Article type
Abstract
Background:
Stem cell therapy is often promoted as a treatment for knee osteoarthritis, despite uncertainty regarding efficacy, safety, and the putative mechanism of action.
Objectives:
To assess the benefits and harms of stem cell injections for people with knee osteoarthritis.
Methods:
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase and trial registries on 15 September 2023 for randomised controlled trials in people with knee osteoarthritis that compared stem cell injection with placebo injection (primary comparison), no treatment or usual care, glucocorticoid injection, or another intervention. Two authors independently extracted data and assessed risk of bias and the GRADE certainty of evidence using standard Cochrane methods. This Cochrane systematic review is maintained as a living review and will be updated as relevant new evidence emerges.
Results:
We included 8 trials (544 participants) comparing stem cell to placebo injections and 17 trials (798 participants) with other comparators. Compared with placebo injection at up to 6 months after treatment, stem cell injection may slightly improve pain (1.2 points better, 95%CI 0 to 2.5 points, 0 to 10 scale) and function (14.2 points better, 95%CI 3.1 to 25.3 points, 0 to 100 scale). The evidence for pain and function was downgraded to low certainty due to indirectness (as the source, method of preparation, and dose of stem cells varied across studies), and suspected publication bias (up to three larger RCTs have been conducted but withdrawn prior to reporting of results). There was very low certainty evidence regarding quality of life and overall treatment success, and very low certainty evidence regarding safety, as serious adverse events were infrequently reported. Radiographic progression was not assessed in any of the included studies. There was generally very low certainty evidence for comparators other than placebo.
Conclusions:
Stem cell injections may offer slight improvements in pain and function for people with knee osteoarthritis compared to placebo injections. Their impact on quality of life, radiographic progression, and safety remains uncertain. Serious adverse events were infrequently reported, although both joint injection and stem cell harvest carry potential risks.
Stem cell therapy is often promoted as a treatment for knee osteoarthritis, despite uncertainty regarding efficacy, safety, and the putative mechanism of action.
Objectives:
To assess the benefits and harms of stem cell injections for people with knee osteoarthritis.
Methods:
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase and trial registries on 15 September 2023 for randomised controlled trials in people with knee osteoarthritis that compared stem cell injection with placebo injection (primary comparison), no treatment or usual care, glucocorticoid injection, or another intervention. Two authors independently extracted data and assessed risk of bias and the GRADE certainty of evidence using standard Cochrane methods. This Cochrane systematic review is maintained as a living review and will be updated as relevant new evidence emerges.
Results:
We included 8 trials (544 participants) comparing stem cell to placebo injections and 17 trials (798 participants) with other comparators. Compared with placebo injection at up to 6 months after treatment, stem cell injection may slightly improve pain (1.2 points better, 95%CI 0 to 2.5 points, 0 to 10 scale) and function (14.2 points better, 95%CI 3.1 to 25.3 points, 0 to 100 scale). The evidence for pain and function was downgraded to low certainty due to indirectness (as the source, method of preparation, and dose of stem cells varied across studies), and suspected publication bias (up to three larger RCTs have been conducted but withdrawn prior to reporting of results). There was very low certainty evidence regarding quality of life and overall treatment success, and very low certainty evidence regarding safety, as serious adverse events were infrequently reported. Radiographic progression was not assessed in any of the included studies. There was generally very low certainty evidence for comparators other than placebo.
Conclusions:
Stem cell injections may offer slight improvements in pain and function for people with knee osteoarthritis compared to placebo injections. Their impact on quality of life, radiographic progression, and safety remains uncertain. Serious adverse events were infrequently reported, although both joint injection and stem cell harvest carry potential risks.