Non-operative treatment for osteoarthritis includes activity modification (do less, reduce impact, reduce load, reduce distance, etc), topical medications, oral medications, bracing, and injections.
A common injection used in orthopedic clinics many times each day is generically referred to as "cortisone." It is a combination of a local anesthetic (like the dentist uses) and a steroid. There are a variety of local anesthetic agents used (lidocaine, bupivacaine, etc.), and a variety of concentrations available. Additionally, there are a variety of steroids that can be used. Each surgeon likely has a preferred combination.
Just a side-note: the steroids orthopedic surgeons inject for anti-inflammatory purposes are completely different from the anabolic steroids associated with body-building. They will not make you grow muscle.
Although not everybody responds the same, a cortisone injection often provides rapid and significant relief from arthritis pain. This relief can last for months. When the pain returns, we have a discussion regarding the amount and duration of relief experienced. I generally allow my patients to undergo up to 3 cortisone injections per joint, per year.
Some patients aggressively pursue these injections and would accept them much more frequently than I recommend. Others prefer to avoid them entirely. Reasons for this vary. Some patients are simply afraid of the needle. This is a shame, because most patients report only mild discomfort when I've performed a cortisone injection. Other patients are more concerned about the potential detrimental effects. They've heard that cortisone destroys cartilage and will hasten their joint deterioration.
Some in vitro (test tube) and animal studies have shown chondrocyte (cartilage cell) toxicity due to local anesthetics, steroids, and combinations of both. Cartilage cell damage in a test tube does not necessarily mean that an injection into a living human's joint will create similar damage. In fact, another study in which samples of living cartilage were taken after the knee was injected with local anesthetic showed no such effect. While I certainly understand that cells in culture may be negatively effected, I have seen no clinical evidence of joint destruction due to cortisone.
I think it is reasonable to assume, like with most medications, that while there is a benefit, there is also some potential for harm. The key is to use cortisone, like all medications, judiciously. That is, only when indicated, not too often, and at the lowest effective dose.
It is important to remember that we are using cortisone in joints that are already moderately to severely damaged due to arthritis. The joint is already irreversibly damaged due to the cumulative effects of gravity, activity, and time. A cortisone injection can provide a significant improvement in quality of life and can potentially delay surgery.
Remember, a total joint replacement involves removing ALL of the cartilage from the joint. I would argue that that is much more toxic to the cartilage than a few cortisone injections.
I am not suggesting people should not have their joints replaced when they wear out. The majority of my practice involves replacing destroyed knees, hips, and shoulders. These operations predictably alleviate pain and restore function. Total knee, total hip, and total shoulder replacements, help hundreds of thousands of patients every year in the U.S.
I am suggesting that appropriate use of cortisone can allow some patients to delay an operation, sometimes for years. And if there is a risk that microscopic cartilage damage occurs, the ability to reduce pain and delay surgery is worth it.
Orthopedic Surgeon focused on the entire patient, not just a single joint.