Success Rate After 2-Stage Spacer-Free Total Hip Arthroplasty Exchange and Risk Factors for Reinfection: A Prospective Cohort Study of 187 Patients.

BACKGROUND: Two-stage prosthesis exchange is the treatment of choice for chronic periprosthetic joint infection (PJI) of a total hip arthroplasty (THA), especially when the bone and surrounding soft tissues are compromised or difficult-to-treat pathogens are implicated. The aims of our study were as follows: (1) to determine the outcome of 2-stage prosthesis exchange for the treatment of PJI after THA and (2) to determine the risk factors for reinfection leading to subsequent revision surgeries after reimplantation. METHODS: We prospectively enrolled 187 consecutive patients who underwent a 2-stage THA exchange with resection arthroplasty for PJI from 2013 to 2019. The mean (± SD) duration of follow-up was 54.2 ± 24.9 months (range, 36 to 96), and the mean interval until reimplantation was 9.8 ± 8.9 weeks (range, 2 to 38). All patients remained in a spacer-free girdlestone situation between the 2 stages of treatment. Patients who remained infection-free after their 2-stage treatment were considered to have achieved treatment success. RESULTS: The overall success rate was 85.6%. The cumulative probability of reinfection was 11.5% after one year and 14% after 2 years after reimplantation. High virulence or difficult-to-treat pathogens were significant and independent risk factors for reinfection (HR [hazard ratio] = 3.71, 95% CI [confidence interval]: 1.47 to 9.36, P = .006 and HR = 3.85, 95% CI: 1.73 to 8.57, respectively, P = .001), as was previous 2-stage hip prosthesis exchange (HR = 3.58, 95% CI: 1.33 to 9.62, P = .01). Overall reoperation and revision rates were 26.2 and 16.6%, respectively. Re-infected patients had an 80% higher probability of reoperation than noninfected ones (P < .001, log-rank = 102.6), and they were 55% more likely to undergo revision surgery during their follow-up (P < .001, log-rank = 55.4). CONCLUSIONS: Reinfection rates after 2-stage spacer-free THA revision for PJI still remain high but are comparable to those including cement spacers. Patients who have had prior failed 2-stage implant exchanges or are infected by high-grade or difficult-to-treat pathogens are at high risk for treatment failure.

The Safety and Efficacy of Microporous Polysaccharide Hemospheres in Terms of the Complication Rates in Total Hip Arthroplasty for Femoral Neck Fractures: A Control-Matched Retrospective Cohort.

AIMS: This study aimed to assess the safety and efficacy of microporous polysaccharide hemospheres (MPSHs) in managing blood loss and reducing the risk of postoperative haematoma and early periprosthetic joint infection (PJI) following total hip arthroplasty (THA) for femoral neck fracture (FNF), in the context of the existing treatment challenges. METHODS: A control-matched retrospective analysis of 163 patients undergoing unilateral primary THA for displaced FNF between 2020 and 2023 was performed. The study group consisted of 74 patients who received MPSH administered intraoperatively. The control group consisted of 89 patients who received no topical haemostatics. One-to-one case-control matching between groups was performed. The primary outcome was a perioperative change in the haematologic values (haemoglobin, red blood cell count, haematocrit, platelet concentration) and transfusion rate. The secondary outcomes were the incidence of postoperative local haematoma formation, prolonged wound secretion, surgical site infection (SSI), and PJI within 3 months of surgery. RESULTS: Our analysis found no statistically significant differences in the haematologic parameters between the control and study cohorts. The changes in the haemoglobin concentration were not significant between the control group (3.18 ± 1.0 g/dL) and the treatment group (2.87 ± 1.15 g/dL) (p = 0.3). There were no significant differences (p = 0.24) in the haematocrit and red blood cell concentration (p = 0.15). The platelet levels did not significantly differ (p = 0.12) between the groups. Additionally, we found no significant discrepancy in the incidence of early PJI or blood transfusion rates between the groups. No adverse effects following MPSH use were recorded in the study group. CONCLUSIONS: Routine use of MPSH in THA for FNF management appears to be safe, with no observed adverse events related to Arista® use. Although there was a tendency towards reduced blood loss in the Arista® AH group, MPSH did not significantly impact bleeding complications, local haematoma formation, or subsequent PJI.

Are Hamstring Grafts a Predisposing Factor to Infection in R-ACL Surgery? A Comparative In Vitro Study.

BACKGROUND: The objective of the present study was to evaluate the formation of biofilms in bone patellar tendon bone grafts (BPTB grafts), and to compare it to the formation of biofilm formation in quadrupled hamstring anterior cruciate ligament grafts (4×Ht graft). METHODS: A descriptive in vitro study was conducted. One 4×Ht graft and one BPTB graft were prepared. They were then contaminated with a strain of S. epidermidis. Later, a quantitative analysis was conducted by means of microcalorimetry and sonication with plating. Additionally, a qualitative analysis was conducted by means of electron microscopy. RESULTS: No significant differences were found between the bacterial growth profiles of the 4×Ht graft and the BPTB graft in microcalorimetry and colony counting. In the samples analyzed with electron microscopy, no specific biofilm growth pattern was identified upon comparing the BPTB graft to the 4×Ht graft. CONCLUSIONS: There were no significant differences found at either the quantitative or qualitative level when comparing bacterial growth in the BPTB graft to that in the 4×Ht graft. Therefore, the presence of sutures in the 4×Ht graft cannot be established as a predisposing factor for increased biofilm growth in this in vitro study.

Interdisciplinary Infection Prevention and Control Bundle in Neurosurgical Patients: Results of a Prospective Cohort Study.

BACKGROUND: Surgical site infections (SSIs) account for one of the most common causes of nosocomial infections. Bundle approaches for infection prevention and control do not capture the full complexity of neurosurgical interventions. OBJECTIVE: To study the efficacy of an interdisciplinary infection prevention and control bundle (IPCB) in neurosurgery. METHODS: This was a prospective, single-center, observational study, analyzing 3 periods: before (2014), during (2017), and after (2019) full implementation of IPCB. IPCB included the following infection prevention measures: preoperative decolonization, patient engagement, operating room (OR) hygiene protocol, and pre-, peri-, and postoperative standard operating procedures (SOPs) while infection control measures included intraoperative sonication, blood culture inoculation, and interdisciplinary SSI management. All neurosurgical patients being readmitted to the hospital for SSIs within 90 days after receiving index surgery were included in the trial (403/9305). RESULTS: Implementation of IPCB resulted in more frequently succeeded pathogen isolation in patients with SSI (2014: 138 isolates in 105 (83%) patients with SSI, 2017: 169 isolates in 124 (91%) patients with SSI, and 2019: 199 isolates in 136 (97%) patients with SSI; P < .001). Proportion of gram-positive SSI and virulence was declining ( P = .041, P = .007). The number of repeated revision surgeries decreased from 26 (20%) in 2014 and 31 (23%) in 2017 to 18 (13%) in 2019 ( P = .085). Significantly, fewer patients experienced sepsis in response to SSI (2014: 12%, 2017: 10%, and 2019: 3.6%, P = .035). In-hospital mortality rate was declining from 12 (9.4%) in 2014 to 9 (6.6%) in 2017 to 5 (3.6%) in 2019 ( P = .148). CONCLUSION: Introducing an interdisciplinary IPCB in neurosurgery leads to a significant reduction of sepsis and decreased in-hospital mortality while a pathogen switch toward gram-negative bacteria was observed. Minimizing diagnostic gap of pathogen detection toward a more efficient anti-infective treatment may be the main reason for the substantial decrease in morbidity and mortality.

Global research characteristics and trends of infection after spinal implant surgery: a bibliometric analysis.

Background: With the growing awareness of postoperative infection, increasing focus has been placed on infection after spinal implant surgery (IASIS). This study aimed to explore the development and trends of research regarding IASIS using bibliometric analysis. Methods: Scientific articles on IASIS research published between February 1, 2000, and December 31, 2020 were retrieved from the Web of Science database. Results: A total of 820 publications were included in the bibliometric analysis, with studies originating from 46 countries and 6 languages. Researchers from the United States published the highest number of articles and collaborated closely with researchers in Canada, Germany, and Japan. The author with the most publications was Alexander R. Vaccaro. The journal with the most articles and citations was Spine. Most of the research was performed on risk factors and the incidence of IASIS. Co-occurrence analysis revealed that the most recent research trend was likely related to the management of IASIS and the international consensus meeting. Three clusters of research were identified through a thematic map: diagnosis and treatment of IASIS, scoliosis-related infection, and risk factors and prevention of IASIS. Conclusions: Research on IASIS increasingly grew between 2000 and 2020. Spinal surgeons and institutes from the United States had the highest number of publications and academic impact in this field. Diagnosis-related problems and multidisciplinary work on IASIS require further attention in the future. Current trends in IASIS are likely associated with IASIS management and the international consensus meeting.

The role of biopsy in diagnosing infection after hip and knee arthroplasty: a meta-analysis.

INTRODUCTION: Early diagnosis of periprosthetic hip and knee infection still represents a major challenge, as no single test can achieve ideal results. Currently, multiple preoperative indicators were performed to diagnose periprosthetic joint infection (PJI) to confirm or exclude infection in the early stage. However, the diagnostic value of biopsy-related tests in diagnosing periprosthetic hip and knee infection remains unclear. MATERIALS AND METHODS: Publications in PubMed, Embase, and the Web of Science databases were searched systematically until October 2020. Inclusion and exclusion criteria were used for screening biopsy-related studies of the diagnosis of periprosthetic hip and knee infection. RESULTS: Three biopsy-related tests were identified in 14 articles and further analyzed in the present meta-analysis. The combined method had the highest value for the area under the curve (0.9805), followed by histology (0.9425) and microbiological tests (0.9292). In the subgroup, statistical differences were identified in sensitivity and specificity for PJI diagnosis between the synovial fluid culture and biopsy culture group, as well as in the biopsy-related combined method and serum C-reactive protein. CONCLUSIONS: Biopsy culture does not appear to be advantageous compared to synovial fluid culture in the preoperative diagnosis of periprosthetic hip and knee infection. In contrast, combined biopsy microbial culture with histology analysis shows great potential in improving the preoperative diagnosis of PJI. The standard procedure of biopsy needs to be further explored. Further research is required to verify our results.

Prevention of Surgical Site Infections in Spine Surgery: An International Survey of Clinical Practices Among Expert Spine Surgeons.

STUDY DESIGN: Questionnaire-based survey. OBJECTIVES: Surgical site infection (SSI) is a common complication in spine surgery but universal guidelines for SSI prevention are lacking. The objectives of this study are to depict a global status quo on implemented prevention strategies in spine surgery, common themes of practice and determine key areas for future research. METHODS: An 80-item survey was distributed among spine surgeons worldwide via email. The questionnaire was designed and approved by an International Consensus Group on spine SSI. Consensus was defined as more than 60% of participants agreeing to a specific prevention strategy. RESULTS: Four hundred seventy-two surgeons participated in the survey. Screening for Staphylococcus aureus (SA) is not common, whereas preoperative decolonization is performed in almost half of all hospitals. Body mass index (BMI) was not important for surgery planning. In contrast, elevated HbA1c level and hypoalbuminemia were often considered as reasons to postpone surgery. Cefazoline is the common drug for antimicrobial prophylaxis. Alcohol-based chlorhexidine is mainly used for skin disinfection. Double-gloving, wound irrigation, and tissue-conserving surgical techniques are routine in the operating room (OR). Local antibiotic administration is not common. Wound closure techniques and postoperative wound dressing routines vary greatly between the participating institutions. CONCLUSIONS: With this study we provide an international overview on the heterogeneity of SSI prevention strategies in spine surgery. We demonstrated a large heterogeneity for pre-, peri- and postoperative measures to prevent SSI. Our data illustrated the need for developing universal guidelines and for testing areas of controversy in prospective clinical trials.

Microbiological Advantages of Open Incisional Biopsies for the Diagnosis of Suspected Periprosthetic Joint Infections.

BACKGROUND: Periprosthetic joint infection (PJI) represents a serious complication following total hip (THA) and knee arthroplasty (TKA). When preoperative synovial fluid cultures remain inconclusive, open incisional joint biopsy (OIB) can support causative microorganism identification. OBJECTIVE: This study investigates the potential benefit of OIB in THA and TKA patients with suspected PJI and ambigious diagnostic results following synovial fluid aspiration. METHODS: We retrospectively assessed all patients treated from 2016 to 2020 with suspected PJI. Comparing the microbiology of OIB and the following revision surgery, we calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and the number needed to treat (NNT). RESULTS: We examined the diagnostic validity of OIB in 38 patients (20 female) with a median age of 66.5 years. In THA patients (n = 10), sensitivity was 75%, specificity was 66.67%, PPV was 60%, NPV was 80%, and NNT was 2.5. In TKA patients (n = 28), sensitivity was 62.5%, specificity was 95.24%, PPV was 83.33%, NPV was 86.96%, and NNT was 1.42. CONCLUSIONS: Our results indicate that OIB represents an adequate diagnostic tool when previously assessed microbiological results remain inconclusive. Particularly in TKA patients, OIB showed an exceptionally high specificity, PPV, and NPV, whereas the predictive validity of the diagnosis of PJI in THA patients remained low.

A bibliometric analysis of clinical research on fracture-related infection.

Background: Infection following orthopaedic trauma surgery is increasingly recognized as one of the major research priorities with as primary goal, improving patient care. This increased interest has been anecdotally recognized through published research, research grants, and, finally, with the development of the fracture-related infection (FRI) consensus group. In 2017, the accepted consensus definition of FRI was published, which has been followed by consensus recommendations from both a surgical and medical perspective. A bibliometric analysis was performed to objectively describe the trends in published clinical research related to FRI. Methods: The terms related to FRI were searched in the Web of Science database between 2000 and 2020. The characteristics of clinical research on FRI regarding the author, country, journal, institution, scientific output, top 100 most cited articles, and trend topics were analyzed using Bibliometrix and WPS Office. Results: A total of 2597 records were eligible for inclusion in this bibliometric approach, with studies originating from 89 countries, including eight languages. The United States of America (USA) published the highest number of articles and citations. International collaborations were present between 72 countries, with the most active country being the USA. The most contributive institution was the University of California. The highest number of papers and citations were from the Injury-International Journal of the Care of the Injured and the Journal of Orthopaedic Trauma. The top 100 most cited articles were published in 27 different journals, with the number of citations ranging between 97 and 1004. The latest trend topics were related to the diagnosis of FRI. Conclusion: The present bibliometric analysis shows the research characteristics and trends of FRI from multiple perspectives. The fact that there is an increasing number of studies being published on FRI shows the agreement among scientists and clinicians that standardization with respect to this topic is very important.

Outcome and Failure Analysis of 132 Episodes of Hematogenous Periprosthetic Joint Infections-A Cohort Study.

Background: The outcomes of hematogenous periprosthetic joint infection (PJI) and reasons for failure are largely unknown. Methods: The outcomes of consecutive patients with hematogenous PJI treated at our institution between 2010 and 2019 were evaluated. Failure was classified as persistence or relapse of infection or new infection. Failure-free survival was assessed using Kaplan-Meier analysis. Proportions between groups were compared with the Fisher exact test. Results: One hundred thirty-two hematogenous PJI episodes involving knee (n = 76), hip (n = 54), shoulder (n = 1), or elbow (n = 1) prostheses experienced by 110 patients were included. The median follow-up (range) was 20.7 (0.2-89.9) months. Hematogenous PJIs were caused by Staphylococcus aureus (n = 49), Streptococcus spp. (n = 36), Enterococcus faecalis (n = 17), Enterobacterales (n = 16), coagulase-negative staphylococci (n = 9), and other (n = 6). Debridement and implant retention were performed in 50 (38%), prosthesis exchange or removal in 79 (60%), and no surgery in 3 episodes (2%). Treatment failed in 42 episodes (32%), including 6 infection-related deaths. Among 36 nonfatal failures, 21 were caused by a new pathogen and 8 by the same pathogen, in 7 episodes no pathogen was isolated. Of all nonfatal failures, 19 (53%) PJIs were of hematogenous origin. Identification of the primary focus, causative pathogen, and CRIME80 Score did not influence treatment outcome, but the failure rate was higher following prosthesis retention compared with multistage exchange. Conclusions: Persistence-/relapse-free survival after treatment of hematogenous PJI was high (84%). New hematogenous PJI due to the same or a new pathogen occurred frequently, reducing treatment success to 62% after 4 years of follow-up, suggesting an individual predisposition to hematogenous PJI. The outcome was similar for different pathogens but worse in episodes treated with prosthesis retention compared with multistage exchange.

Global Publication Trends and Research Hotspots of Revision Hip and Knee Arthroplasty: A 21-Year Bibliometric Approach.

BACKGROUND: As the number of primary hip and knee arthroplasties increases, revision cases correspondingly demonstrate high relative growth, gaining increasing attention. The present research aimed to investigate subject characteristics in revision hip and knee arthroplasty (RHKA) research using a bibliometric approach. METHODS: Publications related to RHKA from 2000 to 2020 were searched in the Web of Science database. WPS Office, CiteSpace, VOSviewer, and Bibliometrix were used to analyze the results. RESULTS: Bibliometric analysis revealed 3290 records. Fifty-nine countries published manuscripts on RHKA. The United States contributed most and also had the highest number of international collaborations. The most relevant institution was the Mayo Clinic. Berry DJ and Parvizi J were the most productive and academic influential authors in RHKA, respectively. The most productive journal was the Journal of Arthroplasty. Co-occurrence analysis demonstrated "infection" to be the trend in RHKA. Thematic analysis displayed 16 keywords in hip arthroplasty and 14 keywords in knee arthroplasty. CONCLUSION: The present study observed an increasing trend of research papers in RHKA. Institutions and scholars from the United States were found to dominate the field. Periprosthetic joint infection was likely a potential development trend and hotspot of RHKA.

Meta-analysis of synovial fluid polymerase chain reaction for diagnosing periprosthetic hip and knee infection.

BACKGROUND AND OBJECTIVE: The purpose of this study was to estimate the diagnostic performance of synovial fluid polymerase chain reaction (PCR) in periprosthetic hip and knee infection, and whether synovial fluid PCR has greater diagnostic significance than conventional methods. METHODS: The literature databases PubMed, Scopus, and the Web of Science were searched for English articles describing periprosthetic joint infection (PJI) diagnosis by synovial fluid PCR. Articles were limited to the period between January 1990 and December 2019. Subsequently, conventional methods that were used on at least two occasions were included for further analysis. Data analysis was performed using the Meta-DiSc and Stata software. RESULTS: Eleven studies with 1360 cases were included in the meta-analysis. The pooled sensitivity, specificity, and diagnostic odds ratio (DOR) of synovial fluid PCR were 0.70 (95% CI 0.66-0.74), 0.92 (95% CI 0.90-0.93), and 37.4 (95% CI 17.77-78.74), respectively. CONCLUSIONS: Synovial fluid PCR provides an effective tool for rapid diagnosis of PJI, and also in the early stages of culture-negative bacterial infections.

High Frequency of Low-Virulent Microorganisms Detected by Sonication of Implanted Pulse Generators: So What?

INTRODUCTION: Deep brain stimulation (DBS) has become a well-established treatment modality for a variety of conditions over the last decades. Multiple surgeries are an essential part in the postoperative course of DBS patients if nonrechargeable implanted pulse generators (IPGs) are applied. So far, the rate of subclinical infections in this field is unknown. In this prospective cohort study, we used sonication to evaluate possible microbial colonization of IPGs from replacement surgery. METHODS: All consecutive patients undergoing IPG replacement between May 1, 2019 and November 15, 2020 were evaluated. The removed hardware was investigated using sonication to detect biofilm-associated bacteria. Demographic and clinical data were analyzed. RESULTS: A total of 71 patients with a mean (±SD) of 64.5 ± 15.3 years were evaluated. In 23 of these (i.e., 32.4%) patients, a positive sonication culture was found. In total, 25 microorganisms were detected. The most common isolated microorganisms were Cutibacterium acnes (formerly known as Propionibacterium acnes) (68%) and coagulase-negative Staphylococci (28%). Within the follow-up period (5.2 ± 4.3 months), none of the patients developed a clinical manifest infection. DISCUSSIONS/CONCLUSIONS: Bacterial colonization of IPGs without clinical signs of infection is common but does not lead to manifest infection. Further larger studies are warranted to clarify the impact of low-virulent pathogens in clinically asymptomatic patients.

Corrigendum: D-lactate is a promising biomarker for the diagnosis of periprosthetic joint infection.

[This corrects the article DOI: 10.3389/fsurg.2022.1082591.].

Clinical application of robotic orthopedic surgery: a bibliometric study.

OBJECTIVES: The present study aimed to evaluate the status and trends of robotic orthopedic surgery in a clinical setting using bibliometrics. METHODS: All relevant publications on the clinical use of robotic surgery in orthopedics were searched from the Web of Science database. Subsequently, data were analyzed using bibliometrics. Visualizing data of bibliographic coupling, co-citation, and co-occurrence analysis were performed using VOSviewer. RESULTS: In total, 224 clinical studies met the included standards between 2000 to 2019. Global publications presented an increasing annual trend, with the United States found to have the largest number of publications and robotic companies active in the field (n = 99), followed by China (n = 38), and the United Kingdom (n = 27). The institution with the most contributions was the Beijing Jishuitan Hospital in China (n = 15). The most productive scholars were Tian Wei and Mont Michael A, with 14 publications each. The top 30 most cited papers list showed 29 publications to be cited on more than 40 occassions. The journal with the most related and influential publications on robotic orthopedic surgery was the Journal of Arthroplasty. Fourteen types of robots were used, with the majority applied in knee and spinal surgery. MAKO was the most widely used robot in hip and knee surgery and Mazor in spinal surgery. Most studies were small sample populations of low-quality in this field. The top 20 most frequently used keywords were identified from 950 author keywords. Research on orthopedic robots were classified into two clusters by co-occurrence networks: spinal-related robotic surgery and joint-related robotic surgery. CONCLUSIONS: The present bibliometric study summarizes the clinical research of orthopedic robots on study type, sample size, type of surgery, robot information, surgical site, most popular keywords, most cited papers, journals, authors, institutions, and countries. These findings may assist the scholars better understand the current status and research trends to guide future practice and directions.

Diagnostic accuracy of multiplex polymerase chain reaction on tissue biopsies in periprosthetic joint infections.

The diagnosis and treatment of periprosthetic joint infection (PJI) currently relies on cultures, which are time-consuming and often fail. Multiplex PCR assays promise reliable and prompt results, but have been heterogeneously evaluated. In this study, we analyse multiplex PCR in pathogen identification using only tissue biopsies. 42 patients after revision arthroplasty of the hip or knee were evaluated using multiplex PCR to identify microorganisms. The patients were classified according to the diagnostic criteria published by Zimmerli et al. and the results were compared to the respective microbiological cultures. PJI was detected in 15 patients and 27 revisions were aseptic. The multiplex PCR of tissue biopsies had a sensitivity of 0.3 (95% CI 0.12-0.62), a specificity of 1.0 (0.87-1.0), a positive predictive value of 1.0 (0.48-1.0) and a negative predictive value of 0.73 (0.56-0.86). The diagnostic accuracy of multiplex PCR on tissue biopsy samples is low in comparison to routine microbiological cultures. The evaluation of tissue biopsies using multiplex PCR was prone to false negative results. However, multiplex PCR assays have the advantage of rapid pathogen identification. We therefore recommend further investigation of multiplex PCR in the setting of suspected PJI with a careful choice of specimens.

The Pertinent Literature of Enhanced Recovery after Surgery Programs: A Bibliometric Approach.

Background and Objectives: The programs of enhanced recovery after surgery are the new revolution in surgical departments; however, features of this concept have not been systematically explored. Therefore, the purpose of this study was to explore Enhanced recovery after surgery (ERAS)-related research using bibliometric analysis. Materials and Methods: The search strategy of ERAS programs was conducted in the Web of Science database. Bibliometric analysis was further performed by Excel and Bibliometrix software. The relationship between citation counts and Mendeley readers was assessed by linear regression analysis. Results: 8539 studies from 1994-2019 were included in the present research, with reporting studies originating from 91 countries using 18 languages. The United States (US) published the greatest number of articles. International cooperation was discovered in 82 countries, with the most cooperative country being the United Kingdom. Henrik Kehlet was found to have published the highest number of studies. The journal Anesthesia and Analgesia had the largest number of articles. Linear regression analysis presented a strong positive correlation between citations and Mendeley readers. Most research was related to gastrointestinal surgery in this field. Conclusion: This bibliometric analysis shows the current status of ERAS programs from multiple perspectives, and it provides reference and guidance to scholars for further research.

Humeral periosteal spur sign with osteolysis as an early radiographic indicator of low-grade Cutibacterium acnes prosthetic shoulder infection.

The early diagnosis of low-grade Cutibacterium acnes prosthetic shoulder joint infection is challenging due to the lack of clinical and laboratory signs. Patients present with atypical symptoms such as stiffness or failure to improve shoulder function. The diagnosis is often delayed with impact on long-term outcomes. We present the case of an 82-year-old man with a surgical site erythema occurring 7 weeks after reverse shoulder arthroplasty associated with a light raise of C reactive protein (20 mg/L). At 9 weeks, radiographs revealed a 'periosteal spur sign' (humeral calcar) and localised adjacent osteolysis. Open surgery showed morphological signs of infection confirmed by growth of C acnes in eight cultures. A 'periosteal spur sign' is a useful early radiographic indicator of low-grade prosthetic joint infection usually occurring with some delay after clinical symptoms. A high clinical index of suspicion is needed to proceed with biopsies and to initiate combined operative and antibacterial treatment.

Soluble Pecam-1 as a Biomarker in Periprosthetic Joint Infection.

A reliable workup with regard to a single diagnostic marker indicating periprosthetic joint infection (PJI) with sufficient sensitivity and specificity is still missing. The immunologically reactive molecule Pecam-1 is shed from the T-cell surface upon activation via proinflammatory signaling, e.g., triggered by specific pathogens. We hypothesized that soluble Pecam-1 (sPecam-1) can hence function as a biomarker of PJI. Fifty-eight patients were prospectively enrolled and assigned to one of the respective treatment groups (native knees prior to surgery, aseptic, and septic total knee arthroplasty (TKA) revision surgeries). Via synovial sample acquisition and ELISA testing, a database on local sPecam-1 levels was established. We observed a significantly larger quantity of sPecam-1 in septic (n = 22) compared to aseptic TKA revision surgeries (n = 20, p ≤ 0.001). Furthermore, a significantly larger amount of sPecam-1 was found in septic and aseptic revisions compared to native joints (n = 16, p ≤ 0.001). Benchmarking it to the gold standard showed a high predictive power for the detection of PJI. Local sPecam-1 levels correlated to the infection status of the implant, and thus bear a strong potential to act as a biomarker of PJI. While a clear role of sPecam-1 in infection could be demonstrated, the underlying mechanism of the molecule's natural function needs to be further unraveled.

[PJI-TNM as new classification system for periprosthetic joint infections : An evaluation of 20 cases]. / PJI-TNM als neues Klassifikationssystem für Endoprotheseninfektionen : Eine Evaluation von 20 Fällen.

BACKGROUND: Current classifications for periprosthetic joint infections (PJIs) often lack a detailed description of the overall underlying situation of a patient. The PJI-TNM classification uses the principles of the TNM classification from oncology for the description of critical parameters in PJIs: affected joint, type of implant and implant stability, soft tissue conditions, maturity of biofilm formation, causative microorganism, comorbidities of the patient and recurrence of infection. The aim of the current work is to evaluate the feasibility of this new PJI-TNM classification in clinical practice. METHODS: The PJI-TNM classification was used in 20 patients with hip, knee and shoulder PJIs. Based on a retrospective chart review, the respective parameters T (tissue and implants), N (non-eukaryotic cells and fungi), M (morbidity) and r (reinfection) were classified for each case. RESULTS: All 20 cases (12 male, 8 female, average age 72.2 (40-88 years)) with 13 hip, 6 knee and 1 shoulder PJIs were to be classified with the new TNM-PJI classification system. There was a considerable heterogeneity among the cases: 12 protheses were fixed (T0), 6 were loosened (T1) and 2 were associated with a soft tissue defect (T2). Biofilm formation was considered immature in 7 cases (N0). Out of the PJIs, 13 were considered to be associated with mature biofilm formation. Out of the patients, 9 were systemically not or only mildly compromised (M0), 7 patients moderately (M1) and 3 patients (M2) severely compromised. One patient refused surgical treatment (M3a). Recurrent infections (r) were diagnosed in three cases. CONCLUSIONS: The principles of the TNM classification from oncology can also be used for the classification of PJIs. Despite the limited number of cases in this study, a considerable heterogeneity of the evaluated PJIs is shown, which is a phenomenon that is also known from clinical practice. This heterogeneity can be adequately addressed by this new classification, which might be beneficial in decision-making in the future.