Abstract
Aim: Lavage aspiration following a dry tap remains a debated technique in the work-up for periprosthetic joint infection (PJI) of the hip and knee. This systematic review critically appraises the available evidence, with a particular focus on the diagnostic yield of lavage aspiration in detecting PJIs that would otherwise be missed. Methods: A comprehensive literature search was conducted in accordance with PRISMA guidelines across PubMed, Embase, MEDLINE, and Cochrane databases. Results: Eleven studies met the inclusion criteria, all level IV case series. Across 1965 patients, 2199 aspirations were performed. Overall, 798 procedures (36 %) resulted in a dry tap. Lavage aspiration was attempted in 698 of these cases, with 691 successful attempts. Among dry taps, 154 PJIs were ultimately identified, corresponding to a PJI prevalence of 19 %. Lavage aspiration contributed to a correct diagnosis in 22 % of successful procedures. Pooled culture sensitivity and specificity following saline lavage were 66 % and 89 %, respectively. The diagnostic performance of polymorphonuclear neutrophils (PMNs) > 80 % was similar between saline lavage and normal aspiration. Although no safety concerns were reported, the potential introduction of pathogens and the risk of false-positive results remain concerns that are not fully mitigated by the available evidence. Conclusion: One in three aspirations result in a dry tap. Lavage aspiration provides analysable fluid in nearly all cases and appears to enable the diagnosis of PJI in roughly one out of five patients in whom standard aspiration fails. However, more robust evidence is needed before it can be recommended as a universal technique.