Cryotherapy in Knee Arthroplasty: Systematic Review and Meta-Analysis.

Total knee arthroplasty is performed to relieve knee pain and disability related to end-stage osteoarthritis. Cryotherapy is used as an analgesic method, reducing the intraarticular temperature. The objective of this study was to review the literature on the efficacy of cryotherapy in knee arthroplasty. A total of 700 articles were found in databases according to the search criteria for each database and the included descriptors (EndNote Web). After exclusion of duplicate articles, automatically and manually, Phase 1 was performed-reading of titles and abstracts of 375 articles according to the eligibility criteria by two blinded reviewers using the Rayyan QCRI (Qatar Computing Research Institute) program, conflicts were resolved in consensus between the 2 reviewers. Thus, 21 articles were selected for Phase 2-reading in full, leaving 5 articles for this review. The Cochrane instrument Rob 2 was used to assess the quality of bias of the selected studies, and RevMan 5.4.1 was used for meta-analysis. The age of study participants ranged from 51 to 74 years. The sample size ranged from 37 to 389 subjects, with a total of 648 subjects. The risk of bias was almost entirely high and moderate for all endpoints: pain, range of motion (ROM), and function. There was a decrease in pain level and as secondary endpoints ROM and functionality, there were divergences between studies. It can be concluded that although cryotherapy is indicated to reduce pain in the postoperative period of knee arthroplasty, studies have many methodological biases and the meta-analysis performed could not confirm the effects; therefore, more primary studies are needed to better understand the effects.