Usefulness of Sonication in Implant-Related Infection

Abstract

Purpose: This study determined whether the sonication of explants could improve the detection of bac-teria and influence the optimal antibiotics treatment. Materials and Methods: This retrospective study included the patients who underwent implant removal surgery followed by sonication culture as well as tissue culture in order to diagnose implant-related infection. A total of 37 consecutive patients with 41 cases were included. The patients ’ demographic data, use of preoperative antibiotics, type of implants, change of antibiotics following the culture results, and recurrence of infection were all reviewed. Results: Among 41 cases, 20 cases met the diagnostic requirements for implant-related infection as defined by musculoskeletal infection society criteria, while the other 21 cases had explant sonication to exclude indolent infection or residual infection. The latter showed negative results on the both explant cultures and tissue cultures. Among the 20 cases that met the requirements for implant-related infection, 19 cases (95.0%) were identified by any cultures. Of the 19 cases with positive culture results, 2 cases (10.5%) showed positive results only on sonication cultures, and one case (5.3%) showed positive results only on tissue culture. In 1 case of culture negative implant-related infection, a drain sinus was present preoperatively, but the cultures were negative according to both methods. The culture results made postoperative antibiotics change in 12 cases among the 19 culture (+) cases. Antibiotics changes were based on the tissue culture in 2 cases, 2 cases were based on the sonication culture, and the remaining 8 cases were based on both cultures. Conclusion: The sonication culture improved the diagnosis of implant-related infection combined with conventional tissue culture and helped to determine administering the proper antibiotics.