thickness, while extracorporeal shockwave therapy resulted in greater improvement in quality of life 5.

Limitations of Steroid Injections

• The effects of corticosteroid injection may not last as long as those of other treatment options, such as oxygen-ozone injection and prolotherapy 2.
• Corticosteroid injection may have adverse effects, such as thinning of the skin and tendons, and may not be suitable for all patients 3.
• The efficacy of corticosteroid injection may vary depending on the individual patient and the severity of their condition 4, 5.

Comparison with Other Treatments

• Oxygen-ozone injection and prolotherapy may be more effective than corticosteroid injection in the long term 2.
• Platelet-rich plasma injection and extracorporeal shockwave therapy may be less effective than corticosteroid injection for reducing pain and enhancing function 3.
• Physical therapy may be as effective as corticosteroid injection in the treatment of pes anserine tendino-bursitis 4.
• Extracorporeal shockwave therapy may result in greater improvement in quality of life than corticosteroid injection 5.