Doctors often inject cortisone-type medications into painful damaged joints and tendons. Single injections can relieve pain and swelling and appear to be safe, but repeated injections can damage joints and delay healing.

Scientists in Greece injected cortisone-type drugs repeatedly into the joints of rabbits and showed that they damage cartilage. A paper in the Journal of Bone and Joint Surgery shows that the injecting cortisone-type medications repeatedly into injured tendons and ligaments, delays healing and weakens tissue.

In light of these findings, you would think that doctors would stop injecting joints and tendons. However, people can be crippled by arthritis and a single injection into a damaged knee joint can allow an arthritic to walk without pain. The same principle applies to athletes and exercisers, who can develop pain in their tendons, muscles, fascia and ligaments from injuries. When injuries heal in a few days, no treatment is indicated, but sometimes they persist for months to cause pain, particularly in the fascia on the bottom or back of the heel, in the large tendon in the back of the lower leg, or in the tendons on the elbows or shoulders. Cortisone-type drugs reduce swelling and lessen pain and can allow an athlete or exerciser to get back to sports, but cortisone injections weaken the tendons for more than 84 days.

If you suffer chronic pain in the tendons, muscles, ligaments or fascia, check with your doctor to see if you have a chronic disease causing it, such as arthritis or hepatitis. The non-steroidals that are usually prescribed block pain but do not help tissue to heal. Your doctor may prescribe light rehabilitation exercises. If you receive a cortisone-type injection, make sure that you protect that area from hard exercise for at least two months after you receive the injection.