Background/Objectives: A missed periprosthetic joint infection (PJI) diagnosis can lead to implant failure. However, to date, no gold standard for PJI diagnosis exists, although several classification scores have been developed in the past years. The primary objective of the study was the evaluation of inter-rater reliability between five PJI classification systems when defining a patient who is infected. Two secondary outcomes were further examined: the inter-rater reliability assessed by comparing the classifications in pairs, and the evaluation of each classification system within the subcategories defined by the World Association against Infection in Orthopaedics and Trauma (WAIOT) definition. Methods: Retrospectively collected data on patients with knee and hip PJIs were used to assess the agreement among five PJI scoring systems: the Musculoskeletal Infection Society (MSIS) 2013 definition, the Infection Consensus Group (ICG) 2018 definition, the European Bones and Joints Infection Society (EBJIS) 2018 definition, the WAIOT definition, and the EBJIS 2021 definition. Results: In total, 203 patients with PJI were included in the study, and the agreement among the examined scores was 0.90 (Krippendorff’s alpha = 0.81; p-value < 0.001), with the MSIS 2013 and ICG 2018 classification systems showing the highest agreement (Cohen’s Kappa = 0.91; p-value < 0.001). Conclusions: There is a strong agreement between the major PJI classification systems. However, a subset of patients (n = 11, 5.42%) still falls into a diagnostic grey zone, especially in cases of low-grade infections. This highlights the need for enhanced diagnostic criteria that incorporate tools that are available even with limited resources, and the potential of artificial intelligence-based techniques in improving early detection and management of PJIs.

Background: Due to an increase in total hip arthroplasties (THAs), the incidence of periprosthetic hip fractures (PPHFs) is forecast to rise considerably in the next decades, with Vancouver B1 fractures (VB1) accounting for one third of total cases. Femur fixation with cerclages (with or without screws) is considered the current treatment option for intraoperative VB1. Methods: The study retrospectively includes data from patients who developed VB1 PPHFs during THAs from 3 December 2020 to 30 November 2022. The primary outcome of this study was to identify the reintervention-free survival rate. The secondary aim was to determine clinical and radiographic assessment at follow-up, based on Harris hip score (HHS) and limb length discrepancy (LLD). Results: Thirty-seven patients with a mean age of 60.03 ± 15.49 (22 to 77) years old were included. Overall, the Kaplan–Meier analysis estimated a reoperation-free survival rate of 99% (CI 95%) at 6 months. The mean limb length discrepancy (LLD) improved from −3.69 ± 6.07 (range −27.9 to 2.08) mm to 0.10 ± 0.67 (range −1.07 to 1.20) mm. The mean HHS improved from 42.72 ± 14.37 (range 21.00–96.00) to 94.40 ± 10.32 (range 56.00–100.00). Conclusions: The employment of cerclage wires represents an effective strategy for handling intraoperative VB1 fractures. Level III retrospective cohort study.

Background: due to increase in total hip arthroplasties (THAs), the incidence of periprosthetic hip fractures (PPHFs) is forecast to raise considerably in the next decades, with Vancouver B1 fractures (VB1) accounting for one third of total cases. Femur fixation with cerclages (with or without screws) is considered the current treatment option for intraoperative VB1. Methods: the study retrospectively includes data from patients who developed VB1 PPHFs during THAs from December 3rd 2020 to November 30th 2022. The primary outcome of this study was to identify the reintervention-free survival rate. The secondary aim was to determine clinical and radiographic assessment at follow-up, based on Harris hip score (HHS) and limb length discrepancy (LLD). Results: 37 patients with mean age 60.03 ± 15.49 (22 to 77) years old were included. Overall, the Kaplan-Meier estimated a re-operation free survival rate of 99% (CI 95%) at 6 months. The mean limb length discrepancy (LLD) improved from -3.69±6.07 (range -27.9 to 2.08) mm to 0.10±0.67 (range -1.07 to 1.20) mm. The mean HHS improved from 42.72±14.37 (range 21.00-96.00) to 94.40±10.32 (range 56.00-100.00).

Introduction: microbiological eradication after two-stage revision is not obtained in up to 18% of cases, yet the prognostic value of positive cultures at reimplantation remains controversial. The primary aim of the study was to evaluate outcomes of patients with positive cultures at second stage, identifying failure predictors. The secondary outcome was to compare reintervention-free survival. Materials and methods: this retrospective cohort study included patients treated using a two-stage protocol between 2016 and 2022. PJI was diagnosed using MSIS 2013 criteria, and treatment failure was defined according to a Delphi-based consensus. Cox regression analysis was employed to assess risk factors for failure, including Charlson Comorbidity Index (CCI); American Society of Anesthesiologists (ASA) score; age; time to reimplantation; joint; number of previous septic revisions; positive cultures number at reimplantation; a difficult to treat organism. Results: 83 cases were reviewed (63 hips, 20 knees). The average interval between stages was 181 days. Over 6 years follow-up (FU), elevated BMI was the only significant predictor of failure (HR 1.19; 95% CI 1.02–1.39; p = 0.03). In contrast, positive cultures at reimplantation were not associated with an increased failure risk ( p = 0.95), even in cases with multiple positive cultures ( p = 0.72). Conclusions: elevated BMI at reimplantation was independently associated with subsequent failure. Clinical outcomes were not significantly associated with the presence or number of positive cultures, although smaller effects cannot be excluded given the limited sample size. These findings emphasize the importance of a patient-focused rather than culture-centered approach. Level of evidence: III.

Background: Debridement, antibiotics, and implant retention (DAIR) is the treatment of choice for early and acute hematogenous periprosthetic joint infections (PJIs), but its success rates vary widely. The primary outcome of this study was to assess 1-year implant survival and treatment failure among DAIR patients. The secondary aims were to identify the causative pathogens and potential predictors of failure. Methods: Patients treated with DAIR for PJI in a single center between 2017 and 2025 were included. Implant survival was evaluated using Kaplan–Meier analysis, and univariate analysis was performed to explore potential associations between baseline variables and treatment failure. Results: 57 patients (58 hips/knees) were included. The mean age at surgery was 67.5 ± 11.5 years, and most procedures involved the hip (93.1%, n = 54). During follow-up, 7 patients (12.06%) experienced treatment failure. Kaplan–Meier analysis demonstrated a 1-year implant survival of 87.9%, with most failures occurring in the early postoperative months. The microbiological profile was dominated by Staphylococci (51.7%, n = 14) and polymicrobial (24.1%, n = 14) species, while Gram-negative bacteria and Enterococci were less frequently identified. Culture-negative infections were observed in 17.2% of cases (n = 10). Univariate analysis identified preoperative glucose levels and BMI as significantly different between groups, although these findings should be interpreted with caution. Conclusions: DAIR achieved favorable short-term outcomes in this cohort. Failures occurred mainly early after treatment, and the microbiological spectrum was consistent with the typical epidemiology of PJI. BMI and perioperative glucose levels may represent potentially modifiable factors associated with treatment failure.

Introduction Periprosthetic joint infections (PJIs) complicate 1–2% of primary and up to 4% of revision arthroplasties, and their diagnosis remains challenging due to the lack of a diagnostic gold standard. Differentiating PJI from aseptic failure is particularly difficult in low-grade or biofilm-related infections. Routine intraoperative microbiological screening is not recommended in presumed aseptic revisions. This study aimed to evaluate the association between routine intraoperative microbiological screening and implant survival in presumed aseptic revision arthroplasty. A secondary objective was to identify preoperative predictors of unexpected PJIs. Methods Retrospectively collected data of patients undergoing presumed aseptic THA and TKA revisions between 2013 and 2019 were included. Two matched cohorts were compared: a screened group (2016–2019) undergoing routine intraoperative microbiological sampling, and an unscreened one (2013–2015) without systematic screening. Kaplan-Meier survival analysis with log-rank testing assessed overall and infection-free survival. Univariate conditional logistic regression and receiver operating characteristic (ROC) analyses evaluated potential associations between preoperative serum markers and unexpected PJI. Results A total of 559 patients were included, of whom 295 underwent screening and 264 did not. Unexpected infections occurred in 20.3% (n = 60) of screened patients. No significant differences in implant survival were observed between groups. Although overall and infection-free survival were numerically higher in the screened cohort, these differences were not statistically significant (p = 0.168 and p = 0.118, respectively). Stratified analyses by joint and failure mechanism showed comparable findings. C-reactive protein and erythrocyte sedimentation rate were associated with unexpected PJI (p = 0.004 and p = 0.046), but ROC analysis suggested limited discrimination of individual markers, whereas a combined serum model improved diagnostic performance (AUC = 0.833). Conclusions Routine intraoperative microbiological screening in presumed aseptic revision arthroplasty was not associated with a significant improvement in implant survival. Future studies should investigate whether selective screening improves outcomes. Level III retrospective cohort study.