Patient Characteristics Affect Hip Contact Forces during Gait

Objective: To examine hip contact force (HCF), calculated through multibody modelling, in a large total hip replacement (THR) cohort stratified by patient characteristics such as BMI, age and function. Design: 132 THR patients undertook one motion capture session of gait analysis at a self-selected walking speed. HCFs were then calculated using the AnyBody Modelling System. Patients were stratified into three BMI groups, five age groups, and finally three functional groups determined by their self-selected gait speed. Independent 1-dimensional linear regression analyses were performed to separately evaluate the influence of age, BMI and functionality on HCF, by means of statistical parametric mapping (SPM). Results: The mean predicted HCF were comparable to HCFs measured with an instrumented prosthesis reported in the literature. The regression analyses revealed a statistically significant positive relationship between BMI and HCF, indicating that obese patients are more likely to experience higher HCF during most of the stance phase, while a statistically significant relationship with age was found only during the late swing-phase. Patients with higher functional ability exhibited significantly increased peak contact forces, while patients with lower functional ability displayed a pathological flattening of the typical double hump force profile. Conclusions: HCFs experienced at the bearing surface are highly dependent on patient characteristics. BMI and functional ability were determined to have the biggest influence on contact force. Current preclinical testing standards do not reflect this

The influence of surgical approach on outcomes of total hip arthroplasty

The vast majority of total hip arthroplasties performed in the UK are undertaken using either a posterior or direct lateral approach. This review describes the functional outcomes of these approaches. Functional outcome can be assessed through motion capture of function, strength testing of muscle groups around the hip and imaging of anatomical structures. Regardless of surgical approach, total hip arthroplasty patients rarely return to the ‘normal’ gait exhibited by healthy age-matched controls. The direct lateral approach is associated with abductor deficiencies whilst the posterior approach may introduce extension and rotation deficits. How long functional differences persist between surgical approaches is unclear. The emergence of improved imaging technologies as well as isokinetic dynamometry (muscle strength testing) and 3D biomechanical modelling provide more comprehensive evaluations than traditional post-operative assessments such as radiology or couch examination. Targeted physiotherapy has been suggested as a possible intervention to counter lasting functional deficits. This review provides a foundation to inform surgeons of the impact of each approach to justify their surgical practice and may inform physical rehabilitation regimens post-surgery

Evidence-based management approaches for patients with severe chronic obstructive pulmonary disease (COPD): A practice review

Background: Patients with chronic obstructive pulmonary disease (COPD) face limited treatment options and inadequate access to palliative care. Aim: To provide a pragmatic overview of clinical guidelines and produce evidence-based recommendations for severe COPD. Interventions for which there is inconsistent evidence to support their use and areas requiring further research were identified. Design: Practice review of guidelines supported by scoping review methodology to examine the evidence reporting the use of guideline-recommended interventions. Data sources: An electronic search was undertaken in MEDLINE, EMBASE, PsycINFO, CINAHL and The Cochrane Database of Systematic Reviews, complemented by web searching for guidelines and publications providing primary evidence (July 2021). Guidelines published within the last 5 years and evidence in the last 10 years were included. Results: Severe COPD should be managed using a multidisciplinary approach with a holistic assessment. For stable patients, long-acting beta-agonist/long-acting muscarinic antagonist and pulmonary rehabilitation are recommended. Low dose opioids, self-management, handheld fan and nutritional support may provide small benefits, whereas routine corticosteroids should be avoided. For COPD exacerbations, systematic corticosteroids, non-invasive ventilation and exacerbation action plans are recommended. Short-acting inhaled beta-agonists and antibiotics may be considered but pulmonary rehabilitation should be avoided during hospitalisation. Long term oxygen therapy is only recommended for patients with chronic severe hypoxaemia. Short-acting anticholinergic inhalers, nebulised opioids, oral theophylline or telehealth are not recommended. Conclusions: Recommended interventions by guidelines are not always supported by high-quality evidence. Further research is required on efficacy and safety of inhaled corticosteroids, antidepressants, benzodiazepines, mucolytics, relaxation and breathing exercises

A systematic review and narrative synthesis of footwear and orthotic devices used in the management of ankle haemarthrosis and haemarthropathy in haemophilia

Introduction Haemarthrosis is a clinical feature of haemophilia leading to haemarthropathy. The ankle joint is most commonly affected, resulting in significant pain, disability and a reduction in health-related quality of life. Footwear and orthotic devices are effective in other diseases that affect the foot and ankle, such as rheumatoid arthritis, but little is known about their effect in haemophilia. Aims To review the efficacy and effectiveness of footwear and orthotic devices in the management of ankle joint haemarthrosis and haemarthropathy in haemophilia. Methods A systematic literature review was conducted. Two review authors independently screened studies for inclusion and appraised methodological quality using Joanna Briggs Institute Critical Appraisal checklists. A narrative analysis was undertaken. Results Ten studies involving 271 male participants were eligible for inclusion. All studies were quasi-experimental; three employed a within-subject design. Two studies included an independent comparison or control group. A range of footwear and orthotic devices were investigated. Limited evidence from non-randomised studies suggested that footwear and orthotic devices improve the number of ankle joint bleeding episodes, gait parameters, and patient-reported pain. Conclusion This review demonstrates a lack of robust evidence regarding the efficacy and effectiveness of footwear and orthotic devices in the management of ankle joint haemarthrosis and haemarthropathy in haemophilia. Methodological heterogeneities and limitations with the study designs, small sample sizes and limited follow-up of participants exist. Future studies utilising randomised designs, larger sample sizes, long-term follow-up, and validated patient-reported outcome measures are needed to inform the clinical management of ankle joint haemarthrosis and haemarthropathy

Changes in microphytobenthos fluorescence over a tidal cycle: implications for sampling designs

Intertidal microphytobenthos (MPB) are important primary producers and provide food for herbivores in soft sediments and on rocky shores. Methods of measuring MPB biomass that do not depend on the time of collection relative to the time of day or tidal conditions are important in any studies that need to compare temporal or spatial variation, effects of abiotic factors or activity of grazers. Pulse amplitude modulated (PAM) fluorometry is often used to estimate biomass of MPB because it is a rapid, non-destructive method, but it is not known how measures of fluorescence are altered by changing conditions during a period of low tide. We investigated this experimentally using in situ changes in minimal fluorescence (F) on a rocky shore and on an estuarine mudflat around Sydney (Australia), during low tides. On rocky shores, the time when samples are taken during low tide had little direct influence on measures of fluorescence as long as the substratum is dry. Wetness from wave-splash, seepage from rock pools, run-off, rainfall, etc., had large consequences for any comparisons. On soft sediments, fluorescence was decreased if the sediment dried out, as happens during low-spring tides on particularly hot and dry days. Surface water affected the response of PAM and therefore measurements used to estimate MPB, emphasising the need for care to ensure that representative sampling is done during low tide

Decline in health-related quality of life and foot and ankle patient reported outcomes measures in patients with haemophilia and ankle haemarthropathy

Background Haemophilia is an X-linked recessive genetic disorder characterised by bleeding within soft tissue and joints. The ankle is disproportionally affected by haemarthropathy when compared to the elbows and knees; reported as the most affected joints in patients with haemophilia. Despite advances in treatment, patients still report ongoing pain and disability, however, the impact has not been evaluated, nor has the effect on health-related quality of life (HRQoL) or foot and ankle patient-reported outcome measures (PROMs). The primary aim of this study was to establish the impact of ankle haemarthropathy in patients with severe and moderate haemophilia A and B. Secondly to identify the clinical outcomes associated with a decline in HRQoL and foot and ankle PROMs. Methods A cross-sectional multi-centre questionnaire study was conducted across 18 haemophilia centres in England, Scotland and Wales with a recruitment target of 245 participants. The HAEMO-QoL-A and Manchester-Oxford Foot Questionnaire (MOXFQ) (foot and ankle) with total and domain scores measured impact on HRQOL and foot and ankle outcomes. Demographics, clinical characteristics, ankle haemophilia joint health scores, multi-joint haemarthropathy and Numerical Pain Rating Scales (NPRS) of “ankle pain over the past six months” were collected as a measure of chronic ankle pain. Results A total of 243 of 250 participants provided complete data. HAEMO-QoL-A and MOXFQ (foot and ankle) total and index scores indicated worse HRQoL with total scores ranging from a mean of 35.3 to 35.8 (100 best-health) and 50.5 to 45.8 (0 best-health) respectively. NPRS (mean (SD)) ranged from 5.0 (2.6) to 5.5 (2.5), with median (IQR) ankle haemophilia joint health score of 4.5 (1 to 12.5) to 6.0 (3.0 to 10.0) indicating moderate to severe levels of ankle haemarthropathy. Ankle NPRS over six months and inhibitor status were associated with decline in outcome. Conclusions HRQoL and foot and ankle PROMs were poor in participants with moderate to severe levels of ankle haemarthropathy. Pain was a major driver for decline in HRQoL and foot and ankle PROMs and use of NPRS has the potential to predict worsening HRQoL and PROMs at the ankle and other affected joints

30 days wild: development and evaluation of a large-scale nature engagement campaign to improve well-being

There is a need to increase people’s engagement with and connection to nature, both for human well-being and the conservation of nature itself. In order to suggest ways for people to engage with nature and create a wider social context to normalise nature engagement, The Wildlife Trusts developed a mass engagement campaign, 30 Days Wild. The campaign asked people to engage with nature every day for a month. 12,400 people signed up for 30 Days Wild via an online sign-up with an estimated 18,500 taking part overall, resulting in an estimated 300,000 engagements with nature by participants. Samples of those taking part were found to have sustained increases in happiness, health, connection to nature and pro-nature behaviours. With the improvement in health being predicted by the improvement in happiness, this relationship was mediated by the change in connection to nature

Mathematical modelling of cell layer growth in a hollow fibre bioreactor.

Generating autologous tissue grafts of a clinically useful volume requires efficient and controlled expansion of cell populations harvested from patients. Hollow fibre bioreactors show promise as cell expansion devices, owing to their potential for scale-up. However, further research is required to establish how to specify appropriate hollow fibre bioreactor operating conditions for expanding different cell types. In this study we develop a simple model for the growth of a cell layer seeded on the outer surface of a single fibre in a perfused hollow fibre bioreactor. Nutrient-rich culture medium is pumped through the fibre lumen and leaves the bioreactor via the lumen outlet or passes through the porous fibre walls and cell layer, and out via ports on the outer wall of the extra-capillary space. Stokes and Darcy equations for fluid flow in the fibre lumen, fibre wall, cell layer and extra-capillary space are coupled to reaction-advection-diffusion equations for oxygen and lactate transport through the bioreactor, and to a simple growth law for the evolution of the free boundary of the cell layer. Cells at the free boundary are assumed to proliferate at a rate that increases with the local oxygen concentration, and to die and detach from the layer if the local fluid shear stress or lactate concentration exceed critical thresholds. We use the model to predict operating conditions that maximise the cell layer growth for different cell types. In particular, we predict the optimal flow rate of culture medium into the fibre lumen and fluid pressure imposed at the lumen outlet for cell types with different oxygen demands and fluid shear stress tolerances, and compare the growth of the cell layer when the exit ports on the outside of the bioreactor are open with that when they are closed. Model simulations reveal that increasing the inlet flow rate and outlet fluid pressure increases oxygen delivery to the cell layer and, therefore, the growth rate of cells that are tolerant to high shear stresses, but may be detrimental for shear-sensitive cells. The cell layer growth rate is predicted to increase, and be less sensitive to the lactate tolerance of the cells, when the exit ports are opened, as the radial flow through the bioreactor is enhanced and the lactate produced by the cells cleared more rapidly from the cell layer

Challenges of using modelling evidence in the visceral leishmaniasis elimination programme in India.

As India comes closer to the elimination of visceral leishmaniasis (VL) as a public health problem, surveillance efforts and elimination targets must be continuously revised and strengthened. Mathematical modelling is a compelling research discipline for informing policy and programme design in its capacity to project incidence across space and time, the likelihood of achieving benchmarks, and the impact of different interventions. To gauge the extent to which modelling informs policy in India, this qualitative analysis explores how and whether policy makers understand, value, and reference recently produced VL modelling research. Sixteen semi-structured interviews were carried out with both users- and producers- of VL modelling research, guided by a knowledge utilisation framework grounded in knowledge translation theory. Participants reported that barriers to knowledge utilisation include 1) scepticism that models accurately reflect transmission dynamics, 2) failure of modellers to apply their analyses to specific programme operations, and 3) lack of accountability in the process of translating knowledge to policy. Political trust and support are needed to translate knowledge into programme activities, and employment of a communication intermediary may be a necessary approach to improve this process