The efficacy and safety of extracorporeal shockwave therapy in knee osteoarthritis: A systematic review and meta-analysis

Background: Extracorporeal shockwave therapy (ESWT) has been widely applied for pain control in musculoskeletal disorders. Whether ESWT can improve pain relief and joint function for knee osteoarthritis remains controversial. Therefore, we designed a meta-analysis based on relevant studies to comprehensively analyze and determine the efficacy and safety of ESWT for knee osteoarthritis. Methods: We identified relevant studies by an electronic search consisting of five English language databases: MEDLINE (1966 to July 2019), the Cochrane Central Register of Controlled Trials (2019 Issue 2), EMBASE (1980 to July 2019), and PubMed (1946 to July 2019). The methodological quality of randomized controlled trials (RCTs) was independently evaluated by two reviewers according to the criteria in the Cochrane Collaboration for Systematic Reviews. The quality of cohort and case-control studies was assessed by the Newcastlee-Ottawa scale (NOS). We performed statistical analysis by the Stata software, version 15. Results: Three RCTs and three cohort studies involving 589 patients were included. The present meta-analysis indicated that ESWT was associated a significant reduction of pain score at 4 weeks (WMD = -0.436; 95% CI = -0.604 to -0.269), 8 weeks (WMD = -0.234; 95% CI = -0.447 to -0.022) and 12 weeks (WMD = -0.239; 95% CI = -0.436 to -0.043). There were significant differences between the two groups in terms of the Western Ontario and McMaster Universities Osteoarthritis Index at 4 weeks (WMD = -3.107; 95% CI = - 5.073 to -1.142), 8 weeks (WMD = -3.617; 95% CI = -5.760 to -1.475) and 12 weeks (WMD = -2.271; 95% CI = -3.875 to -0.667). Conclusion: The ESWT was efficacious and safe for reducing pain and improving knee function in patients with knee osteoarthritis, without increasing the risk of adverse effects.