Stem cell injections for osteoarthritis of the knee

Compared with placebo injections and based upon low-certainty evidence, stem cell injections for people with knee osteoarthritis may slightly improve pain and function. We are uncertain of the effects of stem cell injections on quality of life or the number who report treatment success. Although the putative benefits of stem cell therapies for osteoarthritis include potential regenerative effects on damaged tissues, particularly articular cartilage, we remain uncertain of the effect of stem cell injections on structural progression in the knee (measured by radiographic appearance). There is also uncertainty regarding the safety of stem cell injections. Serious adverse events were infrequently reported, although all invasive joint procedures (including injections) carry a small risk of septic arthritis. The risk of other important harms, including potential concerns related to the use of a therapy with the theoretical capacity to promote cell growth, or to the use of allogeneic cells, remains unknown.