Evaluating the cost of robotic-assisted total and unicompartmental knee arthroplasty.

As uptake of robotic-assisted arthroplasty increases there is a need for economic evaluation of the implementation and ongoing costs associated with robotic surgery. The aims of this study were to describe the in-hospital cost of robotic-assisted total knee arthroplasty (RA-TKA) and robotic-assisted unicompartmental knee arthroplasty (RA-UKA) and determine the influence of patient characteristics and surgical outcomes on cost. This prospective cohort study included adult patients (≥ 18 years) undergoing primary unilateral RA-TKA and RA-UKA, at a tertiary hospital in Sydney between April 2017 and June 2021. Patient characteristics, surgical outcomes, and in-hospital cost variables were extracted from hospital medical records. Differences between outcomes for RA-TKA and RA-UKA were compared using independent sample t-tests. Logistic regression was performed to determine drivers of cost. Of the 308 robotic-assisted procedures, 247 were RA-TKA and 61 were RA-UKA. Surgical time, time in the operating room, and length of stay were significantly shorter in RA-UKA (p < 0.001); whereas RA-TKA patients were older (p = 0.002) and more likely to be discharged to in-patient rehabilitation (p = 0.009). Total in-hospital cost was significantly higher for RA-TKA cases (AU$18580.02 vs $13275.38; p < 0.001). Robotic system and maintenance cost per case was AU$3867.00 for TKA and AU$5008.77 for UKA. Patients born overseas and lower volume robotic surgeons were significantly associated with higher total cost of RA-UKA. Increasing age and male gender were significantly associated with higher total cost of RA-TKA. Total cost was significantly higher for RA-TKA than RA-UKA. Robotic system costs for RA-UKA are inflated by the software cost relative to the volume of cases compared with RA-TKA. Cost is an important consideration when evaluating long term benefits of robotic-assisted knee arthroplasty in future studies to provide evidence for the economic sustainability of this practice.

The Diagnostic Accuracy of the Emergency Department Assessment of Chest Pain (EDACS) Score: A Systematic Review and Meta-analysis.

STUDY OBJECTIVE: We evaluate current evidence for the diagnostic accuracy and safety of the Emergency Department Assessment of Chest Pain Score (EDACS) for patients presenting to the emergency department (ED) with possible acute coronary syndromes. METHODS: MEDLINE, EMBASE, and Cochrane databases were searched for publications reporting data on the EDACS score. No date restrictions were used. Two independent researchers assessed studies for eligibility, bias, and quality. The primary outcome was major adverse cardiac events occurring within 30 days. Heterogeneity was assessed and data were pooled by meta-analysis using a random-effects model. RESULTS: Eight diagnostic test accuracy studies including 11,578 patients and 1 randomized controlled trial including 558 patients were eligible for inclusion. On meta-analysis, the EDACS score had a pooled sensitivity of 96.1% (95% confidence interval 89.6% to 98.6%) and specificity of 61.1% (95% confidence interval 55.5% to 66.3%). A total of 55.0% of patients (n=6,370/11,578) were identified as low risk and eligible for early discharge. Sixty-two patients (0.54%) identified as low risk had an outcome of major adverse cardiac events within 30 days. CONCLUSION: The EDACS score identified greater than 50% of patients with suspected acute coronary syndrome as suitable for discharge after serial troponin sampling during 2 hours. Sensitivity for major adverse cardiac events was relatively high overall and may be acceptable to clinicians.

The rationale for simple approaches for sustainability assessment and management in contaminated land practice.

The scale of land-contamination problems, and of the responses to them, makes achieving sustainability in contaminated land remediation an important objective. The Sustainable Remediation Forum in the UK (SuRF-UK) was established in 2007 to support more sustainable remediation practice in the UK. The current international interest in 'sustainable remediation' has achieved a fairly rapid consensus on concepts, descriptions and definitions for sustainable remediation, which are now being incorporated into an ISO standard. However the sustainability assessment methods being used remain diverse with a range of (mainly) semi-quantitative and quantitative approaches and tools developed, or in development. Sustainability assessment is site specific and subjective. It depends on the inclusion of a wide range of considerations across different stakeholder perspectives. Taking a tiered approach to sustainability assessment offers important advantages, starting from a qualitative assessment and moving through to semi-quantitative and quantitative assessments on an 'as required' basis only. It is also clear that there are a number of 'easy wins' that could improve performance against sustainability criteria right across the site management process. SuRF-UK has provided a checklist of 'sustainable management practices' that describes some of these. This paper provides the rationale for, and an outline of, and recently published SuRF-UK guidance on preparing for and framing sustainability assessments; carrying out qualitative sustainability assessment; and simple good management practices to improve sustainability across contaminated land management activities.

Natural selection for costly nutrient recycling in simulated microbial metacommunities.

Recycling of essential nutrients occurs at scales from microbial communities to global biogeochemical cycles, often in association with ecological interactions in which two or more species utilise each others' metabolic by-products. However, recycling loops may be unstable; sequences of reactions leading to net recycling may be parasitised by side-reactions causing nutrient loss, while some reactions in any closed recycling loop are likely to be costly to participants. Here we examine the stability of nutrient recycling loops in an individual-based ecosystem model based on microbial functional types that differ in their metabolism. A supplied nutrient is utilised by a "source" functional type, generating a secondary nutrient that is subsequently used by two other types-a "mutualist" that regenerates the initial nutrient at a growth rate cost, and a "parasite" that produces a refractory waste product but does not incur any additional cost. The three functional types are distributed across a metacommunity in which separate patches are linked by a stochastic diffusive migration process. Regions of high mutualist abundance feature high levels of nutrient recycling and increased local population density leading to greater export of individuals, allowing the source-mutualist recycling loop to spread across the system. Individual-level selection favouring parasites is balanced by patch-level selection for high productivity, indirectly favouring mutualists due to the synergistic productivity benefits of the recycling loop they support. This suggests that multi-level selection may promote nutrient cycling and thereby help to explain the apparent ubiquity and stability of nutrient recycling in nature.

Assessment of accuracy and reliability in preoperative templating for hip resurfacing arthroplasty.

The current study investigated the accuracy and reliability of hip resurfacing component selection based on digital preoperative templating. Four surgeons made a template of preoperative radiographs on 2 occasions for acetabular and femoral components in 50 randomly selected hip resurfacing patients. Component selection reliability was variable among surgeons (kappa = 0.16-0.73) and fair between surgeons (kappa = 0.23-0.32). The average percentage of agreement for the acetabular component was 47% (range, 32%-64%) and for the femoral component was 54% (range, 38%-70%). Surgeons tended to underestimate implant size if the correct implant was not chosen (acetabular, 29%; femoral, 32%). Selection of an undersized femoral component may lead to femoral neck notching or varus implant alignment. This study emphasizes the need for intraoperative verification of preoperative templating results to ensure optimal implant selection in hip resurfacing.