A population-based epidemiological and health economic analysis of fracture-related infection

Aims

The aim of this study was to perform the first population-based description of the epidemiological and health economic burden of fracture-related infection (FRI).

Methods

This is a retrospective cohort study of operatively managed orthopaedic trauma patients from 1 January 2007 to 31 December 2016, performed in Queensland, Australia. Record linkage was used to develop a person-centric, population-based dataset incorporating routinely collected administrative, clinical, and health economic information. The FRI group consisted of patients with International Classification of Disease 10th Revision diagnosis codes for deep infection associated with an implanted device within two years following surgery, while all others were deemed not infected. Demographic and clinical variables, as well as healthcare utilization costs, were compared.

Results

There were 111,402 patients operatively managed for orthopaedic trauma, with 2,775 of these (2.5%) complicated by FRI. The development of FRI had a statistically significant association with older age, male sex, residing in rural/remote areas, Aboriginal or Torres Strait Islander background, lower socioeconomic status, road traffic accident, work-related injuries, open fractures, anatomical region (lower limb, spine, pelvis), high injury severity, requiring soft-tissue coverage, and medical comorbidities (univariate analysis). Patients with FRI had an eight-times longer median inpatient length of stay (24 days vs 3 days), and a 2.8-times higher mean estimated inpatient hospitalization cost (AU$56,565 vs AU$19,773) compared with uninfected patients. The total estimated inpatient cost of the FRI cohort to the healthcare system was AU$156.9 million over the ten-year period.

Conclusion

The results of this study advocate for improvements in trauma care and infection management, address social determinants of health, and highlight the upside potential to improve prevention and treatment strategies.

Downsizing and minimising medialisation of the acetabular component: Novel technique to preserve bone in THA

Standard practice for acetabular component placement in total hip arthroplasty (THA) is to medialise the acetabular component. Bone preservation techniques during primary THA are beneficial for possible future revisions. The goal of this study is to examine the effect of downsizing and minimising medialisation of the acetabular component on bone resection volume. The volume of bone resected during acetabular preparation for different sizes of components was calculated and the volume of bone preserved by downsizing the cup was determined. Minimising medialisation of the acetabular component by 1-3 mm from the true floor was calculated. Absolute values and percentage of bone volume preserved when acetabular components are downsized or less medialised is presented. Downsizing the acetabular component by one size (2 mm) preserves between 2.6 cm³ (size 40 vs 42) and 8.4 cm³ (size 72 vs 74) of bone volume and consistently reduces resected bone volume by at least 35% (range 35.2%-37.5%). Similarly, reducing medialisation of a 56 mm acetabular cup (as an example of a commonly implanted component) by 3 mm reduces bone loss by 5.9 cm³- 44% less bone volume resection. Downsizing and minimising medialisation of the cup in THA substantially preserves bone which may benefit future revision surgeries. Surgeons could consider implanting the smallest acceptable acetabular shell to preserve bone without compromising on head size.

Single-stage revision of MRSA orthopedic device-related infection in sheep with an antibiotic-loaded hydrogel

Local antimicrobial therapy is an integral aspect of treating orthopedic device-related infection (ODRI), which is conventionally administered via polymethyl-methacrylate (PMMA) bone cement. PMMA, however, is limited by a suboptimal antibiotic release profile and a lack of biodegradability. In this study, we compare the efficacy of PMMA versus an antibiotic-loaded hydrogel in a single-stage revision for chronic methicillin-resistant Staphylococcus aureus (MRSA) ODRI in sheep. Antibiofilm activity of the antibiotic combination (gentamicin and vancomycin) was determined in vitro. Swiss alpine sheep underwent a single-stage revision of a tibial intramedullary nail with MRSA infection. Local gentamicin and vancomycin therapy was delivered via hydrogel or PMMA (n = 5 per group), in conjunction with systemic antibiotic therapy. In vivo observations included: local antibiotic tissue concentration, renal and liver function tests, and quantitative microbiology on tissues and hardware post-mortem. There was a nonsignificant reduction in biofilm with an increasing antibiotic concentration in vitro (p = 0.12), confirming the antibiotic tolerance of the MRSA biofilm. In the in vivo study, four out of five sheep from each treatment group were culture-negative. Antibiotic delivery via hydrogel resulted in 10-100 times greater local concentrations for the first 2-3 days compared with PMMA and were comparable thereafter. Systemic concentrations of gentamicin were minimal or undetectable in both groups, while renal and liver function tests were within normal limits. This study shows that a single-stage revision with hydrogel or PMMA is equally effective, although the hydrogel offers certain practical benefits over PMMA, which make it an attractive proposition for clinical use.

Unlocking the Value of Literature in Health Co-Design: Transforming Patient Experience Publications into a Creative and Accessible Card Tool

BACKGROUND

A wealth of peer-reviewed data exists regarding people's health experience, yet practical ways of using the data to understand patients' experiences and to inform health co-design are needed.

OBJECTIVE

This study aims to develop an applied and pragmatic method for using patient experience literature in co-design by transforming it into an accessible and creative co-design tool.

METHOD

A scoping literature review of the CINAHL, MEDLINE, PsycINFO and PubMed electronic databases was conducted from January 2011 through August 2016. Qualitative publications regarding the experience of living with diabetes in Australia were selected. The Results section of each paper was extracted and affinity analysis was applied to identify insights into the health experience. These insights were developed into a card tool for use in health co-design activities.

RESULTS

Thirteen relevant papers were identified from the review, and affinity analysis of the Results sections of these papers lead to the identification of 85 insights, from 'Shock of diagnosis' (Insight 1), to 'Delay seeking care' (Insight 9), to 'Assess the quality of care' (Insight 28), to 'Avoid or adapt habits' (Insight 78). Each insight was developed into an individual card, which included a high-level theme, insight, quote and a link back to the literature, together making up the Health Experience Insight Cards, Living with Diabetes Edition.

CONCLUSIONS

This was the first study to develop a method for transforming existing patient experience literature into a creative tool for health improvement. The Health Experience Insight Cards collate the diverse experiences of over 300 people living with diabetes in Australia, from 13 studies. Health improvement teams can use the 'Living with Diabetes Edition' cards or they can follow this pragmatic method to create their own cards focused on other health experiences to facilitate person-focused health improvements.

Association between higher ambient temperature and orthopaedic infection rates: a systematic review and meta-analysis

INTRODUCTION

Many infectious diseases display seasonal variation corresponding with particular conditions. In orthopaedics a growing body of evidence has identified surges in post-operative infection rates during higher temperature periods. The aim of this research was to collate and synthesize the current literature on this topic.

METHODS

A systematic review and meta-analysis was performed using five databases (PubMed, Embase, CINAHL, Web of Science and Central (Cochrane)). Study quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation method. Odds ratios (ORs) were calculated from monthly infection rates and a pooled OR was generated using the DerSimonian and Lairds method. A protocol for this review was registered with the National Institute for Health Research International Prospective Register of Systematic Reviews (CRD42017081871).

RESULTS

Eighteen studies analysing over 19 000 cases of orthopaedic related infection met inclusion criteria. Data on 6620 cases and 9035 controls from 12 studies were included for meta-analysis. The pooled OR indicated an overall increased odds of post-operative infection for patients undergoing orthopaedic procedures during warmer periods of the year (pooled OR 1.16, 95% confidence interval 1.04-1.30).

CONCLUSION

A small but significantly increased odds of post-operative infection may exist for orthopaedic patients who undergo procedures during higher temperature periods. It is hypothesized that this effect is geographically dependent and confounded by meteorological factors, local cultural variables and hospital staffing cycles.

A mixed-methods retrospective study: 10 years of diabetic retinopathy screening in urban Aboriginal and Torres Strait Islander primary care

This research applies a mixed-method approach to retrospectively study the history of diabetic retinopathy (DR) screening in an urban Aboriginal and Torres Strait Islander general practice. Data from administrative practice software and publications were extracted and presented as a timeline data visualisation to staff, in six focus groups. Eighteen key staff from the Southern Queensland Centre of Excellence in Aboriginal and Torres Strait Islander Primary Health Care (CoE) were purposively recruited. The main outcome measures were retrospective administrative practice data, publications and staff interpretations regarding DR screening at the CoE. The CoE DR screening initially increased screening rates to 93%. Participants reported that CoE DR screening provides eye care from screening to treatment; all annual care is provided in one appointment; and in a client-focussed environment. From 2012 to 2016, the number of regular CoE clients with diabetes increased by 46%. Consequently, DR screening rates dropped from 44% to 22%. Participants’ recognised the service could reach its full potential if it implements continuous quality improvement focussed on client experience, using rigorous data and supported by engaged staff. Initial investment in setting-up DR screening is not enough, instead ongoing quality improvement is integral to a sustainable, successful service long-term.

Glare-free retinal imaging using a portable light field fundus camera

We present the retinal plenoptoscope, a novel light field retinal imaging device designed to overcome many of the problems that limit the use of portable non-mydriatic fundus cameras, including image quality and lack of stereopsis. The design and prototype construction of this device is detailed and the ideal relationship between the eye pupil, system aperture stop and micro-image separation is investigated. A comparison of the theoretical entrance pupil size, multi-view baseline and depth resolution indicates that a higher degree of stereopsis is possible than with stereo fundus cameras. We also show that the effects of corneal backscatter on image quality can be removed through a novel method of glare identification and selective image rendering. This method is then extended to produce glare-free depth maps from densely estimated depth fields, creating representations of retinal topography from a single exposure. These methods are demonstrated on physical models and live human eyes using a prototype device based on a Lytro Illum consumer light field camera. The Retinal Plenoptoscope offers a viable, robust modality for non-mydriatic color and 3-D retinal imaging.

Orthopaedic surgeon attitudes towards current limitations and the potential for robotic and technological innovation in arthroscopic surgery

PURPOSE

To determine the perceptions of surgeons at both consultant and resident level to the difficulties of performing knee arthroscopy and to determine their willingness to adopt robotic technology.

METHODS

A questionnaire was designed to discern the attitude of orthopaedic consultants and residents to the technical challenges of performing knee arthroscopy and the possible role of robotically enhanced surgery. The questionnaire included 31 questions across five key domains.

RESULTS

Iatrogenic damage to articular cartilage was thought to occur in at least 1 in 10 cases by 50% of respondents with 15% believing that it occurred in every case. One hundred or more procedures were thought to be necessary to overcome the learning curve by 40% of respondents and 77.5% believed that 50 procedures or above were necessary. Ninety-nine per cent of respondents agreed that higher technical skills would decrease unintended damage. Despite such difficulties with the procedure and no prior experience with robotic surgery, 47% of respondents see a role for semiautonomous arthroscopic systems in the future.

CONCLUSIONS

Surgeons believe that knee arthroscopy is a difficult procedure with a long learning curve and a high incidence of iatrogenic cartilage damage. Many find it ergonomically challenging and have frustration with current tools and technology.

CLINICAL RELEVANCE

This is the first study that highlights surgeons' difficulties performing knee arthroscopy despite the commonly held attitudes that it is a straightforward procedure. Systems that are able to decrease these problems should improve patients' outcomes and decrease the risk of harm.

A stimulatory effect of Ca3ZrSi2O9 bioceramics on cementogenic/osteogenic differentiation of periodontal ligament cells

Ca₃ZrSi₂O₉ bioceramics promote the cementogenic/osteogenic differentiation of PDLCs.

Phenotypic characterization of osteoarthritic osteocytes from the sclerotic zones: a possible pathological role in subchondral bone sclerosis

Subchondral bone sclerosis is a well-recognised manifestation of osteoarthritis (OA). The osteocyte cell network is now considered to be central to the regulation of bone homeostasis; however, it is not known whether the integrity of the osteocyte cell network is altered in OA patients. The aim of this study was to investigate OA osteocyte phenotypic changes and its potential role in OA subchondral bone pathogenesis. The morphological and phenotypic changes of osteocytes in OA samples were investigated by micro-CT, SEM, histology, immunohistochemistry, TRAP staining, apoptosis assay and real-time PCR studies. We demonstrated that in OA subchondral bone, the osteocyte morphology was altered showing rough and rounded cell body with fewer and disorganized dendrites compared with the osteocytes in control samples. OA osteocyte also showed dysregulated expression of osteocyte markers, apoptosis, and degradative enzymes, indicating that the phenotypical changes in OA osteocytes were accompanied with OA subchondral bone remodelling (increased osteoblast and osteoclast activity) and increased bone volume with altered mineral content. Significant alteration of osteocytes identified in OA samples indicates a potential regulatory role of osteocytes in subchondral bone remodelling and mineral metabolism during OA pathogenesis.

170. TGFβ SIGNALING IN AN IN VITRO SEMINOMA MODEL

Testicular cancer, the second most common malignancy in young men, has a 95% cure rate but can result in infertility or subfertility. Its incidence has increased significantly in recent decades (1). This cancer is thought to arise during embryogenesis, based on the persistence of embryonic germ cell markers such as Blimp1 (2), Oct3/4 (3) and Nanog (3) in adult seminoma cells. TCam2 cells are a recently characterised in vitro seminoma model (4). We show by Q-PCR and immunofluorescence that they also express these early germ cell markers. TGFβ signaling plays a key role during germ cell development, and is implicated in the development of testicular cancers (5, 6). To investigate this further, we first determined whether the pathway is active in TCam2 cells. By Q-PCR we demonstrate expression of the TGFβ downstream transcription factors Smad 2, 3 and 4, and Activin type I and II receptors. Importantly, ActRIIA, which is undetectable in adult testicular germ cells, but readily detected in human foetal germ cells (7) and clinical seminoma samples (6), is readily detectable at both the mRNA and protein level in TCam2 cells. Furthermore, 24 hour treatment with Activin (5 and 50ng/ml) or BMP4 (5 and 50ng/ml) induces a 3-4 fold increase in ActRIIA mRNA levels, but not ActRIA, ActRIB or ActRIIB. Strikingly, in TCam2 cells BMP4 and to a lesser extent retinoic acid, but not activin, support survival and proliferation of TCam2 cells in the absence of serum. This is consistent with known roles of BMP4 and retinoic acid in enhancing murine foetal germ cell proliferation/self-renewal and survival (8, 9), and activin inhibition of foetal murine germ cell proliferation (10). This study is the first to demonstrate a functional response in seminoma cells consistent with their foetal germ cell-like identity and forms the basis for future mechanistic analyses of the role of TGFβ signaling in human testicular cancer.