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Although extensor mechanism failure remains a catastrophic complication of knee arthroplasty, there are a number of contemporary techniques with reasonable outcomes that restore function. Chronic failures require advanced reconstruction techniques. Similar complication rates have been reported for the use of autografts, allografts, or mesh reconstructions. Here, we describe our surgical technique in allograft extensor mechanism reconstruction for chronic failures in salvage revision knee arthroplasty using a complete extensor mechanism allograft with a modified proximal fixation and case demonstrations.

The aim of this study was to provide an overview of randomized controlled trials (RCTs) of surgical approaches in primary total hip arthroplasty (THA), summarizing the available high-quality evidence. Following Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines, we performed the electronic searches in January 2021. We searched the Cochrane Central Register of Controlled Trials (2021, Issue 1), Ovid MEDLINE (including e-pub ahead of print, in-process, and other non-indexed citations, Ovid MEDLINE Daily, Ovid MEDLINE and Versions) (1946–January 20, 2021), and Embase (1980–January 20, 2021). We limited our search to English language literature. We excluded nonrandomized trials, trials on neck of femur fractures or revision surgery, systematic reviews, and meta-analyses. Trials that met our inclusion criteria were assessed using a binary outcome measure of whether they reported statistically significant findings. These were then classified according to the intervention groups. A total of 72 RCTs met the inclusion criteria. The total number of patients in those trials was 6,728. Only five RCTs (5.9%) reported significant differences between the intervention and the control groups. The largest subgroup of trials was minimally invasive versus standard techniques (18 RCTs) with no significant differences. Standard (lateral, posterior) approaches were compared in 23 RCTs with only 1 RCT reporting significant differences. Thirteen RCTs evaluated mini-incisions, with only 1 RCT reporting significant differences, and the remaining 18 RCTs evaluated variations of surgical approaches and interventions, with 3 RCTs reporting significant differences. The evidence reviewed indicates that for the vast majority of patients, a standard THA approach familiar to the surgeon leads to comparable outcomes. Level of evidence is II.

The use of metaphyseal sleeves in revision total knee arthroplasty has gained popularity with numerous clinical series demonstrating excellent osseointegration and survivorship at medium- to long-term follow up. Once osseointegrated, sleeves provide excellent biological fixation and are difficult to remove. Here, we describe our surgical technique and sequence in removing metaphyseal sleeves in contemporary revision knee systems with case demonstrations.

During prolonged wetting of the fleece, proliferation of bacterial flora often dominated by Pseudomonas aeruginosa or Dermatophilus congolensis can induce dermatitis and fleece damage termed fleece rot and dermatophilosis respectively, which predispose sheep to blowfly strike. A large research effort in the 1980s and 1990s on vaccines to control fleece rot and dermatophilosis met with limited success. This review examines theoretical and technological advances in microbial ecology, pathogenesis, immunology, vaccine development and the characterisation of microbial virulence factors that create new opportunities for development of vaccines against these diseases. Genomic technologies have now created new opportunities for examining microbial dynamics and pathogen virulence in dermatitis. An effective vaccine requires the combination of appropriate antigens with an adjuvant that elicits a protective immune response that ideally provides long-lasting protection in the field. A clinical goal informed by epidemiological, economic and animal welfare values is needed as a measure of vaccine efficacy. Due to dependence of fleece rot and dermatophilosis on sporadic wet conditions for their expression, vaccine development would be expedited by in vitro correlates of immune protection. The efficacy of vaccines is influenced by genetic and phenotypic characteristics of the animal. Advances in understanding vaccine responsiveness, immune defence in skin and immune competence in sheep should also inform any renewed efforts to develop new fleece rot and dermatophilosis vaccines. The commercial imperatives for new vaccines are likely to continue to increase as the animal welfare expectations of society intensify and reliance on pharmacotherapeutics decrease due to chemical resistance, market pressures and societal influences. Vaccines should be considered part of an integrated disease control strategy, in combination with genetic selection for general immune competence and resistance to specific diseases, as well as management practices that minimise stress and opportunities for disease transmission. The strategy could help preserve the efficacy of pharmacotherapeutics as tactical interventions to alleviate compromised welfare when adverse environmental conditions lead to a break down in integrated strategic disease control. P. aeruginosa and D. congolensis are formidable pathogens and development of effective vaccines remains a substantial challenge.

Fleece rot develops following prolonged wetting of sheep when bacterial proliferation in wool and on skin induces exudation of serum proteins onto the skin surface and causes damage to wool follicles and fibres. These processes create an attractive environment for blowflies to lay eggs, leading to body strike. Current reliance on insecticides for prevention and treatment of fly strike is being increasingly challenged by development of insecticide resistance. This review examines the large body of past research on the bacterial causes of fleece rot, the genetics of sheep susceptibility and resistance, the characteristics of the resulting immune defence reactions, and attempts to control fleece rot by vaccination. The high dependence on weather conditions for expression of fleece rot hampers studies on the disease. Normal skin and wool are populated by a dynamic microbial community. During adverse environmental conditions, natural resistance to fleece rot associated with physical characteristics of wool and skin can be overwhelmed and a complex mix of bacteria flourishes. Prolonged hydration alone, and in combination with bacterial exoproducts, induces dermatitis and exudation of immunoglobulins and other serum proteins onto the skin surface. Pathogens do not usually penetrate the epidermis. Nonetheless, during prolonged skin hydration, sheep can become sensitised to fleece rot pathogens and produce antibodies. Antibody titres rise late within a typical (3 week) case of fleece rot. High naturally acquired antibody titres may contribute to resistance to fleece rot. In contrast to some evidence for a protective role of antibody, there is little evidence for innate or adaptive cellular immune responses contributing to protection against fleece rot pathogens. Previous attempts to develop vaccines have met with mixed success. Nonetheless, there remain prospects for development of a new vaccine to control fleece rot. Further knowledge on the microbial ecology of normal and wet skin would assist this endeavour and may help identify other control strategies.

Lumpy wool (dermatophilosis) develops following prolonged wetting of sheep when bacterial proliferation in wool and on skin induce an exudative dermatitis, causing a superficial skin lesion and damage to wool follicles and fibres. The incidence of dermatophilosis is strongly dependent on wet and warm weather and, hence, infection is sporadic. While older animals are less at risk than are lambs, it is unclear whether this reflects naturally acquired immune resistance or the maturation of skin and wool fibres. Dermatophilosis directly causes wool production losses and it also is a risk factor for blowfly strike, which has a substantial economic impact and increasing challenges associated with current control procedures. This review assessed research on the bacterial causes of lumpy wool, the characteristics of the resulting immune defence reactions in sheep, current control strategies, and limitations of previous attempts to control lumpy wool by sheep vaccination.

Aims Single-stage revision total knee arthroplasty (rTKA) is gaining popularity in treating chronic periprosthetic joint infections (PJIs). We have introduced this approach to our clinical practice and sought to evaluate rates of reinfection and re-revision, along with predictors of failure of both single- and two-stage rTKA for chronic PJI. Methods A retrospective comparative cohort study of all rTKAs for chronic PJI between 1 April 2003 and 31 December 2018 was undertaken using prospective databases. Patients with acute infections were excluded; rTKAs were classified as single-stage, stage 1, or stage 2 of two-stage revision. The primary outcome measure was failure to eradicate or recurrent infection. Variables evaluated for failure by regression analysis included age, BMI, American Society of Anesthesiologists grade, infecting organisms, and the presence of a sinus. Patient survivorship was also compared between the groups. Results A total of 292 consecutive first-time rTKAs for chronic PJI were included: 82 single-stage (28.1%); and 210 two-stage (71.9%) revisions. The mean age was 71 years (27 to 90), with 165 females (57.4%), and a mean BMI of 30.9 kg/m2 (20 to 53). Significantly more patients with a known infecting organism were in the single-stage group (93.9% vs 80.47%; p = 0.004). The infecting organism was identified preoperatively in 246 cases (84.2%). At a mean follow-up of 6.3 years (2.0 to 17.6), the failure rate was 6.1% in the single-stage, and 12% in the two-stage groups. All failures occurred within four years of treatment. The presence of a sinus was an independent risk factor for failure (odds ratio (OR) 4.97; 95% confidence interval (CI) 1.593 to 15.505; p = 0.006), as well as age > 80 years (OR 5.962; 95% CI 1.156 to 30.73; p = 0.033). The ten-year patient survivorship rate was 72% in the single-stage group compared with 70.5% in the two-stage group. This difference was not significant (p = 0.517). Conclusion Single-stage rTKA is an effective strategy with a high success rate comparable to two-stage approach in appropriately selected patients. Cite this article: Bone Joint J 2021;103-B(8):1373–1379.

Background Fracture fixation techniques of comminuted periprosthetic distal femoral fractures have high risk of complications. The aim of this study was to evaluate short- to medium-term outcomes of comminuted periprosthetic distal femoral fractures treated with distal femoral replacements (DFR) at a tertiary arthroplasty unit. Methods Retrospective consecutive study of all patients who underwent DFR for periprosthetic fractures with minimum 2-year follow-up between 2010 and 2018. Clinical outcomes, surgical complications, revision for any cause, loosening, Knee Society Score and mortality data were collected at final follow-up. Results Thirty patients with average age 81 years (range, 65-90; 6 males and 24 females) were included. All had comminuted fractures (Rorabeck type-2/3). All patients had cemented DFRs. Three patients (10%) with multiple comorbidities died postoperatively. Average time from admission to being fit for discharge was 9 days (range, 3-14). Clinical outcomes and follow-up were available for 27 patients with a median follow-up duration of 4 years (2-13 years). Complication rate was 7.4% with one reoperation, change of polyethylene insert. None of the components have been revised to date. Average Knee Society Score at final follow-up was 78 (range, 57-92) with median arc of motion flexion-extension being 100° (range, 60°-125°). Conclusions In our experience, DFRs for comminuted periprosthetic fractures allow immediate mobilization and rehabilitation leading to satisfactory clinical outcomes with low complication rate for this challenging group of patients. Level of evidence level IV.

Metaphyseal sleeves have become an integral part of surgeons’ armamentarium in dealing with complex revision knee arthroplasty. They offer the advantages of addressing bone defects with biological fixation techniques, efficient surgical preparation providing a stable tibial platform which optimises joint line positioning and gap balancing leading to excellent long-term survivorship and clinical outcomes. Here, we review the concept of metaphyseal fixation, indications of metaphyseal sleeves and their limitations with our surgical tips on how to remove well-fixed sleeves. We also present our tertiary experience and review clinical outcome studies of metaphyseal sleeves in revision knee arthroplasty literature.

This paper reports the use of near infrared and mid-infrared spectroscopy to detect the presence and quantity of eggs of the gastrointestinal nematode Haemonchus contortus in sheep faeces. Haemonchus contortus eggs were quantified in dried, finely ground sheep faeces and in moist, coarsely ground faeces using near infrared and mid-infrared bench top spectrometers and a portable near infrared spectrometer. When Haemonchus contortus eggs were presented without faecal medium, it was found that the wavelength region of 1880–2100 nm was most important for detection. Broad classes of chemical properties found in the near infrared region were identified for dried Haemonchus contortus eggs using a mid-infrared spectrometer. However, when Haemonchus contortus eggs were mixed into the complex matrix of sheep faeces, the development of a robust calibration model for egg detection proved to be challenging (R2

Flystrike remains a serious financial and animal welfare issue for the sheep industry in Australia despite many years of research into control methods. The present paper provides an extensive review of past research on flystrike, and highlights areas that hold promise for providing long-term control options. We describe areas where the application of modern scientific advances may provide increased impetus to some novel, as well as some previously explored, control methods. We provide recommendations for research activities: insecticide resistance management, novel delivery methods for therapeutics, improved breeding indices for flystrike-related traits, mechanism of nematode-induced scouring in mature animals. We also identify areas where advances can be made in flystrike control through the greater adoption of well-recognised existing management approaches: optimal insecticide-use patterns, increased use of flystrike-related Australian Sheep Breeding Values, and management practices to prevent scouring in young sheep. We indicate that breeding efforts should be primarily focussed on the adoption and improvement of currently available breeding tools and towards the future integration of genomic selection methods. We describe factors that will impact on the ongoing availability of insecticides for flystrike control and on the feasibility of vaccination. We also describe areas where the blowfly genome may be useful in providing impetus to some flystrike control strategies, such as area-wide approaches that seek to directly suppress or eradicate sheep blowfly populations. However, we also highlight the fact that commercial and feasibility considerations will act to temper the potential for the genome to act as the basis for providing some control options.

Multi radius (MR) total knee arthroplasty (TKA) has been associated with mid-flexion instability. Single radius (SR) TKA may provide better anteroposterior stability through single flexion axis and biomechanical advantage for quadriceps function. Medial pivot (MP) TKA and gradually reducing (GR) radius TKA produce better knee kinematics. Clinical outcomes are equivalent for SR, MR and MP TKA. Short-term studies have shown better clinical outcomes and kinematics for GR TKA. Thinner and narrow anterior flange, deeper trochlea groove and more anatomical trochlea design reduces patellofemoral complications in TKA Ultracongruent inserts provide comparable clinical outcomes to posterior-stabilized TKA and cruciate retaining TKA. Cite this article: EFORT Open Rev 2019;4:519-524. DOI: 10.1302/2058-5241.4.180083

This study examined whether a new total knee arthroplasty (TKA) prosthesis improved implant survivorship and reoperation rates compared with a gold-standard, established TKA. A retrospective analysis of the first 500 consecutive new TKAs was compared with a consecutive series of the last 500 currently available TKAs performed by a single senior surgeon in one center. The primary outcome measure was revision of the femoral, tibial, or patellar component. A secondary outcome was reoperation for any reason. The new-TKA group had a significantly reduced revision rate at up to 5 years follow-up (p = 0.02). Reoperation rates for any reason were similar (p = 0.3). The new TKA design has a significantly better early revision rate compared with a currently available gold-standard TKA. This is the largest study of 1,000 cases comparing a new TKA design with a currently available design with excellent midterm results. It demonstrates very favorable early clinical results for the new TKA design, providing reassurance for patients, surgeons, and regulatory bodies.

Background We aimed to evaluate the outcomes of hybrid fixation technique in condylar revision total knee arthroplasty (rTKA) using cementless metaphyseal tibial sleeves and short-cemented femoral stems with a rotating platform articulation. Methods Retrospective consecutive study of all condylar rTKAs with a cemented femoral stem between 2009 and 2016 was conducted. Patients were identified using a local prospective database and linkable data obtained from the National Joint Registry for rTKA. Demographic, clinical, and surgical data were collected from patients’ electronic health records. The primary outcome measure was mechanical failure and implant survivorship using a nationally collected data, complications, re-operations, and “any-cause revision” were also recorded. Results There were 72 consecutive patients (72 knees) with minimum 5-year follow-up: 33 (45.8%) females and 39 (54.2%) males with a median age of 70 years (range 47-88). The indication for revision surgery was aseptic loosening (n = 34, 47.2%), instability (n = 17, 23.6%), infection (n = 14, 19.5%) with 10 patients having 2-stage approach and 4 patients with single-stage approach, stiffness (n = 4, 5.6%), and malalignment (n = 3, 4.1%). At mean follow-up of 6.87 years (median 6.7; range 5-11.8), only 2 patients required revision for infection. Using “any-cause implant revision” as an end point, implant survivorship for this construct was 97.2% at median 6.7 years. To date, none of the femoral stems have been revised for mechanical failure. Conclusion In rTKA with good femoral condylar bone stock, we have shown excellent survivorship with a short-cemented femoral stem, in conjunction with a mobile-bearing and a tibial sleeve. This has the advantage of reducing the length of the revision construct of this complex surgery. Level of Evidence Level IV.

Previous studies have applied genomics and transcriptomics to identify immune and genetic markers as key indicator traits for cattle tick susceptibility/resistance; however, results differed between breeds, and there is lack of information on the use of host proteomics. Serum samples from Santa Gertrudis cattle (naïve and phenotyped over 105 days as tick‐resistant [TR] or tick‐susceptible [TS]) were used to conduct differential abundance analyses of protein profiles. Serum proteins were digested into peptides followed by identification and quantification using sequential window acquisition of all instances of theoretical fragment ion mass spectrometry. Before tick infestation, abundance of 28 proteins differed significantly (adjusted P < 10−5) between TR and TS. These differences were also observed following tick infestation (TR vs TS) with a further eight differentially abundant proteins in TR cattle, suggesting possible roles in adaptive responses. The intragroup comparisons (TS‐0 vs TS and TR‐0 vs TR) showed that tick infestation elicited quite similar responses in both groups of cattle, but with relatively stronger responses in TR cattle. Many of the significantly differentially abundant proteins in TR Santa Gertrudis cattle (before and after tick infestation) were associated with immune responses including complement factors, chemotaxis for immune cells and acute‐phase responses.

Failure of the extensor mechanism is a debilitating complication with significant limitation on patients’ function and quality of life. Allograft reconstruction in selected patients restores function with good outcomes. This chapter discusses the challenges of managing extensor mechanism failure in revision knee surgery and we describe our surgical technique in allograft extensor mechanism reconstruction with case demonstrations.

The principles and concepts of managing periprosthetic joint infection rTKA are well-established. Early intervention in acute infections with thorough debridement and modular exchange is preferred. Patient selection, meticulous surgical debridement, and targeted antibiotic treatment in conjunction with a specialist microbiologist are the most important factors to ensure success in managing chronic PJI in either a single- or two-stage strategy. This chapter focuses on the practical aspects of managing infection in revision knee surgery and present our recent tertiary experience.

Chronic patella dislocation after primary or revision TKA is a major challenge in revision surgery. This chapter describes a surgical technique which had been developed based on the biomechanical principles of changing the vector force to centralise the patella and further reinforced by a viable dynamic vastus medialis obliquus (VMO) stabiliser to ensure durability and a sustained outcome with practical tips and case demonstration.

Periprosthetic distal femoral fractures are the most common around the knee and are expected to increase with the exponential growth of TKA. For acute comminuted fractures, the use of distal femoral replacements leads to satisfactory clinical outcomes with an acceptable complication rate for this challenging group of patients. Meticulous preoperative planning is crucial with appropriate surgical skills in using endoprostheses. This strategy offers patients immediate mobilisation with the ability to fully weight-bear which helps to reduce perioperative medical complications. This chapter discusses the management of periprosthetic knee fractures from an arthroplasty perspective using massive endoprostheses.

Primary total knee arthroplasty is an effective and successful operation that has helped millions of patients worldwide. Over the last few decades, significant advances in our understanding of knee kinematics, implant designs and manufacturing processes have helped to ensure improved outcomes and longevity of knee arthroplasty. Despite its proven success, a significant proportion of patients remain dissatisfied with their knees. In this chapter, we will discuss our surgical philosophy in primary TKA, reverting to first principles and discussing some contentious contemporary variations in practice.

One of the main pillars of a durable revision knee construct is implant fixation. Stemmed components are used in most revision cases. Adjunctive fixation is also needed in cases of bone loss and a compromised epiphysis where surface cementation is not enough to support the implants. In this chapter, we focus on the philosophies of different fixation techniques and our preferred approach to not only achieve durable fixation but also to help in joint reconstruction by the use of tibial metaphyseal sleeves to reliably establish a stable tibial platform with the frame principle.

The common indications for rotating-hinge implants in revision knee practice are soft tissue failure; posterior capsule, MCL and significant complex bone loss. They are also part of segmental bone replacing prostheses, either as a distal femoral replacement or using massive augments to fill in major bone defects. They also play a role in complex primary cases. Contemporary hinge implants have seen improved outcomes and survivorship since the introduction of the rotating-hinge mechanism. However, common complications with hinges remain high with early loosening and patellofemoral issues. This chapter focuses on the practical aspects of hinge implants and their kinematics to avoid common hinge-related complications.

Despite its success and durability, about 20% of patients report unfavourable outcomes following their TKA. This is multifactorial with ongoing knee pain, limited function, and failure to meet preoperative expectations being the issues most likely to result in dissatisfaction. A systematic approach to evaluating problematic knees is essential to ascertain whether a revision surgery, a major undertaking, would solve the patient’s problems. In this chapter, we try to shed light on some practical aspects of evaluating patients presenting to revision knee clinics.

Revision knee arthroplasty is a major undertaking for most patients, particularly septic revisions which carry a high morbidity and mortality. In a large cohort of rTKA cases at our tertiary centre, the 10-year survivorship of septic revisions was 68.7 and 80.2% for aseptic revisions. These findings have important practical implications as these outcomes are comparable to those that we see in some cancer patients; the risk of mortality following septic rTKA is higher than that of some of the most common cancers. This reality should be highlighted in candid discussions when counselling patients not only at time of revision surgery, when patients have little choice when infection has already developed, but more importantly at time of primary TKA, particularly for those patients who are at higher risk for developing periprosthetic joint infection. This chapter focuses on long-term mortality in revision knee patients, particularly focusing on septic versus aseptic revisions.

Orthoplastic rTKA cases are challenging and should be managed closely with plastic reconstructive surgeons within a multidisciplinary team approach. Infrapatellar soft tissue defects are the most commonly encountered ones in rTKA practice. These defects are amenable to a pedicled medial gastrocnemius flap. This is commonly done by transposing the flap, as a muscle-only flap, necessitating a combined split-thickness skin graft. This chapter focuses on managing soft tissue defects in rTKA practice particularly in the presence of infection.

Complex primary total knee arthroplasty includes a variety of clinical scenarios with either compromised surrounding soft tissues, deformity, or lack of suitable bone for fixation. In this chapter, we will provide some tips and lessons that we have learnt over years of practice dealing with complex and unusual cases with some common themes and basic principles that would apply to most complex cases including deformities, previous fractures, previous patellectomy, revising unicompartmental knees and the use of patient-specific instrumentation and primary hinge implants, among others.

There are varying indications to revise a poorly performing TKA. Understanding why a knee is not functioning well and being able to fix the problem is an essential prerequisite before embarking on revision surgery. This chapter focuses on some of the contemporary indications for revision providing a summary of our practical experience and views on the current challenges in rTKA.

The aim of revision surgery is to deliver near-normal knee kinematics in the presence of a compromised bone stock and a compromised soft tissue envelope as a result of the original failure or repeated operations. Constrained implants are often used to provide the stability needed. In this chapter focuses on the practical implications of constraint in rTKA in the context of instability, particularly the kinematics of condylar revision implants, the role of varus valgus constraint and its impact on fixation interfaces as we as the role of mobile bearings.

Your career is often defined by those who teach you in your formative years. It was my time spent under the guidance of Professor David Beverland that formed the basis of my understanding and philosophy of TKA surgery.

The demand for salvage surgery is increasing, with more and more patients coming to their third or fourth revision in a situation with increasing bone loss. Traditionally, salvage options rely on allograft-prosthetic composite techniques, the use of massive endoprostheses which are currently the most commonly used option, implant-arthrodesis techniques and amputation. This chapter focuses on the practical aspects of salvage revision surgery, particularly the use of massive endoprostheses, and presents our tertiary experience with case demonstrations.

In revision knee surgery, adequate exposure to the knee joint is crucial for the safe removal of components, scar tissue, protecting important structures, and minimising iatrogenic complications of bone loss or extensor mechanism injury. In this chapter, we describe our approach to surgical exposure in revision knees particularly focusing on our technique of getting extensile exposure through a tibial crest osteotomy.

The principles of joint reconstruction in condylar revision knee arthroplasty are similar to that of a primary arthroplasty, with a balanced approach relying on a stable tibial platform and intact collaterals with the frame principle. In this chapter, we discuss the principles of surgical reconstruction and discuss the use of a balanced approach for an efficient and reproducible workflow in revision knee practice.

The safe removal of implants with minimal bone loss is a crucial step in revision knee surgery and it paves the way for an efficient and successful reconstruction. While most revised primary knees are cemented implants that require certain techniques for removal, cementless knees, revision components and metaphyseal sleeves or cones for adjunctive fixation are used more commonly and certain techniques are needed to extract those implants safely. In this chapter we describe our practical approach and tips to successful implant removals in revision surgery with the overarching principle that patience is indeed a virtue.

We aimed to evaluate the clinical and radiographic outcomes of complex salvage knee revision arthroplasty (rTKA) using endoprostheses with segmental bone loss.A consecutive study of patients who underwent salvage distal femoral replacement (DFR) or proximal tibial replacement (PTR) with a minimum 2- year follow-up (2005-2018). Patients who had acute DFR for periprosthetic fractures were excluded. Clinical outcomes, complications, reoperations, revision for any cause, loosening and mortality data were collected. Knee Society Score (KSS) at final follow up was used as a patient-reported-outcome-measure.Thirty three consecutive patients were included; average age 79.6 years (range 58-89); 15 males/18 females. All had AORI-III massive bone defects and were reconstructed using DFRs; 6 patients had concurrent PTRs. The indication for salvage rTKA was infection in 16/33 (48.5%) and aseptic-loosening in the remaining 17 patients (51.5%). Complications rate was 12.1%; two patients had significant extensor lag; 1 patella dislocation and one recurrent infection. Median follow-up was 5 years (range 2-15) with median arc of flexion- extension of 100° (range 60-120). KSS was available for 29/33 patients with an average of 73.2 (range 51-86). Patients with infection as their indication had poorer KSS scores (66.1 vs. 81.6; P 0.0001). Eleven patients have died at median 4 years postoperatively (range 2-7) for unrelated causes, none of the components have been revised to date with overall 80% patients' survivorship at 5 years.The use of endoprostheses in salvage knee arthroplasty led to satisfactory medium-term clinical outcomes with an acceptable complication rate for this challenging group of patients with poorer functional scores for infection compared to aseptic loosening.Level IV.

BackgroundExisting diagnostic methods for the parasitic gastrointestinal nematode,Haemonchus contortus, are time consuming and require specialised expertise, limiting their utility in the field. A practical, on-farm diagnostic tool could facilitate timely treatment decisions, thereby preventing losses in production and flock welfare. We previously demonstrated the ability of visible–near-infrared (Vis–NIR) spectroscopy to detect and quantify blood in sheep faeces with high accuracy. Here we report our investigation of whether variation in sheep type and environment affect the prediction accuracy of Vis–NIR spectroscopy in quantifying blood in faeces.MethodsVisible–NIR spectra were obtained from worm-free sheep faeces collected from different environments and sheep types in South Australia (SA) and New South Wales, Australia and spiked with various sheep blood concentrations. Spectra were analysed using principal component analysis (PCA), and calibration models were built around the haemoglobin (Hb) wavelength region (387–609 nm) using partial least squares regression. Models were used to predict Hb concentrations in spiked faeces from SA and naturally infected sheep faeces from Queensland (QLD). Samples from QLD were quantified using Hemastix® test strip and FAMACHA© diagnostic test scores.ResultsPrincipal component analysis showed that location, class of sheep and pooled versus individual samples were factors affecting the Hb predictions. The models successfully differentiated ‘healthy’ SA samples from those requiring anthelmintic treatment with moderate to good prediction accuracy (sensitivity 57–94%, specificity 44–79%). The models were not predictive for blood in the naturally infected QLD samples, which may be due in part to variability of faecal background and blood chemistry between samples, or the difference in validation methods used for blood quantification. PCA of the QLD samples, however, identified a difference between samples containing high and low quantities of blood.ConclusionThis study demonstrates the potential of Vis–NIR spectroscopy for estimating blood concentration in faeces from various types of sheep and environmental backgrounds. However, the calibration models developed here did not capture sufficient environmental variation to accurately predict Hb in faeces collected from environments different to those used in the calibration model. Consequently, it will be necessary to establish models that incorporate samples that are more representative of areas whereH. contortusis endemic.Graphical Abstract

Background: Existing diagnostic methods for the parasitic gastrointestinal nematode, Haemonchus contortus, are time consuming and require specialised expertise, limiting their utility in the field. A practical, on-farm diagnostic tool could facilitate timely treatment decisions, preventing production and welfare loss in the flock. We previously demonstrated the ability of visible-near infrared (vis-NIR) spectroscopy to detect and quantify blood in sheep faeces with high accuracy. Here we investigate whether variation in sheep type and environment affect the prediction accuracy of vis-NIR spectroscopy in quantifying blood in faeces.Methods: Vis-NIR spectra were obtained from worm-free sheep faeces from different environments in South Australia (SA) and New South Wales (NSW), Australia and spiked with various sheep blood concentrations collected. Spectra were analysed using principal component analysis (PCA), and calibration models were built around the haemoglobin (Hb) wavelength region (387 – 609 nm) using partial least squares (PLS) regression. Models were used to predict Hb concentrations in spiked faeces from SA and naturally infected Queensland (QLD) faeces. Naturally occurring blood in QLD samples was quantified using Hemastix® and FAMACHA© scores.Results: PCA showed that location, class of sheep and pooled/individual samples were factors affecting the Hb predictions in sheep faeces. The calibration models successfully differentiated ‘healthy’ SA samples from those requiring anthelmintic treatment with moderate to good prediction accuracy (sensitivity: 57 – 94%, specificity: 44 – 79%). The models were not predictive for naturally infected QLD samples, which may be due in part to variability of faecal background and blood chemistry between samples, or the difference in validation methods used for blood quantification. PCA of QLD samples, however, identified a difference between samples containing high and low quantities of blood.Conclusion: This study demonstrates the potential of vis-NIR spectroscopy for estimating blood concentration in faeces from various types of sheep and environmental backgrounds. However, the calibration models developed here did not capture enough environmental variation to accurately predict Hb in faeces collected from environments different to those used in the calibration model. Consequently, it will be necessary to establish models that incorporate samples that are more representative of areas where H. contortus is endemic for the accurate prediction of H. contortus infections in these regions.

Ectoparasites and livestock-associated insects are a major concern throughout the world because of their economic and welfare impacts. Effective control is challenging and relies mainly on the use of chemical insecticides and acaricides. Wolbachia, an arthropod and nematode-infecting, maternally-transmitted endosymbiont is currently of widespread interest for use in novel strategies for the control of a range of arthropod-vectored human diseases and plant pests but to date has received only limited consideration for use in the control of diseases of veterinary concern. Here, we review the currently available information on Wolbachia in veterinary ectoparasites and disease vectors, consider the feasibility for use of Wolbachia in the control of livestock pests and diseases and highlight critical issues which need further investigation.

Revision knee replacement (KR) is technically challenging, expensive, and outcomes can be poor. It is well established that increasing surgeon and unit volumes results in improved outcomes and cost-effectiveness for complex procedures. The aim of this study was to 1) describe the current provision of revision KR in England, Wales and Northern Ireland at the individual surgeon and unit level and 2) investigate the effect on workload of case distribution in a network model.Current practice was mapped using NJR summary statistics containing all revision KR procedures performed over a three-year period (2016-2018). Units were identified as revision centres based on threshold volumes. Units undertaking20 revisions per year were classified as Primary Arthroplasty Units (PAUs) in calculations on the effect of workload centralisation.Revision KR was performed by 1353 surgeons at 232 NHS sites. The majority of surgeons and units were low-volume;1000 surgeons performed7 and 125 sites performed20 procedures per year. Reallocation of work from these 125 PAUs (1235 cases, 21% of total workload) to a network model with even redistribution of cases between centres undertaking revision surgery would result in an additional average annual case increase of 11 per unit per year (range six to 14).Revision KR workload re-allocation would lift all revision centres above a 30 per year threshold and would appear to be a manageable increase in workload for specialist revision KR centres. Case complexity and local referral agreements will significantly affect the real increase in workload; these factors were not incorporated here.

Biopesticides, such as spinosad, are a new‐generation of ecofriendly pesticides in livestock industry. However, spinosad suffers from short duration of effectiveness and low potency in field conditions. Herein we report the development of a new nanospinosad design with dual adhesion and protection functions. Silica nanoparticles with spiky nanotopography loaded with spinosad possess rough surfaces. When applied topically, this nanospinosad formulation exhibited enhanced adhesion to both cattle hair and pest surface. The dual adhesion property led to significantly higher pest mortality toward tick (Rhipicephalus microplus, an ectoparasite) than a nanospinosad formulation using nanoparticles with smooth surface and a benchmark commercial product. The adhesion performance was further quantitatively measured using rainfastness test. Moreover, solar radiation test revealed that the nanospinosad exhibited >10 times higher photostability over the commercial product. This work paves the way toward the development of high performance nanobiopesticides for sustainable agricultural applications.

Background Buffalo flies (Haematobia irritans exigua) (BF) and closely related horn flies (Haematobia irritans irritans) (HF) are invasive haematophagous parasites with significant economic and welfare impacts on cattle production. Wolbachia are intracellular bacteria found widely in insects and currently of much interest for use in novel strategies for the area wide control of insect pests and insect-vectored diseases. In this paper, we report the transinfection of BF towards the development of area-wide controls. Methods Three stages of BF; embryos, pupae and adult female flies, were injected with different Wolbachia strains (wAlbB, wMel and wMelPop). The success of transinfection and infection dynamics was compared by real-time PCR and FISH and fitness effects were assessed in transinfected flies. Results BF eggs were not easily injected because of their tough outer chorion and embryos were frequently damaged with less than 1% hatch rate of microinjected eggs. No Wolbachia infection was recorded in flies successfully reared from injected eggs. Adult and pupal injection resulted in higher survival rates and somatic and germinal tissue infections, with transmission to the succeeding generations on some occasions. Investigations of infection dynamics in flies from injected pupae confirmed that Wolbachia were actively multiplying in somatic tissues. Ovarian infections were confirmed with wMel and wMelPop in a number of instances, though not with wAlbB. Measurement of fitness traits indicated reduced longevity, decreased and delayed adult emergence, and reduced fecundity in Wolbachia-infected flies compared to mock-injected flies. Effects varied with the Wolbachia strain injected with most marked changes seen in the wMelPop-injected flies and least severe effects seen with wAlbB. Conclusions Adult and pupal injection were the most suitable methods for transinfecting BF and all three strains of Wolbachia successfully replicated in somatic tissues. The Wolbachia-induced fitness effects seen in transinfected BF suggest potential for use of the wMel or wMelPop strains in Wolbachia-based biocontrol programmes for BF.

Heavy infestations of the Barber’s pole worm, Haemonchus contortus, can cause severe wasting, morbidity and mortality in animals if not promptly treated. The current detection methods for this blood-sucking parasite involve faecal worm egg counts and diagnosis of anaemia, both of which are time consuming and require expertise. As blood is detected in sheep faeces sooner during infection than worm eggs, quantitative evaluation of blood may serve as a sensitive indicator of H. contortus infection. Here we investigated the feasibility of rapid estimation of haemoglobin (Hb) in sheep faeces using visible near-infrared spectroscopy. Haemoglobin (Hb) was assessed at various concentrations in moist sheep faeces using portable visible near-infrared (vis-NIR) spectrometers. Calibration models were developed for the region of 400–600 nm, where Hb absorption bands can be found. Within this wavelength region, Hb in sheep faeces can be estimated with minimal interference from background moisture (970 nm) or chlorophyll (670 nm), suggesting that difference in diets in sheep will have minimal effect on prediction accuracy. Predictions for sheep faeces based on a drenching threshold of 3 µg Hb/mg faeces showed high levels of accuracy with minimal sample preparation (Sensitivity = 89%, specificity = 80%). The success in detecting Hb in sheep faeces indicates the potential of vis-NIR spectroscopy as a rapid, on-farm diagnostic method for predicting blood in sheep faeces, and timing treatment of H. contortus infections.

Animal health measures mainly rely on vaccination or chemical control for major pests and pathogens, causing issues of residue, toxicity and development of resistance. For example, control of Sheep flystrike and lice-infestation affecting the Australia’s sheep/wool industry (>3.5 B) have developed resistance to nearly all control chemicals used in the past. Topicals RNAi provides an innovative clean-green, non-toxic, environmentally sustainable biological control solution. Biodegradable clay particles as carriers can be used to deliver double stranded RNA (dsRNA), the key trigger molecule of RNA interference pathway. As an early proof of concept, we investigated the stability dsRNA loaded on two types of Clay particles: Clay 1 (releases dsRNA under acidic conditions) and Clay 2 (releases dsRNA under alkaline conditions) on cattle hide. Cattle skin was treated with Cy3 labelled dsRNA alone and Cy3 labelled dsRNA loaded on Clay1 or Clay2. The skin samples treated with the Cy3 formulations were imaged using confocal microscopy. Once imaged, the skin samples were washed and stored at room temperature for 5 days, later the samples were re-imaged to detect the fluorescent signal (Figure 1). The dsRNA loaded on clay particles was stable unlike naked Cy3-dsRNA which degraded and was not visible after washing. This increased inherent stability of the dsRNA molecules, combined with the environmental stability afforded by the Clay particles, offers promise to provide a sustainable solution for animal health. Topical RNAi can reduce reliance on trade withholding periods of meat/wool without chemical residues, enhance animal welfare and increase production of premium quality meat/wool, improve export potential, competitiveness and long-term profitability of livestock industry.