Diagnosing low-grade periprosthetic joint infections (PJI) can be very challenging due to low-virulent microorganisms capable of forming biofilm. Clinical signs can be subtle and may be similar to those of aseptic failure. To minimize morbidity and mortality and to preserve quality of life, accurate diagnosis is essential. The aim of this study was to assess the performance of various diagnostic tests in diagnosing low-grade PJI. Patients undergoing revision surgery after total hip and knee arthroplasty were included in this retrospective cohort study. A standardized diagnostic workup was performed using the components of the 2021 European Bone and Joint Infection Society (EBJIS) definition of PJI. For statistical analyses, the respective test was excluded from the infection definition to eliminate incorporation bias. Receiver-operating-characteristic curves were used to calculate the diagnostic performance of each test, and their area-under-the-curves (AUC) were compared using the z-test.Aim
Methods
This multicentre retrospective observational study’s aims were to investigate whether there are differences in the occurrence of radiolucent lines (RLLs) following total knee arthroplasty (TKA) between the conventional Attune baseplate and its successor, the novel Attune S+, independent from other potentially influencing factors; and whether tibial baseplate design and presence of RLLs are associated with differing risk of revision. A total of 780 patients (39% male; median age 70.7 years (IQR 62.0 to 77.2)) underwent cemented TKA using the Attune Knee System) at five centres, and with the latest radiograph available for the evaluation of RLL at between six and 36 months from surgery. Univariate and multivariate logistic regression models were performed to assess associations between patient and implant-associated factors on the presence of tibial and femoral RLLs. Differences in revision risk depending on RLLs and tibial baseplate design were investigated with the log-rank test.Aims
Methods
Serum inflammatory parameters are widely used to aid in diagnosing a periprosthetic joint infection (PJI). Due to their limited performances in the literature, novel and more accurate biomarkers are needed. Serum albumin-to-globulin ratio (AGR) and serum CRP-to-albumin ratio (CAR) have previously been proposed as potential new parameters, but results were mixed. The aim of this study was to assess the diagnostic accuracy of AGR and CAR in diagnosing PJI and to compare them to the established and widely used marker CRP. From 2015 to 2022, a consecutive series of 275 cases of revision total hip (n = 129) and knee arthroplasty (n = 146) were included in this retrospective cohort study. Based on the 2021 European Bone and Joint Infection Society (EBJIS) definition, 144 arthroplasties were classified as septic. Using receiver operating characteristic curve (ROC) analysis, the ideal thresholds and diagnostic performances were calculated. The areas under the curve (AUCs) were compared using the z-test.Aims
Methods
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. 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.Aims
Methods
The use of rotating hinge (RH) prostheses for severe primary as well as revision arthroplasty is widely established. Aim of this study was to investigate long term results of a new RH prosthesis (EnduRo®, B Braun, Germany), which uses carbon-fiber reinforced poly-ether-ether-ketone (CFR PEEK) as a new bearing material, first time used in knee arthroplasty. Fifty-six consecutive patients, who received the EnduRo® RH prosthesis were included in this prospective study: 21 patients (37.5%) received the prosthesis as a primary total knee arthroplasty (TKA) and 35 patients (62.5%) underwent revision total knee arthroplasties (rTKA). Clinical and radiographic examinations were performed preoperatively as well as postoperatively after 3 and 12 months and annually thereafter. Min. Follow up was 7 and mean follow up 9,3 years. Clinical examination included Knee Society Score (KSS), Western Ontario and McMaster Osteoarthritis Index (WOMAC), Oxford Knee Score (OKS), and range of motion (ROM). Competing risk analysis was assessed for survival with respect to indication and failure mode. KSS, WOMAC, OKS, and ROM significantly improved from the preoperative to the follow up investigations (p < 0.0001). There was no difference in clinical outcome between the primary and the revision group. The overall cumulative incidence for revision for any reason was 23.6% and the cumulative incidence for complications associated with failure of the prothesis was 5.6% at 7 years, respectively. Complications occurred more frequently in the revision group (p = 0.002). The evaluated RH prosthesis provided reliable and durable results with a minimum follow-up of 7 years. Prosthesis survival was successful considering the complexity of cases. The use of this RH system in primary patients showed high survival rates. Long-term functional and clinical results proved to be satisfying in both revision and primary cases. No adverse events were associated with the new bearing material CFR-PEEK.
Histology is an established tool in diagnosing periprosthetic joint infections (PJIs). Different thresholds, using various infection definitions and histopathological criteria, have been described. This study determined the performance of different thresholds of polymorphonuclear neutrophils (≥ 5 PMN/HPF, ≥ 10 PMN/HPF, ≥ 23 PMN/10 HPF) , when using the European Bone and Joint Infection Society (EBJIS), Infectious Diseases Society of America (IDSA), and the International Consensus Meeting (ICM) 2018 criteria for PJI. A total of 119 patients undergoing revision total hip (rTHA) or knee arthroplasty (rTKA) were included. Permanent histology sections of periprosthetic tissue were evaluated under high power (400× magnification) and neutrophils were counted per HPF. The mean neutrophil count in ten HPFs was calculated (PMN/HPF). Based on receiver operating characteristic (ROC) curve analysis and the z-test, thresholds were compared.Aims
Methods
The diagnosis of periprosthetic joint infection (PJI) remains
demanding due to limitations of all the available diagnostic tests.
The synovial fluid marker, α-defensin, is a promising adjunct for
the assessment of potential PJI. The purpose of this study was to
investigate the qualitative assessment of α-defensin, using Synovasure
to detect or exclude periprosthetic infection in total joint arthroplasty. We studied 50 patients (28 women, 22 men, mean age 65 years;
20 to 89) with a clinical indication for revision arthroplasty who
met the inclusion criteria of this prospective diagnostic study.
The presence of α-defensin was determined using the qualitative
Synovasure test and compared with standard diagnostic methods for
PJI. Based on modified Musculoskeletal Infection Society (MSIS)
criteria, 13 cases were categorised as septic and 36 as aseptic revisions.
One test was inconclusive.Aims
Patients and Methods
Aim of the study was to find out whether patients with positive minor criteria but without meeting the MSIS definition have a difference in the outcome after revision-surgery compared to patients without any MSIS-criteria? And does the reason for revision-surgery (eg. loosening) have an additional influence on the outcome parameters in patients with positive minor criteria? A retrospective matched-pair analysis with 98 patients who had undergone revision-surgery after TJA was performed. Forty-nine patients who showed 1 to 3 positive minor criteria (PMC) whereas 49 patients without any positive minor criteria (aseptic complications control group) were compared regarding re-revision-rate and revision-free survival. Patients were matched regarding sex, age, joint and comorbidities using the classification system by McPherson et al. Reasons for revisions were categorized in loosening, body wear, periprosthetic fracture/mechanical failure and soft-tissue complication. Endpoints were defined as re-revision for any cases.Aim
Method
Quantitative assessment of alpha-Defensin offers a promising approach for diagnosing a periprosthetic joint infection (PJI) with sensitivities and specificities ranging from 97% to 100% and 95% to 100%, respectively. However, to the best of our knowledge and after due inquiry little information exists concerning qualitative measurements of alpha-Defensin. The aim of this study was to assess the diagnostic accuracy of the alpha-Defensin test, a lateral flow test for the qualitative detection of alpha-Defensin. In this study, 50 patient with indicated revision surgery met the inclusion criteria due to septic or aseptic loosening. In addition to clinical standard diagnostics of PJI, the alpha-Defensin testAim
Method
Septic arthritis is a therapeutic emergency with a high mortality rate (about 11%)(1). Inadequate treatment can cause permanent joint damage. Management of the septic arthritis includes prompt antibiotic treatment as well as joint-decompression and removal of purulent material(2). It is still discussed controversially and there is little evidence which surgical concept is preferable: arthroscopy with lavage and debridement or open arthrotomy with synovectomy(3,4). The aim of the study was to compare efficacy of arthroscopy and arthrotomy in patients with septic gonarthritis. We evaluated 70 consecutive patients who underwent arthroscopy or arthrotomy at our clinic, because of a bacterial monarthritis of the knee between 2002 and 2010. Our primary outcome was the early recurrence of infection (> 3 months after surgery), which made a second surgery necessary. We compared patients who suffered reinfection and those who did not, in regard to the surgery type as well as potential confounders like comorbidity (measured by Charlson comorbidity index), age, body mass index (BMI), Gächter's -, Kellgren and Lawrence - and Outerbridge classification, duration of symptoms and inflammatory parameters. Furthermore we evaluated differences of the confounders between the surgery groups. From the 70 patients 41 were treated arthroscopic and 29 with arthrotomy. In total eight patients (11.4%) had to undergo a second surgery because of early reinfection. The rate was significantly higher in patients treated with arthrotomy (n=6; 20.7%) compared to those treated with arthroscopy (n=2; 4.9%) (p=0.041). Whereas we found no significant influence of potential confounders between the reinfection group and the group where primary eradication was achieved. Patients who underwent arthrotomy were significantly older, had more comorbidities (both p<0.001) and higher grades of osteoarthritis according to Kellgren and Lawrence classification (p=0.023). In order to adjust the study population towards confounders we performed a subgroup analysis on patients of the second and third age percentile. When we repeated our analysis we still found a significant higher reinfection rate in the arthrotomy group (p=0.036). At the same time there were no differences in prevalence of confounders, neither between the two surgery groups, nor between the reinfection and the primary eradication group. Patients with bacterial monarthritis of the knee who were treated with arthroscopy had a significantly lower reinfection rate than those treated with arthrotomy. As arthroscopy is the less invasive and more sufficient method it should be considered the routine treatment according to our data.
