Journal of Bone and Joint Infection最新文献

Introduction: Fungal periprosthetic joint infection (PJI) has historically been reported in 1 %-2 % of cases, with Candida species accounting for most isolates. However, the true incidence is likely underestimated. Standard aerobic and anaerobic culture techniques have limited sensitivity for detecting fungi, single positive fungal cultures are often excluded or inconsistently classified, culture-negative infections may mask low-burden fungal pathogens, and polymicrobial cultures may obscure the contribution of fungal organisms. The objective of this study was to quantify the burden of potentially unrecognized fungal involvement and provide a more accurate estimate of the incidence of Candida-associated PJI. Methods: Following a systematic literature search, we performed a quantitative sensitivity analysis using imputation with informative missingness odds ratios (IMORs). Reported Candida cases were adjusted for four predefined sources of under-ascertainment: single positive cultures, negative cultures, polymicrobial cultures, and variability in fungal culture sensitivity. Results: 23 studies met inclusion criteria, reporting a total of 28 253 PJI patients, of whom 590 had Candida involvement (2.1 %; range 0.9 %-10.1 %). After imputation for missing data, the estimated proportion of PJI cases involving Candida ranged from 1.4 %-13.6 %, with a mean of 5.1 %. The odds ratios for known risk factors for chronic refractory PJI exceeded 2.0, suggesting the proportion of Candida in this population likely exceeds 10 %. Conclusion: The involvement of Candida in PJI is likely underreported. The adjusted incidence is approximately 5 % across all PJI cases. Among patients with chronic refractory PJI, especially those that have failed multiple surgeries, the incidence of Candida PJI is approximately 10 %. Level of Evidence: Level III.

Objectives: Periprosthetic joint infections (PJIs) are predominantly caused by gram-positive bacteria. Fluoroquinolones (FQs), combined with rifampicin (RMP), are often used but may be unsuitable due to resistance, side effects, or intolerance. Second-generation tetracyclines (TTCs), such as doxycycline and minocycline, show promise as alternatives. This study compared the efficacy and tolerance of RMP-FQ versus RMP-TTC combinations in PJI treatment. Methods: A retrospective study at Tourcoing Hospital, France, reviewed staphylococcal- and streptococcal-related PJI cases treated with RMP-FQ or RMP-TTC from 2013 to 2021. Patients were followed up for 2 years. A Cox regression analysis was used to compare risk of failure. A propensity score using inverse probability of treatment weighting (IPTW) was performed to balance covariates. Results: Of 105 patients, 70 received RMP-FQ and 35 RMP-TTC. Infections were mainly monomicrobial (80 %). IPTW-adjusted Cox regression revealed no significant difference in treatment failure between the RMP-FQ and RMP-TTC groups (aHR 0.68; 95 % CI $=$ 0.32-1.4). Subgroup analyses suggested no difference for infections caused by S. aureus (HR 1.1; CI 95 % $=$ 0.3-4.0) or coagulase-negative staphylococci (CoNS) (HR 0.54; 95 % CI $=$ 0.1-2.1). Adverse events were similar in both groups (20 % vs. 19 %, $p>0.9$ ). Conclusions: RMP-TTC therapy could be considered a potential therapeutic option for PJIs when FQs cannot be used.

Synovial fluid specific gravity (SG) was evaluated as a rapid, inexpensive test for periprosthetic joint infection (PJI) diagnosis in revision arthroplasties. High diagnostic accuracy (area under the curve 0.89; threshold 1.007) with high specificity (100 %) and moderate sensitivity (65 %) was found, supporting its use as an adjunctive point-of-care (POC) tool for PJI.

Introduction: Among bloodstream infections, Staphylococcus aureus bacteremia (SAB) is associated with a particularly high mortality rate, which may be higher in patients with undiagnosed metastatic infections. The primary objective of the present study was to identify risk factors for osteo-articular infection (OAI) in patients with active SAB. Methods: A retrospective study was conducted in a single-center tertiary-care hospital in Brussels, Belgium. Data were collected on patients diagnosed with SAB between 2017 and 2022. Results: Among the 489 consecutive patients with SAB included in this study, 141 (28.8 %) had a concomitant osteo-articular infection (OAI), accounting for nearly one in three patients. These infections included osteomyelitis (12.7 %), native joint septic arthritis (NJSA) (8.8 %), spondylodiscitis (8.4 %), and prosthetic joint infection (PJI) (3.9 %). Univariate and multivariate analyses were performed to identify risk factors associated with OAI. The duration of bacteremia (OR (odds ratio): 1.27, 95 %, CI (confidence interval): 1.14-1.42, $p<0.001$ ) and community-acquired bacteremia (OR: 3.23, 95 % CI: 1.85-5.88, $p<0.001$ ) were associated with the occurrence of OAI. The presence of active cancer (OR: 0.14, 95 % CI: 0.06-0.31, $p<0.001$ ) and intensive care unit (ICU) admissions for SAB (OR: 0.31, 95 % CI: 0.17-0.56, $p<0.001$ ) were associated with a lower likelihood of OAI. Conclusion: In this cohort, OAI was very frequent during SAB and occurred in 28.8 %, particularly in patients with community-acquired SAB (CA-SAB) or those with a longer duration of bacteremia. These findings highlight the importance of a comprehensive diagnostic evaluation for both primary and secondary infection foci, such as OAI, in the setting of SAB.

Generalizability is critical when evaluating the performance of a diagnostic test to ensure variations in the patient population are represented. We report a case of a patient receiving multiple false positive results from the synovial $\alpha$ -defensin test observed over close to a 3-year period following revision total knee arthroplasty.

Introduction: Topical vancomycin powder is increasingly used in orthopedic surgery to prevent surgical site infections (SSIs). While its efficacy is well established, data on systemic safety - particularly renal effects - are limited. Given vancomycin's known nephrotoxicity when administered systemically, we evaluated whether local intraoperative application affects short-term renal function. Methods: This retrospective single-center cohort included 50 adults who underwent orthopedic surgery with the application of intraoperative topical vancomycin powder (January-July 2024). Serum creatinine (SCr) and estimated glomerular filtration rate (eGFR) were measured preoperatively and at two routine postoperative time points. The primary endpoint was acute kidney injury (AKI) per KDIGO serum creatinine criteria; secondary endpoints were within-patient changes in SCr and eGFR. Prespecified subgroups were nephrotoxic concomitant medication (yes/no), application site (epifascial/subfascial), vancomycin dose ( $<$ 1000 vs. $\ge$ 1000 mg), and indication (aseptic/septic). Analyses used Wilcoxon signed-rank and Fisher's exact tests. Results: The most common applied dose was 1000 mg (48 %; median 1000 mg; range 500-4000). Postoperative labs were obtained at median day 1 and day 3. AKI occurred in $2/50$ patients (4 %), both stage 1; no stage 2-3 events were observed. Both AKI cases had concomitant exposure to potentially nephrotoxic medication; however, AKI incidence did not statistically differ across prespecified subgroups (nephrotoxic co-medication, application plane, dose category, indication; all $p>0.05$ ). Paired analyses showed minimal within-patient change in renal indices: eGFR exhibited no central shift from baseline at either time point, and serum creatinine showed no systematic postoperative increase. Conclusions: Local intraoperative vancomycin powder application was not associated with short-term renal impairment. These findings support its renal safety in orthopedic surgery. Prospective trials with pharmacokinetic monitoring are warranted to confirm long-term safety. Level of evidence: IV (retrospective case series).

Introduction: Fasciocutaneous and muscle flaps are used for the reconstruction of lower-limb composite bone and soft-tissue defects. Flap-mediated contributions to the healing microenvironment are less described. We present a comparative porcine model with a standardized bone and soft-tissue defect reconstructed by fasciocutaneous or muscle flaps and characterize the early tissue response following flap transfer. Methods: Using both hindlimbs of 10 female pigs, symmetrical tibial bone and soft-tissue defects were created and reconstructed with fasciocutaneous flaps ( $n=$ 8) or muscle flaps ( $n=$ 8) or were closed primarily ( $n=$ 4, controls). Interstitial metabolites (glucose, lactate, and pyruvate) were sampled by microdialysis from flap and control tissue for 11 h before, during, and after 60 min of global flap ischemia (simulating free flap transfer). Flap histopathology was graded for the acute inflammatory response. Results: All pigs and flaps completed the study. Both flaps exhibited ischemia-reperfusion-induced metabolic alterations relative to the control tissue. The lactate-to-pyruvate ratio increased 3-fold in muscle flaps during ischemia, while fasciocutaneous flaps showed lactate and a lactate-to-pyruvate ratio that were 1.5-fold higher during reperfusion. Histopathology demonstrated early cellular activity at the bone lesion-flap interface in both flap types, with greater oedema and hyperaemia in fasciocutaneous flaps. Conclusion: We established a reproducible comparative large-animal model integrating interstitial metabolite and histopathological analyses to describe early flap-mediated tissue responses. Early flap-specific differences in metabolic and structural patterns may influence flap function and the healing microenvironment. The model provides a basis for evaluating clinically relevant ortho-plastic outcomes.

Periprosthetic joint infections (PJIs), particularly those caused by multidrug-resistant organisms (MDROs), remain a major therapeutic challenge. Antimicrobial blue light (ABL) offers a promising non-antibiotic approach, inducing bacterial killing through photoexcitation of endogenous chromophores and subsequent reactive oxygen species generation. However, conventional single-point illumination systems are limited by uneven light distribution and poor penetration, restricting their use to superficial infections. We evaluated a novel isotropic optical fiber designed to overcome these geometric and optical constraints. The fiber was tested against vancomycin-resistant Enterococcus faecium (VR-Ef) and carbapenemase-producing Klebsiella pneumoniae (CP-Kp) in time-to-kill assays under low-power (20.1 mW mm^-1) and high-power (40.3 mW mm^-1) conditions over 60 min. Bacterial counts (CFU per mL) were determined at 0, 10, 20, 30, and 60 min. A one-way analysis of variance (ANOVA) with Tukey's post hoc test assessed time-dependent reductions; a two-way ANOVA evaluated the combined effects of illumination power and exposure time. ABL exposure resulted in time- and intensity-dependent bacterial reduction in both strains. Significant CFU reductions occurred from 30 min onward under high-power ABL (HP-ABL) and after 60 min under low-power ABL (LP-ABL) for both VR-Ef and CP-Kp ( $p<0.001$ ). The two-way ANOVA revealed significant main and interaction effects of illumination power and exposure time (all $p<0.001$ ). Although bactericidal thresholds ( $\ge 3{\log }_{10}$  reduction) were not reached, bacterial killing increased markedly with higher power and longer exposure. This novel isotropic optical fiber enables uniform intraluminal ABL delivery, potentially extending blue-light therapy from superficial to deep surgical infections such as PJIs. Further optimization of illumination parameters and potential integration with photosensitizers may enhance its antimicrobial efficacy and clinical applicability.

Introduction: Pubic bone osteomyelitis (PBO) is a rare complication with sometimes delayed development in patients who have received radiotherapy or surgery of the pelvic region for cancer treatment. Treatment options range from antibiotics alone to pubic bone debridement and source control via diversion of gastrointestinal (GI) or genitourinary (GU) tract fistulae. In this single-center case series of patients with cancer, we sought to characterize outcomes of PBO. Methods: We conducted a retrospective analysis of 26 patients, admitted for PBO to Memorial Sloan Kettering Cancer Center between 2017 and 2024. Demographic, clinical presentation, microbiology, treatment, and outcome data were evaluated. Patients were followed until date of death or date of last follow-up. Results: Of the 26 patients, 23 were male (88 %) and 3 were female (12 %), with a median age at diagnosis of 70.5 years. The median follow-up period was 680 d. 18/26 (69 %) had fistulas to the pubic bone. 15 patients (58 %) received antibiotics alone. 11 patients (42 %) underwent pubic bone debridement; 8 underwent additional GI or GU diversion procedures for source control. In the group who received surgery, 9/11 (81 %) were ambulating without assistive devices at end of follow-up. In those receiving antibiotics alone, 9/15 (60 %) died a median of 466 d from diagnosis of PBO. Conclusion: In our case series, a combination of surgical debridement plus targeted antibiotic therapy offered the best outcomes. However, some patients achieved improvement in symptoms with antibiotic management alone when more aggressive surgical interventions were not feasible.

Background: Implant-associated infections remain a major challenge in orthopaedic surgery. This study aimed to evaluate the anti-adherent and anti-biofilm properties of a novel anodized 316L stainless-steel (A 316L SS) surface against common pathogens in osteosynthesis-associated infections (OAIs). Methods: Bacterial adherence and biofilm formation of Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, Cutibacterium acnes, Escherichia coli, and Pseudomonas aeruginosa were assessed on A 316L SS and non-anodized 316L stainless steel (Ref 316L SS). Adherence was evaluated after 90 min using fluorescence microscopy. Biofilm development was examined after 24-48 h in synthetic synovial fluid (SSF) using colony counts and scanning electron microscopy (SEM). Results: A 316L SS significantly reduced bacterial adherence and surface coverage for all species tested compared to Ref 316L SS. In biofilm assays, A 316L SS exhibited notable anti-biofilm properties, with significantly reduced biofilm formation for all species. E. faecalis and C. acnes also showed lower planktonic bacterial counts. Imaging confirmed decreased bacterial presence and extracellular matrix on A 316L SS. Conclusions: A 316L SS shows strong anti-adherent and anti-biofilm properties against common orthopaedic pathogens, even under in vivo-like conditions. This surface modification strategy holds significant potential for reducing implant-associated infections and warrants further investigation for clinical applications.