Search Results (18)

Background/Objectives: The rising demand for total joint arthroplasty (TJA) and increasing incidence of prosthetic joint infections (PJIs) significantly burden patients and healthcare systems. This retrospective study describes the epidemiology, clinical characteristics and outcomes of PJIs in Iceland from 2003 to 2020. Methods: PJI cases were identified through synovial fluid cultures and ICD codes, with classification per EBJIS criteria. Unlikely cases were excluded. Results: Among 293 cases with a mean age of 70 years, 60% (176/293) were males and 58% (171/293) involved the knee. Over half of infections occurred within two years post TJA, with an incidence rate of 0.94%, increasing significantly over time (p = 0.012). Males had significantly higher incidence rates than females (incidence rate ratio 0.42; p < 0.001). The most common pathogens were coagulase-negative staphylococci (30%, 88/293), and 9% (27/293) of cases were culture-negative. DAIR was the first-line treatment in about 50% (147/293) of cases but it failed in nearly half, contributing to an overall treatment failure rate of 38% (98/259). PJI-related mortality was 2% (6/293). Conclusions: The results indicate an increased incidence, with the highest risk within two years of TJA. Males are at greater risk, while females more commonly undergo TJA. DAIR success rates were lower than reported elsewhere but improved significantly over time. Better methods to prevent PJIs are needed. Full article

Background: Periprosthetic joint infections (PJIs) remain a major challenge in arthroplasty. This study tries to evaluate the PJI-TNM classification as predictor for the revision-free implant survival in patients with PJI of the hip or knee joint. Methods: To this end, we perform a retrospective study of all consecutive patients with PJI of an inlying hip or knee arthroplasty between January 2015 and December 2019. Results: A total of 443 cases (hip: n = 247; knee n = 196) were identified. In total, 439 patients underwent surgery (DAIR: n = 138 cases (31%), explantation: n = 272 (61%), irrigation with debridement without exchange of implant components: n = 29 (6.5%)). Four patients refused surgical treatment and 39.5% were lost to follow-up. In total, 78 patients died during follow-up and 27 deaths were directly related to PJI/complications during treatment. Patients with inlying “standard”-implants (p < 0.001) and without previous history of PJI (p = 0.002) displayed a significantly higher postoperative revision-free implant survival. In terms of the PJI-TNM subclassification, patients with loosened implants but without soft-tissue defects (T1) displayed the highest revision-free implant survival. In contrast, patients classified as M3 (no surgical treatment possible) displayed an inferior outcome compared to M0, M1, or M2. Patients with different N-subclassifications (“non-human cells”/causative pathogen) did not display differences in revision-free implant survival. Conclusions: The PJI-TNM classification is well suited to classify PJIs. Its complexity allows for more than 500 different combinations of classifications. Further validation data are needed, but to us, the PJI-TNM classification seems to offer the possibility of comparing patients with PJIs. It may, therefore, be a very valuable tool in order to compare cohorts with PJIs and provide individual data for patient specific outcomes. Full article

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. Full article

The management of septic orthopedic patients, particularly those with periprosthetic joint infections (PJIs) and trauma-related sepsis, remains a significant clinical challenge. This retrospective cohort study evaluated 27 patients admitted to the Intensive Care Unit (ICU) at the Emergency University Hospital in Bucharest between 2021 and 2024. Patients presented with either PJIs or polytrauma-related infections requiring critical care interventions. The PJI-TNM classification system was employed to assess infection complexity, comorbidities, and implant stability. Therapeutic strategies included one- or two-stage revision surgeries and targeted antimicrobial therapy, including the use of antibiotic-impregnated calcium sulfate beads. Infection resolution was achieved in 85.2% of patients, with a mean ICU stay of 13 days. The overall ICU mortality rate was 11%, with two deaths occurring within the first 30 days of admission. Elevated SOFA scores (≥10) and poor glycemic control (HbA1c > 8.5%) were significantly associated with prolonged ICU stays and higher complication rates. Statistical analysis revealed significant differences in CRP normalization and bone healing times across glycemic control groups (p < 0.001). Patients requiring mechanical ventilation exhibited longer ICU stays and increased mortality (25%). The PJI-TNM classification showed potential utility for risk stratification and guiding personalized treatment strategies. These findings underscore the importance of multidisciplinary ICU-level care and metabolic control in improving outcomes for septic orthopedic patients. Future multicenter studies are needed to validate these preliminary observations and refine prognostic models for this high-risk population. Full article

Background: Periprosthetic joint infection (PJI) remains a significant and complex complication following total hip and knee arthroplasty. This study aims to design, validate, and assess a machine learning (ML) model for predicting the likelihood of PJI in individuals undergoing revision arthroplasty procedures. Methods: A retrospective analysis was conducted on patients who underwent hip or knee revision arthroplasty between 1 January 2015 and 31 March 2021. Data were collected from preoperative clinical histories, laboratory results, and patient demographics. The final dataset was used to train multiple classification models for the preoperative prediction of PJI. Results: A total of 1360 patients were included, comprising 1141 cases in the aseptic group and 219 in the infected group. The best-performing model, a Linear Support Vector Machine (SVM), demonstrated reasonable predictive capability for PJI, achieving an area under the curve (AUC) of 0.770 ± 0.008 in the training set and 0.730 ± 0.078 in the testing set. Additionally, three key predictors of PJI were identified. Conclusions: The Linear SVM model, developed using preoperative clinical information, exhibited reasonable performance in predicting PJI. While further refinement and validation are necessary, integrating ML tools into the preoperative evaluation process has the potential to enhance personalized risk assessment, support informed decision-making, and optimize surgical preparation for patients undergoing prosthetic revision surgery. Full article

Background/Objectives: While methicillin-resistant Staphylococcus aureus (MRSA) colonization is a known risk factor for surgical site infections, no definitive recommendations exist regarding preoperative S. aureus screening and decolonization protocols due to inconclusive evidence in Orthopedic Surgery. This study aimed to examine the correlation between preoperative MRSA colonization and postoperative infections in Total Knee Arthroplasty (TKA) patients. Methods: Data from 2005 to 2023 were collected from TriNetX, a global health research network, reviewing 237,360 unique patients. TKA patients were assigned under Current Procedural Terminology, while International Statistical Classification of Diseases Codes were used to identify preoperative comorbidities and postoperative complications. Demographic and analytical statistics were compared between MRSA-positive and control groups before and after propensity matching. Results: The MRSA-positive group had a significantly (p < 0.001) higher proportion of patients over 65 years (47.17% vs. 38.46%), obesity (41.76% vs. 34.67%), smoking disorders (33.36% vs. 19.73%), and diabetes (25.06% vs. 19.85%) compared to the control group. Postoperative complications were significantly (p < 0.001) more frequent in the MRSA-positive group, specifically periprosthetic joint infection (PJI) (4.11% vs. 0.79%, OR = 5.40), deep (0.12% vs. 0.01%, OR = 11.15) and superficial (0.37% vs. 0.09%, OR = 4.17) surgical site infections, and wound dehiscence (1.11% vs. 0.52%, OR = 2.13). The matched analysis confirmed significantly (p < 0.001) higher rates of PJI (4.39% vs. 1.18%, OR = 3.59). Conclusions: Our results illustrated preoperative colonization of MRSA as associated with an increased risk of wound-related complications. Surgeons and patients must consider preoperative MRSA colonization status when deciding if TKA is an optimal treatment option. Full article

Background: Periprosthetic joint infection (PJI) following knee arthroplasty can significantly compromise patient mobility and quality of life. The newly proposed TNM classification system, adapted from oncology, categorizes PJI severity but has not yet been correlated with both subjective and objective outcomes post PJI treatment. Objective: This study evaluates the applicability of the TNM classification system for predicting outcomes in knee PJI revision surgeries. Methods: We conducted a retrospective analysis of 108 patients who underwent revision surgeries for knee PJI at our institution from January 2012 to January 2023. We assessed the correlation between the TNM classification and postoperative outcomes using the Knee Society Score (KSS) function and knee score, as well as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results: The TNM classification demonstrated that higher ‘T’ stages were significantly associated with worse functional and subjective outcomes. The ‘N’ classification had limited predictive value, likely due to treatment adjustments based on pathogen type. The ‘M’ classification correlated with functional outcomes but not with subjective scores, suggesting that patients with more severe preoperative comorbidities might adjust their expectations. Conclusions: While the TNM classification shows potential, its current form as a prognostic tool in PJI management is limited. Enhancing the ‘T’ component, coupled with the integration of a validated morbidity score such as the CCI could improve its prognostic value. Despite its shortcomings, the TNM system may still provide valuable prognostic insights for both patients and surgeons in tackling complex PJI. Full article

Background: The microbiological profile of bone and joint infections is important for determining the empiric choice of both systemic and local antimicrobial therapy. This study assessed whether there was a difference in the bacterial species that were isolated on culture in osteomyelitis (OM), fracture-related infection (FRI) or prosthetic joint infection (PJI). This was a retrospective, observational cohort study of patients who had surgical intervention for PJI or OM or FRI with a positive microbial culture between 2019 and 2022. Methods: Data including patient demographics, the site of injury, JS-BACH score, organism classification and antibiotic resistance to vancomycin and gentamicin were extracted from the medical records. Results: A total of 440 patients were included in this study: 163 patients with osteomyelitis, 109 with fracture-related infection with fixation implants and 168 with prosthetic joint infection. The patients with PJI were older, more likely to be female and had a higher BMI and ASA score compared to those with OM. Patients with PJI were more likely to have a higher JS-BACH score and more complex infections. Staphylococcus aureus was the most commonly isolated organism in all three groups. It was more frequently isolated in osteomyelitis than in PJI (p = 0.016). In both osteomyelitis and FRI, after Staphylococcus aureus, the next most common organisms were Gram-negatives, whilst for PJIs, the most commonly isolated organisms were Staphylococcus aureus, followed by coagulase-negative Staphylococci and then Streptococcus species. The rates of other organisms were broadly similar between the three groups. When adjusted for confounders, including symptom duration, JS-BACH score, the location of injury, age and BMI, there was no statistically significant difference in the presence of Staphylococcus aureus (OR = 0.765; 95% CI 0.633–1.232; p = 0.465) or polymicrobial infection (OR = 1.175; 95% CI 0.803–1.721; p = 0.407). Conclusions: Causative pathogens are similar across bone and joint infections and are independent of the presence of prosthetic material. Full article

Introduction: Periprosthetic joint infection (PJI) remains a serious complication after total knee arthroplasty (TKA). While debridement, antibiotics, and implant retention (DAIR) are considered for acute PJI, success rates vary. This study aims to assess a new scoring system’s accuracy in predicting DAIR success. Methods: 119 TKA patients (2008–2019) diagnosed with PJI who underwent DAIR were included for analysis. Data were collected on demographics, laboratory values, and clinical outcomes. This was used for validation of the novel classification system consisting of PJI acuteness, microorganism classification, and host health for DAIR indication. Statistical analysis was carried out using SPSS programming. Results: Mean follow-up was 2.5 years with an average age of 65.5 ± 9.1 years, BMI of 31.9 ± 6.2 kg/m², and CCI of 3.04 ± 1.8. Successful infection eradication occurred in 75.6% of patients. The classification system demonstrated 61.1% sensitivity, 72.4% specificity, and 87.3% positive predictive value (PPV) when the DAIR cutoff was a score less than 6. For a cutoff of less than 8, sensitivity was 100%, specificity was 37.9%, and PPV was 83.3%. Conclusions: To date, no consensus exists on a classification system predicting DAIR success. This novel scoring system, with high PPV, shows promise. Further refinement is essential for enhanced predictive accuracy. Full article

The comprehensive “PJI-TNM classification” for the description of periprosthetic joint infections (PJI) was introduced in 2020. Its structure is based on the well-known oncological TNM classification to appreciate the complexity, severity, and diversity of PJIs. The main goal of this study is to implement the new PJI-TNM classification into the clinical setting to determine its therapeutic and prognostic value and suggest modifications to further improve the classification for clinical routine use. A retrospective cohort study was conducted at our institution between 2017 and 2020. A total of 80 consecutive patients treated with a two-stage revision for periprosthetic knee joint infection were included. We retrospectively assessed correlations between patients’ preoperative PJI-TNM classification and their therapy and outcome and identified several statistically significant correlations for both classifications, the original and our modified version. We have demonstrated that both classifications provide reliable predictions already at the time of diagnosis regarding the invasiveness of surgery (duration of surgery, blood and bone loss during surgery), likelihood of reimplantation, and patient mortality during the first 12 months after diagnosis. Orthopedic surgeons can use the classification system preoperatively as an objective and comprehensive tool for therapeutic decisions and patient information (informed consent). In the future, comparisons between different treatment options for truly similar preoperative baseline situations can be obtained for the first time. Clinicians and researchers should be familiar with the new PJI-TNM classification and start implementing it into their routine practice. Our adjusted and simplified version (“PJI-pTNM”) might be a more convenient alternative for the clinical setting. Full article

Aims: This study evaluates the value of a new graphic representation of cell count data of synovial fluid in the diagnosis of acute periprosthetic joint infection (PJI). Methods: A total of 75 patients with revisions of 48 primary total knee and 27 hip arthroplasties within the first six weeks after surgery were analyzed with cultivation of the synovial fluid and determination of its cell count as well as microbiological and histological analyses of the periprosthetic tissue obtained during the revision surgery using the ICM classification. The synovial fluid was additionally analyzed for graphic representation of the measured cells using LMNE-matrices. Results: A total of 38 patients (50.7%) had an infection. The following types of LMNE matrices could be differentiated: the indeterminate type (IV) in 14.7%, the infection type (II) in 5.3%, the hematoma type (V) in 33.3%, and the mixed type (VI; infection and hematoma) in 46.7%. Differentiation of LMNE types into infection (types II and VI) and non-infection (types IV and V) resulted in a sensitivity of 100%, a specificity of 97.3%, and a positive likelihood ratio of 37.0. The cell count measurement showed a sensitivity of 78.9%, a specificity of 89.2%, and a positive likelihood ratio of 7.3 at a cut-off of 10,000 cells. The percentage of polymorphonuclear leukocytes showed a sensitivity of 34.2%, a specificity of 100%, and a positive likelihood ratio of >200 at a cut-off of 90%. Conclusion: The graphic representation of the cell count analysis of synovial aspirates is a new and helpful method for differentiating between genuine early periprosthetic infections and postoperative hemarthrosis. Full article

Introduction: Periprosthetic joint infections (PJI) following primary arthroplasty continue to be a serious complication, despite advances in diagnostics and treatment. Two-stage revision arthroplasty has been commonly used as the gold standard for the treatment of PJI. However, much discussion persists regarding the interim of the two-stage procedure and the optimal timing of reimplantation. Serology markers have been proposed as defining parameters for a successful reimplantation. The objective of this matched-pair analysis was to assess the role of serum C-reactive protein (CRP) and white blood cell count (WBC) in determining infection eradication and proper timing of reimplantation. We investigated the delta (∆) change in CRP and WBC values prior to both stages of two-stage revision arthroplasty as a useful marker of infection eradication. Methods: We analyzed 39 patients and 39 controls, matched by propensity score matching (BMI, age, ASA-classification), with a minimum follow-up of 24 months and treated with a two-stage revision THA or TKA in our institution. Data of serum CRP and WBC values were gathered at two selected time points: prior to the explantation of the implant (preexplantation) and following the completion of antibiotic treatment regimen, both systemic and with a drug-eluting cement spacer (prereimplantation). Patient records were reviewed electronically for preexisting comorbidities, overall health status, synovial fluid cultures, inflammatory serologies, revision surgeries, and recurrent or persistent infection based on the modified Musculoskeletal Infection Society criteria. Patient demographics, ∆CRP, ∆WBC, and time interval to reimplantation were statistically analyzed using receiver operator curves (ROC), Pearson’s correlation coefficient, Levene’s test, and Student’s t-test. Results: Infection-free patients exhibited higher mean CRP and WBC than did patients who were reinfected at both time points. When comparing preexplantation with prereimplantation values, the median ∆CRP was 9.48 mg/L (interquartile range (IQR) 2.3–36.6 mg/L) for patients who did not develop a reinfection versus 2.74 mg/L (IQR 1.4–14.2 mg/L) for patients who developed reinfection (p = 0.069). The median ∆WBC was 1.5 × 10⁹/L (IQR 0.6–4.0 × 10⁹/L) for patients who remained infection-free versus 1.2 × 10⁹/L (IQR 0.8–2.2 10⁹/L) for patients who developed reinfection (p = 0.072). Analysis of areas under the curve (AUC) using ROC demonstrated poor prediction of persistent infection by ∆CRP (AUC = 0.654) and ∆WBC (AUC = 0.573). Although a highly significant correlation was found between the interim interval and infection persistence (r = 0.655, p < 0.01), analysis using ROC failed to result in a specific threshold time to reimplantation above which patients are at significantly higher risk for reinfection (AUC = 0.507). Conclusion: No association could be determined between the delta change in serum CRP and WBC before and after two-stage revision arthroplasty for PJI and reinfection risk. Even though inflammatory serologies demonstrate a downtrending pattern prior to reimplantation, the role of CRP and WBC in determining the optimal timing of reimplantation seems to be dispensable. Planning a second-stage reimplantation requires assessing multiple variables rather than relying on specific numeric changes in these inflammatory marker values. Full article

Background: Acetabular cage reconstruction with bone allografts is among the successful strategies to deal with massive acetabular bone loss. However, the nonbiological fixation nature of cages can compromise long-term success. Tantalum trabecular metal acetabular cups (TM cups) have been used in acetabular revision surgery because of their increased initial stability and good bone ingrowth features. This study was performed to determine whether the bone stock of the acetabulum is enough to support a hemispheric TM cup after failed cage reconstruction with bone allografts. Methods: We retrospectively reviewed patients who received acetabular revision surgery with TM cups after failed cage reconstruction with bone allografts from 2006 to 2017. There were 12 patients (5 males and 7 females) included in this study, with a mean age of 61.5 years (38 to 81) at the time of re-revision surgery. The mean follow-up after re-revision surgery was 8.6 years (2.6 to 13.3). The endpoint was defined as the aseptic loosening of the TM cup and reoperation for any causes. The change in bone stock of the acetabulum between index revision and re-revision was assessed according to the Gross classification for acetabular bone loss. Results: One patient died after eight years of follow-up of a cause not related to hip surgery. Two patients received two-stage revision arthroplasty due to PJI after 3.2 and 9.4 years of follow-up, respectively. The bone stock of the acetabulum was significantly improved between index revision and re-revision surgery (p < 0.0001). The Kaplan–Meier survivorship was 100% with aseptic loosening as the endpoint and 90% and 75% at five- and ten-year follow-up, respectively, with reoperation for any reason as the endpoint. Even cage reconstruction with bone allografts will fail eventually, and the bone stock of the acetabulum will improve after union and incorporation between host bone and allografts. The restored bone stocks will facilitate further revision surgery with hemispheric TM cups. The biological fixation between host bone and tantalum trabecular metal can provide longstanding stability of the TM cup. Conclusions: The results of our study offer a viable option for patients with failed cage reconstruction with bone allografts. Full article