Knee injections deliver medication directly into the joint space to manage chronic pain and reduce inflammation, often associated with conditions like osteoarthritis. These injections, which may contain corticosteroids or hyaluronic acid, can provide significant relief and improve mobility. Following specific recovery instructions is necessary to achieve the best outcome and minimize complications. This guidance outlines the immediate steps, the recovery period, and signs requiring urgent medical attention.
Immediate Post-Procedure Care
The first few hours following a knee injection require specific attention to the treated joint and personal safety. Since the injection often includes a local anesthetic, temporary leg weakness or instability may occur. It is advised to avoid driving or operating heavy machinery for the remainder of the day, or until the numbing sensation has completely worn off.
Attention to the injection site is necessary to prevent infection. A small bandage is typically placed over the needle entry point and should be kept clean and dry for the first 24 hours. While showering is permissible, submerging the knee in water—such as bathing, swimming, or using a hot tub—must be avoided for at least one full day. The bandage can usually be removed the following day, or as directed by the healthcare provider.
Managing initial post-injection soreness is best done using cold therapy. Applying an ice pack to the knee helps reduce temporary swelling and discomfort. Apply ice for intervals of 15 to 20 minutes, separated by 45 to 60 minutes of rest, ensuring a thin cloth is placed between the ice and the skin to prevent injury. Consistent icing during the first 24 to 48 hours promotes comfort.
Managing Recovery and Activity Modification
The days immediately following the injection involve careful management of activity and joint discomfort. Patients receiving a corticosteroid injection may experience a temporary increase in pain, known as a “steroid flare-up.” This occurs as the numbing agent wears off and before the anti-inflammatory medication takes effect. This localized discomfort or swelling can last between 48 and 72 hours.
If discomfort arises, over-the-counter medication may be used, but confirm the appropriate pain reliever with your doctor. Acetaminophen is recommended, though some providers advise against using nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen for a short period. The steroid component of the injection takes between two and five days to provide noticeable relief. Hyaluronic acid injections, used for joint lubrication, may take several weeks before the full benefit is felt.
Activity modification is necessary for the proper integration of the medication within the joint. Patients should refrain from high-impact activities, such as running, jumping, or heavy lifting, for at least 48 hours following the procedure. Routine, low-impact activities like walking are permitted, but the goal is to avoid placing undue stress on the treated joint. After the initial recovery period, gradually return to light physical activity as tolerated, monitoring the knee for any signs of increased pain or swelling.
Recognizing Signs of Serious Complication
Knee injections are generally safe, but understanding the distinction between normal soreness and signs of a serious complication is important. The most serious, though rare, complication is a joint infection, known as septic arthritis. Symptoms include a significant increase in pain and swelling that worsens over time instead of improving.
Other indicators of a developing infection include increased warmth across the entire knee, persistent redness extending beyond the injection site, and any drainage or pus coming from the needle entry point. A fever exceeding 100.4 degrees Fahrenheit is a sign of infection. If any of these symptoms appear, immediate contact with a healthcare provider or seeking emergency care is necessary.
Other rare but serious issues can occur, such as a severe allergic reaction to the medications used. Signs of an allergic reaction include hives, a rash, dizziness, or difficulty breathing, which require emergency medical attention. Although rare, signs of a deep vein thrombosis (DVT) in the leg—such as unexplained swelling, warmth, or sharp cramping pain in the calf or thigh—should be reported immediately to a doctor. Chest pain or sudden shortness of breath combined with leg symptoms may signal a pulmonary embolism, which is a medical emergency.