The use of navigation to achieve soft tissue balance in total knee arthroplasty : a randomised clinical study

Background: Achieving soft tissue balance is an operative goal in total knee arthroplasty. This randomised, prospective study compared computer navigation to conventional techniques in achieving soft tissue balance. Methods: Forty one consecutive knee arthroplasties were randomised to either a non-navigated or navigated group. In the non-navigated group, balancing was carried out using surgeon judgement. In the navigated group, balancing was carried out using navigation software. In both groups, the navigation software was used as a measuring tool. Results: Balancing of the mediolateral extension gap was superior in the navigation group (p=0.001). No significant difference was found between the two groups in balancing the mediolateral flexion gap or in achieving equal flexion and extension gaps. Conclusions: Computer navigation offered little advantage over experienced surgeon judgement in achieving soft tissue balance in knee replacement. However, the method employed in the navigated group did provide a reproducible and objective assessment of flexion and extension gaps and may therefore benefit surgeons in training.

NSAM-derived total surface area vs. SMPS-derived "mobility equivalent" surface area for different environmentally relevant aerosols

The surface area of inhaled particles deposited in the alveolar region, as reported by the TSI nanoparticle surface area monitor (NSAM), was compared with the corresponding value estimated by a TSI scanning mobility particle sizer (SMPS) for a range of environmentally relevant aerosols, including petrol emissions, ETS, laser printer emissions, cooking emissions and ambient aerosols. The SMPS values were based on a mobility size distribution assuming spherical particles using the appropriate size-dependent alveolar-deposition factors provided by the ICRP. In most cases, the two instruments showed good linear agreement. With petrol emissions and ETS, the linearity extended to over 103 μm2 cm-3. With printer emissions, there was good linearity up to about 300 μm2 cm-3 while the NSAM increasingly overestimated the surface area at higher concentrations. The presence of a nucleation event in ambient air caused the NSAM to over-estimate the surface area by a factor of 2. We summarize these results and conclude that the maximum number concentration up to which the NSAM is accurate clearly depends on the type of aerosol being sampled and provide guidance for the use of the instrument.

Postprandial total and HMW adiponectin following a high-fat meal in lean, obese and diabetic men

BACKGROUND/OBJECTIVES: Recent work suggests that macronutrients are pro-inflammatory and promote oxidative stress. Reports of postprandial regulation of total adiponectin have been mixed, and there is limited information regarding postprandial changes in high molecular weight (HMW) adiponectin. The aim of this study was to assess the effect of a standardised high-fat meal on metabolic variables, adiponectin (total and HMW), and markers of inflammation and oxidative stress in: (i) lean, (ii) obese non-diabetic and (iii) men with type 2 diabetes mellitus (T2DM). SUBJECTS/METHODS: Male subjects: lean (n=10), obese (n=10) and T2DM (n=10) were studied for 6 h following both a high-fat meal and water control. Metabolic variables (glucose, insulin, triglycerides), inflammatory markers (interleukin-6 (IL6), tumour necrosis factor (TNF)α, high-sensitivity C-reactive protein (hsCRP), nuclear factor (NF)κB expression in peripheral blood mononuclear cells (p65)), indicators of oxidative stress (oxidised low density lipoprotein (oxLDL), protein carbonyl) and adiponectin (total and HMW) were measured. RESULTS: No significant changes in TNFα, p65, oxLDL or protein carbonyl concentrations were observed. Overall, postprandial IL6 decreased in subjects with T2DM but increased in lean subjects, whereas hsCRP decreased in the lean cohort and increased in obese subjects. There was no overall postprandial change in total or HMW adiponectin in any group. Total adiponectin concentrations changed over time following the water control, and the response was significantly different in lean subjects compared with subjects with T2DM (P=0.04). CONCLUSIONS: No consistent significant postprandial inflammation, oxidative stress or regulation of adiponectin was observed in this study. Findings from the water control suggest differential basal regulation of total adiponectin in T2DM compared with lean controls.

Complications of perioperative warfarin therapy in total knee arthroplasty

Patients presenting for knee replacement on warfarin for medical reasons often require higher levels of anticoagulation peri-operatively than primary thromboprophylaxis and may require bridging therapy with heparin. We performed a retrospective case control study on 149 consecutive primary knee arthroplasty patients to investigate whether anti-coagulation affected short-term outcomes. Specific outcome measures indicated significant increases in prolonged wound drainage (26.8% of cases vs 7.3% of controls, p<0.001); superficial infection (16.8% vs 3.3%, p<0.001); deep infection (6.0% vs 0%, p<0.001); return-to-theatre for washout (4.7% vs 0.7%, p=0.004); and revision (4.7% vs 0.3%, p=0.001). Management of patients on long-term warfarin therapy following TKR is particularly challenging, as the surgeon must balance risk of thromboembolism against post-operative complications on an individual patient basis in order to optimise outcomes.

Anatomic fitting of total artificial hearts for in vivo evaluation

Successful anatomic fitting of a total artificial heart (TAH) is vital to achieve optimal pump hemodynamics after device implantation. Although many anatomic fitting studies have been completed in humans prior to clinical trials, few reports exist that detail the experience in animals for in vivo device evaluation. Optimal hemodynamics are crucial throughout the in vivo phase to direct design iterations and ultimately validate device performance prior to pivotal human trials. In vivo evaluation in a sheep model allows a realistically sized representation of a smaller patient, for which smaller third-generation TAHs have the potential to treat. Our study aimed to assess the anatomic fit of a single device rotary TAH in sheep prior to animal trials and to use the data to develop a threedimensional, computer-aided design (CAD)-operated anatomic fitting tool for future TAH development. Following excision of the native ventricles above the atrio-ventricular groove, a prototype TAH was inserted within the chest cavity of six sheep (28–40 kg).Adjustable rods representing inlet and outlet conduits were oriented toward the center of each atrial chamber and the great vessels, with conduit lengths and angles recorded for future analysis. A threedimensional, CAD-operated anatomic fitting tool was then developed, based on the results of this study, and used to determine the inflow and outflow conduit orientation of the TAH. The mean diameters of the sheep left atrium, right atrium, aorta, and pulmonary artery were 39, 33, 12, and 11 mm, respectively. The center-to-center distance and outer-edge-to-outer-edge distance between the atria, found to be 39 ± 9 mm and 72 ± 17 mm in this study, were identified as the most critical geometries for successful TAH connection. This geometric constraint restricts the maximum separation allowable between left and right inlet ports of a TAH to ensure successful alignment within the available atrial circumference.

Using technology to change adult sedentary behaviour, physical activity levels and total wellness

This thesis studied technology’s role in promoting and supporting active lifestyles through behavioural strategies to reduce sedentary time and increase physical activity. The five studies included (1) development of a self-report instrument quantifying daily sedentary behaviour and light-intensity physical activity; (2) establishment of instrument validity and reliability; (3) use of an online personal activity monitor to successfully reduce sedentary time and increase physical activity; (4) identification of positive differences in total wellness as related to high/low levels of sitting time combined with insufficient/sufficient physical activity; and (5) improvement of total wellness through positive changes in sedentary behaviour and physical activity.

Physical activity, sedentary behavior and total wellness changes among sedentary adults : a 4-week randomized controlled trial

Background The construct of total wellness includes a holistic approach to the body, mind and spirit components of life. While the health benefits of reducing sedentary behavior and increasing physical activity are well documented, little is known about the influence on total wellness of an internet-based physical activity monitor designed to help people to achieve higher physical activity levels. Purpose The purpose of this four-week, personal activity monitor-based intervention program was to reduce sedentary behavior and increase physical activity levels in daily living for sedentary adults and to determine if these changes would also be associated with improvement in total wellness. Methods Twenty-two men and 11 women (27 years ± 4.0) were randomly assigned to either an intervention (n = 18) or control group (n = 15). The intervention group interacted with an online personal activity monitor (Gruve Solution™) designed to reduce sedentary time and increase physical activity during activities of daily living. The control group did not interact with the monitor, as they were asked to follow their normal daily physical activities and sedentary behavior routines. The Wellness Evaluation of Lifestyle (WEL) inventory was used to assess total wellness. Sedentary time, light, walking, moderate and vigorous intensity physical activities were assessed for both intervention and control groups at baseline and at week-4 by the 7-day Sedentary and Light Intensity Physical Activity Log (7-day SLIPA Log) and the International Physical Activity Questionnaire (IPAQ). Results Significant increases in pre-post total wellness scores (from 64% ± 5.7 to 75% ± 8.5) (t (17) = -6.5, p < 0.001) were observed in the intervention group by the end of week four. Intervention participants decreased their sedentary time (21%, 2.3 hours/day) and increased their light (36.7%, 2.5 hours/day), walking (65%, 1057 MET-min/week), moderate (67%, 455 MET-min/week) and vigorous intensity (60%, 442 MET-min/week) physical activity (all p < 0.001). No significant differences for total wellness were observed between the groups at baseline and no pre-post significant differences were observed for any outcome variable in the control group. Conclusion Total wellness is improved when sedentary, but sufficiently physically active adults, reduce sedentary time and increase physical activity levels (i.e. light, walking, moderate and vigorous).

Quality demand in vaccination and how to improve service quality under Total Quality Control [论全面质量管理模式下预防接种工作的质量要求与改进对策]

Under the concept of Total Quality Control, based on their experience, the authors discussed potential demand for quality of immunization services and possible solutions to these demands. Abstract in Chinese 全面质量管理(total quality control,TQC)是在20世纪60年代由美国人V,Feigonbaum和J.unan先后提出的新的质量管理观念,众所周知的ISO9000族标准即建立在TQC理念下的质量管理标准,该标准已成为当今世界全球一致、最具权威的质量管理和质量保证的国际规则[1-2].21世纪是质量世纪,推行TQC,不断改进产品和服务质量,目前已成为我国各行各业在不断激烈的市场竞争下完善自我、保证生存和发展的重要手段.实施预防接种是预防和控制传染病,保护人群健康的重要措施,预防接种工作中,产品即预防接种服务,需方(顾客)为接受预防接种服务的广大人群,是产品的消费者.随社会的迅速发展,人们对健康需求的不断提高,对预防接种工作也提出了更高的质量要求.本文对TQC模式下顾客对预防接种服务的质量要求进行了综合分析,并对如何改进服务质量进行了初步探讨.

Design of physiological control and magnetic levitation systems for a total artificial heart

Total Artificial Hearts are mechanical pumps which can be used to replace the failing natural heart. This novel study developed a means of controlling a new design of pump to reproduce physiological flow bringing closer the realisation of a practical artificial heart. Using a mathematical model of the device, an optimisation algorithm was used to determine the best configuration for the magnetic levitation system of the pump. The prototype device was constructed and tested in a mock circulation loop. A physiological controller was designed to replicate the Frank-Starling like balancing behaviour of the natural heart. The device and controller provided sufficient support for a human patient while also demonstrating good response to various physiological conditions and events. This novel work brings the design of a practical artificial heart closer to realisation.

Increase in prevalence of obesity and diabetes and decrease in plasma cholesterol in a central Australian Aboriginal community

Objective: To document change in prevalence of obesity, diabetes and other cardiovascular diease (CVD) risk factors, and trends in dietary macronutrient intake, over an eight-year period in a rural Aboriginal community in central Australia. Design: Sequential cross-sectional community surveys in 1987, 1991 and 1995. Subjects: All adults (15 years and over) in the community were invited to participate. In 1987, 1991 and 1995, 335 (87% of eligible adults), 331 (76%) and 304 (68%), respectively, were surveyed. Main outcome measures: Body mass index and waist : hip ratio; blood glucose level and glucose tolerance; fasting total and high density lipoprotein (HDL) cholesterol and triglyceride levels; and apparent dietary intake (estimated by the store turnover method). Intervention: A community-based nutrition awareness and healthy lifestyle program, 1988-1990. Results: At the eight-year follow-up, the odds ratios (95% CIs) for CVD risk factors relative to baseline were obesity, 1.84 (1.28-2.66); diabetes, 1.83 (1.11-3.03); hypercholesterolaemia, 0.29 (0.20-0.42); and dyslipidaemia (high triglyceride plus low HDL cholesterol level), 4.54 (2.84-7.29). In younger women (15-24 years), there was a trebling in obesity prevalence and a four- to fivefold increase in diabetes prevalence. Store turnover data suggested a relative reduction in the consumption of refined carbohydrates and saturated fats. Conclusion: Interventions targeting nutritional factors alone are unlikely to greatly alter trends towards increasing prevalences of obesity and diabetes. In communities where healthy food choices are limited, the role of regular physical activity in improving metabolic fitness may also need to be emphasised.

Clinical and radiographic outcomes of acetabular impaction grafting without cage reinforcement for revision hip replacement : a minimum ten-year follow-up study

Impaction bone grafting for reconstitution of bone stock in revision hip surgery has been used for nearly 30 years. We used this technique, in combination with a cemented acetabular component, in the acetabula of 304 hips in 292 patients revised for aseptic loosening between 1995 and 2001. The only additional supports used were stainless steel meshes placed against the medial wall or laterally around the acetabular rim to contain the graft. All Paprosky grades of defect were included. Clinical and radiographic outcomes were collected in surviving patients at a minimum of 10 years following the index operation. Mean follow-up was 12.4 years (SD 1.5; range 10.0-16.0). Kaplan-Meier survivorship with revision for aseptic loosening as the endpoint was 85.9% (95% CI 81.0 to 90.8%) at 13.5 years. Clinical scores for pain relief remained satisfactory, and there was no difference in clinical scores between cups that appeared stable and those that appeared loose radiographically.

Total heat transfer measurements on a flight investigation of reentry environment model

Stagnation-point total heat transfer was measured on a 1:27.7 model of the Flight Investigation of Reentry Environment II flight vehicle. Experiments were performed in the X1 expansion tube at an equivalent flight velocity and static enthalpy of 11 km/s and 12.7 MJ/kg, respectively. Conditions were chosen to replicate the flight condition at a total flight time of 1639.5 s, where radiation contributed an estimated 17-36% of the total heat transfer. This contribution is theorized to reduce to <2% in the scaled experiments, and the heating environment on the test model was expected to be dominated by convection. A correlation between reported flight heating rates and expected experimental heating, referred to as the reduced flight value, was developed to predict the level of heating expected on the test model. At the given flow conditions, the reduced flight value was calculated to be 150 MW/m2. Average stagnation-point total heat transfer was measured to be 140 ± 7% W/m2, showing good agreement with the predicted value. Experimentally measured heat transfer was found to have good agreement of between 5 and 15% with a number of convective heating correlations, confirming that convection dominates the tunnel heating environment, and that useful experimental measurements could be made in weakly coupled radiating flow

Prevention of surgical site infection in total joint arthroplasty : an international tertiary care center survery

Background Prevention strategies are critical to reduce infection rates in total joint arthroplasty (TJA), but evidence-based consensus guidelines on prevention of surgical site infection (SSI) remain heterogeneous and do not necessarily represent this particular patient population. Questions/Purposes What infection prevention measures are recommended by consensus evidence-based guidelines for prevention of periprosthetic joint infection? How do these recommendations compare to expert consensus on infection prevention strategies from orthopedic surgeons from the largest international tertiary referral centers for TJA? Patients and Methods A review of consensus guidelines was undertaken as described by Merollini et al. Four clinical guidelines met inclusion criteria: Centers for Disease Control and Prevention's, British Orthopedic Association, National Institute of Clinical Excellence's, and National Health and Medical Research Council's (NHMRC). Twenty-eight recommendations from these guidelines were used to create an evidence-based survey of infection prevention strategies that was administered to 28 orthopedic surgeons from members of the International Society of Orthopedic Centers. The results between existing consensus guidelines and expert opinion were then compared. Results Recommended strategies in the guidelines such as prophylactic antibiotics, preoperative skin preparation of patients and staff, and sterile surgical attire were considered critically or significantly important by the surveyed surgeons. Additional strategies such as ultraclean air/laminar flow, antibiotic cement, wound irrigation, and preoperative blood glucose control were also considered highly important by surveyed surgeons, but were not recommended or not uniformly addressed in existing guidelines on SSI prevention. Conclusion Current evidence-based guidelines are incomplete and evidence should be updated specifically to address patient needs undergoing TJA.