Major Joint Research Articles

Speed-Related Energy Flow and Joint Function Change During Human Walking.

During human walking, mechanical energy transfers between segments via joints. Joint mechanics of the human body are coordinated with each other to adapt to speed change. The aim of this study is to analyze the functional behaviors of major joints during walking, and how joints and segments alter walking speed during different periods (collision, rebound, preload, and push-off) of stance phase. In this study, gait experiment was performed with three different self-selected speeds. Mechanical works of joints and segments were determined with collected data. Joint function indices were calculated based on net joint work. The results show that the primary functional behaviors of joints would not change with altering walking speed, but the function indices might be changed slightly (e.g., strut functions decrease with increasing walking speed). Waist acts as strut during stance phase and contributes to keep stability during collision when walking faster. Knee of stance leg does not contribute to altering walking speed. Hip and ankle absorb more mechanical energy to buffer the strike during collision with increasing walking speed. What is more, hip and ankle generate more energy during push-off with greater motion to push distal segments forward with increasing walking speed. Ankle also produces more mechanical energy during push-off to compensate the increased heel-strike collision of contralateral leg during faster walking. Thus, human may utilize the cooperation of hip and ankle during collision and push-off to alter walking speed. These findings indicate that speed change in walking leads to fundamental changes to joint mechanics.

Exploring “wear and tear” of joints and “muscle function” assumptions in skeletons with known occupation at death

Changes in the joints are believed to result from "wear and tear," a consequence of activity, as entheseal changes (EC) result from muscle use. However, clinical data showed that activity does not necessarily increase the likelihood of degenerative joint changes (DJC) and that exercise results in healthier joints. We tested whether individuals with continuous repetitive biomechanical efforts (Group 1) were more likely to exhibit EC and if occupations known to exert strenuous but discontinued efforts (Group 2) would more likely cause DJC. Eighty-nine males with known occupations from Portuguese identified collections were used: shoemakers and carpenters (Group 1), workers (Group 2), and civil servants, and shop assistants as a control group. Major upper and lower limb joints and entheses sites were used. DJC and EC were tested between occupations - while controlling for age (overall approach) - and within occupation (occupation-specific approach). The overall approach showed that age - as a covariant - had a significant impact on DJC and EC development (p< 0.05), with occupation being non-significant (p> 0.05) despite the variability in the mean-values of lesions. The occupation-specific approach showed a significant variability of DJC and EC correlations, within and between occupations, with no clear trend of DJC and EC development according to occupation. The results showed that exploring overall patterns might conceal occupation-specific joint and muscle use, emphasizing age as a major contributor of changes; and that the occupation-specific approach highlighted particular aspects associated with occupations, allowing for a more informative assessment of strenuous repetitive or discontinuous activity-related technical gestures and their impact on skeletal biology.

STUDY OF EFFICACY OF PIPPALI VARDHAMANAK FOR TREATMENT OF VATARAKTA WITH SPECIAL REFERENCE TO GOUT

Introduction- Vatarakta is an illness where both Vata and Rakta are afflicted by distinct etiological factors. Vata- rakta is also possible when Gati of Vata is hindered by morbid Kapha Dosha. In modern science Gout shows sim- ilar characteristics like Vatarakta. It is occurred by accumulation of urate crystals in tissues. It starts from small joints to major joints. Pippali Vardhamanak is advised by Aacharya Sushruta for treatment of Vatarakta and other Vata-Kaphaj Vyadhi. In this VardhamanMatra of Pippali is given as said by Aacharya. Pippali has anti- inflammatory, rejuvenating properties and also act as Vata-Kapha Shamak. Aim- To evaluate therapeutic efficacy of Pippali Vardhamanak in Vatarakta with special reference to Gout. Objectives- To study therapeutic efficacy of Pippali Vardhamanak to reduce the symptoms of Vatarakta with special reference to Gout. Materials and Methods- The present study was conducted in 30 patients having clas- sical symptoms of Vatarakta. The patients were given Pippali Vardhamanak for 15 days. Pippali has Katu Ras, Laghu-Teekshna Snigdha Guna, Madhur Vipaka and Anshna Veerya, due to these proper- ties it acts as Kaphashamak, Vatashamak and Raktashama, Strotoshodhana. Piperine inhibits monosodium urate crystals. Conclusion- Pippali Vardhamanak gives significant relief in Vatarakta with special reference to Gout. Keywords: Vatarakta, Gout, Pippali, Pippali Vardhamanak

Current favourable 10-year outcome of patients with early rheumatoid arthritis: data from the ESPOIR cohort.

To report the 10-year outcome of an inception cohort of patients with early rheumatoid arthritis (RA), the ESPOIR cohort, and predictors of outcome. From 2003 to 2005, 813 patients were included if they had early arthritis (<6 months) with a high probability of RA and had never been prescribed DMARDs. Multivariate analysis was used to evaluate predictors of outcome. In total, 521 (64.1%) RA patients were followed up for 10 years; 35 (4.3%) died, which appears to be similar to the French general population. Overall, 480 (92.1%) patients received a DMARD; 174 (33.4%) received at least one biologic DMARD, 13.6% within 2 years. At year 10, 273 (52.4%) patients were in DAS28 remission, 40.1% in sustained remission, 14.1% in drug-free remission, 39.7% in CDAI remission. Half of the patients achieved a health assessment questionnaire-disability index (HAQ-DI) < 0.5. SF-36 physical component and pain were well controlled. Structural progression was weak, with a mean change from baseline in modified Sharp score of 11.0 (17.9). Only 34 (6.5%) patients required major joint surgery. A substantial number of patients showed new comorbidities over 10 years. Positivity for anti-citrullinated peptides antibodies (ACPA) was confirmed as a robust predictor of long-term outcome. We report a very mild 10-year outcome of a large cohort of patients with early RA diagnosed in the early 2000s, which was much better than results for a previous cohort of patients who were recruited in 1993. This current favourable outcome may be related to more intensive care for real-life patients.

Predictors of Success in the Bundled Payments for Care Improvement Program.

Hospitals participating in Medicare's Bundled Payments for Care Improvement (BPCI) program were incented to reduce Medicare payments for episodes of care. To identify factors that influenced whether or not hospitals were able to save in the BPCI program, how the cost of different services changed to produce those savings, and if "savers" had lower or decreased quality of care. Retrospective cohort study. BPCI-participating hospitals. We designated hospitals that met the program goal of decreasing costs by at least 2% from baseline in average Medicare payments per 90-day episode as "savers." We used regression models to determine condition-level, patient-level, hospital-level, and market-level characteristics associated with savings. In total, 421 hospitals participated in BPCI, resulting in 2974 hospital-condition combinations. Major joint replacement of the lower extremity had the highest proportion of savers (77.6%, average change in payments -$2235) and complex non-cervical spinal fusion had the lowest (22.2%, average change +$8106). Medical conditions had a higher proportion of savers than surgical conditions (11% more likely to save, P=0.001). Conditions that were mostly urgent/emergent had a higher proportion of savers than conditions that were mostly elective (6% more likely to save, P=0.007). Having higher than median costs at baseline was associated with saving (OR: 3.02, P<0.001). Hospitals with more complex patients were less likely to save (OR: 0.77, P=0.003). Savings occurred across both inpatient and post-acute care, and there were no decrements in clinical care associated with being a saver. Certain conditions may be more amenable than others to saving under bundled payments, and hospitals with high costs at baseline may perform well under programs which use hospitals' own baseline costs to set targets. Findings may have implications for the BPCI-Advanced program and for policymakers seeking to use payment models to drive improvements in care.

Febuxostat as a renoprotective agent for treatment of hyperuricaemia: a meta-analysis of randomised controlled trials.

The objective of this meta-analysis of randomised controlled clinical trials (RCT) was to evaluate the effects of febuxostat on kidney function in patients with hyperuricaemia. Febuxostat is a xanthine oxidase inhibitor that decreases uric acid production. Recent studies suggested the renoprotective effect of febuxostat among hyperuricaemia patients. The aim of this study was to evaluate the effects of febuxostat on kidney function in patients with hyperuricaemia. We conducted electronic searches in PubMed, Embase and Cochrane Central Register of Controlled Trials from January 1960 to July 2019 to identify RCT that examined the effects of febuxostat in adult patients with hyperuricaemia on serum creatinine, estimated glomerular filtration rate (eGFR), albuminuria, blood pressure parameters, major cardiovascular events, diarrhoea, joint pain, stroke and arrhythmia. Nine RCT with 2141 participants were included in this meta-analysis. Compared to placebo, the febuxostat group showed a higher eGFR at 6 months with a weighted mean difference (WMD) of 2.86 mL/min/1.73 m2 (P < 0.001), as well as the end of studies (eGFR WMD 2.69 mL/min/1.73 m2 , P < 0.001). There was also lower serum creatinine (SrCr WMD = -0.04 mg/dL, P < 0.001), reduction in systolic blood pressure (SBP WMD = -1.18 mmHg, P < 0.001) and diastolic blood pressure (DBP WMD = -1.14 mmHg, P = 0.04). There was no statistical difference between febuxostat and placebo in major cardiovascular events, diarrhoea, joint symptoms, stroke events and arrhythmia. Subgroup analysis among chronic kidney disease showed the febuxostat group had higher eGFR than the placebo group (eGFR WMD=2.69 mL/min/1.73 m2 , P < 0.001). Treating hyperuricaemia with febuxostat may slow the progression of chronic kidney disease irrespective of baseline renal function without significantly associated increased risks of major cardiovascular events, diarrhoea, joint symptoms, arrhythmia and stroke, compared to placebo.

Synoviolin is not a pathogenic factor for auto-inflammatory diseases

Auto-inflammatory syndromes are rare diseases characterized by arthritis and joint destruction, symptoms similar to but distinct from rheumatoid arthritis (RA). Therapeutic targets have not been well characterized for auto-inflammatory syndromes, although the E3 ligase Synoviolin was previously shown to be a novel therapeutic target for RA. Here, we show that Synoviolin loss has little impact on a model of auto-inflammatory diseases. We previously established such a model, the hIL-1 cTg mouse, in which IL-1 signaling was constitutively activated, and animals exhibit symptoms recapitulating auto-inflammatory syndromes such as major joint dominant arthritis. Here, we crossed hIL-1 cTg with Synoviolin flox’d mice to yield hIL-1 cTg/Synoviolin cKO mice. Synoviolin gene expression was ablated in adult hIL-1 cTg/Synoviolin cKO mice by injection of pIpC to activate Mx1 promoter-driven Cre recombinase. However, symptoms seen in hIL-1 cTg mice such as arthritis and joint destruction were not alleviated by targeting Synoviolin, ruling out Synoviolin as a therapeutic target for auto-inflammatory disease. Our results indicate that although similar, RA and auto-inflammatory diseases are different diseases, and treatment strategies should differ accordingly.

Impact of Advanced Practice Provider Integration into Multispecialty Group Practices on Outcomes Following Major Surgery.

Background. While advanced practice providers (APPs) are increasingly integrated into care delivery models, little is known about their impact in surgical settings. Given that many patients undergo surgery in multispecialty group practice settings, we examined the impact of APP integration into such practices on outcomes after major surgery. Methods. We used a 20% sample of national Medicare claims to identify 190101 patients who underwent 1 of 4 major surgeries (coronary artery bypass graft [CABG], colectomy, major joint replacement, and cystectomy) at multispecialty group practices from 2010 through 2016. The level of APP integration was measured as the ratio of APPs to physicians within each practice. Rates of mortality, major complications, and readmission within 30days of discharge after the index surgery were compared between patients treated in practices with low, medium, and high levels of APP integration using multivariable regression analysis. Results. Relative to patients treated in practices with low APP integration, those treated in practices with medium or high APP integration had significantly lower rates of mortality (2.4% [low integration] vs 1.9% [medium integration] vs 2.0% [high integration]; P < .01), major complications (34.1% [low] vs 31.2% [medium] vs 30.2% [high]; P < .01), and readmission (11.7% [low] vs 10.6% [medium] vs 10.1% [high]; P < .01). This relationship was consistent for virtually all outcomes when considering each surgery type individually. Conclusions. Integration of APPs into multispecialty group practices was associated with improved postoperative outcomes after major surgery. Future research should identify the mechanisms by which APPs improve outcomes to inform optimal utilization.

Opposing Trends in Total Knee and Hip Arthroplasties for Patients With Rheumatoid Arthritis vs. the General Population-A 14-Year Retrospective Study in Taiwan.

Objective: To determine the trend of incidence rate of total knee arthroplasty (TKA), total hip arthroplasty (THA), and TKA or THA (major joint arthroplasty, MJA) among rheumatoid arthritis (RA) population and compared them with general population (GP) in Taiwan.Methods: Incidence rates and trends of TKA, THA, and MJA were determined over a 14-year period (2000–2013) among RA patients and compared them with GP. RA of patients was diagnosed based on the ACR 1987 criteria and extracted from GP. Subanalyses of incidences of TKA, THA, and MJA by year, 10-year age group, and gender were further conducted for demographic analysis. Patient profiles were extracted from the National Health Insurance Research Database (NHIRD) for interrupted time-series analysis and cohort studies.Results: Patients enrolled were 168,457 receiving TKA, 64,543 receiving THA, and 228,191 receiving MJA surgery. Incidences of TKA, THA, and MJA in RA patients were significantly lower by 49.0, 41.5, and 41.0% compared with concomitantly rises in GP by 131.0, 25.1, and 90.0% among the GP during the study period. The dominant age population for TKA, THA, and MJA were those aged 70–79 years in both GP and RA groups.Conclusions: We found an opposing trend in incidence of TKA, THA, and MJA between RA patients and the GP. The possible influence of pharmacological treatment is implicated for the lower incidence rates of TKA, THA, and MJA surgeries among RA patients.

3'-Sialyllactose Protects SW1353 Chondrocytic Cells From Interleukin-1β-Induced Oxidative Stress and Inflammation.

Osteoarthritis (OA) is a major degenerative joint disease. Oxidative stress and inflammation play key roles in the pathogenesis of OA. 3′-Sialyllactose (3′-SL) is derived from human milk and is known to regulate a variety of biological functions related to immune homeostasis. This study aimed to investigate the therapeutic mechanisms of 3′-SL in interleukin-1β (IL-1β)-treated SW1353 chondrocytic cells. 3′-SL potently suppressed IL-1β-induced oxidative stress by increasing the levels of enzymatic antioxidants. 3′-SL significantly reversed the IL-1β mediated expression levels of reactive oxygen species in IL-1β-stimulated chondrocytic cells. In addition, 3′-SL could reverse the increased levels of inflammatory markers such as nitrite, prostaglandin E2, inducible nitric oxide synthase, cyclooxygenase-2, IL-1β, and IL-6 in IL-1β-stimulated chondrocytic cells. Moreover, 3′-SL significantly inhibited the apoptotic process, as indicated by the downregulation of the pro-apoptotic protein Bax, upregulation of the anti-apoptotic protein Bcl-2 expression, and significant reduction in the number of TUNEL-positive cells in the IL-1β-treated chondrocytic cells. Furthermore, 3′-SL reversed cartilage destruction by decreasing the release of matrix metalloproteinases (MMP), such as MMP1, MMP3, and MMP13. In contrast, 3′-SL significantly increased the expression levels of matrix synthesis proteins, such as collagen II and aggrecan, in IL-1β-treated chondrocytic cells. 3′-SL dramatically suppressed the activation of mitogen-activated protein kinases (MAPK) and phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways, which are related to the pathogenesis of OA. Taken together, our data suggest that 3′-SL alleviates IL-1β-induced OA pathogenesis via inhibition of activated MAPK and PI3K/AKT/NF-κB signaling cascades with the downregulation of oxidative stress and inflammation. Therefore, 3′-SL has the potential to be used as a natural compound for OA therapy owing to its ability to activate the antioxidant defense system and suppress inflammatory responses.

Skeletal remains of five blue foxes (Vulpes lagopus) from St. Paul Island, Pribilof Islands, Alaska: A view of differential diagnosis

AbstractWe evaluated skeletal remains of five blue arctic foxes from St. Paul Island, Pribilof Islands, Alaska. All five had been found dead. Cleared skeletal remains were examined visually and by magnification or backlighting where necessary. Pathological features were described and photographed. Results suggested that more than one disorder may have occurred in these foxes, with primary observations being demineralizing and/or proliferation. Most prominently affected were the skull, maxillae, mandibles, pelvis, long bones, and major diarthrodial joints. It was critically important to recognize certain other pathological features that can be observed on many or most fox skeletal remains but are unlikely to relate to conditions that demineralize bone or cause overt bone loss, multifocal loss of joint architecture, or severe multifocal periarticular boney proliferation. The differential diagnosis of canid skeletal demineralizing includes primary and secondary (nutritional or renal) hyperparathyroidism. Boney proliferation has a wider differential spectrum that can include hypervitaminosis A, osteomyelitis, abnormalities related to inbreeding, and environmental toxicosis. In our view, given the lack of soft tissue for histological evaluation and biochemical analysis, a well‐considered differential diagnosis is an appropriate scientific point of conclusion. In the many similar circumstances that would require additional studies for valid definitive diagnosis during life, investigators should review relevant literature and consider the value of well‐structured differential diagnosis, as contrasted with more speculative definitive diagnoses.

Development of a new genetic model to investigate the role of the chromatin modifying enzyme LSD1 during osteoarthritis

Purpose: Osteoarthritis (OA) is a degenerative pathology of the joint involving the articular cartilage. During ageing, that tissue becomes progressively eroded without efficient spontaneous repair. This is the major chronic joint disease worldwide and a major cause of invalidity but there is still no curative treatment. The causes remain unclear but the role of the chondrocytes, where many gene dysregulations occur, is crucial. There is now growing evidence that epigenetic signaling is a new level of gene regulation important for the homeostasis of articular cartilage.

103 A Retrospective Review of the Utilization of Burn Admission Criteria

Abstract Introduction Evidence-based criteria for burn patient admission are poorly defined. Attempts have been made by commercial entities to align payors and providers with evidence-based admission criteria to optimize resource use. However, these admission criteria have not be examined critically to see if they are appropriate and effective. We developed an admission criteria algorithm based on these existing standards and have utilized it for nearly 18 months. The purpose of this study is to retrospectively review this algorithm with respect to inpatient needs and outcome to assess its effectiveness. Methods A retrospective chart review of patients admitted the burn center over a 1-year period was performed. Incomplete datasets were excluded. Patients were grouped by TBSA, &amp;lt; 10%, 10–20% and &amp;gt; 20%. Appropriateness of admission was measured used length of stay (LOS) as surrogate marker, hospitalizations of &amp;lt; 3 days, unless deceased, were deemed inappropriate (IAP) and 3 days or more as appropriate (AP). Results There were complete datasets for 530 patients, &amp;lt; 10% (n=423), 10–20% (n= 72), &amp;gt;20% (n=35). There were no significant differences in age, gender, or payor sources between the groups. Patients with larger TBSA burns were more likely to have suffered a flame/flash injury. All patients in the two larger TBSA groups met admission criteria per algorithm. All IAP were in the &amp;lt; 10% group. When compared to AP, IAP were younger, 31.6 vs. 44.0 years (p&amp;lt; .0001), had smaller TBSA injuries 2.8% vs. 3.5% (p=.0045), had fewer clinical findings 1.4 vs 1.8 (p&amp;lt; .0001), fewer interventions 1.8 vs 2.6 (p&amp;lt; .0001) but were more likely to have suffered burns to the head 30% vs 13% (&amp;lt; .00001) and neck 9% vs 3% (=.0164). AP patients were more likely to have suffered contact burns 27% vs. 17% (p=.0323), full-thickness injuries 39% vs 14% (p&amp;lt; .0001), involvement of a major joint 42% vs 29% (p=.0085), combined burn and trauma 3% vs. 0% (p=.0444) and burns to the buttocks 7% vs 2% (p=.0357). AP patients were also more likely to require IV analgesia 82% vs 71% (p=.0107) and evaluated as likely needing surgery 82% vs 15% (p&amp;lt; .00001). Conclusions The admission criteria algorithm performed perfectly in patients with a ≥ 10% TBSA injury. For patients with burn &amp;lt; 10% TBSA the algorithm was not followed as closely leading to some inappropriate admissions. Patients with smaller burns admitted appropriately were more likely to have full thickness burns, contact burns, burns over joints and to require surgery. The algorithm was highly accurate in patients with large burns, however additional refinement is needed for those patients with smaller burn injuries.

Recent Progress in Cartilage Lubrication.

Healthy articular cartilage, covering the ends of bones in major joints suchas hips and knees, presents the most efficiently-lubricated surface known in nature, with friction coefficients as low as 0.001 up to physiologically high pressures. Such low friction is indeed essential for its well-being. It minimizes wear-and-tear and hence the cartilage degradation associated with osteoarthritis, the most common joint disease, and, by reducing shear stress on the mechanotransductive, cartilage-embedded chondrocytes (the only cell type in the cartilage), it regulates their function to maintain homeostasis. Understanding the origins of such low friction of the articular cartilage, therefore, is of major importance in order to alleviate disease symptoms, and slow or even reverse its breakdown. This progress report considers the relation between frictional behavior and the cellular mechanical environment in the cartilage, then reviews the mechanism of lubrication in the joints, in particular focusing on boundary lubrication. Following recent advances based on hydration lubrication, a proposed synergy between different molecular components of the synovial joints, acting together in enabling the low friction, has been proposed. Additionally, recent development of natural and bio-inspired lubricants is reviewed.

A Novel Technique for Trochanteric Region Soft-Tissue Reconstruction

Aims: Due to the complex anatomical structure of the trochanteric region, the options for reconstruction are relatively limited. This study aims to present a unique reconstruction of trochanter defects using a coxal region perforator flap and geometric planning to standardize the flaps. Subjects and Methods: Twelve patients with trochanteric defects that had been repaired with coxal region perforator flap following tumor excision between June 2016 and January 2019 were included in this study. The patients were aged between 20 and 68 years. Patients were evaluated with regard to age, gender, etiology, defect side and size, flap size, number of perforators, and complications. Results: Two patients were operated on for squamous cell carcinoma, one for Marjolin's ulcer, two for malignant melanoma, two for malignant fibrous histiocytoma, and five for dermatofibrosarcoma. Defect sizes ranged between 8 cm × 7 cm and 12 × 10 cm. The smallest flap size was 13 cm × 7 cm and the largest flap size was 21 cm × 10 cm. Nine flaps were raised from the single perforator, and three flaps were raised from two perforators. Venous congestion was seen in one patient postoperatively. There was no flap loss, infection, hematoma, suture detachment, and limitation of hip and knee movements in the patients. Conclusions: The pedicled perforator flaps are elevated over the major perforators located close to the defect in many parts of the body. Thus, low surgical morbidity is achieved, and surgery time is decreased. Furthermore, as in this study, preserving the muscles and preventing the functional deficits in the movement hip joint the body's major joint of the body, reveal the importance of using coxal region perforator flaps for reconstruction in ambulatory patients.

Effects of Advanced Practice Providers on Single-specialty Surgical Practice.

To assess the effects of adding advanced practice providers to surgical practices on surgical complications, readmissions, mortality, episode spending, length of stay, and access to care. There has been substantial growth in the number of nurse practitioners and physician assistants (ie, advanced practice providers) in the United States. The extent to which advanced practice providers have been integrated into surgical practice, and their impact on surgical outcomes and access is unclear. Using a 20% sample of national Medicare claims, we performed a retrospective cohort study of fee-for-service beneficiaries undergoing one of 4 major procedures (coronary artery bypass graft, colectomy, major joint replacement, and cystectomy) between 2010 and 2016. We limited our study population for each procedure to patients treated by single-specialty surgical groups to ensure that the advanced practice providers have direct interactions with its surgeons and patients. All outcomes were measured at the practice level for the year before and the year after the addition of the first advanced practice provider. Outcomes included: complications, readmission, mortality, episode payments, length of stay. Models were adjusted for age, race, sex, comorbidity, socioeconomic class and procedure type. Secondary outcome: practice-level office visits by surgical group type. The number of advanced practice providers increased by 13%, from 6713 to 7596 between 2010 and 2016. The largest relative increases occurred in general (46.9%) and urologic (27.6%) surgical practices. The year after an advanced practice provider was added to a surgical practice, the odds of complications were 17% and 16% lower at 30- and 90-days postprocedure, respectively. Additionally, 90-day readmissions were 18% less likely and length of stay was 0.33 days shorter (a 7.1% reduction). Average 30-day and90-day episode spending was $1294.73 and $1427.76 lower, respectively ( P < 0.001). General surgical, orthopedic, and urology practices realized increases of 49.0 (95% CI 13.5-84.5), 112.0 (95% CI 83.0-140.5), and 205.0 (95% CI 117.5-292.0) in-office visits per surgeon, respectively. The addition of advanced practice providers to single-specialty surgical groups is associated with improvements in surgical outcomes and access. Future work should clarify the mechanisms by which advanced practice providers within surgical practices contribute to health outcomes to identify best practices for deployment.

Open-Source Portable Device for the Determination of Fluoride in Drinking Water.

The prolonged exposure to fluorides results in the development of several diseases, from dental fluorosis to crippling deformities of the spine and major joints. The population exposed to high fluoride concentration is located in developing countries where the assurance of water quality is difficult to perform. Addressing this challenge, an open-source system for the determination of fluoride in natural water was developed using the equilibrium between the red Fe-SCN complex and the colorless Fe-F. The reaction develops in cotton substrates to reduce the manipulation of liquid reagents and reduce the errors by nontrained operators. The system was optimized by image analysis and implemented in an open-source Arduino-based device and data was acquired through the serial port of a cell phone, which is also used as a power source, avoiding the use of a battery and reducing production costs. The device showed a detection limit of 0.7 mg L-1 and a linear range of up to 8 mg L-1. This extended detection limit makes the device useful for the application in regions where the fluoride concentration in drinking water is far higher than the United Nations limit (1.5 mg L-1), e.g., the United Republic of Tanzania, where the upper limit of F- was extended to 4 mg L-1 or in USA, where the Environmental Protection Agency established the Maximum Contaminant Level of F- in drinking water at 4 mg L-1. The method was tested with natural waters from the Arusha region in the northeast of Tanzania and validated against the results from ion chromatography showing a good correlation. The developed device exhibits chemical stability of 5 days, allowing it to be manufactured and distributed in local areas and, also, modified according to the requirements of the water composition due to Industry 4.0 concepts used in the design.

Aktueller Stand virtueller Simulatoren für die chirurgische Ausbildung in Orthopädie und Unfallchirurgie

Die praktische chirurgische Ausbildung wird in der Orthopädie und Unfallchirurgie durch den steigenden Kostendruck in den Kliniken sowie die Verlagerung vieler Operationen in den ambulanten Bereich immer schwieriger. Das betrifft besonders die Arthroskopie, die zudem hohe Anforderungen an die Fähigkeiten des Operateurs stellt. In den letzten 20 Jahren wurden daher zahlreiche Arthroskopiesimulatoren entwickelt. Dabei handelt es sich um virtuelle Desktopsysteme, die mit einem Gelenksimulator gekoppelt sind und eine taktile Rückkopplung erlauben. Auf diese Weise können arthroskopische Basisfähigkeiten (z. B. Triangulation) oder auch arthroskopische Operationen (z. B. partielle Meniskektomie) trainiert werden. Die Systeme ermöglichen eine Erfolgskontrolle durch die Erfassung verschiedener Parameter (Operationszeit, Kamera‑/Instrumentenpfadlänge, Knorpelberührungen). Es existieren bereits Simulatoren für alle großen Gelenke. Mittlerweile liegen Daten zur Augenscheinvalidität, Inhaltsvalidität, Konstruktvalidität und zur Transfervalidität dieser Systeme vor. Die erlernten Fähigkeiten lassen sich daher auf den Erfolg im Operationssaal übertragen. Ungelöst ist bisher die Kosteneffizienz dieser Systeme. Von den Desktop-Gelenkmodell-Systemen müssen immersive Virtual-Reality(VR)-Systeme unter Verwendung von 3‑D-Brillen und taktilen Handsensoren abgegrenzt werden. Der Teilnehmende tritt der Applikation dabei meist als Avatar bei. Daher eignen sich immersive Systeme besonders zur Simulation offener Operationen (z. B. Hüftendoprothetik). Erste Studien haben auch für den Einsatz der immersiven virtuellen Realität Evidenz für Inhalts‑, Konstrukt- und Transfervalidität beim Training verschiedener offener Operationen gezeigt. Hier sind in Zukunft weitere Entwicklungen zu erwarten.

The Effect of Fluid-Saturation on Mechanical Behavior of the Coating–Substrate System under Contact Loading

The influence of the fluid saturation of a porous coating on the mechanical properties of the coating and the entire coating-substrate system is addressed. An important practical application is targeted as the wear-resistant coatings of endoprostheses of major human joints. Based on the method of movable cellular automata, a 3D-model of the mechanical behavior of a porous fluid-saturated coating on a titanium substrate is constructed. Using this model, the influence of fluid-saturation of the surface-layer of a ceramic coating on the mechanical characteristics of the coating-substrate system is studied numerically. The simulation results demonstrate that the presence of fluid in a thin surface layer of the coating can strongly affect the mechanical response of the entire coating-substrate system under sufficiently high rates of the local contact loading. In particular, the calculations without taking the fluid into account give overestimated values of strength and hardness of the coated materials under the wetting conditions. A simulation of scratching demonstrates that the material with a fluid-saturated surface layer is more stable to wear.

Association between pre-operative anxiety and/or depression and outcomes following total hip or knee arthroplasty.

While elective primary total hip (THA) and knee (TKA) arthroplasty are effective procedures for addressing the symptoms associated with advanced osteoarthritis, there is evidence to suggest that patient anxiety and depression are linked to poorer outcomes following surgery. A secondary analysis of prospectively-collected data of people undergoing primary elective THA or TKA for osteoarthritis across 19 hospitals was performed. We assessed outcomes at 1 year post-surgery for people with and without medically treated anxiety and/or depression at the time of surgery (A/D and no-A/D). We used unadjusted and adjusted analyses to compare improvement in Oxford Hip or Knee Scores, the incidences of major post-operative complications, satisfaction and index joint improvement by A/D status. 15.2% (254/1669) of patients were identified with anxiety and/or depression at time of surgery. In the unadjusted analysis, the A/D group had greater mean Oxford score improvement by 2.1 points (95% CI 0.8 to 3.4, p = 0.001), increased major complications (OR 1.39, 95% CI 1.05 to 1.85, p = 0.02), were less likely to report a "much better" global improvement for index joint (OR 0.56, 95% CI 0.38 to 0.83, p = 0.003), and there was no statistically significant difference in the rate of satisfaction with the results of surgery (OR 0.64, 95% CI 0.37 to 1.10, p = 0.10). The adjusted analysis found no significant associations between A/D vs. no-A/D and any of the reported outcomes. After adjustment for confounding variables, people with anxiety and/or depression pre-operatively, compared to those without, have similar outcomes following hip or knee arthroplasty.