Use of a Bioresorbable Antibacterial Coating (DAC® Hydrogel) in One-Stage Revision of Infected Knee Arthroplasty: Long-Term Study

Background/Objectives: One-stage revision has become an increasingly accepted strategy for the treatment of chronic periprosthetic joint infection (PJI) of the knee in carefully selected patients. The use of a resorbable defensive antibacterial coating (DAC® hydrogel) represents an attractive adjunct to reduce bacterial adhesion and biofilm formation on revision implants. However, evidence regarding its long-term performance is limited. Methods: We retrospectively reviewed 52 consecutive patients undergoing one-stage revision for knee PJI or an infected spacer between 2014 and 2023 using a standardized surgical and antimicrobial protocol including local application of DAC hydrogel loaded with vancomycin alone or vancomycin plus meropenem. Clinical, microbiological, and radiographic outcomes were evaluated. Infection-free survival was assessed using Kaplan–Meier analysis. Results: Forty-eight patients underwent revision for PJI and four for septic spacers. Four patients were unavailable for final evaluation. At follow-up of 7.7 ± 2.9 years (range 2.5–12.2 years), 47 of 48 clinically evaluable patients remained infection-free, corresponding to a crude infection-free proportion of 97.9%. Kaplan–Meier infection-free survivorship at 12 years was 98.1% (95% CI, 87.1–99.7%). Mean Knee Society Score improved from 47.7 to 84.4 points, while functional KSS improved from 41.9 to 82.9 points. Pain at rest decreased from 6.9 to 0.7 and pain during movement from 8.1 to 1.6 on the visual analogue scale. Conclusions: This series represents, to our knowledge, the longest reported follow-up of one-stage knee revision using the DAC hydrogel coating. The favorable outcomes observed with this hybrid fixation strategy support further investigation of this approach in larger, long-term, comparative multicenter studies.