From the Research
The average time to experience relief from a knee cortisone injection is typically within 24-48 hours, with some patients feeling improvement within hours and others taking up to a week. The effects of a cortisone injection generally last between 6 weeks to 3 months, though this varies significantly between individuals 1. Common corticosteroids used include methylprednisolone (Depo-Medrol), triamcinolone (Kenalog), and betamethasone (Celestone), usually administered in doses of 20-80 mg depending on the specific medication and severity of inflammation.
Key Points to Consider
- The injection is often combined with a local anesthetic like lidocaine for immediate pain relief while waiting for the steroid to take effect 2.
- Cortisone works by reducing inflammation in the joint, decreasing the activity of the immune system cells that cause swelling, redness, and pain.
- Patients should rest the knee for 24-48 hours after injection and avoid strenuous activity for about a week.
- If pain persists beyond 2-3 days after injection or if there's increased swelling, redness, or fever, medical attention should be sought as these could indicate infection, a rare but serious complication.
Evidence-Based Recommendations
Based on the most recent and highest quality study available, triamcinolone (TA) injections resulted in a >5-fold reduction in steroid flare reactions, with statistically superior 6-month efficacy rates, compared with methylprednisolone (MPA) injections 3. However, it's essential to note that the specific context of knee cortisone injections may differ from shoulder injections, and the choice of corticosteroid should be individualized based on patient factors and clinical judgment.
Important Considerations
- The study by 3 compared the efficacy of TA and MPA injections in the shoulder, which may not directly translate to knee injections.
- However, the findings suggest that TA may be a more viable option for reducing steroid flare reactions and improving efficacy rates.
- Further research is needed to confirm these findings in the context of knee cortisone injections.