A small and very rare risk is that the injected joint becomes infected (1 in 15,000). Patients who experience a very painful, red, or swollen joint after injection should seek medical attention immediately. Thankfully, the most common cause of these symptoms is not a concerning infection but a reaction to the injected steroid (called steroid flare ) that occurs in 2-5% of patients. A steroid flare usually begins 6-12 hours after the injection and can last for 2-3 days. Regardless of the cause, it is important for patients with symptoms of infection to see a doctor because infections require immediate treatment.
Following aspiration of the prepatellar bursa, a pressure dressing should be applied, and the patient should remain in the supine position for several minutes. Following injection, the joint or injected region may be put through passive range of motion. The patient should remain in the office for 30 minutes after the injection to monitor for any adverse reactions. In general, patients should avoid strenuous activity involving the injected region for several days. Patients should be cautioned that they may experience worsening symptoms during the first 24 to 48 hours related to a possible steroid flare, which can be treated with ice and nonsteroidal anti-inflammatory drugs. Patients should be instructed against the application of heat. A follow-up appointment should be scheduled within three weeks.