A 40-year-old man, after a left acetabular fracture, had eight surgeries, suffered from chronic multidrug-resistant infection with fistula, and underwent multi-stage hip revision surgery with spacer exchange and reconstruction, combined with systemic and intra-articular antibiotic therapy. He remained infection-free at 3.5-year follow-up.
Introduction: Fracture-related infections (FRIs) represent a severe complication and pose diagnostic challenges due to biofilm-associated microorganisms. While peri-implant tissue culture (PTC) remains the standard, its sensitivity is limited. Sonication of explanted osteosynthesis material has been proposed as a complementary diagnostic tool; however, its contribution remains controversial. The aim of this study was to compare sonication and peri-implant tissue culture and their impact on antimicrobial management. Methods: In this retrospective single-center study, all patients undergoing implant removal for FRI between 2016 and 2023 were screened. Cases with peri-implant tissue cultures and sonication fluid cultures (SFCs) were included. The diagnostic yield and pathogen spectrum of PTC and SFC were compared, including analyses in patients receiving antibiotic therapy. The impact of microbiological findings on antibiotic management was evaluated. Results: Of 287 screened cases, 157 patients met the inclusion criteria. Pathogen detection was achieved in 60.5 % using PTC and 57.3 % using SFC. Incorporating both methods increased the diagnostic yield to 70.1 %. Sonication identified additional pathogens in 17.8 % of cases and PTC in 22.9 %. Under antibiotic therapy, PTC demonstrated a slightly higher diagnostic yield than SFC. Antibiotic therapy was modified after revision surgery in 47.8 % of cases, while sonication alone influenced treatment decisions in 4.5 % of patients. Conclusions: Neither PTC nor SFC alone achieved the diagnostic performance of their combined use. Combined testing improved diagnostic yield, supported targeted antimicrobial management, and reinforced the value of a multimodal microbiological approach to FRI.
Background: Implant-associated bone infections (IAIs) represent a major clinical challenge, causing implant failure, prolonged morbidity, and costly revision surgeries. Infection risk is highest in the immediate perioperative period, but delayed post-implantation contamination, occurring weeks after surgery in a partially healed host, represents an equally important and underappreciated clinical scenario. Bacteria rapidly colonize implant surfaces and form biofilms that resist both antibiotics and host immune responses, making prevention critical. Well-characterized small-animal models that capture both early and delayed post-implantation infections are therefore essential to develop and test antibacterial implants and coatings. Methods: We developed a rat femoral-segmental-defect model stabilized with a polyether-ether-ketone plate and a 3D-printed porous titanium implant. Three studies were performed using a total of 28 animals (3 excluded due to early humane endpoints; n=25 in final analysis): (i) early inoculation during surgery with planktonic Staphylococcus aureus (ATCC 49230) at 104 or 106 CFU (colony-forming units) per rat, (ii) delayed inoculation 28 d after surgery with planktonic S. aureus at 104 or 106 CFU per rat, and (iii) delayed inoculation with 108 CFU per rat delivered as planktonic or ruptured-biofilm inoculum. Controls received phosphate-buffered saline at implantation. The primary endpoint was infection at day 14, quantified by CFU enumeration from homogenized bone and from a sonicated implant, plate, and screws. Micro-computed tomography (micro-CT) was used to visualize fixation and hardware position. Results: Early inoculation with 104 or 106 CFU per rat produced consistent infections across bone, implants, and screws. The same doses given 28 d later yielded low and inconsistent colonization. Escalation to 108 CFU per rat in the delayed setting produced consistent infections; the ruptured-biofilm inoculum generated higher implant-associated bacterial burdens than planktonic suspensions, while bone burdens were consistently high in both arms. Conclusions: This femoral-implant rat model demonstrates feasibility for studying both immediate perioperative and delayed post-implantation infections, providing a platform for preclinical evaluation of anti-infection strategies. Timing, inoculum magnitude, and bacterial state critically determine infection establishment.
Three periprosthetic femoral fractures around chronically infected total hip arthroplasties (THAs) were treated according to a pragmatic two-stage treatment framework. Infection control and fracture healing were achieved. This may serve as a reference for surgeons confronted with these complex and technically demanding situations.
Introduction: Periprosthetic joint infection (PJI) is a major cause of failure after total hip arthroplasty (THA) and total knee arthroplasty (TKA). While primary PJI treatment costs are increasingly recognized, the economic burden of septic re-revision surgery remains poorly defined. This study estimated septic re-revisions and the reimbursement burden across Europe. Methods: A payor-perspective health-economic model was applied to 30 European countries, combining 2023 Eurostat arthroplasty data with published infection rates to estimate PJIs and septic re-revisions (including after aseptic revisions), categorized as DAIR (debridement, antibiotics, and implant retention), one-stage, or two-stage procedures. Reimbursement used 13-country survey data plus GDP-based extrapolation; sensitivity analyses varied key parameters by ±20 %. Results: In 2023, 2.29 million primary arthroplasties were performed in Europe, resulting in an estimated 22 794 PJIs and 8629 septic re-revisions. Total reimbursement costs were estimated at EUR 123.6 million (EUR 74.1 million THA; EUR 49.5 million TKA), split into EUR 111.6 million after primary PJI treatment and EUR 12.0 million after initially aseptic revision. Two-stage exchanges accounted for 82.8 % of expenditures and were the main cost driver; Germany had the highest national costs. A Monte Carlo probabilistic sensitivity analysis yielded a 95 % credibility interval of EUR 102.0–156.2 million. Conclusion: Septic re-revision surgery after arthroplasty represents a substantial economic burden in Europe, largely driven by two-stage exchange procedures. Reducing infection and treatment failure rates may provide major clinical and financial benefits: a 25 % reduction in PJI incidence could save EUR 27.9 million annually (22.6 %), and shifting half of two-stage cases to one-stage a further EUR 22.6 million (18.3 %).
