Two-stage revision for periprosthetic joint infection after hip and knee arthroplasty.

Aims: Histology is widely used for diagnosis of persistent infection during reimplantation in two-stage revision hip and knee arthroplasty, although data on its utility remain scarce. Therefore, this study aims to assess the predictive value of permanent sections at reimplantation in relation to reinfection risk, and to compare results of permanent and frozen sections. Methods: We retrospectively collected data from 226 patients (90 hips, 136 knees) with periprosthetic joint infection who underwent two-stage revision between August 2011 and September 2021, with a minimum follow-up of one year. Histology was assessed via the SLIM classification. First, we analyzed whether patients with positive permanent sections at reimplantation had higher reinfection rates than patients with negative histology. Further, we compared permanent and frozen section results, and assessed the influence of anatomical regions (knee versus hip), low- versus high-grade infections, as well as first revision versus multiple prior revisions on the histological result at reimplantation. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), chi-squared tests, and Kaplan-Meier estimates were calculated. Results: Overall, the reinfection rate was 18%. A total of 14 out of 82 patients (17%) with positive permanent sections at reimplantation experienced reinfection, compared to 26 of 144 patients (18%) with negative results (p = 0.996). Neither permanent sections nor fresh frozen sections were significantly associated with reinfection, with a sensitivity of 0.35, specificity of 0.63, PPV of 0.17, NPV of 0.81, and accuracy of 58%. Histology was not significantly associated with reinfection or survival time for any of the analyzed sub-groups. Permanent and frozen section results were in agreement for 91% of cases. Conclusion: Permanent and fresh frozen sections at reimplantation in two-stage revision do not serve as a reliable predictor for reinfection.

Evaluation of time to reimplantation as a risk factor in two-stage revision with static spacers for periprosthetic knee joint infection.

INTRODUCTION: We investigated the time to reimplantation (TTR) during two-stage revision using static spacers with regard to treatment success and function in patients with chronic periprosthetic joint infection (PJI) of the knee. METHODS: 163 patients (median age 72 years, 72 women) who underwent two-stage exchange for chronic knee PJI between 2012 and 2020 were retrospectively analyzed (based on the 2011 Musculoskeletal Infection Society criteria). A cutoff TTR for increased risk of reinfection was identified using the maximally selected log-rank statistic. Infection control, aseptic revisions and overall survival were analyzed using Kaplan-Meier survival estimates. Adjustment for confounding factors-the Charlson Comorbidity Index (CCI) and C-reactive protein (CRP)-was done with a Cox proportional hazards model. RESULTS: When TTR exceeded 94 days, the adjusted hazard of reinfection was increased 2.8-fold (95% CI 1.4-5.7; p = 0.0036). The reinfection-free rate was 67% (95% CI 52-79%) after 2 years and 33% (95% CI 11-57%) after 5 years for a longer TTR compared to 89% (95% CI 81-94%) and 80% (95% CI 69-87%) at 2 and 5 years, respectively, for a shorter TTR. Adjusted overall survival and number of aseptic revisions did not differ between the longer TTR and shorter TTR groups. Maximum knee flexion was 90° (IQR 84-100) for a longer TTR and 95° (IQR 90-100) for a shorter TTR (p = 0.0431), with no difference between the groups in Oxford Knee Score. Baseline characteristics were similar (body mass index, age, previous surgeries, microorganisms) for the two groups, except that there was a higher CCI (median 4 vs. 3) and higher CRP (median 3.7 vs 2.6 mg/dl) in the longer TTR group. CONCLUSION: A long TTR is sometimes unavoidable in clinical practice, but surgeons should be aware of a potentially higher risk of reinfection. LEVEL OF EVIDENCE: III, retrospective comparative study.

Diagnosing and Managing Infection in Total Ankle Replacement.

Infections after total ankle replacement (TAR) within the first 4 weeks after implantation can be managed successfully with 1 or several debridements, irrigation, and a change of polyethylene inlay. Late infections require implant removal. Low-grade infections might be an underestimated problem so far. Although single-surgery revisions are reported in the literature, the authors' experience with 2-stage revisions using an antibiotics-loaded bone cement spacer is better. Additional antibiotics are used to support the surgical treatment. After antibiotic therapy of 12 weeks, the final treatment includes ankle or tibio-talo-calcaneal fusion and, with limitations, revision TAR.

[A retrospective cohort study of the postoperative prothesis-related complications of single-port endoscopic assisted versus open surgery on nipple sparing mastectomy and immediate prosthesis breast reconstruction].

Objective: To examine the postoperative prosthesis-related complications, short-term surgical outcomes and patient satisfaction with breast reconstruction between patients who underwent endoscopic assisted versus conventional nipple sparing mastectomy and immediate prothesis breast reconstruction. Methods: This study was a retrospective cohort study. A retrospective analysis was performed on clinical data of 104 women with breast cancer who received nipple sparing mastectomy and immediate prothesis breast reconstruction from August 2021 to August 2022 at the Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University. They were divided into two groups according to the surgical approach. A total of 53 patients, aged (43.3±9.9) years (range: 25 to 66 years), underwent endoscopic nipple sparing mastectomy (E-NSM group) and immediate prothesis breast reconstruction. The other 51 patients aged (39.9±7.8) years (range: 25 to 54 years) underwent conventional open surgery (C-NSM group). Short-term surgical outcomes including operation time, postoperative hospital stay, postoperative blood loss, and postoperative drainage volume in 2 days were recorded. Patient satisfaction with breast reconstruction was compared using the Wilcoxon rank sum test. Postoperative prothesis-related complications were investigated to determine the experience to deal with them. Results: No postoperative prosthesis-related infection, prosthesis loss, or necrosis of the nipple-areola complex occurred in the E-NSM group, while 1 patient suffered from hematoma, whose wound was skinned with resuture after disinfection. Five patients in the C-NSM group had prosthesis-related infection, 2 of them received prosthesis removal surgery combined with sufficient antimicrobial agent, another one underwent surgery for subcutaneous placement of the drain, as well as antimicrobial agent therapy, and the rest of them healed up only with antimicrobial agent therapy. All recovered well after treatment. One patient recovered from necrosis of the nipple-areola complex through periodic iodophor disinfection and dressing which ended in improvement of necrotic areas, another patient who had hematoma accepted the same treatment mentioned above and also healed. All the patients mentioned above are now in stable conditions. Patients in the E-NSM group had higher satisfaction with the cosmetic results of the breast prosthesis implant than those in the C-NSM group (Z=-4.511, P<0.01). Conclusions: Both surgical approaches were proven to be safe and effective with a low rate of postoperative prosthesis-related complications. Patients in the E-NSM group were more satisfied with the cosmetic results of breast reconstruction than those in the C-NSM group.

Articulating Spacers in Total Hip Arthroplasty: Surgical Technique and Outcomes.

Although one-stage exchange arthroplasty is gaining popularity, two-stage exchange arthroplasty remains the gold standard for the treatment of periprosthetic joint infections. Use of an articulating spacer for this procedure offers an avenue for maintaining hip motion and controlled weight-bearing, allowing local antibiotic elution. However, there is no uniform consensus on the optimal surgical protocol for using articulating spacers. This review describes the surgical technique for undertaking a first-stage exchange arthroplasty using an articulating spacer and discusses the pertinent literature on key concepts relating to periprosthetic joint infections in total hip arthroplasty to guide effective surgical decision making in these patients.

Diagnostic Evaluation of Prosthetic Joint Infections of the Shoulder: What Does the Literature Say?

The total number of patients with a total shoulder arthroplasty (TSA) is increasing, and the number of patients experiencing a (TSA) prosthetic joint infection (PJI) also will increase. It is important that physicians know how to identify signs of infection, know the common pathogens, and know how to work up a shoulder PJI. This publication reviewed the current literature about presenting signs and symptoms, common shoulder pathogens and how they differ from total knee and hip pathogens, and what images, tests, and procedures can aid in identification of infection.

Systematic review and meta-analysis of single-stage vs two-stage revision for periprosthetic joint infection: a call for a prospective randomized trial.

BACKGROUND: Periprosthetic joint infection (PJI) is a severe complication of joint arthroplasty that causes significant pain and economic loss. This study aimed to determine whether the current evidence supports single-stage revision for PJI based on reinfection and reoperation rates. METHODS: We searched the PubMed, EBSCO, Medline, and Cochrane Library databases from inception to 30 May 2023 to identify studies that compared single-stage revision and two-stage revision for PJI. Data on reinfection and reoperation rates were pooled. RESULTS: This meta-analysis included a total of 40 studies with 8711 patients. Overall, there was no significant difference between single- and two-stage revision regarding the postoperative reinfection rate and reoperation rate. Subgroup analysis by surgery period and different surgical sites revealed no difference between the two groups in the reinfection and reoperation rates. CONCLUSIONS: Based on the available evidence, our study did not identify a significant difference in reinfection and reoperation rates between single- and two-stage revision for PJI. Given the limitations in inclusion/exclusion criteria and the observed heterogeneity, we acknowledge the complexity of drawing strong conclusions. Therefore, we suggest that the choice between single- and two-stage revision should be carefully considered on an individual basis, taking into account patient-specific factors and further research developments.

What Is the Most Effective Treatment for Periprosthetic Joint Infection After Total Joint Arthroplasty in Patients with Rheumatoid Arthritis?: A Systematic Review.

BACKGROUND: Rheumatoid arthritis (RA) is a risk factor for periprosthetic joint infection (PJI) after total joint arthroplasty (TJA). The purpose of this study was to perform a systematic review comparing the failure rates of debridement, antibiotics, and implant retention (DAIR), one-stage exchange arthroplasty/revision (OSR), and 2-stage exchange arthroplasty/revision (TSR) for RA patients with PJI and identify risk factors in the RA population associated with increased treatment failure rate. METHODS: PubMed, Ovid MEDLINE, and Ovid Embase databases were screened with the terms "rheumatoid arthritis," "total joint arthroplasty," "prosthetic joint infection," and "treatment for PJI" on August 29, 2021. Four hundred ninety-one studies were screened, of which 86 were evaluated. The primary outcome evaluated was failure of surgical treatment for PJI. RESULTS: Ten retrospective cohort studies were included after full-text screening, yielding 401 patients with RA. Additional demographic and PJI management data were obtained for 149 patients. Patients with RA who underwent TSR demonstrated a lower failure rate (26.8%) than both DAIR (60.1%) and OSR (39.2%) (χ2 = 37.463, p < 0.00001). Patients with RA who underwent DAIR had a 2.27 (95% CI, 1.66-3.10) times higher risk of experiencing treatment failure than those who underwent TSR. Among risk factors, there was a significant difference in the C-reactive protein of patients who did vs. did not experience treatment failure (p = 0.02). CONCLUSION: TSR has a higher rate of success in the management of PJI patients with RA compared with DAIR and OSR. The complete removal of the infected prosthesis and delayed reimplantation may lower the treatment failure rate. LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.

Risk factors for early septic failure after two-stage exchange total knee arthroplasty for treatment of periprosthetic joint infection.

BACKGROUND: The cause of early septic failure after two-stage exchange revision total knee arthroplasty (TKA) for chronic periprosthetic joint infection (PJI) and the factors affecting it are not well known. The purpose of this study was to determine the surgical outcomes and the risk factors for early septic failure after two-stage revision TKA for chronic PJI. METHODS: We identified a total of 246 adult patients who met the Musculoskeletal Infection Society (MSIS) diagnostic criteria for chronic PJI at two academic tertiary hospitals from March 2012 to December 2018. Finally, 151 patients who consecutively received two-stage exchange revision TKA for chronic PJI and who had a minimum 3-year follow-up were enrolled and retrospectively reviewed. Successful surgical treatment was evaluated for two-stage revision TKA and risk factors for early septic failure were identified. RESULTS: Early septic failures occurred within 3 years after reimplantation in 48 patients (31.8%). After accounting for potentially confounding variables, we found that male patient [odds ratio (OR): 2.753, 95% confidence interval (CI) 1.099-6.893, p = 0.031], fungus or mycobacterial infection (OR: 5.224, 95% CI 1.481-18.433, p = 0.01), and positive culture at reimplantation (OR: 4.407, 95% CI 1.255-15.480, p = 0.021) were independently associated with early septic failure after two-stage exchange revision TKA. CONCLUSION: Male patients, fungus or mycobacterial infection, and positive culture at reimplantation were independently associated with an increased risk of early septic failure after two-stage exchange revision TKA despite normal C-reactive protein values prior to reimplantation. Further prospective and high-quality studies are needed to determine the risk factors of two-stage exchange revision TKA for chronic PJI. LEVEL OF EVIDENCE: level IV; retrospective comparison; treatment study.

Healthcare exposures and associated risk of endocarditis after open-heart cardiac valve surgery.

BACKGROUND: Infective endocarditis (IE) following cardiac valve surgery is associated with high morbidity and mortality. Data on the impact of iatrogenic healthcare exposures on this risk are sparse. This study aimed to investigate risk factors including healthcare exposures for post open-heart cardiac valve surgery endocarditis (PVE). METHODS: In this population-linkage cohort study, 23,720 patients who had their first cardiac valve surgery between 2001 and 2017 were identified from an Australian state-wide hospital-admission database and followed-up to 31 December 2018. Risk factors for PVE were identified from multivariable Cox regression analysis and verified using a case-crossover design sensitivity analysis. RESULTS: In 23,720 study participants (median age 73, 63% male), the cumulative incidence of PVE 15 years after cardiac valve surgery was 7.8% (95% CI 7.3-8.3%). Thirty-seven percent of PVE was healthcare-associated, which included red cell transfusions (16% of healthcare exposures) and coronary angiograms (7%). The risk of PVE was elevated for 90 days after red cell transfusion (HR = 3.4, 95% CI 2.1-5.4), coronary angiogram (HR = 4.0, 95% CI 2.3-7.0), and healthcare exposures in general (HR = 4.0, 95% CI 3.3-4.8) (all p < 0.001). Sensitivity analysis confirmed red cell transfusion (odds ratio [OR] = 3.9, 95% CI 1.8-8.1) and coronary angiogram (OR = 2.6, 95% CI 1.5-4.6) (both p < 0.001) were associated with PVE. Six-month mortality after PVE was 24% and was higher for healthcare-associated PVE than for non-healthcare-associated PVE (HR = 1.3, 95% CI 1.1-1.5, p = 0.002). CONCLUSIONS: The risk of PVE is significantly higher for 90 days after healthcare exposures and associated with high mortality.

Absorbable antibiotic beads for treatment of LVAD driveline infections.

BACKGOUND: Infections of the left ventricular assist device (LVAD) driveline are a dreaded complication that results in high mortality and morbidity. METHOD: We retrospectively reviewed five consecutive patients with severe continuous-flow LVAD (HVAD, Heartmate 2, and Heartmate 3) driveline infection. These infections, which developed on an average of 960.4 ± 843.9 days after LVAD placement, were refractory to systemic antibiotics and local wound care. All were treated with extensive surgical debridement, local installation of absorbable antibiotic-loaded calcium sulfate beads (vancomycin and tobramycin), primary wound closure, and 6 weeks of systemic antibiotics after surgery. RESULTS: Four patients had resolution of DLI, and one had a recurrent infection at another part of the driveline 7 months after the complete resolution of the previous site. This patient was successfully treated with debridement and bead placements. Three patients still have their LVADs, while two received orthotopic heart transplants. At the time of the transplant, there was no evidence of gross infection of the LVAD drivelines or pumps. At the average follow-up time of 425.8 ± 151 days, no patients have an active infection. CONCLUSION: Treatment of LVAD driveline infection with absorbable antibiotic beads with primary wound closure is a viable option and merits further investigation.

Limited value of platelet-related markers in diagnosing periprosthetic joint infection.

OBJECTIVE: To evaluate the diagnostic values of serum platelet count (PC), mean platelet volume ratio (MPV), platelet count to mean platelet volume ratio (PVR), platelet to lymphocyte ratio (PLR), platelet to neutrophil ratio (PNR), PC/Albumin-globulin ratio (PC/AGR), and PC/C-reactive protein (PC/ CRP) in the diagnosis of periprosthetic joint infection (PJI). METHODS: The medical records were retrospectively analyzed of the 158 patients who had undergone hip or knee revisions from January 2018 to May 2022. Of them, 79 cases were diagnosed with PJI and 79 with aseptic loosening (AL). PJI was defined using the Musculoskeletal Infection Society criteria. The plasma levels of CRP, the erythrocyte sedimentation rate (ESR), PC, MPV, PVR, PLR, PNR, PC/AGR, and PC/CRP in the 2 groups were recorded and analyzed. In addition, tests were performed according to different joint types. The receiver operating characteristic curve was used to calculate the sensitivity and specificity of each indicator. The diagnostic value for each indicator was calculated according to the area under the curve (AUC). RESULTS: The PC, PVR, PLR and PC/AGR levels in the PJI group were significantly higher than those in the AL group, while PC/CRP levels were significantly lower (P < 0.001). The AUC for PC/CRP, and PC/AGR was 0.804 and 0.802, respectively, which were slightly lower than that of CRP (0.826) and ESR (0.846). ROC analysis for PC/CRP, and PC/AGR revealed a cut-off value of 37.80 and 160.63, respectively, which provided a sensitivity of 73.42% and 84.81% and a specificity of 75.95% and 65.82% for PJI. The area under the curve of PLR and PC was 0.738 and 0.702. The area under the curve values for PVR, PNR, and MPV were 0.672, 0.553, and 0.544, respectively. CONCLUSIONS: The results of this study suggest that PC, PLR, PC/CRP, and PC/AGR values do not offer significant advantages over ESR or CRP values when employed for the diagnosis of PJI. PVR, PNR, and MPV were not reliable in the diagnosis of PJI.

Optimal reimplantation timing in two-stage exchange for periprosthetic joint infection: an observative cohort study in Asian population.

BACKGROUND: The optimal timing for reimplantation for periprosthetic joint infection (PJI) has not been established and varies from a few weeks to several months. The aim of this study was to assess the commendable time between implant removal and reimplantation in patients who underwent two-stage exchange arthroplasty for PJI. METHODS: We retrospectively reviewed 361 patients who were treated with two-stage exchange arthroplasty for hip and knee chronic PJI at our institution between January 2000 and December 2018. Patient characteristics, comorbidities, surgical variables, microbiology data, and time to reimplantation were recorded. All patients were followed for a minimum of one year. Treatment failure was defined by Delphi criteria. Logistic regression analyses were used to calculate survival rates and adjusted odds ratios (ORs) of treatment failure. RESULTS: In final analysis, 27 (7.5%) had treatment failure. Factors related to treatment failure including interim spacer exchange (OR, 3.13; confidence interval (CI), 1.04-9.09, p = 0.036), higher ESR level at reimplantation (OR, 1.85; CI, 1.05-3.57; p = 0.04), and time to reimplantation (OR, 1.00; CI, 1.003-1.005, p = 0.04). Performing revision arthroplasty surgery from 16 to 20 weeks had highest successful rate. The reimplantation over 24 weeks had a lower successful rate. However, no statistical significance in comparing each interval group. CONCLUSION: Our study emphasized the importance of timely reimplantation in achieving successful outcomes. Factors such as ESR levels, spacer exchange, and the duration of time to reimplantation influenced the likelihood of treatment failure in two-stage exchange arthroplasty for hip and knee PJI.

Risk factors for failure after rotational muscle flap coverage for prosthetic knee infections.

INTRODUCTION: Soft tissue defects are a devastating complication of prosthetic joint infections (PJI) after total knee arthroplasty (TKA). Rotational flaps are commonly utilized to address these defects with variable reports of success. This study aimed to identify predictors of poor outcomes in rotational muscle flap placement after prosthetic knee infections. The authors hypothesized that outcomes may vary based on infecting pathogen and treatment characteristics. METHODS: 44 cases of rotational muscle flaps for prosthetic knee infection were retrospectively evaluated at a tertiary referral hospital from 2007 to 2020. Muscle flap types included 39 medial and four lateral gastrocnemius, and one anterior tibialis. Minimum follow-up was 1 year (median: 3.4 years). Primary outcome was flap-related complications. Secondary outcomes included recurrent infection requiring additional surgery, final joint outcomes, and mortality. RESULTS: One-year complication-free flap survivorship was 83.9%, recurrent infection-free survivorship was 65.7%, and amputation-free survivorship was 79%. Multivariable cox regression revealed that rheumatoid arthritis diagnosis (HR: 3.4; p = .028) and methicillin-resistant Staphylococcus aureus-positive culture (HR: 4.0; p = .040) had increased risk, while Coagulase-negative Staphylococcus infections had reduced risk for recurrent or persistent infection (HR: 0.2; p = .023). Final joint outcome was retained TKA implant in 18 (40.9%), amputation in 15 (34.1%) patients, and definitive treatment with articulating spacer in 10 (22.7%). 5-years survivorship from death was 71.4%. CONCLUSION: Rotational muscle flaps for soft tissue coverage of the knee are often performed in limb salvage situations with poor survivorship from flap complications, reinfections, and amputation. When considering surgical options for limb salvage, patients should be counseled on these risks.

Is Prophylactic Antibiotic Use Necessary Before Dental Procedures in Primary and Revision TKA? A Propensity Score-matched, Large-database Study.

BACKGROUND: The question of whether dental procedures increase the risk of periprosthetic joint infection (PJI) in patients who have undergone total joint arthroplasty (TJA) remains controversial. QUESTIONS/PURPOSES: (1) Are dental procedures associated with an increased incidence of PJI in the setting of either primary or revision TKA after controlling for relevant potentially confounding variables? (2) Is the administration of prophylactic antibiotics before dental procedures associated with any differences in this risk? (3) Which factors are associated with increased incidence of PJI after dental procedures? METHODS: This nationwide, retrospective, comparative, large-database study evaluated 591,602 patients who underwent unilateral primary or revision TKA between 2009 and 2019 using the Health Insurance Review and Assessment Service data in South Korea, in which all people in South Korea were registered and to which all medical institutions must charge any procedures they performed. The study population was divided into 530,156 patients with dental procedures and 61,446 patients without dental procedures based on whether the patients underwent a dental procedure at least 1 year after the index surgery. After propensity score matching, patients were classified into a dental (n = 182,052) and a nondental cohort (n = 61,422). The dental cohort was then divided into two groups: 66,303 patients with prophylactic antibiotics and 115,749 patients without prophylactic antibiotics based on prophylactic antibiotic use. After propensity score matching, patients were categorized into prophylactic (n = 66,277) and nonprophylactic (n = 66,277) cohorts. Propensity score matching was used to control for covariates including posttraumatic arthritis associated with PJI risk according to the dental procedure and prophylactic antibiotic use among the cohorts. After propensity score matching, the standardized mean difference was confirmed to be less than 0.1 for all variables. Kaplan-Meier survival analyses, log-rank tests, and Cox proportional hazards regression analysis was performed. RESULTS: Dental procedures were not associated with an increase in PJI risk after primary (adjusted HR 1.56 [95% CI 0.30 to 8.15]; p = 0.60) or revision TKA (adjusted HR 1.74 [95% CI 0.90 to 3.34]; p = 0.10). Additionally, use of prophylactic antibiotics was not associated with a reduced PJI risk after the index surgery, either for primary (adjusted HR 1.28 [95% CI 0.30 to 5.42]; p = 0.74) or revision TKA (adjusted HR 0.74 [95% CI 0.45 to 1.23]; p = 0.25). Although surgery type and prophylactic antibiotic use exhibited no influence on PJI occurrence after dental procedures, posttraumatic arthritis was associated with PJI. The adjusted HR for posttraumatic arthritis was 4.54 (p = 0.046). CONCLUSION: Our findings suggest that dental procedures were not associated with an increased risk of PJI for up to 2 years after the dental procedure in patients who underwent either primary or revision TKA. Based on these findings, there is insufficient rationale for the use of prophylactic antibiotics before dental procedures in patients who have undergone primary or revision TKA. LEVEL OF EVIDENCE: Level III, therapeutic study.

Assessing the Diagnostic Accuracy of Next-Generation Sequencing in Patients With Antibiotic Spacers Before Reimplantation.

Use of molecular sequencing modalities in periprosthetic joint infection diagnosis and organism identification has gained popularity recently. To date, there is no diagnostic test that reliably predicts infection eradication in patients with antibiotic spacers. The purpose of this study was to compare the diagnostic accuracy of next-generation sequencing (NGS), culture, the Musculoskeletal Infection Society (MSIS) criteria, and the criteria by Parvizi et al in patients with antibiotic spacers. In this retrospective study, aspirate or tissue samples were collected from 38 knee and 19 hip antibiotic spacers for routine diagnostic workup for the presence of persistent infection and sent to the laboratory for NGS. The kappa statistic along with statistical differences between diagnostic studies were calculated using the chi-square test for categorical data. The kappa coefficient for agreement between NGS and culture was 0.27 (fair agreement). The percentages of positive and negative agreement were 22.8% and 42.1%, respectively, with a total concordance of 64.9%. There were 12 samples that were culture positive and NGS negative. Eight samples were NGS positive but culture negative. The kappa coefficient was 0.42 (moderate agreement) when comparing NGS with MSIS criteria. In our series, NGS did not provide sufficient agreement compared with culture or MSIS criteria in the setting of an antibiotic spacer. A reliable diagnostic indicator for reimplantation has yet to be identified. [Orthopedics. 2024;47(1);46-51.].

The Use of Artificial Intelligence for the Prediction of Periprosthetic Joint Infection Following Aseptic Revision Total Knee Arthroplasty.

Periprosthetic joint infection (PJI) following revision total knee arthroplasty (TKA) for aseptic failure is associated with poor outcomes, patient morbidity, and high health care expenditures. The aim of this study was to develop novel machine learning algorithms for the prediction of PJI following revision TKA for patients with aseptic indications for revision surgery. A single-institution database consisting of 1,432 consecutive revision TKA patients with aseptic etiologies was retrospectively identified. The patient cohort included 208 patients (14.5%) who underwent re-revision surgery for PJI. Three machine learning algorithms (artificial neural networks, support vector machines, k-nearest neighbors) were developed to predict this outcome and these models were assessed by discrimination, calibration, and decision curve analysis. This is a retrospective study. Among the three machine learning models, the neural network model achieved the best performance across discrimination (area under the receiver operating characteristic curve = 0.78), calibration, and decision curve analysis. The strongest predictors for PJI following revision TKA for aseptic reasons were prior open procedure prior to revision surgery, drug abuse, obesity, and diabetes. This study utilized machine learning as a tool for the prediction of PJI following revision TKA for aseptic failure with excellent performance. The validated machine learning models can aid surgeons in patient-specific risk stratifying to assist in preoperative counseling and clinical decision making for patients undergoing aseptic revision TKA.

No Association Between Previous General Infection and Prosthetic Joint Infection After Total Hip Arthroplasty-A National Register-Based Cohort Study on 58,449 Patients Who Have Osteoarthritis.

BACKGROUND: Prosthetic joint infection (PJI) following total hip arthroplasty (THA) is a complication associated with increased risk of death. There is limited knowledge about the association between infection before THA, and risk of revision due to PJI. We investigated the association between any previous hospital-diagnosed or community-treated infection 0 to 6 months before primary THA and the risk of revision. METHODS: We obtained data on 58,449 patients who were operated with primary unilateral THA between 2010 and 2018 from the Danish Hip Arthroplasty Register. Information on previous infection diagnoses, redeemed antibiotic prescriptions up to 1 year before primary THA, intraoperative biopsies, and cohabitations was retrieved from Danish health registers. All patients had a 1-year follow-up. Primary outcome was revision due to PJI. Secondary outcome was any revision. We calculated the adjusted relative risk with 95% confidence intervals (CI), treating death as competing risk. RESULTS: Among 1,507 revisions identified, 536 were due to PJI with a cumulative incidence of 1.0% ([CI] 0.9 to 1.2) and 0.9% ([CI] 0.8 to 1.0) for patients who did and did not have previous infection. For any revision, the cumulative incidence was 3.1% ([CI] 2.9 to 3.4) and 2.4% ([CI] 2.3 to 2.6) for patients who did and did not have previous infection. The adjusted relative risk for PJI revision was 1.1 ([CI] 0.9 to 1.4) and for any revision 1.3 ([CI] 1.1 to 1.4) for patients who did have previous infection compared to those who did not. CONCLUSION: Previous hospital-diagnosed or community-treated infection 0 to 6 months before primary THA does not increase the risk of PJI revision. It may be associated with increased risk of any revision.

Adjuvant intra-articular vancomycin for recalcitrant Staphylococcal prosthetic joint infections of the knee.

OBJECTIVE: Chronic prosthetic joint infection patients who fail conventional two-stage revision surgery are an especially difficult to treat patient population. Consequently, the objective of this study was to investigate the safety and long-term effectiveness of adjuvant intra-articular vancomycin therapy in conjunction with two-stage revision knee arthroplasties for recalcitrant Staphylococcal prosthetic joint infections. METHODS: This was an observational cohort study of twelve patients with recalcitrant Staphylococcal prosthetic joint infections of the knee which had failed previous revision surgeries. Each patient subsequently underwent two-stage revision with placement of Hickman catheters to deliver intra-articular vancomycin therapy. In addition, systemic antibiotic therapy was administered for 6 weeks, and long-term follow-up was evaluated then for 5 years. RESULTS: Seventy-five percent of the cohort have had no recurrence of their infections at 5 years. Two patients formed fistulas requiring above the knee amputations, and three patients had acute kidney injury. All patients had maximum measurable serum vancomycin trough levels that ranged from 6.1 to 93.6 mcg/mL. CONCLUSION: The aggressive protocol used in this cohort with repeat two-stage revision surgery, intra-articular vancomycin and systemic antibiotics was able to prevent recurrence of infection in most patients, but higher than expected rates of acute kidney injury were observed in this study. Therefore, while intra-articular vancomycin therapy may have some effectiveness in treating recalcitrant prosthetic joint infections, its ability to eradicate all bacterial niduses is unproven, and clinicians should be cognizant of potential adverse events that can occur with this therapy.

Clinical Outcomes After Revision Hip Arthroplasty due to Prosthetic Joint Infection-A Single-Center Study of 369 Hips at a High-Volume Center With a Minimum of One Year Follow-Up.

BACKGROUND: Prosthetic joint infection (PJI) treatment decisions are traditionally based on treatment algorithms. There is, however, a lack of evidence to support the choice of these treatment algorithms. Therefore, we aimed to assess the one-year survival after PJI revision and compared different surgical strategies in a single-center setting. METHODS: Revisions of the hip due to PJI performed at our institution between January 2008 and September 2021 with at least one-year of follow-up were identified. In total, 134 debridement, antibiotics, and implant retentions (DAIRs), 114 one-stage revisions, and 121 two-stage revisions were performed. Infections were classified as early, acute hematogenous, and chronic. Survival was calculated using the Kaplan-Meier method and cumulative incidence function. Predictors of outcomes were examined with Fine-Gray regressions and Cox proportional hazards regressions. Subdistribution hazard ratios and hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated. RESULTS: At one-year follow-up, 26.6% (CI 22.2 to 31.2%) of the patients had undergone reoperation and 7.9% (CI 5.4 to 10.9%) had died. The risk for reoperation was highest after DAIR (36.6%, CI 28.5 to 44.7%) and lowest after one-stage revision (20.2%, CI 13.4 to 28%). Within the early infections, the one-stage revision almost halved the risk of reoperation (HR 0.51, CI 0.31 to 0.84) with no added mortality risk (HR 1.05, CI 0.5 to 2.2), when compared to DAIR. CONCLUSION: By utilizing 1-stage revision over DAIR in early infections, it might be possible to improve the prognosis by decreasing the risk of reoperation without increasing mortality. However, as the patient selection is undeniably difficult, more research is warranted.