Preoperative antibiotic prophylaxis in prosthetic joint infections: not a concern for intraoperative cultures

Diagnostics in Late Periprosthetic Infections-Challenges and Solutions

The rising number of arthroplasties is combined with a rising number of periprosthetic joint infections, which leads to life-concerning consequences for the patients, including extended antibiotic treatment, further surgery and increased mortality. The heterogeneity of the symptoms and inflammatory response of the patients due to, e.g., age and comorbidities and the absence of a single diagnostic test with 100% accuracy make it very challenging to choose the right parameters to confirm or deny a periprosthetic joint infection and to establish a standardized definition. In recent years, additional diagnostic possibilities have emerged primarily through the increasing availability of new diagnostic methods, such as genetic techniques. The aim of the review is to provide an overview of the current state of knowledge about the various tests, including the latest developments. The combination of different tests increases the accuracy of the diagnosis. Each physician or clinical department must select the tests from the available methods that can be best implemented for them in organizational and technical terms. Serological parameters and the cultivation of the samples from aspiration or biopsy should be combined with additional synovial tests to create an accurate figure for the failure of the prosthesis, while imaging procedures are used to obtain additional information for the planned therapeutic procedure.

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.

Advances in the Microbiological Diagnosis of Prosthetic Joint Infections

A significant number of prosthetic joint infections (PJI) are culture-negative and/or misinterpreted as aseptic failures in spite of the correct implementation of diagnostic culture techniques, such as tissue sample processing in a bead mill, prolonged incubation time, or sonication of removed implants. Misinterpretation may lead to unnecessary surgery and needless antimicrobial treatment. The diagnostic value of non-culture techniques has been investigated in synovial fluid, periprosthetic tissues, and sonication fluid. Different feasible improvements, such as real-time technology, automated systems and commercial kits are now available to support microbiologists. In this review, we describe non-culture techniques based on nucleic acid amplification and sequencing methods. Polymerase chain reaction (PCR) is a frequently used technique in most microbiology laboratories which allows the detection of a nucleic acid fragment by sequence amplification. Different PCR types can be used to diagnose PJI, each one requiring the selection of appropriate primers. Henceforward, thanks to the reduced cost of sequencing and the availability of next-generation sequencing (NGS), it will be possible to identify the whole pathogen genome sequence and, additionally, to detect all the pathogen sequences present in the joint. Although these new techniques have proved helpful, strict conditions need to be observed in order to detect fastidious microorganisms and rule out contaminants. Specialized microbiologists should assist clinicians in interpreting the result of the analyses at interdisciplinary meetings. New technologies will gradually be made available to improve the etiologic diagnoses of PJI, which will remain an important cornerstone of treatment. Strong collaboration among all specialists involved is essential for the correct diagnosis of PJI.

Positive Cultures Can Be Safely Ignored in Revision Arthroplasty Patients That Do Not Meet the 2018 International Consensus Meeting Criteria

BACKGROUND

During aseptic revision total joint arthroplasty (TJA), one or more cultures may occasionally isolate an organism. The hypothesis of this study was that in a portion of patients undergoing revision arthroplasty for aseptic failure, culture may isolate an organism(s) that can be left untreated.

METHODS

All patients undergoing revision TJA from 2000 to 2017 at two institutions were retrospectively reviewed. Patients were categorized as aseptic if they were appropriately investigated preoperatively and did not meet the 2018 International Consensus Meeting criteria. In the aseptic revision cohort, patients with a single positive culture or multiple cultures positive for different organisms ("organism-positive") and patients who had negative intraoperative cultures ("organism-negative") were compared based on demographics, comorbidities, operative details, subsequent reoperations, and periprosthetic joint infection (PJI).

RESULTS

In total, 3,234 International Consensus Meeting-negative aseptic revision TJAs were included, of which 215 patients (6.6%) were organism-positive, 196 (91.2%) had a single positive culture, and 19 (8.8%) were positive for 2 or more distinct organisms (ie, polymicrobial). The most prevalent organisms were coagulase-negative Staphylococci (37.5%), Staphylococcus epidermidis (9.6%), and Cutibacterium acnes (8.0%). Demographics and operative details were comparable between the groups. Using multiple regressions there was no association between culture positivity and the rate of reoperation or PJI.

CONCLUSION

Isolation of organisms by culture in patients undergoing revision for aseptic failure was not uncommon. As long as these patients were appropriately investigated preoperatively and PJI was excluded, these findings suggest that culture results may be ignored without subjecting patients to additional antimicrobial treatment.

Does preoperative antibiotic prophylaxis affect sonication-based diagnosis in implant-associated infection?

As culture-negative implant-associated infection denote a diagnostic challenge, sonicate fluid cultures of the explanted endoprosthesis and osteosynthesis components are frequently used. However, the effect of antibiotic treatment on pathogen detection by sonication fluid cultures in implant-associated infection has not been investigated. Thus, the aim of this study was to evaluate the influence of preoperative antibiotic prophylaxis (PAP) and antibiotic therapy (AT) on sonicate fluid cultures in patients with implant-associated infection. In this retrospective study three groups were compared: (i) standard PAP, (ii) AT for at least one day, and (iii) no antibiotics before surgery. For the inclusion criteria, an established diagnostic protocol for implant-associated infection was used. Sonicate fluid cultures were validated by corresponding microbiological and histopathological samples. In 90 patients with single and multiple infections, 114 pathogens were detected. The detection rate by sonicate fluid cultures in patients receiving PAP (n = 27, 29 pathogens), AT before surgery (n = 33, 48 pathogens) and no antibiotics before surgery (n = 30, 37 pathogens) were 86.2%, 81.3%, and 86.5% (p = .778), respectively. Eleven of 114 infectious agents were detected exclusively by sonicate fluid cultures, while conventional tissue culture failed in these cases. PAP and AT do not affect intraoperative cultures in implant-associated infection. It is therefore not recommended to omit antibiotic prophylaxis in patients with implant-associated infection. Algorithms including both sonicate fluid cultures and tissue samples should be used for appropriate microbiological diagnosis of implant-associated infections.

Reactive Arthritis from Influenza Vaccination: A Novel Presentation That Mimics Prosthetic Joint Infection: A Case Report

CASE

A 50-year-old woman with a history of bilateral knee replacements developed acute-onset bilateral painful knee effusions and inability to weight-bear. She was systemically well, but 2 days before the onset of her symptoms, she received an influenza vaccination. Synovial fluid analysis revealed white cell count (WCC) 190,000 × 109, 85% polymorphomuclear lymphocytes (PMN) on the left knee and WCC 252,200 × 109, 89% PMN on the right knee. Debridement and implant retention and polyethylene exchange was performed. Extended bacterial culture was negative as was 16s RNA polymerase chain reaction for remnants of bacterial DNA. No crystals were seen on any specimen. Both knees are stable and pain free at 12-month follow-up.

CONCLUSION

Reactive arthritis secondary to influenza vaccination is a rare condition that can mimic prosthetic joint infection.

Radiological changes, infections and neurological complications after reverse shoulder arthroplasty related to different design types and their rates: Part II

Early reported complication rates with the Grammont-type reverse shoulder arthroplasty (RSA) were very high, up to 24%.A 'problem' is defined as an intraoperative or postoperative event that is not likely to affect the patient's final outcome, such as intraoperative cement extravasation and radiographic changes. A 'complication' is defined as an intraoperative or postoperative event that is likely to affect the patient's final outcome, including infection, neurologic injury and intrathoracic central glenoid screw placement.Radiographic changes around the glenoid or humeral components of the RSA are very frequently observed and described in the literature.High complication rates related to the Grammont RSA design led to development of non-Grammont designs which led to a dramatic fall in the majority of complications.The percentage of radiological changes after RSA is not negligible and remains unsolved, despite a decrease in its occurrence in the last decade. However, such changes should be now considered as simple problems because they rarely have a negative influence on the patient's final outcome, and their prevalence has dramatically decreased.With further changes in indications and designs for RSA, it is crucial to accurately track the rates and types of complications to justify its new designs and increased indications. Cite this article: EFORT Open Rev 2021;6:1109-1121. DOI: 10.1302/2058-5241.6.210040.

Adherence to a reliable PJI diagnostic protocol minimizes unsuspected positive cultures rate

Background

The aim of the present study was to evaluate the incidence of unsuspected PJI when prosthetic revisions are thoroughly evaluated by PJI dedicated orthopedic surgeon before surgery. The hypothesis is that the incidence of unsuspected PJI is reduced by applying this protocol.

Methods

This is a historical cohort study carried out in one university hospital. The prosthetic revision assessment was carried out in January 2019. From that date on, all patients that were programmed for hip or knee revision (either by an orthopedic surgeon specialized or not in septic revisions) were scheduled for a preoperative visit with the same orthopedic surgeon specialized in septic revisions. The diagnostic algorithm applied was based on the Pro-Implant Foundation diagnostic criteria. Prior to the revision assessment, the indication for joint aspiration was done at the surgeons’ discretion (non-specialized in septic revisions) and the preoperative identification of PJI was also done by a hip or knee surgeon (not specialized in septic surgery).

Results

Based on the PIF criteria, there were 15 infections among the revisions in group 1 and 18 PJI in group 2 (p > 0.05). The most interesting finding was that there were 7 patients with unsuspected positive cultures in group 1. That represents 11% of all revisions. No patient in group 2 was found with unsuspected positive cultures (p < 0.001).

Conclusion

A thorough PJI diagnostic algorithm should be implemented before prosthetic revision to avoid unsuspected positive cultures.

[Infected endoprosthesis in patients with rheumatism]

Infections are a severe complication after an artificial joint replacement. The clinical symptoms are highly variable, particularly in patients with inflammatory rheumatic diseases, which often makes the diagnosis difficult. In addition to clinical and laboratory findings, joint puncture is an essential component of the diagnostics and enables the identification of pathogens. Treatment of periprosthetic infections in patients with rheumatism should be an interdisciplinary cooperation between surgeons, rheumatologists and specialists for infectious diseases. The two essential pillars of treatment are surgical intervention and antibiotics. For acute joint infections an attempt at preservation of the artificial joint can be carried out, whereas for chronic infection situations only replacement of the prosthesis is possible as a curative treatment. In order to reduce the probability of occurrence of a joint infection, modifiable risk factors should be preoperatively identified and specifically treated.

Antibiotic prophylaxis in orthopedics-traumatology

When all rules of hygiene have been scrupulously applied, antibiotic prophylaxis (ABP) is the one remaining means of further reducing surgical site infection risk. Its efficacy in major orthopedic surgical procedures is proven. Guidelines for indications and ABP systemic administration have been long established and are able to address many questions. By extrapolation, the same protocols apply in closed fractures, whereas they are less certain in open fractures, where successive and still incomplete reassessments have been made. There are no specific ABP protocols in implant revision for mechanical or infectious causes or in high-grade open fractures, despite the high associated risk of surgical site infection. All means of prophylaxis need exploring in these contexts: various molecule combinations, and various local applications. Although ideas are by no means lacking, levels of evidence are low or undetermined. Awaiting more objective data, the focus has to be on the quality of implementation. It is easy enough to conceive of ABP in terms of the tissue pharmacokinetics of the antibiotic(s), but real-life implementation is a real organizational challenge. Optimizing practices in clearly defined indications is still the prime objective for surgical ABP.

Think Twice before Prescribing Antibiotics for That Swollen Knee: The Influence of Antibiotics on the Diagnosis of Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) is a rare but devastating complication after total joint arthroplasty. An estimated 7-12% of patients have negative cultures despite clear clinical evidence of infection. One oft-cited reason for this occurrence is the administration of antibiotics in the weeks prior to obtaining cultures. This article reviews the influence of antibiotics on the diagnosis of PJI. Specifically, we examine the effect of prophylactic and therapeutic antibiotic administration on the diagnostic accuracy of microbiological cultures as well as serum and synovial biomarkers. We also explore the potential of molecular techniques in overcoming these limitations in patients who have received antibiotics before specimen collection and propose areas for future research.

Cutibacterium acnes is an intracellular and intra-articular commensal of the human shoulder joint

BACKGROUND

Cutibacterium acnes (C acnes) is a mysterious member of the shoulder microbiome and is associated with chronic postoperative complications and low-grade infections. Nevertheless, it is unclear whether it represents a contaminant or whether it accounts for true infections. Because it can persist intracellularly in macrophages at several body sites, it might in fact be an intra-articular commensal of the shoulder joint.

METHODS

In 23 consecutive, otherwise healthy patients (17 male, 6 female; 58 years) who had no previous injections, multiple specimens were taken from the intra-articular tissue during first-time arthroscopic and open shoulder surgery. The samples were investigated by cultivation, genetic phylotyping, and immunohistochemistry using C acnes-specific antibodies and confocal laser scanning microscopy.

RESULTS

In 10 patients (43.5%), cultures were C acnes-positive. Phylotype IA1 dominated the subcutaneous samples (71%), whereas type II dominated the deep tissue samples (57%). Sixteen of 23 patients (69.6%) were C acnes-positive by immunohistochemistry; in total, 25 of 40 samples were positive (62.5%). Overall, 56.3% of glenohumeral immunohistochemical samples, 62.5% of subacromial samples, and 75% of acromioclavicular (AC) joint samples were positive. In 62.5% of the tested patients, C acnes was detected immunohistochemically to reside intracellularly within stromal cells and macrophages.

DISCUSSION

These data indicate that C acnes is a commensal of the human shoulder joint, where it persists within macrophages and stromal cells. Compared with culture-based methods, immunohistochemical staining can increase C acnes detection. Phylotype II seems to be most prevalent in the deep shoulder tissue. The high detection rate of C acnes in osteoarthritic AC joints might link its intra-articular presence to the initiation of osteoarthritis.

The vancomycin soaking technique: no differences in autograft re-rupture rate. A comparative study

PURPOSE

The main aim of this study was to evaluate the re-rupture risk after an anterior cruciate ligament reconstruction (ACL-R) using the vancomycin soaking technique and to compare it with the re-rupture risk in patients on whom this technique was not utilized. The secondary purpose was to compare the functional outcomes of those two subsets of patients operated on for ACL-R. The hypotheses are that the vancomycin soaking technique does not affect the re-rupture risk or the functional outcomes.

MATERIAL AND METHODS

A retrospective historical cohort study was conducted. Two groups were compared in terms of the re-rupture rate (traumatic or atraumatic) and functional outcomes (International Knee Documentation Committee (IKDC), Tegner, and Lysholm). Group 1 consisted of patients that received pre-operative IV antibiotics. In group 2, the patients received pre-operative IV antibiotics along with a graft that had been presoaked in a vancomycin solution. A minimum follow-up of five years was required.

RESULTS

There were 17 patients that suffered a re-rupture in group 1 (4.7%) and 15 in group 2 (3.9%) (n.s.). IKDC was 82.0 in group 1 and 83.9 in group 2 (p = 0.049); Tegner scored 4 in both groups (n.s.) and Lysholm was 90.3 in group 1 and 92.0 in group 2 (p = 0.015).

CONCLUSION

The vancomycin soaking technique for ACL autografts is a safe procedure for the daily clinical practice, in terms of re-ruptures. Moreover, it does not impair functional outcomes after an ACL-R.

Bacterial adhesion on orthopedic implants

Orthopedic implants are routinely used for fixation of fractures, correction of deformities, joint replacements, and soft tissue anchorage. Different biomaterials have been engineered for orthopedic implants. Previously, they were designed merely as mechanical devices, now new strategies to enhance bone healing and implant osteointegration via local delivery of molecules and via implant coatings are being developed. These biological coatings should enhance osteointegration and reduce foreign body response or infection. This article reviews current and future orthopedic implants, materials and surface characteristics, biocompatibility, and mechanisms of bacterial adhesion. Additionally, the review is addressing implant-related infection, the main strategies to prevent it and suggest possible future research that may control implant related-infection.

Antibiotic prophylaxis in primary and revision shoulder replacement: a systematic review

Background

One of the most common bacteria responsible for most Periprosthetic joint infection (PJI) is Propionibacterium acnes. Even though the rate of infections in patients undergoing total shoulder arthroplasty is increasing, effective diagnostic tests and the precautions taken during the surgery are not yet adequate. This systematic review aims to evaluate the effectiveness of antimicrobial prophylaxis in PJI in shoulder replacement and to provide health workers with the best approach to the use of antimicrobial agents based on currently available clinical evidence.

Methods

a systematic review of the literature was carried out in accordance with the PRISMA Statement. Studies concerning the effectiveness of antimicrobial prophylaxis in the prevention of PJI in patients undergoing shoulder replacement were included.

Results

Seven studies were included in the final analysis because they were considered valid. A total of 3272 patients underwent a surgical procedure, most of which were males. The male population has a greater presence of hair, therefore a greater risk of P. acnes. in surface cultures. Patients were assessed at an average follow-up period of 20 months ranging from 9 weeks to 53 months.

Conclusion

The optimal perioperative antimicrobial regimen is controversial. The clinical guidelines recommend the use of only one antibiotic as prophylaxis but considering the increase in the rates of antibiotic-resistant infections, the question arises whether antibiotic prophylaxis should be extended for adequate coverage. Shoulder arthroplasty performed on the male population must be carefully checked after surgery for the possible presence of P. Acnes.

Specificities of total hip and knee arthroplasty revision for infection

Hip or knee revision for infection requires careful planning of the debridement phase. Bacteriological sample management needs to be planned. Multidisciplinary decisions have to be taken as to 1- or 2-stage strategy, reconstruction technique and soft-tissue management. Surgical resection should be complete while economical. There must be no shortcomings in the technical procedure. Implant removal and surgical debridement are the keys to curing the infection, and planning is essential to optimize this phase. Bacteriological techniques are well codified. Wide-spectrum curative antibiotic therapy should be initiated immediately after intraoperative sampling and secondarily adapted to culture findings. A high-level microbiology laboratory is indispensable to good quality treatment. Prophylactic antibiotic therapy is controversial, but probably contributive. Two-stage exchange has not demonstrated superiority in curing infection. A 1-stage procedure may be preferred if all prerequisites are met. In the knee, any need for flap coverage should be planned for rather than encountered intraoperatively. The principles of reconstruction are unchanged by infection, but extended resection may require a larger revision implant. The temptation to oversimplify has to be resisted, and non-escalation or indeed "de-escalation" in implant size should be sought. Bone defect management is unaffected by infection. Fixation technique is at the surgeon's discretion. Pain relief and functional results are probably less good than after exchange without infectious context. The creation of regional complex bone and joint infection centers in France (CRIOACs) constitutes a considerable advance in periprosthetic infection management, and an opinion should be systematically requested; transfer is to be considered on a case-by-case basis.

Effect of prior receipt of antibiotics on the pathogen distribution: a retrospective observational cohort study on 27,792 patients

Background

There have been no systematic studies of microbiological differences before and after antibiotics treatment. The aim of this study was to evaluate the effect of prior receipt of antibiotics on the microorganism distribution.

Methods

A retrospective, observational cohort study was conducted in a 3200-bed tertiary, referral, teaching hospital in eastern China. During a 2-year period, all hospitalized patients treated with antimicrobial agents were enrolled in this study. Among 48,692 patients evaluated, the 27,792 (57.1%) who were sampled within 2 days before or after administration of the first dose of antimicrobial agents were included. Distribution of clinical specimens and the microorganism were compared between before and after antibiotic drug treatment groups.

Results

Compared to specimens taken after antibiotics exposure, specimens taken before antibiotics exposure had a higher proportion of blood and urine specimens and a higher culture positive rate (all P < 0.001). Higher percentages of Staphylococcus aureus (9.9% vs. 8.5%, P = 0.041), non-fermenting bacteria (27.7% vs. 19.9%, P < 0.001), and fungi (8.4% vs. 4.0%, P < 0.001) were isolated from the group after antibiotics exposure, while the percentages of Streptococcus spp. (4.8% vs. 2.7%, P < 0.001), Haemophilus influenzae (2.3% vs. 0.8%, P < 0.001), and Moraxella catarrhalis (0.7% vs. 0.1%, P < 0.001) were higher in the group before antibiotics exposure. Further analysis found significant differences of microbes derived from respiratory secretions, blood or urine samples. We found, after antibiotics exposure, the separation rate of non-fermenting bacteria was significantly increased (all P < 0.05), and the separation rate of Candida spp. was higher, with statistical significance in airway secretion and urine samples (both P < 0.05), but the separation rate of Staphylococcus aureus among the three groups was not affected by antibiotics. In addition, the isolation rate of Streptococcus spp. in blood and urine samples decreased significantly (both P < 0.05) after antibiotics exposure. Interestingly, no statistical difference was found for microbes isolated from body fluid specimens between the two groups.

Conclusions

The outcome revealed that antibiotic-insensitive organisms such as non-fermentative bacteria and fungi were more frequently isolated after antibiotics exposure. However, this trend might be specimen dependent and was not obvious in body fluid specimens.

Diagnosing Fracture-Related Infection: Current Concepts and Recommendations

Fracture-related infection (FRI) is a severe complication after bone injury and can pose a serious diagnostic challenge. Overall, there is a limited amount of scientific evidence regarding diagnostic criteria for FRI. For this reason, the AO Foundation and the European Bone and Joint Infection Society proposed a consensus definition for FRI to standardize the diagnostic criteria and improve the quality of patient care and applicability of future studies regarding this condition. The aim of this article was to summarize the available evidence and provide recommendations for the diagnosis of FRI. For this purpose, the FRI consensus definition will be discussed together with a proposal for an update based on the available evidence relating to the diagnostic value of clinical parameters, serum inflammatory markers, imaging modalities, tissue and sonication fluid sampling, molecular biology techniques, and histopathological examination. Second, recommendations on microbiology specimen sampling and laboratory operating procedures relevant to FRI will be provided. LEVEL OF EVIDENCE:: Diagnostic Level V. See Instructions for Authors for a complete description of levels of evidence.

Prosthetic joint infection caused by Candida lusitaniae: report of a unique case

Background: Candida prosthetic joint infection (PJI) is a rare complication of total knee arthroplasty (TKA). The literature regarding its diagnosis and management is scarce. Case summary: We present the case of a 79-year-old woman with history of TKA and femoral intramedullary nailing, who developed PJI caused by Candida lusitaniae. A two-stage exchange arthroplasty was performed. She underwent implant removal, debridement and placement of temporary antibiotic impregnated spacer. Postoperatively, the patient received treatment with micafungin for 24 weeks. Eleven months after the first stage, the spacer was removed and a new knee prosthesis was placed. Complete eradication of infection was demonstrated by negative culture of cement spacer, synovial fluid and periprosthetic tissue. Histology of surgical samples was unremarkable. Empiric treatment with micafungin was given for 6 weeks after placement of the new prosthesis. At 6-month follow-up, there was no evidence of recurrent infection. Conclusion: To our knowledge, this is the first reported case of Candida lusitaniae PJI.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: prevention of periprosthetic shoulder infection

The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. Over 800 international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology were assembled to form a consensus workgroup. The following proceedings on the prevention of periprosthetic shoulder infection come from 16 questions evaluated by delegates from the shoulder section.

Proceedings from the 2018 International Consensus Meeting on Orthopedic Infections: management of periprosthetic shoulder infection

The Second International Consensus Meeting on Orthopedic Infections was held in Philadelphia, Pennsylvania, in July 2018. A multidisciplinary team of international experts from all 9 subspecialties of orthopedic surgery and allied fields of infectious disease, microbiology, and epidemiology was assembled to form the International Consensus Group. The following consensus proceedings from the International Consensus Meeting involve 30 questions pertaining to the management of periprosthetic shoulder infection.

A Comparison of the Effect of Sevoflurane and Propofol on Ventricular Repolarisation after Preoperative Cefuroxime Infusion

The aim of this study is to investigate the changes in QT, QTc, and Tp-e intervals and Tp-e/QT ratio on surface electrocardiogram (ECG) signals during anaesthesia induction using propofol or sevoflurane after preoperative cefuroxime infusion. Some 120 cases of gynaecological patients are randomly divided into propofol (P) and sevoflurane (S) groups (n=60). After cefuroxime (1.5 g) was infused in the two groups of patients, propofol target controlled infusion (TCI) was conducted in the P group for 5 min to realise a plasma concentration of 4 μg/ml while patients in the S group inhaled anaesthesia by infusing 1.3 MAC sevoflurane for 6 min. The 12-lead ECGs were separately collected before infusing cefuroxime (T₁), after infusing cefuroxime (T₂), and after infusing propofol or sevoflurane (T₃) to measure QT and Tp-e intervals, calculate QTc and Tp-e/QT, and record MAP and HR. Finally, we demonstrated that QT, QTc, and Tp-e intervals and Tp-e/QT ratio had no change (P > 0.05) after cefuroxime infusion in the two groups of patients compared with that before infusing antibiotics. Moreover, after conducting preoperative cefuroxime infusion, using propofol and sevoflurane had no influence on Tp-e interval, but sevoflurane can significantly prolong QT and QTc intervals (P < 0.05).

Foot and ankle infections: Debridement, early fixation and rifampicin provide earlier recovery of function and quality of life

BACKGROUND

Infection after foot and ankle fractures is a major concern for orthopedic surgeons. It is widely believed that final osteosynthesis should be delayed until the infection is cured. However, there is no literature that supports this practice. In addition, the delay impairs patient function and quality of life (QoL).

METHODS

In the present study, four cases of ankle infection treated with aggressive debridement, early fixation and antibiofilm antibiotics are described. It is thought that, like other implant related infections, ankle infections can be rapidly treated with the definitive fixation and by curing the infection to make for a fast recovery of QoL and function.

RESULTS

The infections were caused by MSSA and Pseudomonas aeruginosa in case 1, MSSA in case 2 and MRSA as well as K. pneumonia in case 3. Case 4 was a culture negative infection. They were susceptible to antibiofilm antibiotics (the gram-negative bacilli susceptible to ciprofloxacin and the gram-positive cocci susceptible to rifampicin). Cases 1, 3 and 4 were treated with a tibio-talo-calcaneal arthrodesis and case 2 was treated with a de-rotational fibular osteotomy and a medial closing wedge supramalleolar osteotomy. All cases improved at a median time of 4 weeks in terms of quality of life (SF-36) and function (AOFAS). At 2-years follow-up, no recurrence of infection was observed in any of the cases. All the cases achieved fusion or osteotomy healing at final follow-up.

CONCLUSIONS

Early fixation after debridement combined with antibiofilm antibiotics can be performed in foot and ankle inflections to provide early recovery of QoL and function in patients.

Culturing Periprosthetic Joint Infection: Number of Samples, Growth Duration, and Organisms

BACKGROUND

Owing to the difficulty isolating microorganisms in periprosthetic joint infection (PJI), current guidelines recommend that 3-5 intraoperative samples be cultured and maintained for 3-14 days. We investigated (1) the optimal number of culture samples and growth duration to diagnose PJI and (2) the microbiology profile at our institution.

METHODS

A retrospective review of 711 patients (329 hips, 382 knees) with PJI that met Musculoskeletal Infection Society criteria from 2000 to 2014 was performed. Two thousand two hundred ninety aerobic and anaerobic cultures were analyzed. A manual chart review collected demographic, surgical, and microbiological data. Microbiology profiles were trended. Logistic regression analysis was performed to determine statistical significance.

RESULTS

Obtaining 5 samples provided the greatest yield positive cultures for diagnosing PJI. The percentage of positive cultures overall was 62.6% and stratified by organism type: antibiotic resistant (80.0%), Staphylococcus aureus (76.0%), gram negative (58.9%), Pseudomonas (52.0%), variant PJI organisms (28.2%), Propionibacterium acnes (20.0%), and Escherichia coli (8.0%). Although most organisms were cultured in 5 days or less, 10.8 days were needed for Propionibacterium acnes, 6.6 for variant PJI organisms, and 5.2 for coagulase-negative Staphylococcus. At 3 days, only 42.2% of cultures turned positive compared with 95.0% at 8 days. There was a significant decrease in time in gram-positive PJIs and an increase in culture-negative PJIs.

CONCLUSION

The optimal number of cultures and growth duration depended on the type of organism. This study provides evidence that 5 samples should be obtained and held for at least 8 days given that the type of organisms is likely to be unknown at the time of surgery.

Perioperative Antibiotic Prophylaxis Has No Effect on Time to Positivity and Proportion of Positive Samples: a Cohort Study of 64 Cutibacterium acnes Bone and Joint Infections

If a bone or joint infection is suspected, perioperative antibiotic prophylaxis is frequently withheld until intraoperative microbiological sampling has been performed. This practice builds upon the hypothesis that perioperative antibiotics could render culture results negative and thus impede tailored antibiotic treatment of infections. We aimed to assess the influence of antibiotic prophylaxis within 30 to 60 min before surgery on time to positivity of microbiological samples and on proportion of positive samples in Cutibacterium acnes bone and joint infections. Patients with at least one sample positive for C. acnes between January 2005 and December 2015 were included and classified as having an "infection" if at least 2 samples were positive; otherwise they were considered to have a sample "contamination." Kaplan-Meier curves were used to illustrate time to culture positivity. We found 64 cases with a C. acnes infection and 46 classified as having a C. acnes contamination. Application of perioperative prophylaxis significantly differed between the infection and contamination groups (72.8% versus 55.8%; P < 0.001). Within the infection group, we found no difference in time to positivity between those who had or had not received a perioperative prophylaxis (7.07 days; 95% confidence interval [CI], 6.4 to 7.7, versus 7.11 days; 95% CI, 6.8 to 7.5; P = 0.3). Also, there was no association between the proportion of sample positivity and the application of perioperative prophylaxis (71.6% versus 65.9%; P = 0.39). Since perioperative prophylaxis did not negatively influence the microbiological yield in C. acnes infections, antibiotic prophylaxis can be routinely given to avoid surgical site infections.

The Effect of Preoperative Antimicrobial Prophylaxis on Intraoperative Culture Results in Patients with a Suspected or Confirmed Prosthetic Joint Infection: a Systematic Review

Obtaining reliable cultures during revision arthroplasty is important to adequately diagnose and treat a prosthetic joint infection (PJI). The influence of antimicrobial prophylaxis on culture results remains unclear. Since withholding prophylaxis increases the risk for surgical site infections, clarification on this topic is critical. A systematic review was performed with the following research question: in patients who undergo revision surgery of a prosthetic joint, does preoperative antimicrobial prophylaxis affect the culture yield of intraoperative samples in comparison with nonpreoperative antimicrobial prophylaxis? Seven articles were included in the final analysis. In most studies, standard diagnostic culture techniques were used. In patients with a PJI, pooled analysis showed a culture yield of 88% (145/165) in the prophylaxis group versus 95% (344/362) in the nonprophylaxis group (P = 0.004). Subanalysis of patients with chronic PJIs showed positive cultures in 88% (78/89) versus 91% (52/57), respectively (P = 0.59). In patients with a suspected chronic infection, a maximum difference of 4% in culture yield between the prophylaxis and nonprophylaxis groups was observed. With the use of standard culture techniques, antimicrobial prophylaxis seems to affect cultures in a minority of patients. Along with the known risk of surgical site infections due to inadequate timing of antimicrobial prophylaxis, we discourage the postponement of prophylaxis until tissue samples are obtained in revision surgery. Future studies are necessary to conclude whether the small percentage of false-negative cultures after prophylaxis can be further reduced with the use of more-sensitive culture techniques, like sonication.

Withholding Preoperative Antibiotic Prophylaxis in Knee Prosthesis Revision: A Retrospective Analysis on Culture Results and Risk of Infection

BACKGROUND

A significant amount of patients undergoing revision surgery of a prosthetic joint turn out to have an infection. Withholding preoperative antibiotic prophylaxis in these patients to optimize culture yield during revision surgery remains a matter of debate. The aim of our study was to determine (1) the rate of positive intraoperative cultures with or without preoperative antibiotic prophylaxis and (2) the incidence of a prosthetic joint infection (PJI) during the follow-up in the 2 groups.

METHODS

Medical files of patients in whom preoperative antibiotic prophylaxis was withheld until culture samples were taken (2007-2010, n = 284) and in whom antibiotic prophylaxis was given during the induction of anesthesia (2010-2013, n = 141) were retrospectively reviewed.

RESULTS

The percentage of ≥1 positive cultures was the same in the group without (26%) and with preoperative prophylaxis (27%; P value, .7). PJI was diagnosed during revision surgery according to the Musculoskeletal Infection Society criteria in 6.7% patients not receiving preoperative prophylaxis and in 7.0% receiving it (P value, .79). We found no important differences in the type of microorganisms that were isolated in both groups. During a 3-month follow-up, an early PJI developed in patients undergoing total revision surgery in 6.4% of the nonpreoperative prophylaxis group vs 1.6% in the preoperative prophylaxis group (P value, .1).

CONCLUSION

Preoperative antibiotic prophylaxis does not reduce culture yield in patients undergoing knee revision surgery. Our data show a trend toward a higher PJI rate in the postoperative period of total revision surgery when preoperative prophylaxis is withheld.