SONOSTANDARD: SONICATION FOR IMPLANT-ASSOCIATED INFECTIONS. A SWISS CONSENSUS PROTOCOL

Background Sonication of explanted implants has improved microbiological detection in implant-associated infections. However, large inter-laboratory variability in sonication protocols limits comparability and clinical interpretability. Thus, a national consensus-driven initiative was launched to standardize the diagnostic sonication process, using current Swiss practice and the published evidence as a foundation. Methods A Delphi-informed process was conducted, including a national protocol survey and a scoping literature review of published sonication workflows, key parameters, and reporting practices. An online consensus meeting followed, with structured item-by-item discussion and anonymous voting (completeness >80% per item; abstentions excluded from percentage calculations). Results Twenty-one laboratories participated in the national survey; four without sonication, and one duplicate response was identified. T Consensus was reached in 8 of 9 domains: sonication frequency (40 kHz, 100%), intensity (0.22 W/cm 2 , 100%), temperature (room temperature, 100%), duration (1 min, 90.5%), fluid (Ringer's solution, 95.5%), pre- and post-sonication vortexing (30 s each, 94.4%), processing within 6 h (87.5%), culture media panel (aerobic blood agar 93.8%, chocolate agar +5% CO 2 100%, thioglycolate broth 100%, anaerobic Schaedler agar +5% sheep blood 87.5%), incubation (14 days, 84.6%), and quantitative reporting (CFU/mL, 100%). In contrast, volume standardization proposal was predominantly rejected (weight-based volume: 33.3% agreement,; minimum-volume rule: 37.5% agreement), reflecting ongoing feasibility and implementation concerns also noted in the literature. Conclusion A national consensus protocol was developed to harmonize sonication-based implant microbiology processing across key technical, handling, culture, incubation, and reporting domains informed by a scoping synthesis of published workflows and an assessment of current Swiss practice, while volume standardization remained open due to operational constraints. This framework now represents a reproducible baseline to facilitate inter-laboratory comparability and places future work in the position of implementation evaluation and evidence-based interpretive thresholds.