Randomised controlled trials (RCTs) or quasi-RCTs that compared DMSO or MSM to placebo or standard care in the treatment of osteoarthritis were eligible for the review. Validated outcome measures needed to be used for osteoarthritis. Studies that included patients with other joint pathology were excluded.
All studies evaluated osteoarthritis of the knee joint. Studies varied in DMSO or MSM treatment regimens. Treatment periods for DMSO were from three weeks up to a month. The treatment period for MSM was 12 weeks. Outcomes included pain (measured on a variety of scales), mobility, swelling, global assessment of efficacy and tolerability, amount of rescue medication taken, walking time, physical function and stiffness and adverse events.
The authors did not say how studies were selected for the review.