Patients with mild to moderate knee osteoarthritis face a range of treatment options, without any clear evidence on which options are most effective. Among injectable therapies, platelet-rich plasma is a relatively new option which has had mixed evidence to date. Some previous studies have compared PRP to hyaluronic acid (HA), but with differing numbers of injections in each group. In this study, the authors performed a meta-analysis of studies which provided PRP and HA injections in a 1:1 ratio. They found that PRP had significantly better WOMAC, IKDC and VAS pain scores but no difference in KOOS scores.