RESUMO
PURPOSE: Local infiltration analgesia, an essential component of multimodal analgesia after total knee arthroplasty (TKA), can be classified into periarticular injection (PAI) and intra-articular injection (IAI) as per administration techniques. Currently, there is no definite answer of the optimal choice between the two techniques. This meta-analysis aims to determine whether PAI provides superiority of pain relief and functional recovery than IAI after TKA. DESIGN: Systematic review and meta-analysis. METHODS: Comparative studies that compared PAI and IAI in patients after TKA were searched in the Embase, PubMed, MEDLINE, and the Cochrane Library databases. The primary outcomes were visual analog scale scores for pain and opioid consumption. The secondary outcomes were complications, function of recovery, and length of hospital stay. FINDINGS: Four randomized controlled trials and two case-controlled studies with a total of 769 patients were enrolled. There were no significant differences in mean visual analog scale scores at postoperative day 0 (P = .17) and day 1 (P = .27), maximum visual analog scale scores at day 0 (P = .89) and day 1 (P = .82), total opioid consumption at day 1 (P = .96), opioid complications (P = .15), and length of hospital stay (P = .84) between PAI and IAI. CONCLUSIONS: Based on the available evidence, PAI does not offer superior effects at pain control and discharge than IAI after TKA. However, owing to the limited sample size and heterogeneity of the included studies, further large well-designed randomized controlled trials are still needed to validate this conclusion. REGISTRATION: The protocol has been registered in the PROSPERO international database under number CRD42020165138.
