What Are the Long-term Outcomes of Mortality, Quality of Life, and Hip Function after Prosthetic Joint Infection of the Hip? A 10-year Follow-up from Sweden

Unsuspected Positive Intra-Operative Cultures in Aseptic Revision Hip Arthroplasty: Prevalence, Management, and Infection-Free Survivorship

BACKGROUND

This study aimed to describe the management and outcomes of aseptic revision total hip arthroplasty (arTHA) with unsuspected intraoperative positive cultures (UPCs) compared to those with sterile cultures.

METHODS

A single tertiary center's institutional database was retrospectively reviewed for arTHA from January 2013 to October 2023. Preoperative Musculoskeletal Infection Society scores were assigned to patients based on available infectious workup, and those who met the criteria for periprosthetic joint infection (PJI), received antibiotic spacers, or had less than 1-year follow-up were excluded. Patients were grouped and compared according to intraoperative culture results as follows: sterile cultures, one unexpected positive culture with a new organism, one UPC with the same organism as prior PJI, ≥ two UPCs with different organisms, and ≥ 2 UPCs with the same organism.

RESULTS

There was a total of 604 arTHAs included in this study, of which 0.8% [5 of 604] had ≥ two UPCs with different organisms, 1.5% [9 of 604] had ≥ two UPCs with the same organism, 9.8% [59 of 604] had one UPC with a new organism, 0.2% [one of 604] had one UPC with an organism from prior PJI, and 87.7% [530 of 604] of patients had sterile cultures. When comparing 5-year infection-free survival between patients who had one UPC with a new organism and sterile cultures, there was no difference (P = 0.40); however, patients who had ≥ two UPCs with different organisms (P < 0.001), patients who had ≥ two UPCs with the same organism (P = 0.001), and patients who had one UPC of an organism from prior PJI (P < 0.001) had statistically worse infection-free survival compared to patients with sterile cultures.

CONCLUSIONS

Infection-free survival at five years was similar between patients who had one UPC with a new organism and those who had sterile cultures; however, ≥ two UPCs and a history of PJI are both significant risk factors for rerevision for infection after arTHA.

How Dutch orthopedic healthcare professionals perceive antibiotic resistance: A mixed-methods application of the mental model approach

Healthcare professionals must act to curb antibiotic resistance (ABR), one of today's greatest threats to global health. This study applied the mental model approach to understanding perceptions of ABR among different Dutch orthopedic healthcare professionals. The expert model (step 1) was based on evidence-based ABR information and expert interviews (n = 3). This model prompted the step 2 questionnaire to inquire about perceived causes, consequences, and actions related to ABR (open-ended, n = 12). In the step 3 questionnaire (Likert-scales, n = 55), participants rated the impact of causes of ABR, the likelihood and severity of consequences of ABR, and the effectiveness of actions against ABR. Step 3 showed that no specific causes, consequences, or actions are perceived to strongly outweigh the others. Dutch orthopedic healthcare professionals perceive the causes of ABR to be mostly external, the consequences of ABR to be abstract and the most effective actions against ABR to be performed by others.

Successful Management of Periprosthetic Joint Infection Following Total Joint Arthroplasty, as Defined by the Patient: A Qualitative Study

BACKGROUND

The literature on the subjective experience of patients undergoing treatment for periprosthetic joint infection (PJI) following total joint arthroplasty (TJA) is scarce, and treatment success is defined without consideration of patient values. The primary objective of this study was to characterize the experience of patients undergoing PJI management. The secondary and tertiary aims were to identify factors that patients associate with successful treatment and to assess alignment with a 2019 outcome-reporting tool (ORT) by the Musculoskeletal Infection Society (MSIS).

METHODS

Patients treated for PJI at 2 international tertiary arthroplasty centers and for whom no less than 1 year and no more than 5 years had elapsed since their most recent revision surgery were included. From August 2023 to April 2024, patients participated in semistructured interviews with a phenomenological approach-an approach that aims to provide detailed examinations of personal lived experiences and to identify themes regarding how a particular phenomenon is experienced. Interview topics included experiences with primary TJA, PJI diagnosis and management, and patient perceptions of the success of their PJI management. Interviews were transcribed, and a thematic analysis was performed. The concordance between patient-defined and MSIS ORT-defined treatment success was calculated.

RESULTS

Of 27 total patients, 21 (78%) reported considerable mental health impacts during the period from PJI onset to treatment conclusion. In defining successful PJI management, patients consistently emphasized the importance of function, pain relief, mobility, and independence. Nine (33%) of the patients (p < 0.001) did not agree with their MSIS ORT classification of success versus failure.

CONCLUSIONS

PJI is a devastating complication following TJA, and success as defined by patients does not align with success as defined by clinicians. As a result, there is insufficient support offered to patients throughout the PJI management process. Future avenues for research include the exploration of the feasibility and impact of implementing patient-centered care models that feature psychological support.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Critical Management of Septic Orthopedic Patients: The Impact of Intensive Care on Survival and Recovery

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.

Medicaid Insurance Is Associated With Increased Readmissions and Mortality After Surgery for Periprosthetic Joint Infection

BACKGROUND

Patients with Medicaid insurance are at an increased risk of postoperative complications following total knee arthroplasty and total hip arthroplasty (TJA); however, their outcomes following revision TJA for periprosthetic joint infection (PJI) requires further study.

METHODS

A retrospective query was conducted for adult patients undergoing implant explantation and antibiotic spacer placement for TJA PJI from the Premier Healthcare Database between December 1, 2016, and December 31, 2021. Patients were then grouped by Medicaid or non-Medicaid insurance status and were age matched through exact caliper matching. Multivariable regression models addressed potential confounding. Adjusted risks of 90-day postoperative complications were reported.

RESULTS

Of the 40,346 patients identified, 2,711 Medicaid patients were matched to 10,844 non-Medicaid patients on age (56.1 vs. 56.1 years, P = 1.000). Patients with Medicaid experienced higher risk of sepsis (adjusted odds ratio [aOR] = 1.20, P = 0.010), readmission (aOR = 1.12, P = 0.022), being discharged to a skilled nursing facility (aOR = 1.13, P = 0.031), and had longer length of stay (9.48 vs. 6.67 days, P < 0.001), compared with patients with non-Medicaid. Medicaid patients had a higher rate of inpatient mortality (0.81% vs. 0.48%, P = 0.038); however, the risk was similar after accounting for differences in comorbidities.

CONCLUSION

Following revision TJA for PJI, patients with Medicaid were at an increased risk for postoperative complication, including sepsis and readmission. They experienced a higher rate of inpatient mortality that may be driven by differences in comorbidities. Insurers and policy makers should consider this information to develop risk stratification-based payment strategies that take into account the healthcare burden of this high-risk patient population.

LEVEL OF EVIDENCE

IV.

Comparison of surgical treatments for hip and knee periprosthetic joint infections using the desirability of outcome ranking in a prospective multicentre study

Introduction: In periprosthetic joint infection (PJI), there is a paucity of prospective data comparing debridement, antibiotics and implant retention (DAIR) with two-stage revision while also accounting for time since the initial arthroplasty. Additionally, comparisons often lack patient-centred measures. A desirability of outcome ranking for PJI (DOOR-PJI) unifies joint function, infection cure and mortality into one outcome. We aimed to describe the DOOR-PJI distribution in a large patient cohort and use it to compare DAIR and two-stage revision. Methods: Adults with a newly diagnosed hip or knee PJI from the prospective Prosthetic joint Infection in Australia and New Zealand Observational (PIANO) study were analysed. Patients from 27 hospitals were included. PJI was classified as "early" or "late". The primary outcome was the novel DOOR-PJI at the 2-year follow-up. Results were expressed using win ratio (WR) values. A WR > 1.0 indicates that two-stage revision was superior to DAIR. Results: A DOOR was available for 533 patients. The most common treatments were DAIR (297 patients, 56 %) and two-stage revision (139 patients, 26 %). In early PJI, DAIR was superior to two-stage revision (WR 0.51, 95 % confidence interval (CI) [0.30-0.86], p = 0.012). In late PJI, two-stage revision was superior to DAIR (WR 1.61, 95 % CI [1.11-2.33], p = 0.012). These findings persisted following stratification by comorbidities, affected joint, symptom duration and a sensitivity analysis applying the initial (rather than the main) surgical strategy at day 90. Conclusions: In the first application of a DOOR in orthopaedics, DAIR was superior to two-stage revision for early PJI. Conversely, two-stage revision was superior compared with DAIR for late PJI. These findings were independent of comorbidities and symptom duration.

Preoperative Synovial Fluid Cultures, and Biopsy Cultures After Dry Tap Aspiration, Are Valuable in Diagnosing a Periprosthetic Joint Infection: A Retrospective Study

Periprosthetic joint infection (PJI) is a devastating complication after total hip arthroplasty. Synovial fluid aspiration and preoperative tissue biopsy cultures can be helpful diagnostic tools for PJI. The aim of this study is to evaluate the diagnostic value of synovial fluid aspirations in general, and preoperative biopsies after inconclusive or dry tap aspiration in patients undergoing revision hip arthroplasty in particular. Patients who underwent diagnostic aspiration and subsequent preoperative biopsy and/or revision surgery between January 2015 and January 2024 were included in the study. Synovial fluid aspirations and tissue samples obtained from biopsy and revision surgery were interpreted using the European Bone and Joint Infection Society criteria for PJI. In total, 207 patients were included with 231 synovial fluid aspirations. The sensitivity and specificity of synovial fluid aspiration cultures were 76% and 98%. In 62 cases, tissue biopsies were performed, of which 23 were after dry tap aspiration. Tissue biopsies after dry tap aspiration had a sensitivity of 44% and a specificity of 93%. Tissue biopsies after dry tap aspiration led to the confirmation of PJI in 7/23 cases. Synovial fluid aspiration yields reliable results when evaluating a patient for suspicion of PJI. Diagnosing PJI can, however, be troublesome if the synovial fluid aspiration provides a dry tap or inconclusive result. Tissue biopsy cultures after dry tap aspiration are a feasible way to confirm PJI.

Differences in Success Rate of Two-Stage Revision for Periprosthetic Joint Infection of the Knee Depending on the Applied Definition

BACKGROUND

Success rates of two-stage exchange arthroplasty are subject to substantial variance in the literature. An explanation is the lack of a universally accepted definition of what constitutes treatment success for periprosthetic joint infection. Therefore, the main objective of this study was to assess success rates, applying four definitions to identify the one definition that best captures "true" success from both a clinical and patient-centered perspective.

METHODS

This was a retrospective study investigating the outcome of a consecutive series of 78 chronic knee periprosthetic joint infections that were treated with a two-stage revision at a single center between 2017 and 2020. Kaplan-Meier survival analyses were conducted to estimate success rates.

RESULTS

After a mean follow-up of 36 months (range, 25 to 60), 64 patients (82%) were reimplanted after a mean interim period of 90 days (range, 22 to 201). There was one patient (1%) lost to follow-up, and the overall mortality was 15% (n = 12). Kaplan-Meier survival analyses were used to estimate treatment success at two and three years: implant survival was 93% (95% confidence interval [CI]: 82 to 97) and 87% (95% CI: 73 to 94), infection control was 90% (95% CI: 79 to 95) and 87% (95% CI: 73 to 93), success according to Delphi criteria was 88% (95% CI: 78 to 94), and success according to Musculoskeletal Infection Society criteria was 65% (95% CI: 53 to 74) at both timepoints.

CONCLUSIONS

Success rates were ranging between 65 and 93% depending on the applied definition, highlighting the need for universal success criteria. This variability mainly results from the differing approaches to patients who did not undergo reimplantation or passed away within a year of surgery. These patients exemplify cases of fatal treatment failures. Consequently, the Musculoskeletal Infection Society criteria should be routinely employed to accurately report the "true" success rate.

Mid-term to long-term outcome and risk factors for failure of 158 hips with two-stage revision for periprosthetic hip joint infection

Introduction: This study aimed to evaluate infection-free survival and outcomes after two-stage revision surgery for hip periprosthetic joint infection (PJI) performed in a specialised arthroplasty unit over 20 years. Methods: We retrospectively identified 158 hips (154 patients) treated with two-stage revision surgery for hip PJI between 2001 and 2021. We analysed their data and presented their infection-free survival, re-operation rate, mortality, risk factors and complications. Results: The mean follow-up time was 9 (2 to 21.7) years. A total of 22 hips (13.9 %) were re-infected. The infection-free survival was 94.4 % at 2 years, 89.3 % at 5 years, 84.2 % at 10 years, and 82.6 % at 15 and 20 years. The re-operation rate for aseptic causes was 12 %, and the most common cause of re-operation was dislocation (7 %). The cumulative survival for re-operation for aseptic causes was 93.6 % at 2 years, 89.7 % at 5 years, 88.8 % at 10 years, and 82.8 % at 15 and 20 years. The cumulative survival for all-cause re-revision was 88.8 % at 2 years, 80.8 % at 5 years, 74.9 % at 10 years, and 68 % at 15 and 20 years. The mean Western Ontario and McMaster Universities Arthritis Index (WOMAC) hip score significantly improved from 68.3 at the pre-operative stage to 35.9 at 2.1 (2 to 3.3) years, 35.3 at 5.3 (5 to 8.4) years, 38.3 at 11.3 (10-15) years and 43.8 at 18.7 (16.5 to 21.7) years ( p < 0.01 ). Duration of antibiotics and gram-negative infection were the only predictive risk factors for re-infection. Conclusion: Our results of the two-stage revision protocol for hip PJI were satisfactory and comparable with the best reported outcomes.

Effect of Antiseptic Irrigation Solutions on Primary Human Knee Fibroblasts Cultured in Human Platelet Lysate

BACKGROUND

Native and periprosthetic joint infections are devastating conditions fraught with patient morbidity and mortality. Aseptic and septic joints are often debrided and irrigated to decrease bacterial loads when preventing or treating infection. However, the effect of clinically used irrigation solutions on the native cellular components of the synovial joint is unknown.

METHODS

Patients consented, and their suprapatellar knee tissue was surgically excised for fibroblast isolation. Cultured knee fibroblasts were treated with normal saline for three minutes or one of the following experimental solutions: acetic acid, chlorhexidine-gluconate, Dakin's solution, hydrogen peroxide, or povidone-iodine. The exposure time for the antiseptic solutions was one and three minutes. At 24 hours after irrigation treatment, metabolic activity was measured via MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] activity assay, and deoxyribonucleic acid content was assessed by Hoechst staining as a surrogate for cell number. Phase-contrast imaging elucidated proliferation potential, progressive cell loss, and cell morphology over a 5-day period. All experiments were repeated in triplicate.

RESULTS

All experimental antiseptic irrigation solutions, regardless of application time, caused a significant reduction in metabolic activity and DNA content, indicating extensive cell death. Phase-contrast imaging showed halted cellular proliferation, progressive cell loss, and distinct changes in cellular morphology, indicating decreased cellular viability and progressive cell death.

CONCLUSIONS

All antiseptic irrigation solutions investigated in this study were severely cytotoxic to human knee fibroblasts regardless of their chemical composition. The concentrations of these solutions are commonly used in orthopaedic surgery. Although these solutions have high bactericidal properties, it may be beneficial to use them in combination at lower doses to retain their effect on bacteria while remaining benign to native synovial cells.

Bibliometric Analysis of Outpatient Hip and Knee Arthroplasty Research Evolution

Objectives

Total joint arthroplasty is an effective treatment for end stage osteoarthritis. As perioperative protocols are developed, outpatient arthroplasty has been gaining traction to facilitate earlier recovery and same day discharge. The aim of this manuscript is to analyze the trends in outpatient arthroplasty over a 17-year duration. This analysis seeks to predict emerging themes in the literature on patient optimization and outcomes in outpatient arthroplasty.

Methods

This study conducted a literature review on outpatient arthroplasty with the Web of Science Core Collection over a 17-year period between 2005 and 2022. Bibliometric data was imported and analyzed with Bibliometrix and VOSviewer.

Results

198 articles were identified demonstrating an annual growth of 19.61% with notable bursts in 2017 and 2021. United States was the top global contributor followed by Canada and European nations. There were significant contributions across 219 institutions and 758 authors, with the Journal of Arthroplasty being the most productive and influential journals. Key themes identified include the feasibility of outpatient surgery, pain management, and perioperative complications and costs.

Conclusion

This bibliometric analysis highlights the ongoing growth and development within outpatient arthroplasty since 2005. The United States remain the global leader within outpatient related arthroplasty research. Previous, current, and ongoing trends are highlighted within this field for further development as hotspots.

Early Periprosthetic Joint Infections in Total Hip and Knee Arthroplasty: Microorganisms, Mortality, and Implant Survival Using a Combined Dataset From the Dutch Arthroplasty Register and the Dutch National Nosocomial Surveillance Network

BACKGROUND

Periprosthetic joint infections (PJIs) can lead to higher re-revision rates and even higher mortality rates that may be associated with the responsible microorganism. We evaluated microorganisms that cause early PJIs in primary total hip and knee arthroplasty (THA and TKA) and examined mortality as well as PJI re-revision rates after these PJIs, using a combined dataset from the Dutch Arthroplasty Register and the Dutch National Nosocomial Surveillance Network (PREZIES). Secondly, the most common microorganisms that cause PJIs were described according to patient and implant survival.

METHODS

We included all PREZIES-confirmed PJIs (n = 1,648) from the combined dataset in which primary THAs and TKAs (2012 to 2018) from the Dutch Arthroplasty Register and PREZIES were case-level matched. Kaplan-Meier survival analyses were performed to determine mortality and PJI re-revision rates following PJI revision.

RESULTS

The most prevalent microorganism in THAs and TKAs was Staphylococcus aureus (THA 34%; TKA 39%), followed by Coagulase-negative staphylococci (THA 20%; TKA 19%), with Staphylococcus epidermidis (THA 12%; TKA 11%) as the most common subtype, and Enterococcus species (THA 8.6%; TKA 5.9%). The 5-year mortality was 15% (95% confidence interval [CI]: 13 to 18) and 18% (CI: 14 to 21) for THA and TKA patients, respectively. The 5-year PJI re-revision rate was 28% (CI: 24 to 34) for THAs and 30% (CI: 24 to 38) for TKAs. In deceased THA patients who had a PJI, Enterococcus species (14%) were more often registered as microorganisms responsible for the PJI than S. epidermidis (8.5%).

CONCLUSIONS

Over half of the early PJIs in THAs and TKAs in the Netherlands were caused by Staphylococcus aureus and Coagulase-negative staphylococci including Staphylococcus epidermidis. Both 5-year mortality and PJI re-revision rates following PJI were relatively high.

Periprosthetic joint infections: state-of-the-art

In general, periprosthetic joint infection (PJI) is regarded as one of the most common complications of total joint arthroplasty (TJA) and may lead to surgical failure, revision surgery, amputation or death. Nowadays, PJI has become a global health concern, which brings a great burden to public healthcare. In addition, there are still obstacles to achieve high success rates in the prevention, diagnosis and treatment of PJI. However, promising studies are also available with the advancements in biotechnology. This article will present an overview of the current methods used in the prevention, diagnosis and management of PJI while underlining the new technologies utilized.

Identification of preoperative predictive markers of periprosthetic joint infection in presumed aseptic revisions of total hip arthroplasty: a retrospective observational study

INTRODUCTION

Periprosthetic joint infections (PJIs) occur at a rate of 1-2% in primary arthroplasties and 4% in revisions, posing a significant healthcare challenge. PJI diagnosis is hindered by absence of a universally accepted diagnostic standard. The primary outcome was to develop a predictive model to identify patients at risk of developing unforeseen PJI subsequent to presumed aseptic revision of total hip arthroplasty (THA). The secondary aim was to determine the reintervention-free survival rate among aseptic patients and those presenting unexpected positive cultures.

METHODS

This study included all ascertained septic and presumed aseptic patients without mechanical causes of THA failure and with sufficient clinical and laboratory data. Patients with incomplete anamnestic data, mechanical loosening related causes, rheumatologic conditions, or immunosuppression were excluded. Univariable and multivariable logistic regression analyses identified preoperative predictive markers for unexpected hip PJI.

RESULTS

283 inpatients from a high volume referral center were recruited from 2016 to 2019. The predictive preoperative parameters related with hip PJI were: presence of comorbidities (OR: 0.28; 95% CI 0.10-0.78), erythrocyte sedimentation rate (OR: 1.02; 95% CI 1.00-1.03), leukocyte count (OR: 1.18; 95% CI 1.02-1.36) and prothrombin time (OR: 1.42; 95% CI 1.02-1.98). Gender, age, body mass index (BMI) and previous surgery were not significantly related with unexpected PJI. Overall, the Kaplan-Meier analysis estimated a reoperation-free survival rate at 36 months of 96% (CI 95%) for the aseptic and 98% (CI 95%) for the unexpected group; however, the relation between the two survival curves was not significant (p = 0.086).

CONCLUSIONS

Erythrocyte sedimentation rate, leukocyte count, and increased prothrombin time were risk factors for PJI, whereas comorbidities were associated with a lower risk. Further research is needed to understand this association fully. Larger datasets are recommended to explore the complex interplay between risk factors and PJI development.

Prevalence of unexpected intraoperative cultures (UPIC) in revision total knee arthroplasty (TKA) and risk of periprosthetic joint infection (PJI)

INTRODUCTION

Prevalence of unexpected positive intraoperative cultures (UPIC) in revision total knee arthroplasty (TKA) is reported to be 8.32% with largely varying findings in individual studies (5.92-62.07%) due to a heterogeneity in preoperative diagnostic work-up and diagnostic criteria for periprosthetic joint infection (PJI). When diagnosed as unsuspected PJI, re-revision rate is reported to be as high as 18.45% compared to 2.94% in patients with UPIC classified as contamination (p = 0.0237). We performed a monocentric retrospective analysis of revision TKA surgery to determine prevalence of UPIC, risk of developing a subsequent PJI and re-revision rate after 24 months compared to those without UPIC.

MATERIALS AND METHODS

All presumed aseptic total knee revision procedures from 2008 until 2017 were retrospectively reviewed. Single stage femorotibial revisions of TKA with at least 3 intraoperative cultures and a minimum follow-up of 24 months were included, whereas partial revisions or revisions from unicompartimental knee prosthesis to TKA were excluded. Demographic data were collected as well as initial reason for revision, preoperative aspiration results, micro-organism identified and postoperative antibiotics' administration. Primary outcome was survival rate after 24 months with differentiation based on UPIC interpretation: sterile, contamination, unsuspected PJI.

RESULTS

Of 256 included cases, 75 (29.3%) were found to have at least 1 UPIC during revision surgery, 72% of whom a single UPIC was found. Thirty-four cases (13.28%) were interpreted as unsuspected PJI and therefore treated with antibiotics. In total, 13 of the 256 patients (5.08%) had to be re-revised during follow-up with 7 PJI (2.73%), none of them developing reinfection defined as PJI with the same microorganism. A statistically significant trend towards earlier failure in the unsuspected PJI group compared to the contaminant group was not observed. However, a higher incidence of re-revisions attributed to septic reasons was noted in the former group.

CONCLUSIONS

Presence of UPIC in presumed aseptic revision TKA does not correlate with a lower survival rate, but a higher incidence of subsequent PJI was observed in cases interpreted as unsuspected PJI.

Genomic characterization and clinical evaluation of prosthetic joint infections caused by Cutibacterium acnes

Cutibacterium acnes is a major skin commensal that may act as an opportunistic pathogen. It is difficult to interpret findings of C. acnes in tissue cultures obtained during arthroplasty revision surgery, since they may represent true infection or contamination. This study investigated whether C. acnes obtained from prosthetic joint infections (PJIs) were related and shared common genomic traits that might correlate with clinical courses and patient outcomes. C. acnes isolates from revision surgery of patients with PJIs of the hip, shoulder, and knee were characterized using molecular methods to determine the sequence type (ST) and the presence of possible virulence determinants (Christie-Atkins-Munch-Peterson factors, dermatan sulfate-binding adhesion 1, hyaluronidase lyase, and linear plasmid). A standardized review of the patients' medical charts was performed. The study included 37 patients with C. acnes culture-positive tissue samples where multiple isolates of C. acnes belonged to the same ST. Most of the isolates belonged to phylotype IA1. Phylogenetic analysis of virulence determinants revealed no shared pattern among PJI isolates. Seven patients had a polymicrobial infection. Exchange revision was performed in 70% of the patients, and >50% of all patients received antibiotic treatment for ≥3 months. Failure was noted in seven patients. No specific ST or any identifiable unique feature among virulence determinants were found among C. acnes isolated from PJIs of hips and shoulders. The majority of patients had low inflammatory markers and were treated successfully, even polymicrobial infections. However, failure was more common among shoulder infections compared with hip infections.

IMPORTANCE

Prosthetic joint infection (PJI) is a rare complication after arthroplasty surgery. The infection seldom resolves without a combination of both surgical and antibiotic treatment and can cause significant suffering among affected patients. Cutibacterium acnes is a common skin bacterium that is most often found in shoulder PJIs but can also infect other prostheses. In this study, we conducted a review of patients with previously verified PJIs involving C. acnes in hip or shoulder prostheses, along with a genomic analysis of the bacteria causing the infections. The majority of patients had successful outcomes. We did not identify any specific phylogenetic lineage or specific molecular signature of virulence factors among these PJI-associated C. acnes isolates that seemed to be associated with increased potential to cause infection among this species. This indicates that C. acnes isolated from PJIs originates from the patients' own skin microbiome and is inoculated during the arthroplasty surgery.

Perioperative Demographic and Laboratory Characteristics of Failed Debridement, Antibiotics, and Implant Retention: Can We Determine Which Patients Will Fail?

BACKGROUND

Debridement, antibiotics, and implant retention (DAIR) are the mainstays surgical treatment for acute periprosthetic joint infection (PJI). However, reoperation following DAIR is common and the risk factors for DAIR failure remain unclear. This study aimed to assess the perioperative characteristics of patients who failed initial DAIR treatment.

METHODS

A retrospective review was conducted on 83 patients who underwent DAIR for acute PJI within 3 months following index surgery from 2011 to 2022, with a minimum one-year follow-up. Surgical outcomes were categorized using the Musculoskeletal Infection Society outcome reporting tool (Tiers 1 to 4). Patient demographics, laboratory data, and perioperative outcomes were compared between patients who had failed (Tiers 3 and 4) (n = 32) and successful (Tiers 1 and 2) (n = 51) DAIR treatment. Logistic regression was also performed.

RESULTS

After logistic regression, Charlson Comorbidity Index (odds ratio [OR]: 1.57; P = .003), preoperative C-reactive protein (OR: 1.06; P = .014), synovial white blood cell (OR: 1.14; P = .008), and polymorphonuclear cell (PMN%) counts (OR: 1.05; P = .015) were independently associated with failed DAIR. Compared with total hip arthroplasty, total knee arthroplasty patients (OR: 6.08; P = .001) were at increased risk of DAIR failure. The type of organism and time from primary surgery were not correlated with DAIR failure.

CONCLUSIONS

Patients who had failed initial DAIR tended to have significantly higher Charlson Comorbidity Index, C-reactive protein, synovial white blood cell, and PMN%. The total knee arthroplasty DAIRs were more likely to fail than the total hip arthroplasty DAIRs. These characteristics should be considered when planning acute PJI management, as certain patients may be at higher risk for DAIR failure and may benefit from other surgical treatments.

LEVEL OF EVIDENCE

III.

Antimicrobial susceptibility testing of bone and joint pathogens using isothermal microcalorimetry

The rise in osteomyelitis and periprosthetic joint infections, in combination with increasing life expectancy and the prevalence of diabetes, underscores the urgent need for rapid and accurate diagnostic tools. Conventional culture-based methods are often time-consuming and prone to false-negatives, leading to prolonged and inappropriate antibiotic treatments. This study aims to improve osteomyelitis diagnostics by decreasing the time to detection and the time to an antibiotic susceptibility result to enable a targeted treatment using isothermal microcalorimetry (IMC). IMC measures heat flow in real-time, providing insights into bacterial metabolism without the need for labeling. Using clinical isolates from bone infections, assessing their response to antibiotics through IMC, we demonstrated that IMC could detect bacteria within 4 h and determine antimicrobial susceptibility profiles within 2-22 h (median 4.85, range 1.28-21.78). This is significantly faster than traditional methods. A decision tree, based on antibiotic susceptibility, accurately categorized pathogens, achieving high accuracy (74-100%), sensitivity (100%), and specificity (65-100%). These findings suggest that IMC could redefine diagnostics of bone and joint infections and potentially infections in general, offering timely and precise treatment guidance, thereby improving patient outcomes and reducing health care burdens. Further optimization and clinical validation are needed to fully integrate IMC into routine diagnostics.

Antibiotic Prophylaxis for Genitourinary Procedures in Patients with Artificial Joint Replacement and Artificial Heart Valves

Prosthetic joint infection (PJI) and prosthetic valve endocarditis (PVE) are uncommon but serious complications. According to current best practice statements, prior to a genitourinary procedure, patients with prosthetic joints should receive antibiotic prophylaxis if they are within 2 years of arthroplasty, if they are high risk for infection due to their individual comorbidities, or if the procedure poses a high risk for bacteremia. Patients with prosthetic valves should not receive antibiotic prophylaxis for the sole purpose of prevention of endocarditis. Enterococcus species are the uropathogens most often associated with PJI and PVE. Antibiotic selection should take into account local resistance patterns.

What Is the Incidence of and Outcomes After Debridement, Antibiotics, and Implant Retention (DAIR) for the Treatment of Periprosthetic Joint Infections in the AJRR Population?

BACKGROUND

Debridement, antibiotics, and implant retention (DAIR) is used to manage acute periprosthetic joint infections (PJIs) after total joint arthroplasty (TJA). Given the uncertain success of single or multiple DAIR attempts and possible long-term deleterious effects this treatment can create when trying to treat persistent infection, it is important to understand the frequency with which surgeons in the United States are attempting multiple debridements for PJI and whether those procedures are achieving the desired goal.

QUESTION/PURPOSES

In the context of the American Joint Replacement Registry (AJRR), we asked: (1) What proportion of patients who undergo DAIR have only one DAIR, and what percentage of those patients have more than one? (2) Of the patients who undergo one or more DAIR procedures, what is the proportion who progress to additional surgical procedures? (3) What is the cumulative incidence of medical or surgical endpoints related to infection on the affected leg (other than additional DAIR procedures)?

METHODS

DAIR procedures to treat PJI, defined by ICD-9/10 and CPT (Current Procedural Technology) codes, reported to the AJRR from 2012 to 2020 were merged with Centers for Medicare and Medicaid Services (CMS) data from 2012 to 2020 to determine the incidence of patients aged 65 and older who underwent additional PJI-related procedures on the same joint. Linking to CMS ensures no loss to follow-up or patient migration to a non-AJRR site. As of 2021, the AJRR captures roughly 35% of all arthroplasty procedures performed in the United States. Of the total 2.2 million procedures in the AJRR, only 0.2% of the procedures were eligible based on our inclusion criteria. Additionally, 61% of the total population is Medicare eligible, and thus, these patients are linked to CMS. Of the 5029 DAIR attempts after a TKA, 46% (2318) were performed in female patients. Similarly, there were a total of 798 DAIR attempts after a THA, and 50% (398) were performed in female patients. For the purposes of decreasing confounding factors, bilateral THAs and TKAs were excluded from the study population. When querying for eligible procedures from 2012 to 2020, the patient population was limited to those 65 years and older, and a subsequent reoperation for infection had to be reported after a primary TJA. This limited the patient population as most infections reported to AJRR resulted in a revision, and we were searching for DAIRs. Although 5827 TJAs were identified as a primary TJA with a subsequent infectious event, more than 65% (3788) of that population did not have a reported event. The following conditions were queried as secondary outcomes after the first DAIR: sepsis, cellulitis, postoperative infection, endocarditis, amputation, knee fusion, resection, drainage, arthrotomy, and debridement. To answer our first and second study questions, we used frequency testing from the available AJRR data. Because of competing risks and issues with incomplete data, we used the cumulative incidence function to evaluate the outcomes specific to study question 3.

RESULTS

Of the patients who underwent DAIR, 93% (5406 of 5827) had one DAIR and 8% (421 of 5827) had more than one. Among the DAIR population, at least 35% of TKAs and 38% of THAs were identified as having experienced an additional PJI-related event (an additional surgical procedure on the same joint, sustained an infectious endpoint in the linked CMS-AJRR dataset, or they had died). The cumulative incidence of developing a further medical or surgical condition related to the joint that had the initial DAIR were as follows: 48% (95% CI 42% to 54%) at 8 years after a DAIR following a TKA and 42% (95% CI 37% to 46%) at 4 years after a DAIR following a THA. The timepoints for TKA and THA are different because there are more longitudinal procedure data available for TKAs regarding DAIR procedures than for THAs.

CONCLUSION

In this study, we used data from the AJRR to assess the incidences of single and multiple DAIR attempts and additional surgical- and infection-related sequalae. Continued investigation is required to determine the fate of infected joints that undergo DAIR with regard to ultimate patient outcome. Future cross-sectional studies using large datasets are necessary to assess functional outcomes and determine the risk of persistent infection after DAIR more precisely.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Bone allograft impregnated with tobramycin and vancomycin delivers antibiotics in high concentrations for prophylaxis against bacteria commonly associated with prosthetic joint infections

Local delivery of antibiotics as prophylaxis for prosthetic joint infections (PJIs) is frequently used during total hip replacement surgery. Morselized bone allograft impregnated with vancomycin and tobramycin (TobraVanc) could provide effective prophylaxis against bacteria commonly associated with PJIs. In this study, the concentrations of antibiotics released by bone allograft impregnated with TobraVanc were determined by using an in vitro bioassay system entailing measuring inhibition zone diameters caused by antibiotic-impregnated bone chips cast in agar against standard curves. The concentrations were determined in samples of TobraVanc-impregnated bone graft taken before and after the application of the bone graft in the patients undergoing acetabular revision surgery. Antibiotic-impregnated bone grafts, sampled prior to application in the patient, delivered antibiotics in the concentration ranges of 730-9,800 mg/L for tobramycin and 1,300-11,000 mg/L for vancomycin. Samples taken after application in the patient released lower concentrations of tobramycin (490-1,900 mg/L; P < 0.01) and vancomycin (3,000-5,100 mg/L; P < 0.05); however, these concentrations remained well above the tobramycin minimum inhibitory concentrations (MICs) for investigated, highly tobramycin-resistant Staphylococcus epidermidis strains (MICs > 256 mg/L). At the tested concentrations, bone graft material mixed with TobraVanc delivered antibiotics in potent concentrations above the MICs for bacteria causing PJIs. Clinical trials are needed to evaluate the efficacy and risk of TobraVanc-impregnated bone graft as a prophylactic agent for patients undergoing hip replacement surgery.IMPORTANCEAntibiotic prophylaxis is the cornerstone of successful joint replacement surgery, reducing the risk for the dreaded complication of prosthetic joint infection (PJI) to roughly 0.5%-2% in standard total hip replacement (THR). In addition to systemic antibiotics, antibiotics added locally have the potential to reduce the PJI risk even further, because of the high concentrations that can be achieved in the joint with limited risk for systemic toxicity. The results in the current study show that bone chips impregnated with a combination of tobramycin and vancomycin (TobraVanc) release antibiotics in concentrations that are potent against common bacteria causing PJIs. Especially in high-risk patients, our results support the prophylactic use of TobraVanc in hip replacement surgery requiring the use of a bone graft. A clinical study testing the efficacy of TobraVanc-impregnated bone graft in reducing the incidence of PJI in hip replacement surgery is currently ongoing (EudraCT: 2021-001708-14).

Systematisation of the causes that required revision hip replacement, methods of their solution, treatment results in Ukraine

BACKGROUND

The objective of this study is to organise data on complications following total hip replacement (THA) over a span of 10 years, specifically focussing on cases that necessitated revision endoprosthetic surgeries. The objective is to create a recommendation for an All-Ukrainian registry of initial and repeated hip arthroplasty (HA) and standardise the terminology used to define "revision of total hip replacement surgery".

METHODS

The retrospective analysis examined 236 instances of revision hip arthroplasty (rTHA) performed at the Institute of Traumatology and Orthopaedics Centre between January 2005 and December 2021. The primary factors for revision were identified through an analysis of the patient's medical records, laboratory results, visual inspection, and the state of the previously implanted prosthesis. Demographic information, primary and revision HA dates, diagnoses, and causes of complications were recorded. The statistical analysis was conducted using the Statistica package (StatSoft), version 12.6 (2015), with a significance level of p < 0.05.

RESULTS

Out of the 364 patients who were diagnosed with complications, 236 of them (55.17%) needed a procedure called 1rTHA. Among these cases, 152 (41.76%) were specifically diagnosed with aseptic component instability. Significant factors for mechanical loosening were a high body mass index (BMI ≥ 30) and older age, with respective t-values of 2.08 (p = 0.004) and 2.59 (p = 0.045). Osteoporosis significantly contributed to aseptic loosening and fractures around the implant. The occurrence of infectious complications was frequently linked to chronic infectious diseases (t = 3.37, p = 0.001). The overall percentage of need for 2rTHA was 27.22% (43 cases), with one case of infectious lesion following the revision.

CONCLUSIONS

The study emphasises the urgent requirement for standardised terminology and a comprehensive registry for hip arthroplasty procedures. Primary results indicate that cement-free fixation is more effective than cement-based fixation for revision in patients with aseptic instability and that two-stage arthroplasty is effective for treating infectious inflammation. Furthermore, the most effective treatment for femoral fractures with periprosthetic involvement was determined to be open repositioning and osteosynthesis with metal retainers. The aforementioned observations emphasise the need to create a comprehensive registry across Ukraine to support patient care, enable evidence-based practices, and enhance the overall effectiveness of hip arthroplasty operations.

CLINICAL TRIAL NUMBER

Not applicable.

High Demand for Psychological Support in Patients Who Have Periprosthetic Hip and Knee Joint Infections: An Analysis of 13,976 Patients

BACKGROUND

There is only sparse knowledge on the psychological burden of patients who have periprosthetic joint infections. The aim of our study was to assess the need for psychological support following total joint arthroplasty of the hip and knee. A special focus was set on patients who had aseptic and septic complications.

METHODS

A total of 13,976 patients who underwent total hip (n = 6,926) or total knee arthroplasty (n = 7,050) between January 1, 2012 and December 31, 2019 at a single institution were retrospectively evaluated for the postoperative need for a psychological consultation. Data were collected on age, sex, type of surgery, and indications for revision procedures. The need for a psychological consultation was assessed during the daily postoperative visits, which were further coordinated by 2 institutional psychologists.

RESULTS

The average age was 68 years (range, 12 to 100), and there were 63.5% women. The overall rate of psychological consultations was 1.7%. Patients who had a septic indication for revision surgery had an 18.7-fold higher rate of postoperative psychological consultations compared to patients following primary surgery and a 5.4-fold higher rate compared to patients who had an aseptic indication. In detail, this rate was 1.0% in the primary subgroup, compared to 7.7% following revision arthroplasty (P < .001). In the revision subgroup, the rate was 17.9% for septic and 3.3% for aseptic revision arthroplasty cases (P < .001). Postoperative psychological consultations were twice as frequent in women (2.1%) compared to men (1.0%), P < .001.

CONCLUSIONS

The present study raises awareness of the markedly high psychological burden in revision arthroplasty cases, in the view of the high estimated number of unknown cases. There is a significant correlation between periprosthetic joint infectionsand the postoperative need for a psychological consultation, with women being at an even higher risk. Health care providers should aim at offering psychological support for patients who have a septic complication, with affected patients being at risk for psychological stress.

LEVEL OF EVIDENCE

IV.

Association Between Periprosthetic Joint Infection and Mortality Following Primary Total Hip Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) remains a dreaded and unpredictable complication after total hip arthroplasty (THA). In addition to causing substantial morbidity, PJI may contribute to long-term mortality risk. Our objective was to determine the long-term mortality risk associated with PJI following THA.

METHODS

This population-based, retrospective cohort study included adult patients (≥18 years old) in Ontario, Canada, who underwent their first primary elective THA for arthritis between April 1, 2002, and March 31, 2021. The primary outcome was death within 10 years after the index THA. Mortality was compared between propensity-score-matched groups (PJI within 1 year after surgery versus no PJI within 1 year after surgery) with use of survival analyses. Patients who died within 1 year after surgery were excluded to avoid immortal time bias.

RESULTS

A total of 175,432 patients (95,883 [54.7%] women) with a mean age (and standard deviation) of 67 ± 11.4 years underwent primary THA during the study period. Of these, 868 patients (0.49%) underwent surgery for a PJI of the replaced joint within 1 year after the index procedure. After matching, patients with a PJI within the first year had a significantly higher 10-year mortality rate than their counterparts (11.4% [94 of 827 patients] versus 2.2% [18 of 827 patients]; absolute risk difference, 9.19% [95% confidence interval (CI), 6.81% to 11.6%]; hazard ratio, 5.49 [95% CI, 3.32 to 9.09]).

CONCLUSIONS

PJI within 1 year after surgery is associated with over a fivefold increased risk of mortality within 10 years. The findings of this study underscore the importance of prioritizing efforts related to the prevention, diagnosis, and treatment of PJIs.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Immunohistochemistry Study of Antimicrobial Peptides as a Future Diagnostic and Prognostic Tool for Periprosthetic Joint Infections

Periprosthetic joint infection (PJI) is a reputable complication of arthroplasty surgery. Septic loosening is an implant biofilm-related infection with different characteristics and treatment than aseptic loosening. Misdiagnosing PJI results in choosing an inappropriate treatment and, in most cases, failure to achieve asepsis. The worldwide increase of arthroplasty surgeries forces us to research more accurate ways to detect PJIs earlier, cheaper, and faster. In the current study, we investigated 52 arthroplasty revision surgeries (septic and aseptic) and, using immunohistochemistry staining of periprosthetic tissue, successfully demonstrated an important increase in antimicrobial peptides human β defensin-3 (HBD-3) and cathelicidin (LL-37) in the PJI group. Furthermore, we observed that patients with a positive LL-37 stain were associated with a more reserved prognosis at one-year follow-up. These promising results suggest that antimicrobial peptides HBD-3 and LL-37 could be used as future biomarkers for PJI detection.

Evaluating Modern Spacer Options and Outcomes in Revision Hip Arthroplasty

BACKGROUND

A 2-stage revision continues to be the standard treatment for periprosthetic joint infection (PJI) in hip arthroplasty. The use of "functional" spacers may allow patients to return to daily living while optimizing their health for revision surgery. We aimed to evaluate the clinical outcomes of different spacer types regarding infection eradication, mechanical complications, and functional outcomes.

METHODS

Patients who have complete Musculoskeletal Infection Society criteria for diagnosis of PJI that underwent one-stage or 2-stage revision were queried in an institutional surgical database between 2002 and 2022. Out of 286 patients, 210 met our inclusion criteria and were retrospectively reviewed for demographics, laboratory values, functional and patient-reported outcomes, and subsequent revisions. The study population had 54.3% women, a mean age of 61 years old, and a mean follow-up of 3.7 ± 3.2 years. There was no difference between age, body mass index, or Charlson Comorbidity Index scores between each cohort. Spacers were categorized as nonfunctional static, nonfunctional articulating, or functional articulating. Functional spacers were defined as those that allowed full weight bearing with no restrictions. Delphi criteria were used to define revision success, and failure was defined as a recurrent or persistent infection following definitive surgery.

RESULTS

There was a significantly lower reoperation rate after a definitive implant in the functional articulating cohort (P = .003), with a trending higher infection eradication rate and a lower rate of spacer failure compared to the nonfunctional spacer cohort. At 5 years, functional articulating spacers had a 94.1% survivorship rate, nonfunctional articulating spacers had an 81.2% survival rate, and nonfunctional static spacers had a 71.4% survival rate. In the functional articulating spacer cohort, 14.6% had yet to get reimplanted, with an average follow-up time of 1.4 years.

CONCLUSIONS

Within this large cohort of similar demographics, functional articulating spacers may result in better clinical outcomes and infection eradication during 2-stage revision arthroplasty for PJI.

Health-related quality of life and mental health in patients with major bone and joint infections

Aims

It is well described that patients with bone and joint infections (BJIs) commonly experience significant functional impairment and disability. Published literature is lacking on the impact of BJIs on mental health. Therefore, the aim of this study was to assess health-related quality of life (HRQoL) and the impact on mental health in patients with BJIs.

Methods

The AO Trauma Infection Registry is a prospective multinational registry. In total, 229 adult patients with long-bone BJI were enrolled between 1 November 2012 and 31 August 2017 in 18 centres from ten countries. Clinical outcome data, demographic data, and details on infections and treatments were collected. Patient-reported outcomes using the 36-Item Short-Form Health Survey questionnaire (SF-36), Parker Mobility Score, and Katz Index of Independence in Activities of Daily Living were assessed at one, six, and 12 months. The SF-36 mental component subscales were analyzed and correlated with infection characteristics and clinical outcome.

Results

The SF-36 physical component summary mean at baseline was 30.9 (95% CI 29.7 to 32.0). At one month, it was unchanged (30.5; 95% CI 29.5 to 31.5; p = 0.447); it had improved statistically significantly at six months (35.5; 95% CI 34.2 to 36.7; p < 0.001) and at 12 months (37.9; 95% CI 36.4 to 39.3; p < 0.001). The SF-36 mental component summary mean at baseline was 42.5 (95% CI 40.8 to 44.2). At one month, it was unchanged (43.1; 95% CI 41.4 to 44.8; p = 0.458); it had improved statistically significantly at six months (47.1; 95% CI 45.4 to 48.7; p < 0.001) and at 12 months (46.7; 95% CI 45.0 to 48.5; p < 0.001). All mental subscales had improved by the end of the study, but mental health status remained compromised in comparison with the average USA population.

Conclusion

BJIs considerably impact HRQoL, particularly mental health. Patients suffering from BJIs reported considerable limitations in their daily and social activities due to psychological problems. Impaired mental health may be explained by the chronic nature of BJIs, and therefore the mental wellbeing of these patients should be monitored closely.

Diagnostic and Predictive Efficacy of Synovial Fluid Versus Serum C-Reactive Protein Levels for Periprosthetic Joint Infection and Reimplantation Success

BACKGROUND

A 2-stage exchange revision for periprosthetic joint infection (PJI) is associated with major risks for reinfection. Although serum markers are frequently used for diagnosis, their effectiveness remains debatable. Synovial fluid markers may offer a more accurate diagnosis of PJI; however, the importance of these biomarkers, notably synovial fluid C-reactive protein (syCRP), remains controversial, particularly in the context of reimplantation. The present study aimed to clarify these diagnostic uncertainties by evaluating the diagnostic efficacy of syCRP versus serum CRP (seCRP) levels in the context of PJI and recurring or persisting infections before reimplantation.

METHODS

A total of 186 patients were enrolled and divided into 2 groups: aseptic revision (n = 112) and PJI revision (n = 74). Of the PJI group, 65 were categorized as success and 9 as failure, based on the presence of recurrent or persistent infection before reimplantation. The syCRP and seCRP levels and their changes were assessed preoperatively and in the first-stage and second-stage revisions. Additionally, receiver operating characteristic (ROC) curves and area under the ROC curves (AUCs) were analyzed.

RESULTS

Both seCRP and syCRP levels were significantly elevated in the PJI group compared with the aseptic group (P < .001). The ROC curve analysis highlighted the enhanced diagnostic accuracy of syCRP for PJI, with an AUC of 0.93 versus 0.80 for seCRP. Furthermore, syCRP proved to be more reliable in predicting reimplantation success, exhibiting an AUC of 0.86 versus 0.63 for seCRP. In evaluating trends in CRP levels to determine reimplantation timing, changes in syCRP levels demonstrated superior diagnostic utility, exhibiting an AUC of 0.79 versus 0.63 for changes in seCRP levels.

CONCLUSIONS

In assessing PJI and infections before reimplantation, syCRP may offer enhanced accuracy compared with seCRP. Nevertheless, variations in both syCRP and seCRP levels did not consistently predict the outcome of reimplantation.

Patient-Reported Outcomes Following Periprosthetic Joint Infection of the Hip and Knee: A Longitudinal, Prospective Observational Study

BACKGROUND

The role of patient-reported outcome measures (PROMs) as tools for monitoring the impact and outcomes of periprosthetic joint infection (PJI) is not well described. This study analyzed the Oxford Hip Score (OHS) or Oxford Knee Score (OKS) in a prospective observational cohort of patients with hip or knee PJI.

METHODS

The PIANO (Prosthetic joint Infection in Australia and New Zealand, Observational study) cohort prospectively enrolled patients with newly diagnosed PJI from multiple centers. The OHS and OKS were evaluated at PJI diagnosis (baseline) and at 3, 12, and 24 months. Scores and score changes were examined according to PJI type, patient characteristics, and management. A successful functional outcome at 12 months was defined as an OHS of >38 or OHS of >36 and/or an improvement from baseline of >12 or >9, respectively.

RESULTS

Of the 741 participants, PROMs were available at 12 months for 233 with hip and 342 with knee PJI. Significant improvements (p < 0.0001) were seen at 12 months for both the OHS (24.5 to 36) and OKS (25 to 34), with no further improvement at 24 months. Patients with late-acute PJI had a higher median baseline OHS (35; interquartile range [22 to 46]) and OKS (30 [18 to 41]) than those with early PJI (OHS: 19 [15 to 29]; OKS: 22 [16 to 29.5]) or chronic PJI (OHS: 23 [14 to 34]; OKS 22 [14 to 28]). Logistic regression showed that a clinical cure (adjusted odds ratio [aOR] = 1.88, 95% confidence interval [CI] = 1.28 to 2.76, p = 0.001) and early PJI (aOR = 2.56, 95% CI = 1.64 to 4.07, p < 0.0001) independently predicted a successful functional outcome. Chronic renal impairment (aOR = 0.31, 95% CI = 0.13 to 0.71, p = 0.007), congestive cardiac failure (aOR = 0.41, 95% CI = 0.17 to 0.95, p = 0.04), and clinical signs of inflammation (aOR = 0.53, 95% CI = 0.33 to 0.85, p = 0.009) at diagnosis independently predicted failure to achieve a successful functional outcome.

CONCLUSIONS

The OHS and OKS varied significantly at baseline and 12 months according to PJI type, emphasizing the need to consider the PJI type when evaluating treatment success. This study highlights superior functional outcomes associated with early PJI and with achievement of a clinical cure.

LEVEL OF EVIDENCE

Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Point of care testing for the diagnosis of periprosthetic joint infections: a review

BACKGROUND

Periprosthetic joint infection (PJI) remains a major complication following total joint arthroplasties (TJA), significantly affecting patient outcomes and healthcare costs. Despite advances in diagnostic techniques, challenges persist in accurately diagnosing PJI, underscoring the need for effective point-of-care testing (POCT).

METHODS

This review examines the current literature and latest developments in POCT for diagnosing PJI, focusing on biomarkers such as alpha-defensin, leukocyte esterase, calprotectin, and C-reactive protein (CRP). Criteria from various societies like the Musculoskeletal Infection Society, Infectious Diseases Society of America, and the International Consensus Meeting were compared to evaluate the effectiveness of these biomarkers in a point-of-care setting.

RESULTS

POCT provides rapid results essential for the timely management of PJI, with alpha-defensin and leukocyte esterase showing high specificity and sensitivity. Recent advancements have introduced novel biomarkers like calprotectin, which demonstrate high diagnostic accuracy. However, challenges such as the variability in test performance and the need for validation under different clinical scenarios remain.

DISCUSSION

While POCT for PJI shows promising results, their integration into clinical practice requires standardized protocols and further validation. The evolution of these diagnostic tools offers a potential shift toward more personalized and immediate care, potentially improving outcomes for patients undergoing TJA.

Is Penicillin Allergy a Clinical Problem? A Systematic Review of Total Joint Arthroplasty Procedures With Implications for Patient Safety and Antibiotic Stewardship

BACKGROUND

Patients undergoing total joint arthroplasty (TJA) who report penicillin allergy (PA) are frequently administered second-line antibiotics, although recent evidence suggests that this may be unnecessary and could increase infection risk. Many institutions have aimed to improve antibiotic deployment via allergy testing and screening; however, there is little standardization to this process. This review aimed to evaluate (1) antibiotic selection in patients who report PA and assess the impact of screening and testing interventions, (2) rates of allergic reactions in patients who report PA, and (3) the association between reported PA and screening or testing programs and odds of surgical site infection or periprosthetic joint infection.

METHODS

PubMed, EBSCOhost, and Google Scholar electronic databases were searched on February 4, 2023 to identify all studies published since January 1, 2000 that evaluated the impact of PA on patients undergoing TJA (PROSPERO study protocol registration: CRD42023394031). Articles were included if full-text manuscripts in English were available, and the study analyzed the impact of PA and related interventions on TJA patients. There were 11 studies evaluating 1,276,663 patients included. Interventions were compared via presentation of key findings regarding rates of clinically relevant or high-risk PA reported upon screenings or testings, cephalosporin utilizations, allergic reactions, and postoperative infections (surgical site infection and periprosthetic joint infection).

RESULTS

All 6 studies found that PA screening and testing markedly increase the use of first-line antibiotics. Testing showed low rates of true allergy (0.7 to 3%) and allergic reaction frequency for patients who have reported PA receiving cephalosporins was between 0% and 2%. Although there were mixed findings across studies, there was a trend toward second-line antibiotic prophylaxis being associated with a slightly higher rate of infection in PA patients.

CONCLUSIONS

Using PA screening and testing can promote antibiotic stewardship by safely increasing the use of first-line antibiotics in patients who have a reported PA.

LEVEL OF EVIDENCE

Level III, Therapeutic Study.

Effect of a national infection control programme in Sweden on prosthetic joint infection incidence following primary total hip arthroplasty: a cohort study

OBJECTIVES

Prosthetic joint infection (PJI) is a serious complication following total hip arthroplasty (THA) entailing increased mortality, decreased quality of life and high healthcare costs.The primary aim was to investigate whether the national project: Prosthesis Related Infections Shall be Stopped (PRISS) reduced PJI incidence after primary THA; the secondary aim was to evaluate other possible benefits of PRISS, such as shorter time to diagnosis.

DESIGN

Cohort study.

SETTING

In 2009, a nationwide, multidisciplinary infection control programme was launched in Sweden, PRISS, which aimed to reduce the PJI burden by 50%.

PARTICIPANTS

We obtained data on patients undergoing primary THA from the Swedish Arthroplasty Registry 2012-2014, (n=45 723 patients, 49 946 THAs). Using personal identity numbers, this cohort was matched with the Swedish Prescribed Drug Registry. Medical records of patients with ≥4 weeks' antibiotic consumption were reviewed to verify PJI diagnosis (n=2240, 2569 THAs).

RESULTS

The cumulative incidence of PJI following the PRISS Project was 1.2% (95% CI 1.1% to 1.3%) as compared with 0.9% (95% CI 0.8% to 1.0%) before. Cox regression models for the PJI incidence post-PRISS indicates there was no statistical significance difference versus pre-PRISS (HR 1.1 (95% CI 0.9 to 1.3)). There was similar time to PJI diagnosis after the PRISS Project 24 vs 23 days (p=0.5).

CONCLUSIONS

Despite the comprehensive nationwide PRISS Project, Swedish PJI incidence was higher after the project and time to diagnosis remained unchanged. Factors contributing to PJI, such as increasing obesity, higher American Society of Anesthesiology class and more fractures as indications, explain the PJI increase among primary THA patients.

Barriers and facilitators of implementation of new antibacterial technologies in patient care: an interview study with orthopedic healthcare professionals at a university hospital

BACKGROUND

Antimicrobial resistance is a major global health threat. Therefore, promising new antibacterial technologies that could minimize our dependence on antibiotics should be widely adopted. This study aims to identify the barriers and facilitators of the adoption of new antibacterial technologies in hospital patient care.

METHODS

Semi-structured interviews, based on the Consolidated Framework for Implementation Research, were conducted with healthcare professionals related to the orthopedics department of an academic hospital in The Netherlands.

RESULTS

In total, 11 healthcare professionals were interviewed. Scientific evidence for the effectiveness of the technology was the most explicitly mentioned facilitator of adoption, but other (often contextual) factors were also considered to be important. At the level of the inner and outer setting, high costs and lacking coverage, competition from other firms, and problems with ordering and availability were the most explicit perceived barriers to adoption. Participants did not collectively feel the need for new antibacterial technologies.

CONCLUSIONS

Barriers and facilitators of the adoption of new antibacterial technologies were identified related to the technology, the hospital, and external factors. The implementation climate might have an indirect influence on adoption. New antibacterial technologies that are scientifically proven effective, affordable, and easily obtainable will most likely be adopted.

Current Concepts on the Clinical and Economic Impact of Periprosthetic Joint Infections

Total joint arthroplasty (TJA) is a common procedure performed throughout the entire world in hopes of alleviating debilitating hip or knee pain. The projected number of TJAs performed in the United States alone is projected to exceed 1.9 million by 2030 and 5 million by 2040. With the significant increase in TJA performed, more periprosthetic joint infections (PJIs) are likely to be encountered. PJIs are a devastating complication of TJA. The economic and clinical burden must be understood and respected to minimize occurrence and allow optimal patient outcomes.

Vastus Lateralis Muscle Flap for High-Risk Patients Undergoing Orthopaedic Hip Surgery

INTRODUCTION

Chronic infections and soft-tissue defects are serious complications after total hip arthroplasties (THAs) that may require hip disarticulation (HD). HD is a relatively high-risk procedure with poor long-term outcomes and survival. This is the first study to analyze the effect of an ipsilateral, pedicled vastus lateralis (VL) muscle flap in preventing HD in patients with recurrent complications after THA.

METHODS

This retrospective case review analyzed the 6-month postoperative outcomes of 14 patients who underwent soft-tissue hip reconstruction with a VL muscle flap by a single surgeon.

RESULTS

Most (86%) patients fully recovered after 6 months with preserved hip range of motion, no pain, and no weakness on ambulation. Two (14%) patients ultimately required HD despite introducing a VL flap.

DISCUSSION

A VL muscle flap is an effective treatment of nonhealing THA and prophylactic intervention for patients at high risk for HD. The VL muscle is optimal because of its large size allowing reduction of soft-tissue dead space, its local anatomical location to the hip, and its exceptional vascularity. Additional prospective studies are necessary to determine the most appropriate population for this technique.

What to Know about Antimicrobial Coatings in Arthroplasty: A Narrative Review

Periprosthetic joint infections (PJIs) are one of the most worrying complications orthopedic surgeons could face; thus, methods to prevent them are evolving. Apart from systemic antibiotics, targeted strategies such as local antimicrobial coatings applied to prosthetics have been introduced. This narrative review aims to provide an overview of the main antimicrobial coatings available in arthroplasty orthopedic surgery practice. The search was performed on the PubMed, Web of Science, SCOPUS, and EMBASE databases, focusing on antimicrobial-coated devices used in clinical practice in the arthroplasty world. While silver technology has been widely adopted in the prosthetic oncological field with favorable outcomes, recently, silver associated with hydroxyapatite for cementless fixation, antibiotic-loaded hydrogel coatings, and iodine coatings have all been employed with promising protective results against PJIs. However, challenges persist, with each material having strengths and weaknesses under investigation. Therefore, this narrative review emphasizes that further clinical studies are needed to understand whether antimicrobial coatings can truly revolutionize the field of PJIs.

Antibiotic prophylaxis before tissue biopsy has no effect on culture results in presumed aseptic revision total hip arthroplasty

Background: Antibiotic prophylaxis (AP) is considered to be the gold standard for revision total hip arthroplasty (R-THA) due to the high incidence of prosthetic joint infection (PJI). To diagnose PJI, intraoperative tissue biopsies for culture are of particular importance. However, antibiotic interference could theoretically lead to less reliable culture results. Currently, there is no consensus on whether AP should be administered before or after tissue biopsy. In this study, we aimed to investigate the effect of AP timing on culture results and PJI rates in presumed aseptic R-THA. Methods: A retrospective single-center cohort study among 490 patients was performed; 61 patients received AP pre-incision, and 429 patients received AP post-biopsy. At least three intraoperative tissues were sampled for each patient and cultured for a minimum of 2 weeks. Minimum follow-up was 6 months. Epidemiological and clinical data (including culture results and incidence of PJI during follow-up) were gathered and analyzed. Results: Positive (4.9 % vs. 5.4 %, p = 0.89 ) and contaminated culture results (23.0 % vs. 22.6 %, p = 0.95 ) were not significantly different between pre-incisional and post-biopsy AP administration. Post-operative PJI incidence during follow-up was 1.6 % and 3.0 %, respectively. This difference was not statistically significant (p = 0.54 ). Conclusion: Pre-incisional AP administration does not yield fewer culture results compared to post-biopsy AP administration. Although statistically not significant, PJI during follow-up was almost twice as high when AP was withheld until after tissue biopsy. Other literature also supports the additional protective benefit of pre-incisional AP. Therefore, we believe pre-incisional AP administration is preferable for presumed aseptic R-THA.

Demographics and Early Outcomes of Commercial Antibiotic Cement Usage for Infection Prophylaxis During Primary Total Knee Arthroplasty in Patients Older Than 65 Years: An American Joint Replacement Registry Study

INTRODUCTION

The use of antibiotic-laden bone cement (ALBC) for infection prophylaxis in the setting of primary total knee arthroplasty (TKA) remains controversial. Using data from the American Joint Replacement Registry (AJRR), (1) we examined the demographics of ALBC usage in the United States and (2) identified the effect of prophylactic commercially available ALBC on early revision and readmission for prosthetic joint infection (PJI) after primary TKA.

METHODS

This is a retrospective cohort study of the AJRR from 2017 to 2020. Patients older than 65 years undergoing primary cemented TKA with or without the use of commercially available antibiotic cement were eligible for inclusion (N = 251,506 patients). Data were linked to available Medicare claims to maximize revision outcomes. Demographics including age, sex, race/ethnicity, Charlson Comorbidity Index (CCI), preoperative inflammatory arthritis, region, and body mass index (BMI) class were recorded. Cox proportional hazards regression analysis was used to evaluate the association between the two outcome measures and ALBC usage.

RESULTS

Patients undergoing cemented TKA with ALBC were more likely to be Non-Hispanic Black ( P < 0.001), have a CCI of 2 or 3 ( P < 0.001), reside in the South ( P < 0.001), and had a higher mean BMI ( P < 0.001). In the regression models, ALBC usage was associated with increased risk of 90-day revision for PJI (hazards ratio 2.175 [95% confidence interval] 1.698 to 2.787) ( P < 0.001) and was not associated with 90-day all-cause readmissions. Male sex, higher CCI, and BMI >35 were all independently associated with 90-day revision for PJI.

DISCUSSION

The use of commercial ALBC in patients older than 65 years for primary TKA in the AJRR was not closely associated with underlying comorbidities suggesting that hospital-level and surgeon-level factors influence its use. In addition, ALBC use did not decrease the risk of 90-day revision for PJI and was not associated with 90-day readmission rates.

The PJI-TNM classification for periprosthetic joint infections

AIMS

This study aimed to evaluate the clinical application of the PJI-TNM classification for periprosthetic joint infection (PJI) by determining intraobserver and interobserver reliability. To facilitate its use in clinical practice, an educational app was subsequently developed and evaluated.

METHODS

A total of ten orthopaedic surgeons classified 20 cases of PJI based on the PJI-TNM classification. Subsequently, the classification was re-evaluated using the PJI-TNM app. Classification accuracy was calculated separately for each subcategory (reinfection, tissue and implant condition, non-human cells, and morbidity of the patient). Fleiss' kappa and Cohen's kappa were calculated for interobserver and intraobserver reliability, respectively.

RESULTS

Overall, interobserver and intraobserver agreements were substantial across the 20 classified cases. Analyses for the variable 'reinfection' revealed an almost perfect interobserver and intraobserver agreement with a classification accuracy of 94.8%. The category 'tissue and implant conditions' showed moderate interobserver and substantial intraobserver reliability, while the classification accuracy was 70.8%. For 'non-human cells,' accuracy was 81.0% and interobserver agreement was moderate with an almost perfect intraobserver reliability. The classification accuracy of the variable 'morbidity of the patient' reached 73.5% with a moderate interobserver agreement, whereas the intraobserver agreement was substantial. The application of the app yielded comparable results across all subgroups.

CONCLUSION

The PJI-TNM classification system captures the heterogeneity of PJI and can be applied with substantial inter- and intraobserver reliability. The PJI-TNM educational app aims to facilitate application in clinical practice. A major limitation was the correct assessment of the implant situation. To eliminate this, a re-evaluation according to intraoperative findings is strongly recommended.

Analysis of fracture-related infections from Swedish insurance claims between 2011 and 2021

Fracture-related infections (FRI) pose a serious complication with an incidence of 1-2%. This study aimed to analyze compensation claims submitted to The Swedish National Patient Insurance Company (LÖF) because of FRI after closed/open reduction and internal fixation (C/ORIF) in the four most common fracture sites (proximal humerus, distal radius, hip, ankle). Patients registered in the LÖF database with a suspected FRI between 2011 and 2021 were identified by matching International Classification of Diseases and procedural codes indicative of a combination of fractures to the proximal humerus, distal radius, hip and ankle, C/ORIF and infection. Medical records were reviewed for fracture sites, pathogens and complications. Data from the Swedish Fracture Register (SFR) were extracted to estimate the proportion of reported claims to the presumed number of FRI. Of 122 FRI identified in the LÖF database, 34 were after C/ORIF in the proximal humerus, 12 in the distal radius, 28 in the hip and 48 in the ankle. LÖF compensated 111 patients (91%). Median time from C/ORIF to an FRI was 3 weeks (interquartile range 2-6), and 95% of all FRI occurred within 1 year after C/ORIF. Staphylococcus aureus was the most common pathogen in patients with a distal radius, hip and ankle FRI. In contrast, Cutibacterium spp. were the most common aetiology in FRI of the proximal humerus. The total number of fractures treated with C/ORIF in the four fracture sites registered in the SFR during 2021 was 18,711. Most of the FRI patients were diagnosed within the first year after C/ORIF, and 91% of the patients received compensation. Given an expected FRI incidence of 1-2%, our estimates with extrapolated data from the SFR indicate that < 10% of affected patients applied for compensation.

The Effect of Prosthetic Joint Infection on Work Status and Quality of Life: A Multicenter, International Study

BACKGROUND

Periprosthetic joint infection (PJI) and subsequent revision surgeries may affect patients' social and physical health, ability to complete daily activities, and disability status. This study sought to determine how PJI affects patients' quality of life through patient-reported outcome measures with minimum 1-year follow-up.

METHODS

Patients who suffered PJI following primary total joint arthroplasty (TJA) from 2012 to 2021 were retrospectively reviewed. Patients met Musculoskeletal Infection Society criteria for acute or chronic PJI, underwent revision TJA surgery, and had at least 1 year of follow-up. Patients were surveyed regarding how PJI affected their work and disability status, as well as their mental and physical health. Outcome measures were compared between acute and chronic PJIs. In total, 318 patients (48.4% total knee arthroplasty and 51.6% total hip arthroplasty) met inclusion criteria.

RESULTS

Following surgical treatment for knee and hip PJI, a substantial proportion of patients reported that they were unable to negotiate stairs (20.5%), had worse physical health (39.6%), and suffered worse mental health (25.2%). A high proportion of patients reported worse quality of life (38.5%) and social satisfaction (35.3%) following PJI. Worse reported patient-reported outcome measures including patients' ability to complete daily physical activities were found among patients undergoing treatment for chronic PJI, and also, 23% of patients regretted their initial decision to pursue primary TJA.

CONCLUSIONS

A PJI negatively affects patients' ability to carry out everyday activities. This patient population is prone to report challenges overcoming disability and returning to work. Patients should be adequately educated regarding the risk of PJI to decrease later potential regrets.

LEVEL OF EVIDENCE

Case series (IV).

Ototoxicity associated with extended dalbavancin treatment for a shoulder prosthetic joint infection

BACKGROUND

Dalbavancin is a lipoglycopeptide antibiotic approved for treatment of skin and soft tissue infections, administered as a single or two-dose treatment. The extended half-life, good penetration into bone and synovial fluid, and bactericidal activity against gram-positive bacteria, including those in biofilm, make dalbavancin an appealing choice for treatment of bone and joint infections in outpatient settings. However, we present a rare case of ototoxicity associated with off-label extended dalbavancin treatment of a prosthetic joint infection.

CASE PRESENTATION

A 55-year-old man with a prosthetic joint infection of the shoulder underwent off-label extended dalbavancin treatment, receiving a cumulative dose of 2500 mg. The patient experienced a gradual onset of hearing loss following the first dose, leading to a diagnosis of bilateral sensorineural hearing loss that persisted 1 year after dalbavancin was discontinued.

CONCLUSIONS

This case report highlights the importance of exercising caution when administering dalbavancin beyond approved dosing guidelines, and emphasizes the need for vigilance regarding the potential for ototoxicity.

In Vitro Efficacy of Dalbavancin as a Long-Acting Anti-Biofilm Agent Loaded in Bone Cement

Based on previous studies by our group in which we demonstrated that dalbavancin loaded in bone cement had good elution capacity for the treatment of biofilm-related periprosthetic infections, we now assess the anti-biofilm activity of dalbavancin and compare it with that of vancomycin over a 3-month period. We designed an in vitro model in which we calculated the percentage reduction in log cfu/mL counts of sonicated steel discs contaminated with staphylococci and further exposed to bone cement discs loaded with 2.5% or 5% vancomycin and dalbavancin at various timepoints (24 h, 48 h, 1 week, 2 weeks, 6 weeks, and 3 months). In addition, we tested the anti-biofilm activity of eluted vancomycin and dalbavancin at each timepoint based on a 96-well plate model in which we assessed the percentage reduction in metabolic activity. We observed a significant decrease in the dalbavancin concentration from 2 weeks of incubation, with sustained anti-biofilm activity up to 3 months. In the case of vancomycin, we observed a significant decrease at 1 week. The concentration gradually increased, leading to significantly lower anti-biofilm activity. The percentage reduction in cfu/mL counts was higher for dalbavancin than for vancomycin at both the 2.5% and the 5% concentrations. The reduction in log cfu/mL counts was higher for S. epidermidis than for S. aureus and was particularly more notable for 5% dalbavancin at 3 months. In addition, the percentage reduction in metabolic activity also decreased at 3 months in 5% dalbavancin and 5% vancomycin, with more notable values recorded for the latter.

Mortality, patient-reported outcome measures, and the health economic burden of prosthetic joint infection

Prosthetic joint infection (PJI) is one of the most devastating complications for a patient following arthroplasty. This scoping review aims to evaluate the burden of PJI on individual patients and the healthcare system regarding the mortality rate, patient-reported quality of life, and healthcare resource utilisation. Patients with PJI have up to a five-fold higher mortality rate than those who have undergone an uninfected primary arthroplasty. There is an increased use of ambulatory aids and reduced joint function scores in patients with PJI. Global quality of life is poorer, specifically measured by the EQ-5D. Direct hospitalisation costs are two- to five-fold higher, attributed to surgery and prostheses, antibiotics, and a prolonged inpatient stay. There is an immense clinical and health economic burden secondary to PJI worldwide. This is expected to rise exponentially due to the increasing number of primary procedures and an ageing population with comorbidities Improving preventative and treatment strategies is imperative for patients and the healthcare system.

Periprosthetic joint infection after total hip arthroplasty induces histological degeneration of the gluteus medius tendon

Aims

A revision for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) has a major effect on the patient's quality of life, including walking capacity. The objective of this case control study was to investigate the histological and ultrastructural changes to the gluteus medius tendon (GMED) in patients revised due to a PJI, and to compare it with revision THAs without infection performed using the same lateral approach.

Methods

A group of eight patients revised due to a PJI with a previous lateral approach was compared with a group of 21 revised THAs without infection, performed using the same approach. The primary variables of the study were the fibril diameter, as seen in transmission electron microscopy (TEM), and the total degeneration score (TDS), as seen under the light microscope. An analysis of bacteriology, classification of infection, and antibiotic treatment was also performed.

Results

Biopsy samples from the GMED from infected patients revealed a larger fibril diameter than control patients, as seen in the TEM (p < 0.001). Uninfected patients were slightly older and had their revisions performed significantly later than the infected patients. Histologically, samples from infected patients revealed significantly more vascularity (p < 0.001), the presence of glycosaminoglycans (p < 0.001), and a higher TDS (p = 0.003) than the control patients. The majority of patients had staphylococcal infections of various species.

Conclusion

More histological degeneration in the GMED was found in patients undergoing THA revision surgery due to PJI than in patients undergoing THA revision surgery due to other reasons.

Novel diagnostic markers for periprosthetic joint infection: a systematic review

Background

Identifying novel biomarkers that are both specific and sensitive to periprosthetic joint infection (PJI) has the potential to improve diagnostic accuracy and ultimately enhance patient outcomes. Therefore, the aim of this systematic review is to identify and evaluate the effectiveness of novel biomarkers for the diagnosis of PJI.

Methods

We searched the MEDLINE, EMBASE, PubMed, and Cochrane Library databases from January 1, 2018, to September 30, 2022, using the search terms "periprosthetic joint infection," "prosthetic joint infection," or "periprosthetic infection" as the diagnosis of interest and the target index, combined with the term "marker." We excluded articles that mentioned established biomarkers such as CRP, ESR, Interleukin 6, Alpha defensin, PCT (procalcitonin), and LC (leucocyte cell count). We used the MSIS, ICM, or EBJS criteria for PJI as the reference standard during quality assessment.

Results

We collected 19 studies that analyzed fourteen different novel biomarkers. Proteins were the most commonly analyzed biomarkers (nine studies), followed by molecules (three studies), exosomes (two studies), DNA (two studies), interleukins (one study), and lysosomes (one study). Calprotectin was a frequently analyzed and promising marker. In the scenario where the threshold was set at ≥50-mg/mL, the calprotectin point-of-care (POC) performance showed a high sensitivity of 98.1% and a specificity of 95.7%.

Conclusion

None of the analyzed biomarkers demonstrated outstanding performance compared to the established parameters used for standardized treatment based on established PJI definitions. Further studies are needed to determine the benefit and usefulness of implementing new biomarkers in diagnostic PJI settings.

Local Antibiotic Delivery Options in Prosthetic Joint Infection

Prosthetic Joint Infection (PJI) causes significant morbidity and mortality for patients globally. Delivery of antibiotics to the site of infection has potential to improve the treatment outcomes and enhance biofilm eradication. These antibiotics can be delivered using an intra-articular catheter or combined with a carrier substance to enhance pharmacokinetic properties. Carrier options include non-resorbable polymethylmethacrylate (PMMA) bone cement and resorbable calcium sulphate, hydroxyapatite, bioactive glass, and hydrogels. PMMA allows for creation of structural spacers used in multi-stage revision procedures, however it requires subsequent removal and antibiotic compatibility and the levels delivered are variable. Calcium sulphate is the most researched resorbable carrier in PJI, but is associated with wound leakage and hypercalcaemia, and clinical evidence for its effectiveness remains at the early stage. Hydrogels provide a versatile combability with antibiotics and adjustable elution profiles, but clinical usage is currently limited. Novel anti-biofilm therapies include bacteriophages which have been used successfully in small case series.