How many cortisone injections in the knee are safe?

Why there are limits

A single steroid injection is generally safe and can be very effective for a painful flare. Concerns arise with frequent, repeated injections. Some research suggests that regular steroid injections over a long period may be associated with faster cartilage thinning, although the evidence is not conclusive. If each injection gives less relief or wears off sooner, that is a sign to look at other options rather than to keep repeating it.

Possible side effects

• A flare of pain for a day or two after the injection, which usually settles
• Temporary rise in blood sugar for several days, important for people with diabetes
• Facial flushing or a short-lived change in sleep or mood
• Thinning or lightening of the skin at the injection site, uncommon in the knee
• Infection inside the joint, which is rare but serious

Steroid injections are usually avoided when there is infection anywhere in the body or on the skin over the knee.

Timing before knee surgery

If knee replacement is being considered, many surgeons avoid steroid injections into that knee for about three months before the operation, because a recent injection may raise the risk of joint infection. If you are planning surgery, tell your doctor about any recent injections, including those given at other clinics in Qatar or abroad.

When to seek urgent help

Go to an emergency department the same day if, in the days after an injection, the knee becomes hot, red, increasingly swollen and very painful, or if you develop a fever or feel unwell. These can be signs of septic arthritis, which needs urgent treatment. For routine follow-up or to discuss whether more injections are sensible, book a review with Dr. Gelber at Aman Hospital.