Predictive value of the Global Activity Limitation Indicator (GALI) on all-cause mortality

OBJECTIVES

The Global Activity Limitation Indicator (GALI) is an instrument that measures long-term overall disability. The objective of this study was to evaluate GALI's predictive value on mortality while examining variations according to sex, age, and educational level.

STUDY DESIGN

Longitudinal study.

METHODS

This longitudinal study was based on 42,991 individuals aged ≥15 years who participated in the 2011-2012 National Health Survey and the 2014 European Health Survey in Spain. These records were linked to mortality data up to December 2021. GALI assessed self-reported functional limitation in the past 6 months and classified individuals into three categories: severely limited, limited but not severely, and not limited. Incidence rate ratios (IRR) were calculated using Poisson regression models, adjusting for sociodemographic, lifestyle, and health status variables.

RESULTS

Compared to individuals with no limitations, those with non-severe limitations had an IRR for mortality of 1.27 (95% CI: 1.16-1.38), and 2.04 (95% CI: 1.81-2.31) in those with severe limitations. Women with severe limitations exhibited a higher IRR (2.32; 95% CI: 1.98-2.71) compared to men (1.73; 95% CI: 1.45-2.08) (P for interaction = 0.005). Individuals <65 years with severe limitations showed a greater association (2.22; 95% CI: 1.58-3.10) than those ≥65 (1.49; 95% CI: 1.32-1.69) (P for interaction <0.001). Among individuals with lower educational attainment, the IRR was 2.08 (95% CI: 1.83-2.37), and 1.87 (95% CI: 1.37-2.56) for the higher education group (P for interaction = 0.017).

CONCLUSIONS

GALI is a robust predictor of all-cause mortality in the general population and subgroups. The association is stronger in women, individuals <65 years, and those with lower educational levels.

Venous Thromboembolism Prophylaxis in Foot and Ankle Surgery: A Worldwide Survey

Current recommendations on thromboprophylaxis for foot and ankle (FA) surgery are often inconsistent and generally based on weak evidence. The aim of this survey study was to evaluate the current practice among orthopedic surgeons regarding venous thromboembolism (VTE) prophylaxis following FA surgery. From February 2019 to March 2020, an online questionnaire was sent by e-mail to orthopedic societies across the world. The questionnaire was hosted by the International Society of Thrombosis and Haemostais RedCAP platform. Topics of interest were VTE rates following FA surgery, duration and type of thromboprophylaxis, bleeding complications, VTE risk factors for prophylaxis and use of risk assessment. A total of 693 FA orthopedic surgeons from all continents completed the survey of whom 392 (57%) performed more than 200 FA procedures per year. A total of 669/693 (97%) respondents stated that thromboprophylaxis is necessary in FA surgeries. When thromboprophylaxis was prescribed, half of surgeons prescribed it for the duration of immobilization. Acetylsalicylic acid, low molecular weight heparin and direct-oral anticoagulants were, in this order, the preferred choice. Acetylsalicylic acid and low molecular weight heparin were predominantly prescribed in North America and Europe, respectively. Previous deep vein thrombosis, immobility, obesity and inherited thrombophilia were considered the main risk factors indicative of thromboprophylaxis use. In this survey, most surgeons agree that thromboprophylaxis is indicated for FA surgery, but the prescription, type and duration of prophylaxis differs greatly with a large intercontinental discrepancy. These survey results could be a foundation for developing uniform guidelines to optimize thromboprophylactic strategies in FA procedures around the world.

The Lucy Thermal Emission Spectrometer (L'TES) Instrument

The Lucy Thermal Emission Spectrometer (L'TES) will provide remote measurements of the thermophysical properties of the Trojan asteroids studied by the Lucy mission. L'TES is build-to-print hardware copy of the OTES instrument flown on OSIRIS-REx. It is a Fourier Transform spectrometer covering the spectral range 5.71-100 μm (1750-100 cm-1) with spectral sampling intervals of 8.64, 17.3, and 34.6 cm-1 and a 7.3-mrad field of view. The L'TES telescope is a 15.2-cm diameter Cassegrain telescope that feeds a flat-plate Michelson moving mirror mounted on a linear voice-coil motor assembly to a single uncooled deuterated l-alanine doped triglycine sulfate (DLATGS) pyroelectric detector. A significant firmware change from OTES is the ability to acquire interferograms of different length and spectral resolution with acquisition times of 0.5, 1, and 2 seconds. A single ∼0.851 μm laser diode is used in a metrology interferometer to provide precise moving mirror control and IR sampling at 772 Hz. The beamsplitter is a 38-mm diameter, 1-mm thick chemical vapor deposited diamond with an antireflection microstructure to minimize surface reflection. An internal calibration cone blackbody target, together with observations of space, provides radiometric calibration. The radiometric precision in a single spectrum is ≤2.2 × 10-8 W cm-2 sr-1 /cm-1 between 300 and 1350 cm-1. The absolute temperature error is <2 K for scene temperatures >75 K. The overall L'TES envelope size is 37.6 × 29.0 × 30.4 cm, and the mass is 6.47 kg. The power consumption is 12.6 W average. L'TES was developed by Arizona State University with AZ Space Technologies developing the electronics. L'TES was integrated, tested, and radiometrically calibrated on the Arizona State University campus in Tempe, AZ. Initial data from space have verified the instrument's radiometric and spatial performance.

Generation of LexA enhancer-trap lines in Drosophila by an international scholastic network

Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic, and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II, and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in CNS neurons known to produce and secrete insulin, an essential regulator of growth, development, and metabolism. Fly lines described here were generated and characterized through studies by students and teachers in an international network of genetics classes at public, independent high schools, and universities serving a diversity of students, including those underrepresented in science. Thus, a unique partnership between secondary schools and university-based programs has produced and characterized novel resources in Drosophila, establishing instructional paradigms devoted to unscripted experimental science.

Biological activities of 4H-thiochromen-4-one 1,1-dioxide derivatives against tropical disease parasites: A target-based drug design approach

A promising strategy for developing novel therapies against tropical diseases, including malaria, leishmaniasis, and trypanosomiasis, is to detect biological targets such as trypanothione reductase, a vital parasite enzyme that regulates oxidative stress. This enzyme is highly selective and conserved in the Trypanosotidae family and has an ortholog in the Plasmodium genus. Previous studies have established that an isosteric replacement of naphthoquinone's carbonyl group with a sulfone group leads to compounds with high bioactivity and selectivity (half-maximal inhibitory concentration = 3 μM against intracellular amastigotes of L. panamensis, selectivity index = 153 over monocytes U-937). In this study, we analyzed the reactive oxygen species (ROS) levels of parasites through indirect measurements of the tryparedoxin system after treatment with these isosteric compounds. This strategy proved that a significant increase in the ROS levels and strong mitochondrial perturbation led to the death of parasites due to cell homeostatic imbalance, confirming the compounds' effectiveness in disrupting this important metabolic pathway. To improve understanding of the parasite-molecule interaction, 27 new compounds were synthesized and assessed against parasites of the three principal tropical diseases (malaria, leishmaniasis, and trypanosomiasis), displaying an EC₅₀ below 10 μM and good correlation with in-silico studies, indicating that the 4H-thiochromen-4-one 1,1-dioxide core is a special allosteric modulator. It can interact in the binding pocket through key amino acids like Ser-14, Leu-17, Trp-21, Ser-109, Tyr-110, and Met-113, leading to interhelical disruption.

Gravitational friction from d'Alembert's principle

The least action principle played a central role in the development of modern physics. A major drawback of the principle is that its applicability is limited to holonomic constraints. In the present work, we investigate the energy lost by particles as a result of the gravitational interaction in a homogeneous low-density medium subject to non-holonomic constraints. We perform the calculation for an arbitrary particle and outline the specific result for photons. The energy lost is calculated from first principles based on the principle of virtual work and the d'Alembert principle. Under the formalism mentioned above, the dissipative nature of the effect is established. Furthermore, we show that the results agree with an alternative derivation based on continuum mechanics and the Euler-Cauchy stress principle.

Short-term Results of Hemiarthroplasty of the Ankle Joint for Talar-Sided Cartilage Loss

Background

Ankle hemiarthroplasty is a 1-piece implant system replacing the talar side of the tibiotalar joint. Hemiarthroplasty offers limited bone resection and may provide easier revision options than joint-ablating procedures.

Methods

Prospective, multicenter, noncomparative, nonrandomized clinical study with short term follow-up on patients undergoing hemiarthroplasty of the ankle. Radiologic and functional outcomes (Foot and Ankle Outcome Score FAOS, Foot and Ankle Ability Measure [FAAM], Short Form-36 Health Survey [SF-36], Short Musculoskeletal Functional Assessment [SMFA], and visual analog scale [VAS] pain scores) were obtained at 3 and 12 months and the last follow-up (mean 31.9 months).

Results

Ten patients met the inclusion criteria. Three were converted to total ankle replacement at 14, 16, and 18 months. Pain VAS scores improved on average from 6.8 to 4.8 (P = .044) of the remaining 7 at a mean of 31.9 months' follow-up. For these 7 in the Survival Group, we found that SF-36 physical health component improved from 25.03 to 42.25 (P = .030), SMFA dysfunction and bother indexes improved from 46.36 to 32.28 (P = .001), and from 55.21 to 30.14 (P = .002) in the Survival Group, and FAAM sports improved from 12.5 to 34.5 (P = .023).

Conclusion

Patients undergoing hemiarthroplasty of the ankle joint for talar-sided lesions had a 30% failure rate by 18 months. Those who did not have an early failure exhibited modest pain reduction, functional improvements, and better quality of life in short-term follow-up. This procedure offers a possible alternative for isolated talar ankle cartilage cases.

Level of Evidence

Level IV, prospective case series.

Environmental impact of the shadow economy, globalisation, and human capital: Capturing spillovers effects using spatial panel data approach

Most of the environmental degradation literature evaluates the determinants of polluting gas emissions as a spatially static process. However, environmental pollution is a problem that is not limited to the borders of the countries. One way to capture temporal and spatial changes in pollutant emissions is by using the benefits of spatial panel data models. This research aims to empirically examine the environmental impact of the shadow economy, the globalisation index, and the human capital index in 101 countries during 1995-2018. We employ a set of spatial autoregressive models (SAR), Durbin spatial models (SDM), and spatial lag models (SLX) of panel data to estimate direct, indirect, and total impacts. The results are stable before changes in the econometric specification and different ways of calculating spatial weights matrix. The results show that polluting gas emissions have a high spatial dependence on all specifications. The interdependence between the countries explains the spillover effect of environmental pollution on the rest of the countries that are geographically close. The policy implications derived from our research point to achieving sustainable economic and environmental development, where coordinated actions among countries and greater regulation of the behaviors of economic agents related to the shadow economy are recommended.

One-Stage Lengthening and Minimally Invasive Distal Metatarsal Metaphyseal Osteotomy (DMMO) for Brachymetatarsia

Level of Evidence: Level V.

Estimating the non-pecuniary benefit of engaging in pro-environmental behaviors: Incorporating both heterogeneous preferences and income endogeneity

This article estimates the individuals' non-pecuniary benefit of engaging in pro- environmental behaviors (PEB) using a large sample from Ecuador. As a novelty, we estimate a model that allows incorporating both unobserved heterogeneity in preferences and controlling for the potential endogeneity of income through instrumental variables. Although both problems have been addressed separately in the literature, we show that considering both sources of bias allows finding more accurate and credible monetary values. Our results show that subjective monetary evaluations regarding PEBs are generally overestimated (the income coefficient is underestimated), but not including unobserved heterogeneity hides important patterns for an important group of the sample with completely different preferences.

[An Early Obesity Prevention Program: HaViSa UC (2009-2019)]

INTRODUCTION

Prevention is the definitive solution to the serious nutritional epidemiological pro blem of children in our country and the world, obesity.

OBJECTIVE

To describe the results of an obesi ty prevention program for infants and preschoolers, ten years after its implementation.

SUBJECTS AND METHODS

Retrospective, and quasi-experimental study of the overweight and obesity prevalence, in children attending three nursery and preschool centers located at the Universidad Católica de Chile, since the implementation of a multidimensional program for early promotion of healthy lifestyle habits (HaViSa-UC) between 2009 and 2019. This study obtained ethical approval. Annual records of anthropometric assessment (WHO 2006) were analyzed using Minitab 17 software. The actions applied by the HaViSa-UC program were the assessment of nutritional status and communication with parents, delivery of healthy food, promotion of an active lifestyle, and education to encourage such healthy habits.

RESULTS

The annual mean was 319 subjects, 14% younger than two years old, and 49.5% were girls. In March 2009 (baseline), 32.6% had overweight and 8.6% obesity; both figures decreased reaching 23.8% and 4.7% respectively, in March 2019. Normal weight increased from 56.9 to 67.4% and malnutrition presented no increase. In the same period, zW/H dropped from 0.84 ± 0.94 to 0.55 ± 0.87 (p: 0.00), and zH/A increased from -0.36 ± 0.87 to -0.32 ± 0.90 (p > 0.05). Con clusion: Since the implementation of the HaViSa-UC Program, the frequency of obesity decreased by 45.4% and overweight by 27.2% in this sample of infants and preschoolers, remaining stable after 10 years.

Dynamics of clinical biomarkers as predictors of immunotherapy benefit in metastatic melanoma patients

PURPOSE

Baseline LDH, derived neutrophil-lymphocyte ratio (dNLR) and immune-related adverse events (irAEs) are associated with outcomes of patients with metastatic melanoma (MM). We hypothesized whether dynamic shifts in LDH, dNLR and incidence of irAEs may impact the prognosis of MM patients treated with anti-CTLA4 or anti-PD1 as single agents.

METHODS

Retrospective analysis of medical charts from MM patients with prospective monitoring of dNLR, LDH values and irAE incidence. Primary endpoint was overall survival (OS).

RESULTS

Patients switching from either high dNLR (≥2.5) to low dNLR (HR: 0.14; 0.03-0.74; p = 0.02) or high LDH (≥1.5 × ULN) to low LDH levels (HR: 0.08; 0.01-0.68; p = 0.02) had significantly better OS than those with high dNLR or LDH scores at the end of cycle 2. Longer OS was also observed in patients developing irAEs ≥ grade 2 as compared to no irAEs (HR: 0.2; 0.05-0.89; p = 0.03).

CONCLUSIONS

We found that major shifts in dNLR and LDH measures from baseline to cycle 2 measures and shifts from baseline to cycle 2 are significantly associated with OS in MM patients receiving single agent anti-PD1 therapy. Laboratory changes and clinical variables may help optimize prognostic estimates.

Achilles tendoscopy for non insertional Achilles tendinopathy. A case series study

BACKGROUND

Achilles non-insertional tendinopathy is usually treated with conservative means. If resistant to a rehabilitation protocol surgical treatment could be proposed. The aim of this research is to report the mid-term clinical results of endoscopic assisted surgery for patients suffering from recalcitrant painful non-insertional Achilles tendinopathy.

METHODS

A consecutive series of 11 patients (6 men and 5 women), median age of 54 (range 40-67) years, with chronic recalcitrant painful non-insertional Achilles tendinopathy were included. All patients completed at least 20 physical therapy sessions and 6 months of no sports activities before surgery. All underwent Achilles tendoscopy, without tendon excision or transfer with a median follow-up of 87 (27-105) months. We report the preoperative symptoms duration, treatment before surgery, complications and satisfaction after surgery, return to previous sport level, and postoperative VISA-A score.

RESULTS

Mean preoperative symptoms duration was 1 year, having all performed at least 20 physical therapy sessions. No postoperative complications were reported, achieving a complete satisfaction in 10 of 11 patients. All patients returned to their preoperative sports level with a median postoperative VISA-A functional score of 100 (30-100) points.

CONCLUSIONS

The mid-term results of Achilles tendoscopy in patients with chronic painful non-insertional Achilles tendinopathy are satisfactory with a rapid rehabilitation. This procedure is safe and has a low complication rate.

LEVEL OF EVIDENCE

IV. Retrospective case series.

GWAS revealed a novel resistance locus on chromosome 4D for the quarantine disease Karnal bunt in diverse wheat pre-breeding germplasm

This study was initiated to identify genomic regions conferring resistance to Karnal Bunt (KB) disease in wheat through a genome-wide association study (GWAS) on a set of 179 pre-breeding lines (PBLs). A GWAS of 6,382 high-quality DArTseq SNPs revealed 15 significant SNPs (P-value <10^-3) on chromosomes 2D, 3B, 4D and 7B that were associated with KB resistance in individual years. In particular, two SNPs (chromosome 4D) had the maximum R² values: SNP 1114200 | F | 0-63:T > C at 1.571 cM and R² of 12.49% and SNP 1103052 | F | 0-61:C > A at 1.574 cM and R² of 9.02%. These two SNPs displayed strong linkage disequilibrium (LD). An in silico analysis of SNPs on chromosome 4D identified two candidate gene hits, TraesCS4D02G352200 (TaNox8; an NADPH oxidase) and TraesCS4D02G350300 (a rhomboid-like protein belonging to family S54), with SNPs 1103052 | F | 0-61:C > A and 1101835 | F | 0-5:C > A, respectively, both of which function in biotic stress tolerance. The epistatic interaction analysis revealed significant interactions among 4D and 7B loci. A pedigree analysis of confirmed resistant PBLs revealed that Aegilops species is one of the parents and contributed the D genome in these resistant PBLs. These identified lines can be crossed with any elite cultivar across the globe to incorporate novel KB resistance identified on 4B.

Synthesis and Evaluation of Antileishmanial and Cytotoxic Activity of Benzothiopyrane Derivatives

In continuation of our efforts to identify promising antileishmanial agents based on the chroman scaffold, we synthesized several substituted 2H-thiochroman derivatives, including thiochromenes, thichromanones and hydrazones substituted in C-2 or C-3 with carbonyl or carboxyl groups. Thirty-two compounds were thus obtained, characterized, and evaluated against intracellular amastigotes of Leishmania (V)panamensis. Twelve compounds were active, with EC₅₀ values lower than 40 µM, but only four compounds displayed the highest antileishmanial activity, with EC₅₀ values below 10 µM; these all compounds possess a good Selectivity Index > 2.6. Although two active compounds were thiochromenes, a clear structure-activity relationship was not detected since each active compound has a different substitution pattern.

Urban concentration, non-renewable energy consumption, and output: do levels of economic development matter?

The accelerated urbanization process generates a significant increase in energy, whose sources are mainly polluting. The harmful effects of both processes are reflected in climate change. This article examines the equilibrium and causality relationship among urban concentration, non-renewable energy consumption, and the real per capita output in 110 countries during 1971-2017. Using data from the World Bank's World Development Indicators (2018), we classify countries into four groups according to their level of development. Our evidence suggests that urban concentration has a negative effect on real per capita output in high-income countries, while non-renewable energy consumption has a positive effect on all groups of countries. The cointegration tests show that there is short- and long-term equilibrium in all groups of countries. The results of the DOLS and PDOLS models indicate that the strength of the cointegration vector is weak in most of the countries and groups analyzed. The Granger-type causality tests show that there is bidirectional causality from the real per capita output to the urban concentration in high and middle-low-income countries. There is unidirectional causality from the population concentration towards the real per capita output in the low-income countries; from the non-renewable energy consumption to the real per capita output in high-income countries; from the real per capita output to the non-renewable energy consumption in the countries of medium-high and medium-low income; and from urban concentration to non-renewable energy consumption in high- and medium-high-income countries. Our results highlight the importance of promoting policies of urban planning and generation and consumption of renewable energy without limiting the expansion of the output.

Emergent groin hernia repair at a County Hospital in Guatemala: patient-related issues vs. health care system limitations

BACKGROUND

The rate of emergent groin hernia repair in developing countries is poorly understood.

MATERIALS AND METHODS

A retrospective analysis of groin hernia repairs performed at a county hospital in Guatemala [Hospital Nacional de San Benito (HSNB)] was undertaken and compared to a literature review in developed countries. Patients with incarcerated hernias were interviewed to determine factors related to late presentation.

RESULTS

Twenty-five percent of patients with groin hernias in this analysis presented at HNSB emergently (vs. 2.5-7.7% in developed countries). Most patients were male in their fifth decade of life. Ten percent of hernias were femoral. There was no delay in scheduling patients for surgery presenting for elective repair. Most patients lived within 20 miles of the hospital, but only 50% of patients returned for their follow-up appointment. Most patients with an incarcerated inguinal hernia (56%) did not seek medical attention because of family obligations, but when they did, this decision was influence by their children (66%). None of the patients presenting with an incarcerated hernia had education past secondary school. In fact, most (56%) did not have any form formal education. Nearly 90% of patients who had an incarcerated hernia repaired thought that the hospital provided good-to-excellent care.

CONCLUSION

A high number of patients present emergently for groin hernia repair at a county hospital in Guatemala compared to developed countries. Our data suggest that emergent hernias are likely the result of patient-related issues rather than health care system limitations.

Knotless Modified Arthroscopic-Broström Technique for Ankle Instability

Instability is a common sequela after repeated ankle sprains. When nonoperative treatment fails, open lateral ligament complex repair and reinforcement with the inferior extensor retinaculum has been the gold standard procedure. The recent advancements in arthroscopic techniques have created comparable biomechanical and functional results to open procedures. The authors' modification to the standard arthroscopic technique permits ligament approximation to the distal fibula over a larger surface area, using knotless anchors to avoid the need of an accessory portal and limit potential suture knot-related complications. Level of Evidence: Level V, expert opinion.

An Atypical Case of Idiopathic Pulmonary Fibrosis in a Patient from Africa

A 39 years old African man presented with fatigue, loss of weight and night sweats; radiology showed a possible usual interstitial pneumonia pattern. The patient missed follow-up visits, and presented again after 3 years with productive cough and general illness. Pulmonary function tests showed a decline of FVC compared to a previous investigation. The CT scans showed progression of the interstitial lung disease, and a multidisciplinary conference recommended to proceed with a surgical lung biopsy. Histopathology showed an atypical pattern, with bronchiolar metaplasia. A new multidisciplinary conference made a diagnosis of IPF, and the patient was treated with antifibrotic drugs with a good effect, reaching stability of lung function. This case report highlights the need to improve knowledge and to better characterize rare pulmonary diseases, and especially IPF, among African patients.

Driver distraction by smartphone use (WhatsApp) in different age groups

This paper investigates the effect that texting with WhatsApp, one of the most common applications for instant messaging, exerts on driving performance. Because distracted driving also affects older drivers, who can have seriously compromised vision, we also analysed the associations between visual-function parameters and driving performance. A total of 75 drivers, experienced in sending WhatsApp messages (≥10WhatsApp messages/week), participated in this study and were divided into four age categories. Visual-function tests included contrast sensitivity with and without glare, retinal straylight and objective assessment of optical quality. Simulated driving performance was assessed under a baseline driving condition (without distraction) as well as a texting condition (WhatsApp messages) while driving. The participants used their own mobile phone. Lastly, objective results of driving performance were compared with subjective self-report data from the Driver Behaviour Questionnaire (DBQ). The analysis indicated that functional changes occurring with age, such as a lower contrast sensitivity and greater retinal straylight, were correlated with a higher number of collisions, longer distances driven outside the lane, and greater standard deviation of lateral position (SDLP). The results showed a significant main effect of age for the driving-performance parameters. Also, compared to the baseline, texting WhatsApp messages while driving worsens driving performance for all age groups, most notably among older participants. Thus, the older drivers' SDLP was ∼14% higher than that for the baseline average of all the other drivers and rose to 29% under distraction, reflecting the impact of secondary tasks. The negative effect of the use of the smartphone during driving was also reflected in the number of collisions, with a greater risk of accidents in all the groups of drivers (by 8.3% for young adults, 25.0% for adults, 80.5% for middle-aged adults, and 134.5% for older drivers). Lastly, participants' subjective responses indicated that younger drivers (18-24 years) had a higher risk of deliberately violating safe driving practices (p < 0.05). The present study demonstrates that texting WhatsApp messages while driving significantly impairs the ability to drive safely, with older drivers being the group most adversely affected. It would be recommendable to include other nonstandard vision tests, which have shown associations with driving performance, in the examination for driver licensing. This would help raise the awareness of older drivers concerning their visual limitations, permitting them to adopt compensatory measures to improve their driving safety. Nevertheless, it is also necessary to raise awareness among the younger drivers of the risks involved in behaviour behind the wheel.

Biomechanical Cadaveric Evaluation of Partial Acute Peroneal Tendon Tears

BACKGROUND

No clear guideline or solid evidence exists for peroneal tendon tears to determine when to repair, resect, or perform a tenodesis on the damaged tendon. The objective of this study was to analyze the mechanical behavior of cadaveric peroneal tendons artificially damaged and tested in a cyclic and failure mode. The hypothesis was that no failure would be observed in the cyclic phase.

METHODS

Eight cadaveric long leg specimens were tested on a specially designed frame. A longitudinal full thickness tendon defect was created, 3 cm in length, behind the tip of the fibula, compromising 66% of the visible width of the peroneal tendons. Cyclic testing was initially performed between 50 and 200 N, followed by a load-to-failure test. Tendon elongation and load to rupture were measured.

RESULTS

No tendon failed or lengthened during cyclic testing. The mean load to failure for peroneus brevis was 416 N (95% confidence interval, 351-481 N) and for the peroneus longus was 723 N (95% confidence interval, 578-868 N). All failures were at the level of the defect created.

CONCLUSION

In a cadaveric model of peroneal tendon tears, 33% of remaining peroneal tendon could resist high tensile forces, above the physiologic threshold.

CLINICAL RELEVANCE

Some peroneal tendon tears can be treated conservatively without risking spontaneous ruptures. When surgically treating a symptomatic peroneal tendon tear, increased efforts may be undertaken to repair tears previously considered irreparable.

Spatial variability in threshold temperatures of heat wave mortality: impact assessment on prevention plans

Spain's current heat wave prevention plans are activated according to administrative areas. This study analyses the determination of threshold temperatures for triggering prevention-plan activation by reference to isoclimatic areas, and describes the public health benefits. We subdivided the study area - the Madrid Autonomous Region (MAR) - into three, distinct, isoclimatic areas: 'North', 'Central' and 'South', and grouped daily natural-cause mortality (ICD-10: A00-R99) in towns of over 10,000 inhabitants (2000-2009 period) accordingly. Using these three areas rather than the MAR as a whole would have resulted in a possible decrease in mortality of 73 persons (38-108) in the North area, and in aborting unnecessary activation of the plan 153 times in the Central area and 417 times in the South area. Our results indicate that extrapolating this methodology would bring benefits associated with a reduction in attributable mortality and improved effectiveness of public health interventions.

Peroneal Tendon Tears

Category:

Ankle, Basic Sciences/Biologics, Sports

Introduction/Purpose:

Peroneus brevis tendon tears are frequently diagnosed when ankle instability is present. No clear guideline exists as to when to repair or resect peroneal tendon tears, as most of the available literature uses Meyer’s work published in 1924 where a risk of spontaneous rupture would exist when less than 50% of the tendon remains undamaged. Our objective was to analyze the mechanical behavior of cadaveric peroneal tendons subjected to an artificially made damage, compromising 66% of its visible width and tested in a cyclic and failure phase. Our hypothesis was that no failure would be observed in the cyclic phase.

Methods:

8 cadaveric foot- ankle – distal tibia specimens were included in this study. A longitudinal full thickness tendon defect was created, 3 cms in length, centered behind the tip of the fibula, compromising 66% of the visible width of the peroneal tendons as measured by a caliper. The peroneal retinaculum was kept intact. All specimens were mounted onto a special frame specifically designed for the study. All tendons were tested in a cyclic fashion using 100 repetitions between 50 N and 200 N. If no visual change or tendon failure was observed after the initial testing, a load to failure test was performed until tendon rupture or fixation failure was observed. Tendon stiffness and load to failure were registered. Statistical analysis was performed using the SPSS software.

Results:

No tendon failed during the cyclic testing. No defect lengthening was observed after the cyclic phase. On the failure phase, the mean load resisted by the peroneus brevis was 416 N, with a 95% confidence interval between 351 N -481 N. The mean load resisted by the peroneus longus was 723 N, with a 95% confidence interval between 578 N – 868 N. All failures were at the level of the defect created. The coefficient of variation was low for both tendons.

Conclusion:

A 33% of remaining peroneal tendon was able to resist very high tensile forces; therefore, it can be suggested that a 66% defect can be repaired and does not necessarily need a tenodesis as it has been historically recommended. The high resistance offered by the peroneus longus tendon offers the theoretical potential to use part of it as a free graft to repair peroneus brevis tears. The 50% rule, which determines when a peroneal tendon tear needs a tenodesis or repair, should be revisited.

Biomechanical evaluation of metatarsal osteotomies for Hallux Rigidus. A cadaveric testing

Category:

Basic Sciences/Biologics, Midfoot/Forefoot

Introduction/Purpose:

Metatarsal osteotomies for Hallux Rigidus (HR) is a treatment option when neither a cheilectomy nor an arthrodesis are indicated. Different osteotomies exist that elevate, shorten or depress the metatarsal head. No biomechanical information exists that evaluates the effect of osteotomies on hallux range of motion (ROM) and stiffness. Our objective was to evaluate, in a cadaveric model, the first metatarsophalangeal joint (MTPJ) stiffness and kinematics changes, after three different metatarsal osteotomies.

Methods:

8 cadaveric foot-ankle–distal tibia specimens were prepared, identifying all extensor and flexor tendons proximally. The skin and subcutaneous tissue was kept intact. Each specimen was mounted on a special frame and luminous markers were attached to the skin (Oxford Foot Model). A dead weight equal to 50% of the stance phase force was applied to each tendon, except for the Achilles tendon and the posterior tibialis. Each specimen served as its own control, testing hallux dorsiflexion when pulling the extensor hallucis longus tendon. 10 cycles were performed for every condition: control (A), and three different metatarsal extraarticular neck osteotomies: vertical osteotomy with 5 mm of depression (B), 5 mm of shortening (C) and 5 mm of shortening and depression (D). All osteotomies were performed on a Hallux Rigidus cadaveric model. We registered the MTPJ stiffness and kinematic changes after each intervention using a tensile testing machine and high definition cameras.

Results:

B and C were significantly stiffer than group A and D (p<0.05). D was the only condition with a similar stiffness to the control group (A) (p>0.05). Groups B, C and D achieved similar kinematics (range of motion) to group A (p>0.05).

Conclusion:

Different metatarsal osteotomies exist for HR. The osteotomy of choice, should be one that recreates the healthy MTPJ motion and stiffness. According to our study, the osteotomy of choice should be one that results in metatarsal head depression and shortening. A possible explanation to our finding, is that a pure shortening or depression osteotomy is really elevating or depressing the head respectively, hence altering the tendon pull and relative head position. Only with metatarsal shortening and depression, the Hallux MTPJ biomechanics in a Hallux Rigidus cadaver model, returns to a healthy state.

Early Weight Bearing on Weber C Fractures with Retained Syndesmotic Screws

Category:

Ankle, Sports, Trauma

Introduction/Purpose:

There is no consensus about when to allow weight bearing in ankle fractures treated with syndesmotic screw fixation. There has been no evaluation of the radiographic fate of the syndesmosis when syndesmotic screws are retained and early weight bearing is encouraged, or the clinical result depending on the screw status, which can be intact, broken or loose. Our objective was to evaluate the radiographic and clinical parameters of patients who had a screw fixation of the syndesmosis and early weight bearing was allowed. Our hypothesis was that no difference would be observed on syndesmotic reduction or clinical function depending on the screw status.

Methods:

We analyzed 42 patients with ankle fractures treated with syndesmotic screws in which early weight bearing was allowed (3 weeks postoperatively). Weight bearing radiographs were obtained at 2 weeks, 2 months and at final follow up (41.2 months). Radiologically we measured medial clear space (MCS), tibiofibular overlap (OL), tibiofibular clear space (CS), talar shift (TS) and screw condition (intact, broken, loose). Clinical function was measured with the AOFAS score and stratified by the screw condition. Statistical analysis was performed with the SPSS software and a non-inferiority confidence interval for the mean was calculated.

Results:

At final follow up, 66,6% of the screws were broken, 30,9% showed significant loosening and only 1 patient (4,7%) had a screw that remained solid with no signs of osteolysis. MCS at 2 weeks, 2 months and at final follow up was 2,94 mm; 3,03 mm; 3,02, respectively. OL was 6,76 mm; 6,78 mm; 6,83 and CS was 4,26 mm; 4,66 mm; 4,6 mm. No TS was detected. There was no difference in measurements along time (p>0,05). Relative to clinical function, the mean AOFAS score was 95 points. No difference was found between the clinical scores of patients stratified by the screw condition (p>0,05).

Conclusion:

Early weight bearing on a fixed syndesmosis appears to be safe, with no measurable radiographic or clinical consequences regarding ankle joint function. Despite screw breakage or loosening on x-rays, loss of reduction is seldom observed. We suggest that routine removal of syndesmotic screws is not necessary in these group of patients.

Development of a cadaveric Hallux Rigidus model. Biomechanical testing

Category:

Bunion

Introduction/Purpose:

Hallux Rigidus (HR) is characterized initially by a decrease in Hallux metatarsophalangeal joint (MTPJ) dorsiflexion, decreasing the total range of motion. To be able to study different surgical treatment options, a cadaveric model has to be developed that recreates the limited range of motion. Our objective was to develop an Hallux Rigidus cadaveric model by shortening the plantar fascia (PF). Hallux MTPJ range of motion and joint stiffness were evaluated.

Methods:

8 cadaveric foot- ankle – distal tibia specimens were prepared, identifying all extensor and flexor tendons proximally. The skin and subcutaneous tissue was kept intact. Each specimen was mounted on a special frame and luminous markers were attached to the skin (Oxford Foot Model). A dead weight equal to 50% of the stance phase force was applied to each tendon, except for the Achilles tendon and the posterior tibialis. 10 Hallux MTPJ dorsiflexion-plantarflexion cycles were performed by pulling the Extensor Hallucis longus tendon using an tensile testing machine (Kinetecnics). A Hallux Rigidus model was then developed by shortening the PF by 6 mm using a triple fiberwire suture technique. The same 10 cycles were repeated with a shortened PF. Each specimen served as its own control. Hallux metatarsophalangeal stiffness and kinematics were tested using a tensile testing machine and high definition cameras.

Results:

The group with a shortened PF significantly reduced the hallux dorsiflexion (18.6 degrees) compared to the native foot (23.7 degress) (p<0.05). No significant difference in joint stiffness was seen between groups: 3.3 N per degree for the native foot and 4.3 N per degree for the Hallux Rigidus model (P>0.05).

Conclusion:

To create a HR model is vital to allow further understanding of the pathology. The cadaveric model should not alter the joint stability (intact periarticular soft tissues) but has to limit Hallux range of motion. The model we present successfully recreates HR by limiting MTPJ dorsiflexion. The absence of stiffness change shows that joint congruity and isometry were not modified. There are a few reports that state a PF shortening as the first stage in HR. This would lead to a hinge-like MTPJ dorsiflexion, creating a dorsal metatarsal head impingement that could evolve to a dorsal exostosis.