Journal of Bone and Joint Infection最新文献

Arthrofibrosis is a well-known complication of arthroplasty. However, the underlying causes that may lead to this pathology are unclear. A possible relationship between undiagnosed low-grade infections and the development of arthrofibrosis has been proposed (Ibrahim et al., 2020). This study aims to investigate whether colonization of the joint by low-virulence pathogens may cause arthrofibrosis.

Introduction: Periprosthetic joint infections (PJIs) have a severe physical impact and impose a significant psychological burden. This study aimed to compare patient-reported outcome measures (PROMs) and qualitative interview data within the same study cohort. Methods: A total of 28 PJI patients were identified after completing treatment for hip or knee PJIs. Qualitative interviews were conducted, and PROMs - such as the hip disability and osteoarthritis outcome score (HOOS), knee injury and osteoarthritis outcome score (KOOS), hospital anxiety and depression scale - total (HADS-T) score, and brief pain inventory (BPI) score - were assessed. The data were then evaluated for correlations between the PROMs and the qualitative interview findings. Results: A total of 20 out of 28 (71.4 %) patients scored above the accepted threshold of  $\ge 10$ on the HADS-T. A total of 8 out of 28 (28.6 %) patients scored low on the HADS-T. Through semi-structured interviews, we further evaluated the two groups: a high-HADS-T-scoring group and a low-HADS-T-scoring group. PJI patients scoring high on the HADS-T experienced a heavier psychological burden than those scoring low on the HADS-T. Our qualitative data show that the high-HADS-T-scoring group perceived their PJI experience as troubling and psychologically distressing; moreover patients in the high-HADS-T-scoring group did not deal with the PJI as well as those in the low-HADS-T-scoring group. Conclusions: This study provides valuable information regarding the screening of PJI patients who are at risk of psychological disorders using the HADS-T. Following screening, it also provides insight into which patients should be closely monitored and which patients should be offered professional psychological support, as the latter resource is limited and needs to be distributed sensibly. PJI patients scoring above  $\ge 10$ on the HADS-T are high-risk patients and should be offered professional psychological support.

Introduction: Empirical antibiotics should only target the most likely pathogens if antibiotic stewardship is being heeded. However, there is a drive for broader-spectrum empirical antibiotics in orthopedic infections due to the concern of therapeutic failure if a regimen fails to target subsequently identified pathogens. Methods: Retrospective case-control study with surgically managed orthopedic infections from July 2018 to June 2024 with a minimum follow-up of 6 months. Patients were stratified by the initial empirical treatment of either accurate empirical choice or inaccurate empirical choice. Results: Of 482 infection episodes, 79 antibiotic regimens (43 broad-spectrum; 9 %) were used with a median postoperative duration of 42 d (interquartile range 19-45 d); 290 infection episodes (60 %) were correctly targeted. In 192 cases (40 %), the initial empirical choice was inaccurate, with a median switching time to a targeted treatment of 4 d. There was no difference between accurate and inaccurate empirical treatment in terms of ultimate failures (18/290 vs. 15/192; Pearson ${\chi }^2$ test, $p=0.49$ ), overall adverse events of therapy (15 % vs. 7 %, $p=0.11$ ), duration of hospital stay (median 9 d vs. 9 d, $p=0.96$ ), or supplementary surgical debridement (median 0 vs. 0 intervention, $p=0.58$ ). In multivariate logistic regression analysis, the duration of an inaccurate antibiotic treatment failed to alter the risk of "failures" (odds ratio 0.9, 95 % confidence interval 0.8-1.1). Conclusions: A delay in commencing targeted antibiotics does not increase the risk of a negative outcome. Narrower-spectrum empirical regimens are appropriate for clinically mild to moderate infections as a broader spectrum does not provide any clinical advantage.

Introduction: While Gram-negative periprosthetic joint infections (PJIs) are generally known for their poor outcome, few data on Proteus species exist. Therefore, we investigated the prevalence, clinical characteristics, microbial spectrum, outcomes, antimicrobial treatment, and surgical procedures of Proteus-species-associated PJIs. Methods: We retrospectively evaluated 1776 culture-positive revision hip and knee arthroplasties (hereafter rTHA and rTKA, respectively) from a single institution between 2008 and 2024. The European Bone and Joint Infection Society and International Consensus Meeting criteria were used for classification. The Charlson comorbidity score and tier classification were used for evaluating risk factors and success and failure rates. Statistical analysis was performed using the chi-square test and binary logistic regression. Results: Among 1776 culture-positive revision arthroplasties, we identified 26 (1.5 %) Proteus-species-associated PJIs. The majority were observed in rTHA, mostly in chronic (65.4 %) and polymicrobial (57.7 %) infections. Chronic PJIs were associated with polymicrobial infections ( $p=0.027$ ), resulting in a higher failure rate ( $p=0.041$ ). Among polymicrobial infections (15 of 26 cases), Enterococcus faecalis (5 of 15), Staphylococcus epidermidis (4 of 15), and Pseudomonas aeruginosa (3 of 15) were most frequently observed. The most frequently used surgical approach was a two-stage revision (46.2 %), with a success rate of 25 % (3 of 12). Proteus-species-associated PJIs were mainly treated with fluoroquinolone, especially ciprofloxacin showed higher success rates ( $p=0.018$ ). The reinfection-free survival rate was 48.5 % after 12 months and 22.6 % after 40 months. Conclusion: Proteus species represent a rare group of pathogens and are predominantly found in chronic and polymicrobial PJIs, with a higher occurrence in rTHA than rTKA. Despite an overall high clinical failure rate, ciprofloxacin showed promising antimicrobial treatment efficacy.

Introduction: Two-stage revision with an antibiotic spacer is the gold-standard treatment of prosthetic joint infection (PJI) for total knee arthroplasty (TKA). Multiple spacer designs exist, including static, articulated, and prosthetic low-friction (PALF) spacers. However, current literature is limited on variant superiority for infection eradication. This study aimed to compare outcomes of two-stage exchange for TKA PJI between patients with static cement, articulated cement, and PALF spacers. Methods: This retrospective study included 93 patients who underwent two-stage revision for PJI following primary TKA and received a static ( $n=17$ ), articulating ( $n=54$ ), or low-friction ( $n=22$ ) spacer. The primary outcome was failure at 2 years, defined as spacer retention, reoperation, or death. Secondary outcomes included reimplantation and discontinued antibiotics by 1 year, time to failure, duration of hospital stay, functional measures, and adverse events. Outcomes were compared between groups using hypothesis testing for continuous or categorical measures. Results: At 2 years, no significant difference in failure was seen for static (58.82 %), articulating (35.19 %), and PALF (22.73 %) spacers ( $p=0.064$ ). Articulating spacers demonstrated greater range of motion than static spacers at the final follow-up ( $p=0.0$ 3). Static spacers were associated with a higher adverse-event frequency ( $p=0.03$ ). No other significant differences in outcomes were observed (all $p>0.05$ ). Conclusions: The three spacer variants demonstrated similar failure rates for two-stage revision of TKA PJI at 2 years. Static spacers may lead to adverse events more frequently compared to other designs, and a longer interstage duration for prosthetic spacers may reflect greater functionality.

Introduction: Long-term dalbavancin use is increasingly adopted off-label for osteoarticular infections (OAIs), but data on administration timing and long-term effects beyond 12 weeks are scarce. This study evaluated the pharmacological efficacy of proactive therapeutic drug monitoring (TDM) to optimize dalbavancin administration. Methods: This single-center, retrospective study included adult OAI patients treated with $\ge 4$ doses of dalbavancin from July 2022 to October 2024. Initial doses were given on days 1, 8, and 43. From the third dose onward, $C_{min}$ and $C_{max}$ values informed dosing schedules via log-linear regression models, targeting $C_{min}\ge 8$ mg L^-1. The primary outcome was the pharmacological efficacy of dalbavancin, assessed by the proportion of patients with $C_{min}\ge 8$ mg L^-1 and $\ge 4$ mg L^-1 after the third dose. Clinical outcomes and safety data were collected as descriptive data. Results: A total of 33 patients provided 118 $C_{min}$ determinations. Pharmacological efficacy was achieved in 93 $/$ 118 (78.8 %) and 114 $/$ 118 (96.6 %) determinations for $C_{min}$ thresholds of $\ge 8$ mg L^-1 and $\ge 4$ mg L^-1, respectively. Efficacy improved when considering only determinations at the correct timing. A total of 18 (54.5 %) patients are still in treatment, while 11 (33.3 %) completed therapy with clinical success. Three patients experienced a relapse after the end of the treatment, while one patient experienced failure, and no adverse events were reported. Conclusions: Dalbavancin is a viable option for prolonged OAI management when other therapies are unavailable or high-risk. Proactive TDM effectively supports this approach by ensuring adequate drug exposure while preventing accumulation.

Introduction: Treatment of chronic periprosthetic joint infections (PJIs) involves prosthesis removal, reimplantation, and antibiotic treatment. This process can be performed as a two-stage replacement or a one-stage replacement. One-stage replacement is classically performed only in patients who meet very strict criteria. The objective of this study was to analyse the healing and failure rates of one-stage knee replacement in patients with positive preoperative cultures and in those with negative preoperative cultures. Secondarily, we analysed the healing rate in patients with a sinus tract. Material and methods: We included 56 patients diagnosed with likely or confirmed PJI who underwent one-stage knee replacement in our centre between January 2016 and December 2021, with a minimum follow-up of 1 year. We evaluated the differences between cases with positive and negative preoperative cultures. Survival differences were assessed according to preoperative culture positivity and the presence of a sinus tract. Results: Preoperative cultures had positive results in 43 patients (76.8 %) and negative results in 13 patients (23.2 %). The overall failure rate was 12.5 % (seven patients), with one of these patients having had negative preoperative cultures. Of the 49 patients (87.5 %) with good results, 12 had negative preoperative cultures, and 37 had positive cultures ( $p=1.00$ ). Only 6 (10.7 %) of the 56 patients studied presented with a sinus tract. The differences in terms of healing and failure rates between patients with and without a sinus tract were not statistically significant ( $p=0.57$ ). Discussion: Using less strict criteria for patients, such as allowing preoperative negative cultures or the presence of a sinus tract, produced similar results to those for patients with only positive cultures or intact soft tissue.

Introduction: In periprosthetic joint infection (PJI) following total knee arthroplasty (TKA), debridement, antibiotics, and implant retention (DAIR) is a common procedure with a high rate of failure. Timing of infection can be used to stratify acute PJI into acute postoperative, intermediate, and hematogenous infections. Potential differences in prognosis between classifications remain unclear. This investigation assessed the current overall failure of DAIR procedures, compared DAIR failure between three types of acute PJI, and analyzed DAIR outcomes in an "optimal" cohort of patients with a minimal number of medical comorbidities. Methods: This retrospective study compared 122 patients with acute TKA PJI who underwent DAIR between 2016 and 2022. Categorization was based on timing between index TKA and PJI diagnosis, with $<$ 6 weeks termed postoperative ( $n=$ 43), 6 weeks to 1 year termed intermediate ( $n=$ 19), and $>$ 1 year termed hematogenous ( $n=$ 60). The primary outcome was DAIR failure, defined as reoperation for PJI. Subgroup analysis was performed after removing patients with high-risk comorbidities. Results: The overall failure rate was 42 %; 78.4 % of failures occurred within 1 year. No significant differences in the failure rate were found between PJI types at any time point. At 1 year, 58 % postoperative, 58 % intermediate, and 77 % hematogenous cases remained failure-free ( $p=$ 0.09). Failure rates of 45 % postoperative, 44 % intermediate, and 36 % hematogenous cases were seen in the optimal cohort, without significant differences. Conclusions: DAIR failure for acute TKA PJI is high. Although no differences in failure rates were observed based on the PJI type, DAIR failure trended lower for the hematogenous group in this study. Outcomes for DAIR appear similar regardless of the PJI type in optimal patients.

Background: Patients with rheumatoid arthritis (RA) with late acute periprosthetic joint infections (PJIs) treated with surgical debridement, antibiotics, and implant retention (DAIR) have a high failure rate. We conducted a case-control study to identify risk factors for DAIR failure in this specific patient population. Methods: Data from an international multicenter retrospective observational study were used. Late acute PJI was defined as a sudden and acute onset of PJI symptoms occurring more than 3 months after implantation in a previously asymptomatic joint. Cases with RA were matched with cases without RA based on the affected joint. A multivariate Cox regression, stratified for RA, was used to identify risk factors and calculate hazard ratios (HRs) for failure. Subgroup analysis was done to explore the role of immunosuppressive therapy. Results: A total of 40 patients with RA and 80 control patients without RA were included. The use or continuation of immunosuppressive drugs was not associated with a higher failure rate. No significant association was found between the duration of symptoms, causative microorganisms, and therapy failure. Bacteremia was an independent predictor for treatment failure (HR of 1.972; 95 % confidence interval, CI, of 1.088-3.573; $p$ $=$ 0.025), and the exchange of modular components was associated with a lower risk of treatment failure (HR of 0.491; 95 % CI of 0.259-0.931; $p=0.029$ ). Conclusion: In patients with RA and a late acute PJI treated with DAIR, bacteremia is an important predictor of treatment failure. Exchanging the modular components seems to be especially important in this patient group and is associated with a lower failure rate.

Background and purpose: Debridement, antibiotics, and implant retention (DAIR) is the proposed initial treatment of early periprosthetic joint infection (PJI), but it may fail to provide infection control. Subsequently, either implant removal or repeated DAIR may be considered. This study aims to identify the failure rate of repeated DAIR for early PJI in primary total knee arthroplasty (TKA) and total hip arthroplasty (THA). Methods: All DAIRs performed following primary THA or TKA for early PJI from 2010 to 2019 were retrospectively analysed. Patient demographics, comorbidities, surgical details, and pre-DAIR C-reactive protein (CRP) levels were recorded. Failure of early infection control (within 1 month after DAIR) prompted a second DAIR. Follow-up was performed up to 2 years post-surgery. A Kaplan-Meier survival analysis was performed in single- and repeated-DAIR groups. Cox regression analyses explored potential risk factors for implant failure after repeated DAIR. Results: A total of 124 cases of early PJI were included. Single DAIR achieved adequate infection control in 69.4 % ( $n=86$ ) of cases, while 30.6 % ( $n=38$ ) of cases underwent repeated DAIR within 3-23 d. After 2 years, implant removal was performed in 8 cases (9.9 %; 95 %CI 3.0 %-16.0 %) in the single-DAIR group and in 8 cases (22.2 %; 95 %CI 7.3 %-34.7 %) in the repeated-DAIR group. No statistically significant associations between the failure of repeated DAIR and its potential risk factors were found. Conclusion: If initial DAIR does not achieve early PJI control, repeated DAIR can still be considered, as it may avoid implant removal in 77.8 % of cases. The authors advocate for tailored decisions considering implant revisability, patient comorbidity, and pathogen susceptibility.