Chronic Periprosthetic Infection Research Articles

Clinical and Radiographic Outcomes of a Long Cementless Monobloc Stem for Revision Total Hip Arthroplasty Due to Chronic Periprosthetic Infection

BackgroundA long cementless monobloc stem is widely used for aseptic loosening, with satisfactory five-to-ten-year outcomes reported. Nonetheless, related studies on chronic periprosthetic joint infection (PJI) are scant. This study evaluated the clinical and radiographic outcomes of the stem in two-stage revisions due to PJI. MethodsThis prospective multicenter cohort study consisted of patients from three medical centers who were enrolled in a single arm from January 2017 to May 2022. All patients were diagnosed with chronic PJI based on International Consensus Meeting (ICM) criteria and underwent two-stage revisions using a long monobloc cementless revision stem. Among 44 patients, 37 (12 women and 25 men) completed an average follow-up of 35.6 months (range, 14 to 75). The primary outcome was the stability of the stem; secondary outcomes included infection eradication, Harris hip score, leg length discrepancy, major complications, and isolated pathogens at intraoperative cultures. ResultsAt one year after revision, the infection-free prosthesis survival rate was 97.3% (95% CI [confidence interval]: 96.4 to 98.2%). At the last follow-up, the mean subsidence was 2.9 ± 2.1 mm (range, 0.8 to 4.8). Postoperative leg length discrepancy averaged −4.6 ± 4.9 mm (range, −16 to 0). The Engh score averaged 14.1 ± 6.9 (range, 0 to 22). The Harris hip score improved from a preoperative average of 35.7 ± 8.5 (range, 12 to 50) to 80.4 ± 9.3 (range, 58 to 92) at the 1-year postoperative follow-up (P < 0.01). ConclusionThe long cementless monobloc stem used in the current study presents a feasible option for two-stage revision in cases of chronic PJI. The bone ingrowth and stability could be observed within the short follow-up time.

Can a 1.5-Stage Revision be an Effective Alternative for Chronic Periprosthetic Hip and Knee Infections? A Systematic Review and Meta‐Analysis

BackgroundA 1.5-stage revision could be an alternative to a 2-stage revision for treating hip and knee chronic periprosthetic infections, guaranteeing the maintenance of joint function and infection control and preventing infection-free patients from undergoing further surgery. Our systematic review aimed to answer several questions about the indication, the infection eradication rate, and the long-term functional outcome of 1.5-stage revisions used to treat chronic periprosthetic infections of the hip and knee. MethodsA systematic review of the literature was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, including studies dealing with the use of 1.5-stage and two-stage surgery for chronic periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) or total hip arthroplasty (THA). The Coleman Methodology Score and the Methodological Index for Non-randomized Studies (MINORS) score were used to assess the quality of the studies. A meta-analysis was performed to evaluate the infection eradication rate using either the 1.5-stage revision or the two-stage technique. A total of 494 patients (111 hips and 385 knees) who underwent 1.5-stage with a mean age of 69 years (range, 61 to 82) were identified in the ten included studies. ResultsThe most common cause of reoperation was the conversion to the definitive prosthesis, followed by aseptic loosening. Infection control was reached in 84.6% of the 1.5-stage and 76.1% of the two-stage cohorts. The infection recurrence rate was higher in the two-stage cohort than the 1.5-stage group (21.8 versus 14.3%). ConclusionThe 1.5-stage technique represents a valid treatment option in selected patients who have chronic PJI who cannot undergo further surgeries, adding together the benefits of the one- and two-stage procedures. Furthermore, the 1.5-stage showed a better success rate in the infection resolution than the two-stage technique.

MANAGEMENT OF A PERIPROSTHETIC INFECTION AFTER TOTAL LEFT KNEE REPLACEMENT USING AN ORIGINAL METHOD FOR ARTICULATING SPACER MANUFACTURING: CASE STUDY

Periprosthetic infection (PPI) is one of the most severe complications after total knee replacement. While managing patients with chronic deep PPI after total knee replacement, two-stage revision arthroplasty with intermediate installation of an antimicrobial knee joint spacer is used. The advantage of an articulating spacer is the ability to maintain motor activity until reimplantation of a permanent endoprosthesis. However, factory moulds including 3D-printed are not always available in routine clinical practice, given the high cost and limited equipment accessibility.&#x0D; We present a case study of a patient with chronic deep PPI after total left knee replacement. An original method of intraoperative manufacturing of the tibial component of the articulating spacer was used in the course of treatment. The technique involves sterile mould making using a fitting plastic liner and soft polymer mass. Bone cement impregnated with antibacterial drugs is placed into the mould. When the bone cement hardens, a tibial spacer component is ready. The sterilized femoral and fabricated tibial spacer components are implanted using antibiotic-impregnated bone cement. If it is not technically possible to use fitting inserts, a previously removed plastic insert from the endoprosthesis can be used. The developed original method has a number of advantages: individual selection of spacer sizes, independent addition of the required quantity and type of antibacterial drugs, and economic efficiency. Successful infection relief in the patient allowed further revision endoprosthetics with installation of a permanent endoprosthesis.

Utilizing an antibiotic-eluting articulated cemented spacer in the two-stage management of infected total hip arthroplasty: a technical note.

Two-stage revision is generally preferred to eradicate chronic periprosthetic infections after total hip arthroplasty (THA) because of its good infection control and promising results. During two-stage revision, a temporary antibiotic-impregnated cement spacer was initially used for the local delivery of antibiotics, thereby reducing the risk of infection recurrence. Many researchers have reported various techniques for fabricating cemented spacers; however, there is no established standard technique. We share our cost-effective and easily reproducible technique for creating an articulated cemented spacer for managing infected THA.

Two-Stage Treatment of Chronic Periprosthetic Knee Infections With the Use of Gentamicin-Articulated Spacers: Success Rate and Predictors of Failure at the Minimum Seven-Year Follow-Up.

The purpose of this study was to assess the survivorship rates of 2-stage treatment with gentamicin-impregnated polymethylmethacrylate articulated knee spacer in patients with chronic periprosthetic joint infection and to identify risk factors associated with failure. We conducted a retrospective study among 73 patients with chronic periprosthetic joint infection after primary total knee replacement with articulated polymethylmethacrylate gentamicin-impregnated spacers (Subiton, Medical Labs, Ind Argentina), performed in a single institution with a minimum follow-up of 7years. Clinical and functional assessment was performed with Knee Society Score and Western and Ontario McMaster Universities Osteoarthritis Index. A univariate and multivariate analysis was performed to identify the variables that influenced the success and failure rates. We included 73 patients. There were 53 (71.3%) monomicrobial, 11 (15%) polymicrobial, and 10 (13.7%) negative cultures infections. The success and failure rates were 90.5% (n= 66) and 9.5% (n= 7), respectively. Multivariate analysis identified that age (odds ratio= 1.77; P= .039), greater erythrocyte sedimentation rate values prior to the first stage (odds ratio= 1.04; P= .006), and polymicrobial infections (odds ratio= 7.32; P= .0003) were independent variables associated with failure. Two-stage revision with polymethylmethacrylate gentamicin-impregnated knee spacers is an effective strategy for the treatment of chronic periprosthetic joint infection after total knee arthroplasty. Age, higher erythrocyte sedimentation rate values prior first stage, and polymicrobial infections were independent risk factors for treatment failure.

One-stage revision for infected shoulder arthroplasty: prospective, observational study of 37 patients

Periprosthetic joint infection is a severe complication of joint replacement surgery. Thus two-stage exchange remains the gold standard, one-stage exchange is now widely recommended. We hypothesized that, for patients with chronic periprosthetic shoulder infection (PSI), treatment with a one-stage exchange would be an effective approach to eradicate infection, relieve pain, and restore function to the involved shoulder. This monocenter cohort study in a Bone and Joint Infection Referral Center (11/2003-05/2020) included all patients with confirmed PSI treated by one-stage revision. Data were extracted from the prospective database, including demographics, infection characteristics, and functional evaluations (range of motion and Constant Score at admission and last follow-up). The primary outcome was the 2-year reinfection-free rate. We included 37 patients. The refection-free rate was 5%. The most commonly isolated pathogen was Cutibacterium acnes (68%), isolated alone (15 patients, 41%) or as polymicrobial infections (10 patients, 27%). The Constant Score increased significantly from 24 to 53 (P=.001). Range of motion (forward elevation, abduction) was also significantly improved after surgery. Mean active forward elevation increased significantly by 45° from 60° to 105° postoperatively (P<.001), mean abduction increased by 42° from 55° to 97° (P<.001). Results from our prospective cohort-extracted series suggest that one-stage revision is a reliable treatment with a low infection recurrence rate. Improved functional outcomes can be achieved with one-stage exchange. Our patients' overall functional results were similar to those previously reported for one-stage revision and better than those reported after two-stage exchange. Patients with multiple previous surgeries seem to have worse functional outcomes than the subgroup without surgery before the index arthroplasty. Our results and literature search findings suggest that one-stage revisions effectively eradicate PSIs, with good functional outcomes.

Novel, static, permanent spacers to treat chronic knee periprosthetic joint infections

PurposeTo discuss a static and permanent spacer in the treatment of chronic periprosthetic knee infection. MethodsIn this study, patients who were diagonised with chronic periprosthetic knee infection and not appropriate to undergo revision operations were included and were treated with static and permanent spacers. Infection recurrence rate was recorded, Visual Analogue Scale (VAS) score and Knee Society Score (KSS) were used to record patients’ pain and knee function before the operation and at the final follow-up (minimum 24 months).ResultsFifteen patients were identified for this study. Pain and function were significantly improved at the latest follow-up evaluation. One patient had a recurrent infection and underwent amputation. No patients had signs of residual instability at the final follow-up evaluation, and no breakage or subsidence of the antibiotic spacer were identified at the final radiographic follow-up evaluation.ConclusionOur study provided evidence that the static and permanent spacer was a reliable salvage procedure to treat periprosthetic knee infection in compromised patients.

Is long time to reimplantation a risk factor for reinfection in two-stage revision for periprosthetic infection? A systematic review of the literature.

The two-stage revision arthroplasty is a common treatment option for chronic periprosthetic infection (PJI). The time to reimplantation (TTR) reported in the literature varies substantially from a few days to several hundred days. It is hypothesized that longer TTR could be associated with worse infection control after second stage. A systematic literature search was performed according to Preferred Reporting items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, in Pubmed, Cochrane Library and Web of Science Core Collection in clinical studies published until January 2023. Eleven studies investigating TTR as a potential risk factor for reinfection met the inclusion criteria (ten retrospective and one prospective study, published 2012-2022). Study design and outcome measures differed notably. The cutoff points above which TTR was regarded as "long" ranged from 4 to 18 weeks. No study observed a benefit for long TTR. In all studies, similar or even better infection control was observed for short TTR. The optimal TTR, however, is not yet defined. Larger clinical studies with homogeneous patient populations and adjustment for confounding factors are needed.

Globulin and Albumin/Globulin Ratios as Potential Biomarkers for the Diagnosis of Acute and Chronic Peri-Prosthetic Joint Infections: A Retrospective Study.

Background: Peri-prosthetic joint infection (PJI) is the most serious complication after prosthetic joint replacement. However, the diagnosis of PJI remains challenging for clinicians because of the lack of a gold standard. The purpose of this study was to investigate the diagnostic significance of serum globulin, albumin/globulin, and other biomarkers in acute and chronic periprosthetic infections. Patients and Methods: A retrospective study of 162 patients with PJI and aseptic loosening between January 2016 and March 2021 at our institution was performed in three groups. There were 20 patients with acute infection in group A, 36 patients with chronic infection in group B, and 106 patients with aseptic loosening in group C. Globulin, albumin/globulin, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), platelet count (PLT), mean platelet volume (MPV), d-dimer, and platelet count/mean platelet volume ratio (PMR) levels were recorded. The area under the curve (AUC) was used to measure the diagnostic value of globulin and albumin/globulin with other biomarkers for PJI. Results: Compared with the aseptic loosening group, the acute and chronic PJI group had higher levels of CRP, ESR, d-dimer, globulin, PLT, and PMR (p < 0.01) and lower levels of albumin/globulin and MPV (p < 0.01). The optimal cutoff, AUC, sensitivity, and specificity of CRP, albumin/globulin, ESR, and globulin were: CRP, 8.3 mg/L, 0.903, 78.57%, and 88.68%; albumin/globulin, 1.31, 0.899, 91.07%, and 73.58%; ESR, 32 mm/h, 0.888, 75.%, and 85.85%; globulin, 29.5 g/L, 0.880, 91.07%, and 72.64%. Conclusions: Globulin and albumin/globulin have excellent diagnostic value for acute and chronic PJI and are promising potential biomarkers for the diagnosis of PJI. The diagnostic performance of albumin/globulin is superior to that of ESR and similar to that of CRP.

One and a Half-Stage Revision With Prosthetic Articulating Spacer for Definitive Management of Knee Periprosthetic Joint Infection.

This paper is a comprehensive review that describes indications, contraindications, clinical outcomes, and pearls and pitfalls of 1.5-stage revision total knee arthroplasty (TKA) utilizing a primary TKA femoral component, all-polyethylene tibial component, and hand-crafted antibiotic cement for the management of chronic periprosthetic joint infection. The 1.5-stage exchange TKA details placement of an articulating spacer for an indefinite period, prolonging revision until reinfection, deterioration of functional status, or construct failure. A 1.5-stage revision TKA technique is a viable option for treatment of chronic periprosthetic knee infections. The inherent advantages of decreased health-care costs, decreased morbidity and mortality, and improved emotional ease from having a single procedure is attractive, especially if reinfection rates are determined to be equivocal to 2-stage revision.

Treatment of patients with periprosthetic infection

The review article presents the main questions of pathogenesis, early diagnosis, and surgical management of patients with paraprosthetic infection that developed after surgery for fractured limb bones and deforming arthrosis. The main factors that influenced the occurrence of purulent complications and the ways of their prevention, treatment, taking into account the current ideas about wound infection, are indicated. Pathogenetic mechanisms of paraprosthetic infection development are directly related to the presence of hematoma in the operated joint. Risk factors for large joint arthroplasty can be divided into three conditional types: general and local patient status; conditions for the operation; features of surgery. To detail the risk factors associated with the general or local status of the patient, two subtypes are highlighted — primary and secondary. The main subtype includes: 1) focus infection, located in the operated joint; 2) focus infection, located in the paraarticular tissues of the operated joint; 3) generalization of the infectious process — sepsis. The additional subtype includes: 1) history of previous joint surgery; 2) critical changes in body mass index; 3) uncontrolled diabetes mellitus; 4) presence of systemic diseases associated with prolonged administration of glucocorticosteroids and cytostatics and others. Two-stage revision endoprosthesis in patients with chronic periprosthetic infection is the gold standard to date. In many ways, the success of treatment depends on the correctness of all stages, on the adequacy of diagnostic measures, the scrupulousness of compliance with surgical technique and is determined by the surgeon’s experience, as well as the equipment of the hospital.

Debridement antibiotics irrigation and implant retention in the treatment of chronic periprosthetic infection of FEMUR.

Debridement antibiotics irrigation and implant retention in the treatment of chronic periprosthetic infection of FEMUR.

Preliminary tribological results of a new total temporary hip joint prosthesis spacer

Temporary antibiotic-loaded cement spacers are widely used for treating chronic periprosthetic hip infections. The aim of this study is to evaluate the short-term tribological performance of ultra-high-molecular-weight polyethylene (UHMWPE) and (60Co) gamma-irradiated cross-linked UHMWPE (XLPE) self-mated systems as frictional pairs for temporary total hip spacers. A three-axial hip joint simulator, FIME II, was used to test the UHMWPE and XLPE self-mated systems under variable load profiles. A fetal bovine serum solution was used as a lubricant. After simulation tests, wear measurements of damaged coupled surfaces were made with a coordinate measuring machine. Finally, surfaces were characterized with scanning electron microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy, and nanoindentation tests. The mass loss test results for UHMWPE were 11.91 ± 3.43 mg for the cups and 4.57 ± 0.92 mg for the heads. Whereas, the results for XLPE showed a significant reduction, with mean mass loss values of 6.59 ± 0.14 mg for the cups and 2.82 ± 0.59 mg for the heads, suggesting the viability of the self-mated XLPE contact pair for a temporary total hip spacer.

Factors affecting range of motion following two-stage revision arthroplasty for chronic periprosthetic knee infection

IntroductionThe purpose of this study was to evaluate factors that affect range of motion (ROM) following two-stage revision arthroplasty as a treatment for chronic periprosthetic knee infection.Materials and methodsA total of 98 patients diagnosed with chronic periprosthetic joint infection (PJI) following primary total knee arthroplasty between January 2009 and December 2019 and then underwent two-stage revision arthroplasty were reviewed retrospectively. Multiple regression analysis was performed to evaluate the factors that affect ROM after two-stage revision arthroplasty. ROM after two-stage revision arthroplasty was used as a dependent variable, while age at the time of surgery, ROM at PJI diagnosis, ROM after the first-stage surgery, the interval between the first-stage surgery and the second-stage surgery, whether a re-operation was performed before the second-stage surgery, culture results (culture negative or culture positive), and body mass index (BMI) were used as independent variables.ResultsMultiple regression analysis (R2 = 0.843) revealed that among the independent variables, ROM (β = 0.604, P < 0.001) after the first-stage surgery, whether a re-operation was performed before the second-stage surgery (β = − 8.847, P < 0.001), the interval between the first-stage surgery and the second-stage surgery (β = − 0.778, P = 0.003), and BMI (β = − 0.698, P = 0.041) were associated with ROM after two-stage revision arthroplasty, the dependent variable.ConclusionsIn two-stage revision arthroplasty for chronic periprosthetic knee infection, ROM after the first-stage surgery, whether a re-operation was performed before the second-stage surgery, the interval between the first-stage surgery and the second-stage surgery, and BMI were found to be factors that were associated with ROM after two-stage revision arthroplasty.

Cell-free Deoxyribonucleic Acid: A Potential Biomarker of Chronic Periprosthetic Knee Joint Infection

BackgroundThe correct diagnosis of a chronic periprosthetic joint infection (PJI) is a major challenge in clinical practice, with the “gold standard” for diagnosis yet to be established. Synovial fluid analysis has been proven to be a useful tool for that purpose. Cell-free DNA (cf-DNA) levels have been shown to be increased in several conditions such as cancer, trauma, and sepsis. Therefore, this study was designed to evaluate the potential of synovial fluid cf-DNA quantification for the diagnosis of chronic periprosthetic infections following total knee arthroplasty. MethodsA prospective study with patients undergoing total knee arthroplasty revision surgery for any indication was performed. PJI diagnosis was defined according to the Second International Consensus Meeting on Musculoskeletal Infection (2018) criteria. The study cohort consisted of 26 patients classified as infected and 40 as noninfected. Synovial fluid cf-DNA direct quantification by fluorescent staining was made. Sensitivity, specificity, and receiver operating characteristic curve were calculated. ResultsThe cf-DNA levels were significantly higher in patients who had PJIs (122.5 ± 57.2 versus 4.6 ± 2.8 ng/μL, P < .0001). With a cutoff of 15 ng/μL, the area under the receiver operating characteristic, sensitivity, and specificity of cf-DNA were 0.978, 96.2%, and 100%, respectively. ConclusionThe present study has shown that cf-DNA is increased in synovial fluid of patients who have chronic PJIs. It is a promising biomarker for knee PJI diagnosis and further studies are needed to confirm its utility.

Long Term Results of Two-Stage Revision for Chronic Periprosthetic Knee Infection: A Multicenter Study.

Long-term reinfection and mortality rates and clinical outcomes with sufficient subject numbers remain limited for patients undergoing two-stage exchange arthroplasty for chronic periprosthetic knee infections. The purpose of this study was to determine the long-term reinfection, complication, and mortality following reimplantation for two-stage exchange following knee arthroplasty. Retrospective review of 178 patients who underwent two-stage exchange knee arthroplasty for chronic PJI at three large tertiary referral institutions with an average of 6.63-year follow-up from reimplantation from 1990 to 2015. Rates of reinfection, mortality, and all-cause revision were calculated along with the cumulative incidence of reinfection with death as a competing factor. Risk factors for reinfection were determined using Cox multivariate regression analysis. Overall rate of infection eradication was 85.41%, with a mortality rate of 30.33%. Patients with minimum 5-year follow-up (n= 118, average 8.32 years) had an infection eradication rate of 88.98%, with a mortality rate of 33.05%. This is a large series with long-term follow-up evaluating outcomes of two-stage exchange knee arthroplasty resulting in adequate infection eradication and high mortality. Results were maintained at longer follow-up. This technique should be considered in patients with chronic PJI; however, realistic expectations regarding long-term outcomes must be discussed with patients.

Long Term Results of Two-Stage Revision for Chronic Periprosthetic Hip Infection: A Multicenter Study.

Background: Two-stage exchange arthroplasty remains the gold standard in the United States for treatment of chronic periprosthetic joint infection (PJI). Long-term reinfection rates and clinical outcomes with sufficient subject numbers remain limited. The purpose was to evaluate the long-term outcomes following two-stage exchange following hip arthroplasty. Methods: Retrospective review of 221 patients who underwent two-stage exchange hip arthroplasty for chronic PJI at three large tertiary referral institutions from 1990–2015. Outcomes including reinfection, mortality, and all-cause revision were calculated. Cumulative incidence of reinfection with death as competing factor was also calculated. Risk factors for reinfection were determined using Cox multivariate regression analysis. Results: Rate of infection eradication and all-cause revision was 88.24% and 22.6%, respectively. Overall mortality rate was 40.72%. Patients with minimum five-year follow-up (n = 129) had a success rate of 91.47% with mortality rate of 41.1%. Major risk factors for reinfection included polymicrobial infection (HR = 2.36, 95% CI: 1.08–5.14) and antibiotic resistant organism (HR = 2.36, 95% CI: 1.10–5.04). Conclusion: This is the largest series with greater than 5-year follow-up evaluating outcomes of two-stage exchange hip arthroplasty. This technique resulted in a relatively high infection eradication, however, the mortality rate is alarmingly high. Antibiotic resistant organisms appear to be highest risk factor for failure.

New Primary Total Knee Arthroplasty Components Versus Other Contemporary Types of Spacers for the Treatment of Chronic Periprosthetic Knee Infection With a Two-Stage Protocol.

The optimal type of antibiotic spacer for the treatment of a knee periprosthetic joint infection (PJI) remains a topic of debate. Although the ultimate goal of an antibiotic spacer is infection control, contemporary spacer iterations, such as the use of a new femoral component (NFC), may offer unique advantages. The primary goal of this study was to compare rates of infection control and functional outcomes between contemporary spacer types. We retrospectively reviewed 96 patients who underwent removal of a total knee arthroplasty with insertion of an antibiotic spacer for knee PJI over a 14-year period at a single institution with a minimum 1-year follow-up. Three patient cohorts were defined based on spacer type: NFC (n=30), cement-on-cement (n=19), and static (n=47). There was no association between spacer type and the odds of infection clearance (P=.60). The NFC spacers resulted in increased knee range of motion before replantation and improved ambulatory status at 8 weeks postre-plantation, although no difference was seen at final follow-up. The use of NFC spacers may provide functional advantages over their contemporary counterparts, and the potential of NFC spacers to be used in single-stage exchange arthroplasty remains an appealing area of investigation. Future high-powered, prospective, noninferiority studies between contemporary spacer types are needed. [Orthopedics. 2022;45(2):109-115.].

Does the Implementation of the PRO-IMPLANT Foundation Treatment Algorithm Improve the Outcome of Chronic Periprosthetic Knee Infections? Mid-Term Results of a Prospective Study.

Several treatment options for chronic periprosthetic joint infections have been published in the current literature, with an on-going discussion to determine effective management algorithms. To compare outcomes of the two-stage exchange procedure in revision TKA prior to and after implementation of the PRO-IMPLANT Foundation treatment algorithm. The primary endpoints were defined as (i) revisions during the interval time, (ii) duration of the interval time and (iii) successful PJI eradication. Between 02/2013 and 09/2016, 122 patients were included in a single-centre cohort analysis. 55patients were treated according to the previously used algorithm (K1) and 67 according to the PRO-IMPLANT Foundation algorithm (K2). A minimum follow-up period of 3 years was set as the inclusion criterion. Successful eradication of infection was defined in accordance with the consensus criteria by Diaz-Ledezma et al. RESULTS: Successful eradication was achieved in 42 (67%) patients in K1 and 47 (85.5%) in K2 (p ≤ 0.005). The mean interval time was 88 days (range 51 - 353) in K1 and 52 days (range 42 - 126) in K2 (p ≤ 0.005). In K1, a mean of 0.8 (range 0 - 6) revisions were necessary during the interval period compared with 0.5 (range 0 - 4) in K2 (p = 0.066). Implementation of the PRO-IMPLANT treatment algorithm led to significant improvement in the outcome of periprosthetic joint infections. During mid-term follow-up, infection eradication was highly successful, with decreases in the interval time as well as the number of revisions.

Analysis of pathogen distribution and drug resistance of acute,delayed and chronic periprosthetic joint infection

Objective: To analyze the pathogen distribution and drug resistance in acute,delayed and chronic periprosthetic joint infection (PJI). Methods: The clinical data of 316 patients with periprosthetic infection after primary hip and knee arthroplasty admitted to the Department of Arthroplasty,the First Affiliated Hospital,Xinjiang Medical University from August 2010 to August 2020 were retrospectively analyzed.There were 146 males and 170 females,aged (62.3±14.2) years (range:22 to 89 years).One hundred and sixty one patients underwent total hip arthroplasty and 155 patients underwent total knee arthroplasty.According to the time of postoperative infection,the patients were divided into acute PJI group (65 cases),delayed PJI group (83 cases) and chronic PJI group (168 cases).The results of pathogen species,composition ratio and drug susceptibility tests were collected,and the independent sample t test,Chi-square test or Fisher's exact probability test were used for comparison. Results: Gram-positive bacteria were the main pathogens of PJI (49.7%,157/316),and the positive rates of culture in patients with acute PJI,delayed PJI and chronic PJI were 33.8% (22/65),55.4% (46/83) and 53.0% (89/168),and the difference was statistically significant(χ²=8.343,P=0.015).The common bacteria were coagulase-negative Staphylococcus (54.8%,86/157) and Staphylococcus aureus (30.6%,48/157),The drug-sensitivity to linezolid,vancomycin and tigacycline was 100%.The gram-negative bacteria were mainly Escherichia coli and Enterobacter cloacae,and the drug resistance rate to carbapenems was low,ranging from 0 to 9.09%.The drug resistance rates of acute PJI patients to rifampicin,ciprofloxacin and erythromycin were significantly higher than those of late onset and chronic PJI patients,the difference was statistically significant(rifampicin:χ²=14.332,P=0.001;ciprofloxacin:χ²=12.086,P=0.002;erythromycin:χ²=9.096,P=0.010);The drug resistance rate of acute PJI patients to levofloxacin,clindamycin and tetracycline was higher than that of chronic PJI patients,and the difference was statistically significant(levofloxacin:χ²=10.500,P=0.002; clindamycin: χ²=7.103,P=0.007; tetracycline: χ²=6.909,P =0.012).The resistance rate of ampicillin/sulbactam in acute PJI (60.0%) was significantly higher than that in chronic PJI (16.7%),and the difference was statistically significant(χ²= 5.853,P=0.040). Conclusion: Gram-positive bacteria are the main pathogens of PJI,and the resistance rate of pathogens of acute PJI is higher than that of late onset and chronic PJI.