Isavuconazole in the Treatment of Aspergillus fumigatus Fracture-Related Infection: Case Report and Literature Review

Aspergillus fracture-related infection (FRI) is a rare, but severe complication in trauma surgery. The optimal antifungal treatment for Aspergillus osteomyelitis, including FRI, has not been established yet, as only cases have been documented and data on bone penetration of antifungal drugs are scarce. We describe a patient with Aspergillus fumigatus FRI of the tibia who was treated with isavuconazole after developing liver function disturbances during voriconazole therapy. Isavuconazole, the active moiety formed after hydrolysis of the prodrug isavuconazonium sulfate by plasma esterases, was administered in a maintenance dose of 200 mg q24 h, followed by 150 mg q24 h. The patient completed a six-month antifungal treatment course. Although fracture union was not achieved during six months of follow-up after therapy cessation, no confirmatory signs of FRI were observed. Additionally, two literature searches were conducted to review available data on antifungal treatment of Aspergillus osteomyelitis and bone penetration of antifungals. One hundred and eight cases of Aspergillus osteomyelitis, including six (5.6%) FRI cases, were identified. Voriconazole and (lipid formulations of) amphotericin B were the most commonly used antifungals. In three (2.8%) cases isavuconazole was prescribed as salvage therapy. Data on antifungal bone penetration were reported for itraconazole, voriconazole, amphotericin B, anidulafungin and 5-fluorocytosin. Isavuconazole might be a promising alternative for the treatment of Aspergillus osteomyelitis. However, standardized case documentation is needed to evaluate the efficacy of isavuconazole and other antifungals in the treatment of Aspergillus osteomyelitis, including FRI.

Accelerated Rehabilitation in Non-operative Management of Acute Achilles Tendon Ruptures: A Systematic Review and Meta-analysis

The optimal treatment and rehabilitation strategy for Achilles tendon ruptures is still under debate. There is a paradigm shift toward early mobilization and weightbearing. We examined the treatment effect of accelerated functional rehabilitation in nonoperative management of acute Achilles tendon ruptures. A systematic search of PubMed, EMBASE, and Web of Science databases for articles comparing accelerated versus delayed rehabilitation in the nonoperative management of acute Achilles tendon rupture was performed. Outcomes of interest were Achilles tendon rupture score (ATRS) (standardized patient-reported instrument related to symptoms and physical activity after treatment of an acute Achilles tendon rupture), rerupture rate, strength, range of motion, return to work, and sports. A total of 2001 articles were identified using our search strategy. We included 6 randomized controlled trials of interest. Although the concept of accelerated rehabilitation has gained popularity in recent years, no statistically significant differences could be revealed in any of the outcomes of interest. We performed a meta-analysis on the following outcomes: ATRS (mean difference -0.93 95% confidence interval [CI] -6.01 to 4.14), Rerupture rate (odds ratio [OR] 0.97, 95% CI: 0.46-2.03), Return to sports (OR 1.31, 95% CI 0.76-2.25), Return to work (mean difference 5.24, 95% CI to -12.04 to 22.51). The treatment effect of accelerated rehabilitation in nonoperatively treated patients seems to be small. However, we recommend accelerated rehabilitation for all conservatively treated patients, because it is a safe option and no detrimental effects have been described in the literature. Furthermore, many patients prefer this type of rehabilitation to avoid the practical disadvantages of prolonged immobilization.

Ninety-Day Follow-up Is Inadequate for Diagnosis of Fracture-related Infections in Patients with Open Fractures

BACKGROUND

Fracture-related infection (FRI) is a challenging complication in musculoskeletal trauma surgery and often complicates the management of open fractures. The CDC currently advocates a surveillance period of 90 days after fracture fixation, but it is unclear what duration of follow-up constitutes adequate surveillance for FRI. Inadequate follow-up will underestimate infections and, in clinical research, will make any interventions studied appear better than they really are, thereby resulting in misleading conclusions.

QUESTIONS/PURPOSES

(1) What is the timing of FRI onset in patients with open fractures? (2) What is the proportion of FRIs captured when follow-up is limited to 90 days postoperatively versus when follow-up is extended to 1 year?

METHODS

This is a secondary analysis of patient data from a previous retrospective cohort study that investigated whether the duration of perioperative antibiotic prophylaxis was independently associated with FRI in patients with open fractures. Of the 530 eligible patients in the source study, 3% (14) died. Of the remaining 516 patients, 97% (502) patients with 559 long-bone open fractures had 2 years of follow-up constituted the base cohort. Forty-seven fractures in 46 patients were complicated by FRI and were the focus of this secondary analysis. Medical records were reviewed in detail specifically for the current study. Seventy-eight percent (36 of 46) of patients were male, and the mean ± SD age was 42 ± 16 years. The most common mechanism of injury was a motor vehicle accident (63% [29 of 46] of patients), and the tibia was the most involved site (53% [25 of 47] of fractures). The median (interquartile range) time to debridement was 3.0 hours (IQR 2.0 to 4.0). FRIs developed in 3% (7 of 247) of Type I open fractures, 7% (11 of 164) of Type II, 17% (18 of 107) of Type IIIA, 29% (9 of 31) of Type IIIB, and 20% (2 of 10) of Type IIIC open fractures. Each clinic visit of each patient was reviewed, and data about the time of onset of any symptoms and signs suggesting or confirming an FRI, as reported by patients and/or determined by treating surgeons, were recorded. The proportions of FRIs with onset by specific time periods were determined. A Kaplan-Meier survival analysis was performed, and the FRI event rates with 95% confidence intervals were calculated.

RESULTS

The median (IQR) time to the onset of FRI was 52 days (IQR 15 to 153). Follow-up of 90 days captured only 64% (30 of 47) of FRIs, whereas follow-up of 1 year captured 89% (42 of 47) of FRIs. The proportion of FRIs with onset within 1 year increased to 95% (42 of 44) in the presence of an already healed fracture.

CONCLUSION

Follow-up of 90 days after the management of an open long-bone fracture is inadequate for postoperative surveillance, especially for research purposes. Clinical research on interventions would report results appearing to be much better than they really are, potentially resulting in misleading conclusions. Follow-up of 1 year is preferable because most FRIs will develop before that time, especially when fracture union has occurred. A small percentage of patients may still develop infections beyond the first year after the management of an open fracture. The risk of missing these infections by not extending follow-up beyond 1 year must be balanced against the additional logistical burden. Future prospective multicenter studies and registries with long-term patient follow-up would help clarify this issue.Level of Evidence Level III, diagnostic study.

Pre-clinical In Vitro Models of Vascular Graft Coating in the Prevention of Vascular Graft Infection: A Systematic Review

OBJECTIVE

Vascular graft infection (VGI) is a feared complication. Prevention is of the utmost importance and vascular graft coatings (VGCs) could offer a potential to do this, with in vitro research a first crucial step. The aim of this study was to summarise key features of in vitro models investigating coating strategies to prevent VGI in order to provide guidance for the setup of future translational research.

DATA SOURCES

A comprehensive search was performed in MEDLINE, Embase, and Web of Science.

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. For each database, a specific search strategy was developed. Quality was assessed with the Toxicological data Reliability Assessment Tool (ToxRTool). In vitro models using a VGC and inoculation of the graft with a pathogen were included. The type of graft, coating, and pathogen were summarised. The outcome assessment in each study was evaluated.

RESULTS

In total, 4 667 studies were identified, of which 45 papers met the inclusion criteria. The majority used polyester grafts (68.2%). Thirty-one studies (68.9%) included antibiotics, and nine studies (20%) used a commercial silver graft in their protocol. New antibacterial strategies (e.g., proteolytic enzymes) were investigated. A variety of testing methods was found and focused mainly on bacterial adherence, coating adherence and dilution, biofilm formation, and cytotoxicity. Ninety-three per cent of the studies (n = 41) were considered unreliable.

CONCLUSION

Polyester is the preferred type of graft to coat on. The majority of coating studies are based on antibiotics; however, new coating strategies (e.g., antibiofilm coating) are coming. Many in vitro setups are available. In vitro studies have great potential, they can limit the use, but cannot replace in vivo studies completely. This paper can be used as a guidance document for future in vitro research.

Bacteriophage Therapy for the Prevention and Treatment of Fracture-Related Infection Caused by Staphylococcus aureus: a Preclinical Study

Although several studies have shown promising clinical outcomes of phage therapy in patients with orthopedic device-related infections, questions remain regarding the optimal application protocol, systemic effects, and the impact of the immune response. This study provides a proof-of-concept of phage therapy in a clinically relevant rabbit model of fracture-related infection (FRI) caused by Staphylococcus aureus. In a prevention setting, phage in saline (without any biomaterial-based carrier) was highly effective in the prevention of FRI, compared to systemic antibiotic prophylaxis alone. In the subsequent study involving treatment of established infection, daily administration of phage in saline through a subcutaneous access tube was compared to a single intraoperative application of a phage-loaded hydrogel and a control group receiving antibiotics only. In this setting, although a possible trend of bacterial load reduction on the implant was observed with the phage-loaded hydrogel, no superior effect of phage therapy was found compared to antibiotic treatment alone. The application of phage in saline through a subcutaneous access tube was, however, complicated by superinfection and the development of neutralizing antibodies. The latter was not found in the animals that received the phage-loaded hydrogel, which may indicate that encapsulation of phages into a carrier such as a hydrogel limits their exposure to the adaptive immune system. These studies show phage therapy can be useful in targeting orthopedic device-related infection, however, further research and improvements of these application methods are required for this complex clinical setting. IMPORTANCE Because of the growing spread of antimicrobial resistance, the use of alternative prevention and treatment strategies is gaining interest. Although the therapeutic potential of bacteriophages has been demonstrated in a number of case reports and series over the past decade, many unanswered questions remain regarding the optimal application protocol. Furthermore, a major concern during phage therapy is the induction of phage neutralizing antibodies. This study aimed at providing a proof-of-concept of phage therapy in a clinically relevant rabbit model of fracture-related infection caused by Staphylococcus aureus. Phage therapy was applied as prophylaxis in a first phase, and as treatment of an established infection in a second phase. The development of phage neutralizing antibodies was evaluated in the treatment study. This study demonstrates that phage therapy can be useful in targeting orthopedic device-related infection, especially as prophylaxis; however, further research and improvements of these application methods are required.

Clinical Studies Reporting on Vascular Graft Coatings for the Prevention of Aortic Graft Infection: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of this study was to investigate the efficacy of vascular graft coatings used in the aortic position to prevent vascular graft infection (VGI).

METHODS

A systematic review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using a pre-registered protocol (CRD42020206436). Eligible studies used a vascular graft coating in the aortic position and reported on VGI. A search was performed in MEDLINE (PubMed), Embase, Web of Science, and the Cochrane Library. Primary outcome parameters were VGI, patency, and mortality. Pooled estimates of VGI were calculated using odds ratio (OR) and 95% confidence intervals (CIs) wherever possible. Quality assessment was performed with the Newcastle-Ottawa Assessment Scale and the Revised Cochrane risk of bias tool for randomised trials.

RESULTS

In total, 6 873 papers were identified. Only eight studies were included. Six of eight studies (75%) reported on known antimicrobial coating strategies such as antibiotics (n = 3) and silver (n = 3). In the other two studies, polymer coated grafts were used. Only three of eight studies compared coated with uncoated grafts (two antibiotic and one silver). Two randomised controlled trials reported on the effect of rifampicin soaked (1 mg/mL) grafts and showed no significant effect in the early (2 months; OR 0.69, 95% CI 0.29 - 1.62) or late (2 years; OR 0.73, 95% CI 0.23 - 2.32) post-operative periods. A retrospective cohort study focusing on the effect of silver coated grafts did not reveal any advantage (OR 0.19, 95% CI 0.02 - 1.64). Two polymer coated grafts were not considered to have a potential benefit in the prevention of VGIs.

CONCLUSION

Clinical studies reporting on the antibacterial effect of vascular graft coatings in the aortic position to prevent VGI are scarce. For silver and antibiotic coatings, no significant protection for VGI was observed. New types of grafts or long acting coating strategies are mandatory to prevent this complication in the future.

Definition of long-bone nonunion: A scoping review of prospective clinical trials to evaluate current practice

AIM

Although nonunions are among the most common complications after long-bone fracture fixation, the definition of fracture nonunion remains controversial and varies widely. The aim of this study was to identify the definitions and diagnostic criteria used in the scientific literature to describe nonunions after long-bone fractures.

METHODS

A comprehensive literature search was performed in PubMed, Cochrane Library, Web of Science, and Embase. Prospective clinical studies, in which adult long-bone fracture nonunions were investigated as main subject, were included in this analysis. Data on nonunion definitions described in each study were extracted and collected in a database.

RESULTS

Although 148 studies met the inclusion criteria, only 50% (74/148) provided a definition for their main study subject. Nonunion was defined in these studies based on time-related criteria in 85% (63/74), on radiographic criteria in 62% (46/74), and on clinical criteria in 45% (33/74). A combination of clinical, radiographic and time-related criteria for definition was found in 38% (28/74). The time interval between fracture and the time point when authors defined an unhealed fracture as a nonunion showed considerable heterogeneity, ranging from three to twelve months.

CONCLUSION

In the current orthopaedic literature, we found a lack of consensus with regard to the definition of long-bone nonunions. Without valid and reliable definition criteria for nonunion, standardization of diagnostic and treatment algorithms as well as the comparison of clinical studies remains problematic. The lack of a clear definition emphasizes the need for a consensus-based approach to the diagnosis of fracture nonunion centred on clinical, radiographical and time-related criteria.

Management of periprosthetic infection after reverse shoulder arthroplasty

BACKGROUND

Periprosthetic shoulder infection (PSI) remains a devastating complication after reverse shoulder arthroplasty (RSA). Currently, scientific data related to the management of PSI are limited, and the optimal strategy and related clinical outcomes remain unclear. Guidelines from the Infectious Diseases Society of America for the management of periprosthetic joint infection are mainly based on data from patients after hip and knee arthroplasty. The aim of this study was to evaluate whether these guidelines are also valid for patients with PSI after RSA. In addition, the functional outcome according to the surgical intervention was assessed.

METHODS

An RSA database was retrospectively reviewed to identify infections after primary and revision RSAs, diagnosed between 2004 and 2018. Data collected included age, sex, indication for RSA, causative pathogen, surgical and antimicrobial treatment, functional outcome, and recurrence.

RESULTS

Thirty-six patients with a PSI were identified. Surgical treatment was subdivided into débridement and implant retention (DAIR) (n = 6, 17%); 1-stage revision (n = 1, 3%); 2-stage revision (n = 16, 44%); multiple-stage revision (>2 stages) (n = 7, 19%); definitive spacer implantation (n = 2, 6%); and resection arthroplasty (n = 4, 11%). The most common causative pathogens were Staphylococcus epidermidis (n = 11, 31%) and Cutibacterium acnes (n = 9, 25%). Recurrence was diagnosed in 4 patients (11%), all of whom were initially treated with a DAIR approach. The median follow-up period was 36 months (range, 24-132 months).

CONCLUSION

PSI is typically caused by low-virulence pathogens, which often are diagnosed with a delay, resulting in chronic infection at the time of surgery. Our results indicate that treatment of patients with chronic PSI with DAIR has a high recurrence rate. In addition, implant exchange (ie, 1- and 2-stage exchange) does not compromise the functional result as compared with implant retention. Thus, patients with chronic PSI should be treated with implant exchange. Future research should further clarify which surgical strategy (ie, 1-stage vs. 2-stage exchange) has a better outcome overall.

Fracture-related infection in long bone fractures: A comprehensive analysis of the economic impact and influence on quality of life

OBJECTIVES

Fracture-related infection (FRI) is a feared complication with substantial clinical and economic consequences. The main objective of this study was to compare direct and indirect healthcare costs related to long bone fractures in patients with and without FRI and to assess its impact on the patient's quality of life (QoL).

PATIENTS AND METHODS

Between January 2015 and March 2019, 175 patients with FRI were treated at the University Hospitals Leuven (Belgium). Using a matched-pair analysis, patients with an FRI were matched by age, sex, and fracture location (humeral, femoral, or tibial shaft) to a non-FRI cohort treated during the same time period. Clinical and process-related variables, direct hospital-related healthcare costs, and indirect costs due to absenteeism were compared between the two groups. Furthermore, the patient's QoL was evaluated using Patient-Reported Outcomes Measurement Information System (PROMIS) physical function and pain interference.

RESULTS

After matched-pair analysis, 15 patients in both the FRI and non-FRI group were included. FRI was associated with direct hospital-related costs being eight times that of non-FRI patients (€ 47,845 [€ 43,072-€ 82,548] vs. € 5,983 [€ 4,519-€ 8,428], p < 0.001). Furthermore, FRI was associated with prolonged absenteeism (340 [340-676] vs. 86 [65-216] days, p = 0.007) and a median indirect cost that was nearly four times that of patients without FRI (€ 77,909 vs. € 19,706). Lastly, FRI patients showed significantly poorer outcomes on both physical function (35.6 vs. 48.4, p < 0.001) and pain interference (60.4 vs. 46.3, p < 0.001) PROMIS scales.

CONCLUSION

Direct hospital-related healthcare costs of FRI are eight times that of non-FRI long bone fractures. Total healthcare costs are mainly driven by hospitalisation costs, wherein FRI is associated with prolonged length of stay. To the best of our knowledge, this study is the first to demonstrate that FRI is also associated with substantial absenteeism, which is almost four times higher compared to non-FRI patients. In addition to this economic impact, FRI significantly deteriorates QoL. Generalizing the outcome of this study should be done cautiously due to the small sample size of 15 patients in both the FRI and non-FRI group after matched-pair analysis.

The Role of Negative-Pressure Wound Therapy in Patients with Fracture-Related Infection: A Systematic Review and Critical Appraisal

INTRODUCTION

Fracture-related infection (FRI) is a severe musculoskeletal complication in orthopedic trauma surgery, causing challenges in bony and soft tissue management. Currently, negative-pressure wound therapy (NPWT) is often used as temporary coverage for traumatic and surgical wounds, also in cases of FRI. However, controversy exists about the impact of NPWT on the outcome in FRI, specifically on infection recurrence. Therefore, this systematic review qualitatively assesses the literature on the role of NPWT in the management of FRI.

METHODS

A literature search of the PubMed, Embase, and Web of Science database was performed. Studies that reported on infection recurrence related to FRI management combined with NPWT were eligible for inclusion. Quality assessment was done using the PRISMA statement and the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

After screening and quality assessment of 775 unique identified records, eight articles could be included for qualitative synthesis. All eight studies reported on infection recurrence, which ranged from 2.8% to 34.9%. Six studies described wound healing time, varying from two to seven weeks. Four studies took repeated microbial swabs during subsequent vacuum dressing changes. One study reported newly detected pathogens in 23% of the included patients, and three studies did not find new pathogens.

CONCLUSION

This review provides an assessment of current literature on the role of NPWT in the management of soft tissue defects in patients with FRI. Due to the lack of uniformity in included studies, conclusions should be drawn with caution. Currently, there is no clear scientific evidence to support the use of NPWT as definitive treatment in FRI. At this stage, we can only recommend early soft tissue coverage (within days) with a local or free flap. NPWT may be safe for a few days as temporarily soft tissue coverage until definitive soft tissue management could be performed. However, comparative studies between NPWT and early wound closure in FRI patients are needed.

Bacteriophage Therapy for Difficult-to-Treat Infections: The Implementation of a Multidisciplinary Phage Task Force (The PHAGEFORCE Study Protocol)

In times where only a few novel antibiotics are to be expected, antimicrobial resistance remains an expanding global health threat. In case of chronic infections caused by therapy-resistant pathogens, physicians have limited therapeutic options, which are often associated with detrimental consequences for the patient. This has resulted in a renewed interest in alternative strategies, such as bacteriophage (phage) therapy. However, there are still important hurdles that currently impede the more widespread implementation of phage therapy in clinical practice. First, the limited number of good-quality case series and clinical trials have failed to show the optimal application protocol in terms of route of administration, frequency of administration, treatment duration and phage titer. Second, there is limited information on the systemic effects of phage therapy. Finally, in the past, phage therapy has been applied intuitively in terms of the selection of phages and their combination as parts of phage cocktails. This has led to an enormous heterogeneity in previously published studies, resulting in a lack of reliable safety and efficacy data for phage therapy. We hereby present a study protocol that addresses these scientific hurdles using a multidisciplinary approach, bringing together the experience of clinical, pharmaceutical and molecular microbiology experts.

Use of antibiotic coated intramedullary nails in open tibia fractures: A European medical resource use and cost-effectiveness analysis

PURPOSE

In patients with open tibial fractures, bone and wound infections are associated with an increased hospital length of stay and higher costs. The infection risk increases with the use of implants. Innovations to reduce this risk include antibiotic-coated implants. This study models whether the use of a gentamicin-coated intramedullary tibial nail is cost-effective for trauma centers managing patients with a high risk of infection.

EFFICACY

Absolute infection risk and relative risk reduction, by fracture grade, for antibiotic-coated nails compared to standard nails for patients with open tibial fractures were estimated based on the results of a meta-analysis, which assessed the additional benefit of locally-administered prophylactic antibiotics in open tibia fractures treated with implants. The observed efficacy of antibiotic-coated nails in reducing infections was applied in an economic model.

METHODS

The model compared infection rates, inpatient days, theatre usage and costs in high risk patients, with a Gustilo-Anderson (GA) grade III open fracture, for two patient cohorts from a trauma center perspective, with a 1-year time horizon. In one cohort all GAIII patients received a gentamicin-coated nail whilst GAI and GAII patients received a standard nail. All patients in the comparator cohort received a standard nail. Four European trauma centers provided patient-level data (n=193) on inpatient days, procedures and related costs for patients with and without infections.

RESULTS

Using the gentamicin-coated nail in patients at high risk of infection (GAIII) was associated with 75% lower rate of infection and cost savings (€477 - €3.263) for all included centers; the higher cost of the implant was offset by savings from fewer infections, inpatient days (-26%) and re-operations (-10%). This result was confirmed by extensive sensitivity analyses.

CONCLUSIONS

Analyses demonstrated that infection rates and total costs for in-hospital treatment could be potentially reduced by 75% and up to 15% respectively, by using a gentamicin-coated nail in patients at high risk of infection. Fewer infections, reduced inpatient days and re-operations may be potentially associated with use of antibiotic-coated implants. Results are sensitive to the underlying infection risk, with greatest efficacy and cost-savings when the coated implant is used in high risk patients.

The Potential Role of Bacteriophages in the Treatment of Recalcitrant Chronic Rhinosinusitis

Chronic rhinosinusitis is a common condition affecting 5-12% of the general population worldwide. In a limited number of cases, the disease is recalcitrant to medical and surgical interventions, causing a major impact on physical, social and emotional well-being and increasing pressure on healthcare systems. Biofilm formation and dysbiosis caused by Staphylococcus aureus and Pseudomonas aeruginosa play a role in the pathogenesis of recalcitrant chronic rhinosinusitis. In these cases, a promising treatment alternative is the application of bacteriophages, which are viruses that infect and lyse bacteria. In this review, we appraise the evidence for the use of bacteriophages in the treatment of recalcitrant chronic rhinosinusitis. Additionally, (dis)advantages of bacteriophages and considerations for implementation of phage therapy in otorhinolaryngology practice will be discussed.

A systematic review of preclinical data regarding commercial silver-coated vascular grafts

OBJECTIVE

Vascular graft infection (VGI) is a serious complication with high mortality and morbidity rates. Several measures could be taken to decrease this risk, including the use of silver-containing vascular grafts. However, to date, no clinical advantages have been reported. This study reviews the outcome of preclinical studies focusing on the role of commercially available silver-coated grafts in the prevention of VGI.

METHODS

A systematic review was performed with a focus on the preclinical role of commercially available silver-coated vascular grafts in the prevention and treatment of VGI. A comprehensive search was conducted in Medline, Embase, and Web of Science.

RESULTS

Nine in vitro and five in vivo studies were included. Two commercial grafts were used (INTERGARD SILVER and Silver Graft). In vitro studies used both gram-positive and gram-negative strains. A positive antimicrobial effect was observed in seven of nine studies (77.8%). A delayed antifungal effect against Candida species was observed in vitro, but disappeared when adding serum proteins. In vivo studies witnessed a microbicidal effect in two out of five studies (40%), but only tested a single causative pathogen (ie, Staphylococcus aureus).

CONCLUSIONS

Both in vitro and in vivo studies demonstrated conflicting and mixed results concerning the antimicrobial efficacy of commercially available silver-containing grafts in the prevention of VGI. In general, the study setup was heterogeneous in the different articles. Given the lack of convincing preclinical evidence and their poor performance in clinical studies, more data are needed at this time to guide the appropriate use of silver grafts.

An Improved 2-Aminoimidazole Based Anti-Biofilm Coating for Orthopedic Implants: Activity, Stability, and in vivo Biocompatibility

Orthopedic device-related infections remain a serious challenge to treat. Central to these infections are bacterial biofilms that form on the orthopedic implant itself. These biofilms shield the bacteria from the host immune system and most common antibiotic drugs, which renders them essentially antibiotic-tolerant. There is an urgent clinical need for novel strategies to prevent these serious infections that do not involve conventional antibiotics. Recently, a novel antibiofilm coating for titanium surfaces was developed based on 5-(4-bromophenyl)-N-cyclopentyl-1-octyl-1H-imidazol-2-amine as an active biofilm inhibitor. In the current study we present an optimized coating protocol that allowed for a 5-fold higher load of this active compound, whilst shortening the manufacturing process. When applied to titanium disks, the newly optimized coating was resilient to the most common sterilization procedures and it induced a 1 log reduction in biofilm cells of a clinical Staphylococcus aureus isolate (JAR060131) in vitro, without affecting the planktonic phase. Moreover, the antibiofilm effect of the coating in combination with the antibiotic cefuroxime was higher than cefuroxime treatment alone. Furthermore, the coating was successfully applied to a human-scale fracture fixation device resulting in a loading that was comparable to the titanium disk model. Finally, an in vivo biocompatibility and healing study in a rabbit osteotomy model indicated that these coated implants did not negatively affect fracture healing or osteointegration. These findings put our technology one step closer to clinical trials, confirming its potential in fighting orthopedic infections without compromising healing.

Pre-clinical in vivo Models of Vascular Graft Coating in the Prevention of Vascular Graft Infection: A Systematic Review

OBJECTIVE

Vascular graft infection (VGI) remains an important complication with a high mortality and morbidity rate. Currently, studies focusing on the role of vascular graft coatings in the prevention of VGI are scarce. Therefore, the aims of this study were to survey and summarise key features of pre-clinical in vivo models that have been used to investigate coating strategies to prevent VGI and to set up an ideal model that can be used in future preclinical research.

DATA SOURCES

A systematic review was conducted in accordance with the Preferred reporting items for Systematic Reviews and Meta-Analysis guidelines. A comprehensive search was performed in MEDLINE (PubMed), Embase, and Web of Science.

REVIEW METHODS

For each database, a specific search strategy was developed. Quality was assessed with the Toxicological data Reliability Assessment Tool (ToxRTool). The type of animal model, graft, coating, and pathogen were summarised. The outcome assessment in each study was evaluated.

RESULTS

In total, 4 667 studies were identified, of which 94 papers focusing on in vivo testing were included. Staphylococcus aureus was the organism most used (n = 65; 67.7%). Most of the graft types were polyester grafts. Rifampicin was the most frequently used antibiotic coating (n = 43, 48.3%). In the outcome assessment, most studies mentioned colony forming unit count (n = 88; 91.7%) and clinical outcome (n = 72; 75%). According to the ToxRTool, 21 (22.3%, n = 21/94) studies were considered to be not reliable.

CONCLUSION

Currently published in vivo models are very miscellaneous. More attention should be paid to the methodology of these pre-clinical reports when transferring novel graft coatings into clinical practice. Variables used in pre-clinical reports (bacterial strain, duration of activity coating) do not correspond well to current clinical studies. Based on the results of this review, a proposal for a complete and comprehensive set up for pre-clinical invivo testing of anti-infectious properties of vascular graft coatings was defined.

Intramedullary tissue cultures from the Reamer-Irrigator-Aspirator system for diagnosing fracture-related infection

Fracture-related infection (FRI) is a serious complication following musculoskeletal trauma. Accurate diagnosis and appropriate treatment depend on retrieving adequate deep tissue biopsies for bacterial culture. The aim of this cohort study was to compare intraoperative tissue cultures obtained by the Reamer-Irrigator-Aspirator system (RIA)-system against standard tissue cultures obtained during the same surgical procedure. All patients had long bone fractures of the lower limbs and were assigned to the FRI or Control group based on the FRI consensus definition. The FRI group consisted of 24 patients with confirmed FRI and the Control group consisted of 21 patients with aseptic nonunion or chronic pain (in the absence of other suggestive/confirmatory criteria). Standard tissue cultures and cultures harvested by the RIA-system showed similar results. In the FRI group, standard tissue cultures and RIA cultures revealed relevant pathogens in 67% and 71% of patients, respectively. Furthermore, in four FRI patients, cultures obtained by the RIA-system revealed additional relevant pathogens that were not found by standard tissue culturing, which contributed to the optimization of the treatment plan. In the Control group, there were no false-positive RIA culture results. As a proof-of-concept, this cohort study showed that the RIA-system could have a role in the diagnosis of FRI as an adjunct to standard tissue cultures. Since scientific evidence on the added value of the RIA-system in the management of FRI is currently limited, further research on this topic is required before its routine application in clinical practice.

Fracture-related outcome study for operatively treated tibia shaft fractures (F.R.O.S.T.): registry rationale and design

Background

Tibial shaft fractures (TSFs) are among the most common long bone injuries often resulting from high-energy trauma. To date, musculoskeletal complications such as fracture-related infection (FRI) and compromised fracture healing following fracture fixation of these injuries are still prevalent. The relatively high complication rates prove that, despite advances in modern fracture care, the management of TSFs remains a challenge even in the hands of experienced surgeons. Therefore, the Fracture-Related Outcome Study for operatively treated Tibia shaft fractures (F.R.O.S.T.) aims at creating a registry that enables data mining to gather detailed information to support future clinical decision-making regarding the management of TSF’s.

Methods

This prospective, international, multicenter, observational registry for TSFs was recently developed. Recruitment started in 2019 and is planned to take 36 months, seeking to enroll a minimum of 1000 patients. The study protocol does not influence the clinical decision-making procedure, implant choice, or surgical/imaging techniques; these are being performed as per local hospital standard of care. Data collected in this registry include injury specifics, treatment details, clinical outcomes (e.g., FRI), patient-reported outcomes, and procedure- or implant-related adverse events. The minimum follow up is 12 months.

Discussion

Although over the past decades, multiple high-quality studies have addressed individual research questions related to the outcome of TSFs, knowledge gaps remain. The scarcity of data calls for an international high-quality, population-based registry. Creating such a database could optimize strategies intended to prevent severe musculoskeletal complications. The main purpose of the F.R.O.S.T registry is to evaluate the association between different treatment strategies and patient outcomes. It will address not only operative techniques and implant materials but also perioperative preventive measures. For the first time, data concerning systemic perioperative antibiotic prophylaxis, the influence of local antimicrobials, and timing of soft-tissue coverage will be collected at an international level and correlated with standardized outcome measures in a large prospective, multicenter, observational registry for global accessibility.

Trial registration

ClinicalTrials.gov: NCT03598530.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03930-x.

Antimicrobial Resistance, the COVID-19 Pandemic, and Lessons for the Orthopaedic Community

Antimicrobial resistance (AMR) is widely regarded as one of the most important global public health challenges of the twenty-first century. The overuse and the improper use of antibiotics in human medicine, food production, and the environment as a whole have unfortunately contributed to this issue. Many major international scientific, political, and social organizations have warned that the increase in AMR could cost the lives of millions of people if it is not addressed on a global scale. Although AMR is already a challenge in clinical practice today, it has taken on a new importance in the face of the coronavirus disease 2019 (COVID-19) pandemic. While improved handwashing techniques, social distancing, and other interventional measures may positively influence AMR, the widespread use of antibiotics to treat or prevent bacterial coinfections, especially in unconfirmed cases of COVID-19, may have unintended negative implications with respect to AMR. Although the exact number of bacterial coinfections and the rate at which patients with COVID-19 receive antibiotic therapy remain to be accurately determined, the pandemic has revived the discussion on antibiotic overuse and AMR. This article describes why the COVID-19 pandemic has increased our awareness of AMR and presents the immense global impact of AMR on society as a whole. Furthermore, an attempt is made to stress the importance of tackling AMR in the future and the role of the orthopaedic community in this worldwide effort.

Management of critical-sized bone defects in the treatment of fracture-related infection: a systematic review and pooled analysis

PURPOSE

This systematic review determined the reported treatment strategies, their individual success rates, and other outcome parameters in the management of critical-sized bone defects in fracture-related infection (FRI) patients between 1990 and 2018.

METHODS

A systematic literature search on treatment and outcome of critical-sized bone defects in FRI was performed. Treatment strategies identified were, autologous cancellous grafts, autologous cancellous grafts combined with local antibiotics, the induced membrane technique, vascularized grafts, Ilizarov bone transport, and bone transport combined with local antibiotics. Outcomes were bone healing and infection eradication after primary surgical protocol and recurrence of FRI and amputations at the end of study period.

RESULTS

Fifty studies were included, describing 1530 patients, the tibia was affected in 82%. Mean age was 40 years (range 6-80), with predominantly male subjects (79%). Mean duration of infection was 17 months (range 1-624) and mean follow-up 51 months (range 6-126). After initial protocolized treatment, FRI was cured in 83% (95% CI 79-87) of all cases, increasing to 94% (95% CI 92-96) at the end of each individual study. Recurrence of infection was seen in 8% (95% CI 6-11) and amputation in 3% (95% CI 2-3). Final outcomes overlapped across treatment strategies.

CONCLUSION

Results should be interpreted with caution due to the retrospective and observational design of most studies, the lack of clear classification systems, incomplete data reports, potential underreporting of adverse outcomes, and heterogeneity in patient series. A consensus on classification, treatment protocols, and outcome is needed to improve reliability of future studies.

Definition and diagnosis of fracture-related infection

Fracture-related infection (FRI) is common and often diagnosed late.Accurate diagnosis is the beginning of effective treatment.Diagnosis can be difficult, particularly when there are no outward signs of infection.The new FRI definition, together with clear protocols for nuclear imaging, microbiological culture and histological analysis, should allow much better study design and a clearer understanding of infected fractures.In recent years, there has been a new focus on defining FRI and avoiding non-specific, poorly targeted treatment. Previous studies on FRI have often failed to define infection precisely and so are of limited value. This review highlights the essential principles of making the diagnosis and how clinical signs, serum tests, imaging, microbiology, molecular biology and histology all contribute to the diagnostic pathway. Cite this article: EFORT Open Rev 2020;5:614-619. DOI: 10.1302/2058-5241.5.190072.

General treatment principles for fracture-related infection: recommendations from an international expert group

Fracture-related infection (FRI) remains a challenging complication that creates a heavy burden for orthopaedic trauma patients, their families and treating physicians, as well as for healthcare systems. Standardization of the diagnosis of FRI has been poor, which made the undertaking and comparison of studies difficult. Recently, a consensus definition based on diagnostic criteria for FRI was published. As a well-established diagnosis is the first step in the treatment process of FRI, such a definition should not only improve the quality of published reports but also daily clinical practice. The FRI consensus group recently developed guidelines to standardize treatment pathways and outcome measures. At the center of these recommendations was the implementation of a multidisciplinary team (MDT) approach. If such a team is not available, it is recommended to refer complex cases to specialized centers where a MDT is available and physicians are experienced with the treatment of FRI. This should lead to appropriate use of antimicrobials and standardization of surgical strategies. Furthermore, an MDT could play an important role in host optimization. Overall two main surgical concepts are considered, based on the fact that fracture fixation devices primarily target fracture consolidation and can be removed after healing, in contrast to periprosthetic joint infection were the implant is permanent. The first concept consists of implant retention and the second consists of implant removal (healed fracture) or implant exchange (unhealed fracture). In both cases, deep tissue sampling for microbiological examination is mandatory. Key aspects of the surgical management of FRI are a thorough debridement, irrigation with normal saline, fracture stability, dead space management and adequate soft tissue coverage. The use of local antimicrobials needs to be strongly considered. In case of FRI, empiric broad-spectrum antibiotic therapy should be started after tissue sampling. Thereafter, this needs to be adapted according to culture results as soon as possible. Finally, a minimum follow-up of 12 months after cessation of therapy is recommended. Standardized patient outcome measures purely focusing on FRI are currently not available but the patient-reported outcomes measurement information system (PROMIS) seems to be the preferred tool to assess the patients' short and long-term outcome. This review summarizes the current general principles which should be considered during the whole treatment process of patients with FRI based on recommendations from the FRI Consensus Group.Level of evidence: Level V.