David A. George

Can National Joint Registries play a role in improving our understanding of periprosthetic infections

Whilst there is agreement of the challenges periprosthetic infections (PPI) pose for our community, there is little agreement about its true incidence, and far too little concordance in the way that we manage it and document its course and outcome. Despite an attempt to find a consensus for the

The management of periprosthetic infections in the future: a review of new forms of treatment

The number of arthroplasties being undertaken is expected to grow year on year, and periprosthetic joint infections will be an increasing socioeconomic burden. The challenge to prevent and eradicate these infections has resulted in the emergence of several new strategies, which are discussed in this review. Cite this article: Bone Joint J 2015;97-B:1162-9.

Periprosthetic joint infection in total hip arthroplasty: prevention and management.

Periprosthetic joint infection is a devastating complication. Orthopaedic surgeons must prevent, anticipate, rapidly diagnose and effectively manage such patients in the multidisciplinary setting. This review discusses current strategies in the management of these patients following total hip arthroplasty.

Surgical Management of Periprosthetic Joint Infections: Two-Stage Exchange

The presence of a periprosthetic joint infection (PJI) following knee arthroplasty is devastating to the patient, with significant loss of function and independence, with risk of systemic compromise with sepsis and organ failure, and loss of life. This article reviews the management of knee PJIs, with particular emphasis on the two-stage exchange arthroplasty.

One-Stage Exchange Arthroplasty: A Surgical Technique Update

BACKGROUND Standard surgical treatment for a periprosthetic knee infection has been based on a staged surgical technique, in order to assure infection eradication prior to implantation of a new prosthesis. METHODS In this article, we discuss our surgical technique in undertaking a single-stage exchange of a chronic knee periprosthetic infection. RESULTS This technique, which is based on the fundamental principles of controlling infection, preventing recurrence, and restoring function, has been shown to deliver high success rates. CONCLUSION As demonstrated, when undertaken under appropriate circumstances, a single-stage exchange combined with local and systemic antibiotic delivery can result in infection eradication comparable to a 2-staged exchange.

Antibiotic sensitivities of coagulase-negative staphylococci and Staphylococcus aureus in hip and knee periprosthetic joint infections: does this differ if patients meet the International Consensus Meeting Criteria?

Introduction Coagulase-negative staphylococci (CoNS) are the main pathogens responsible for prosthetic joint infections (PJIs). As normal inhabitants of human skin, it is often difficult to define if they are contaminants, or if they have an active role in initiating infection. This study aims to evaluate differences in CoNS organisms (Staphylococcus hominis, Staphylococcus capitis, Staphylococcus haemolyticus, Staphylococcus warneri) and Staphylococcus aureus in terms of isolation rate and antimicrobial susceptibility from patients who met the International Consensus Meeting (ICM) criteria for PJIs and those who did not. Methods Staphylococci isolates from January 2014 to December 2015 retrieved from patients undergoing revision joint arthroplasty were classified in accordance with criteria established by the ICM of Philadelphia. Results As per the consensus classification, 50 CoNS and 39 S. aureus infections were recognized as pathogens, while 16 CoNS and four S. aureus were considered as contaminants. Frequency of isolation of S. aureus was significantly higher in infected patients than in those without infection, while no significant differences were observed among CoNS. Resistance to levofloxacin, erythromycin, gentamicin trimethoprim/sulfamethoxazole, and rifampicin was significantly more frequent in S. haemolyticus than in the other species, as well as resistance to erythromycin and gentamicin in S. hominis. In comparison to S. aureus, CoNS were significantly more resistant to daptomycin and gentamicin and more susceptible to rifampicin. Conclusion CoNS, other than Staphylococcus epidermidis, are frequently isolated from PJIs, and their infective role and antimicrobial susceptibility need to be assessed on an individual patient basis. S. haemolyticus seems to emerge as responsible for PJI in a large volume of patients, and its role needs to be further investigated, also considering its pattern of resistance.

Predicting lower limb periprosthetic joint infections: A review of risk factors and their classification

AIM To undertook a systematic review to determine factors that increase a patient’s risk of developing lower limb periprosthetic joint infections (PJI). METHODS This systematic review included full-text studies that reviewed risk factors of developing either a hip or knee PJI following a primary arthroplasty published from January 1998 to November 2016. A variety of keywords were used to identify studies through international databases referencing hip arthroplasty, knee arthroplasty, infection, and risk factors. Studies were only included if they included greater than 20 patients in their study cohort, and there was clear documentation of the statistical parameter used; specifically P-value, hazard ratio, relative risk, or/and odds ratio (OR). Furthermore a quality assessment criteria for the individual studies was undertaken to evaluate the presence of record and reporting bias. RESULTS Twenty-seven original studies reviewing risk factors relating to primary total hip and knee arthroplasty infections were included. Four studies (14.8%) reviewed PJI of the hip, 3 (11.21%) of the knee, and 20 (74.1%) reviewed both joints. Nineteen studies (70.4%) were retrospective and 8 (29.6%) prospective. Record bias was identified in the majority of studies (66.7%). The definition of PJI varied amongst the studies but there was a general consensus to define infection by previously validated methods. The most significant risks were the use of preoperative high dose steroids (OR = 21.0, 95%CI: 3.5-127.2, P < 0.001), a BMI above 50 (OR = 18.3, P < 0.001), tobacco use (OR = 12.76, 95%CI: 2.47-66.16, P = 0.017), body mass index below 20 (OR = 6.00, 95%CI: 1.2-30.9, P = 0.033), diabetes (OR = 5.47, 95%CI: 1.77-16.97, P = 0.003), and coronary artery disease (OR = 5.10, 95%CI: 1.3-19.8, P = 0.017). CONCLUSION We have highlighted the need for the provider to optimise modifiable risk factors, and develop strategies to limit the impact of non-modifiable factors.

Managing large bone defects in children: a systematic review of the ‘induced membrane technique’

Thirty years after its description by Masquelet in 1986, this is the first systematic review aiming to critically evaluate the ‘induced membrane technique’ effectiveness in achieving bone union in children. Only six papers fulfilled our inclusion criteria (54 patients). The relatively small number of reported cases did not allow a formal meta-analysis. The tibia was the most involved bone. Most frequent aetiologies were congenital pseudoarthrosis and tumour resections. Although effective in achieving bone healing in ∼91% of the patients (bone defects ⩽24 cm long), the induced membrane technique was associated with a high rate of complications (54% of patients). Level of Evidence: IV.

One-Stage Revision Arthroplasty in the Infected Total Knee Arthroplasty

A single-stage exchange arthroplasty is becoming an increasingly viable option in patients with chronic periprosthetic knee infections. In this chapter, we discuss the history of a single-stage exchange, its advantages, patient inclusion criteria, the surgical technique, role of antibiotics, and outcomes in terms of infection eradication, functional outcome, and economic impact.

Cost-benefit analysis of antibiofilm microbiological techniques for peri-prosthetic joint infection diagnosis

BackgroundImplant-related infections, including those of peri-prosthetic joint (PJIs), osteosynthesis and other biomaterials, are biofilm-related. Pathogen identification is considered the diagnostic benchmark; however, the presence of bacterial biofilms makes pathogen detection with traditional microbiological techniques only partially effective. To improve microbiological diagnostic accuracy, some biofilm debonding techniques have been recently proposed. Aim of this health economics assessment study was to evaluate their economic impact on hospital costs.MethodsDirect and indirect hospital costs connected with the routine introduction of sonication and dithiothreitol treatment applied to hip and knee PJIs and of tissue cultures were examined. In particular the consequences of diagnostic inaccuracy, the opportunities, costs, and risks of each technique were calculated.ResultsConsidering an average of five samples per patient, processed separately with traditional tissue culture with or without sonication of prosthetic components, or pooled together using the MicroDTTect device (a close system for sample collection, transport and treatment with Dithiothreitol for microbial release from biofilm), the overall mean direct cost per patient was € 397 and € 393 for sonication or MicroDTTect, respectively, compared to € 308 for traditional tissue cultures. In terms of opportunity costs, MicroDTTect was the most effective technique, allowing for a 35% or 55% reduction in time required for sample treatment, compared to tissue cultures combined or not with sonication, respectively.Pooling together direct and indirect costs associated with false positive and negative results of the different diagnostic techniques, unnecessary medical treatments and possible medical claims, MicroDTTect or sonication become increasingly cost-effective when the extra-costs, generated by diagnostic inaccuracy of traditional tissue culture, took place, respectively, in 2% or 20% or more of the patients.ConclusionsThis is the first study specifically focused on the economic impact of the routine clinical use of microbiological antibiofilm sampling and processing techniques in orthopaedics. Although our results may suffer from a potential country and hospital bias, as the data collection process for direct and indirect costs is specific to each institution and country, this analysis highlights the potential economic advantage to hospitals associated with the routine introduction of antibiofilm techniques for microbiological diagnosis of PJI.