ObjectiveTo investigate the effectiveness of extracorporeal shock wave therapy combined with platelet-rich plasma (PRP) injection in treatment of knee osteoarthritis (KOA) by prospective clinical study.MethodsBetween June 2015 and June 2018, 180 patients with KOA met the inclusion criteria were included in study and randomly allocated to group A (n=60), group B (n=60), and group C (n=60). The patients were treated with autologous PRP intra-articular injection in group A, extracorporeal shock wave therapy in group B, and extracorporeal shock wave therapy combined with autologous PRP intra-articular injection in group C, once a week and 5 times a duration of treatment. There was no significant difference in age, gender, disease duration, side of KOA, and Kellgren-Lawrence grading between groups (P>0.05). The pain and function of knee joint were assessed by visual analogue scale (VAS) score, Lequesne Index score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and knee joint activity before treatment and at 1, 3, and 5 weeks after the first treatment.ResultsThere were significant differences in VAS score, Lequesne Index score, WOMAC score, and knee joint activity between pre- and post-treatment in all groups (P<0.05). VAS score, Lequesne Index score, and WOMAC score gradually decreased with the prolongation of treatment time (P<0.05); but there was no significant difference in knee joint activity between different time points (P>0.05). There was no significant difference in VAS score, Lequesne Index score, WOMAC score, and knee joint activity between groups before treatment (P>0.05); the scores of group C were superior to groups A and B (P< 0.05) at different time points after treatment; while the knee joint activities of 3 groups were similar (P>0.05).ConclusionThe extracorporeal shock wave therapy combined with PRP injection can relieve the pain synergistically for KOA.