Elevated fluid and glycosaminoglycan content in the Achilles tendon contribute to higher intratendinous pressures:Implications for Achilles tendinopathy

Background:Tendinopathy alters the compositional properties of the Achilles tendon by increasing fluid and glycosaminoglycan content.It has been speculated that these changes may affect intratendinous pressure,but the extent of this relationship remains unclear.Therefore,we aimed to investigate the impact of elevated fluid and glycosaminoglycan content on Achilles tendon intratendinous pressure and to determine whether hyaluronidase(HYAL) therapy can intervene in this potential relationship.Methods:Twenty paired fresh-frozen cadaveric Achilles tendons were mounted in a tensile-testing machine and loaded up to 5% strain.Intratendinous resting(at 0% strain) and dynamic pressure(at 5% strain) were assessed using the microcapillary infusion technique.First,intratendinous pressure was measured under native conditions before and after infusion of 2 mL physiological saline.Next,80 mg of glycosaminoglycans were administered bilaterally to the paired tendons.The right tendons were additionally treated with 1500 units of HYAL.Finally,both groups were retested,and the glycosaminoglycan content was analyzed.Results:It was found that both elevated fluid and glycosaminoglycan content resulted in higher intratendinous resting and dynamic pressures(p <0.001).HYAL treatment induced a 2.3-fold reduction in glycosaminoglycan content(p=0.002) and restored intratendinous pressures.Conclusion:The results of this study demonstrated that elevated fluid and glycosaminoglycan content in Achilles tendinopathy contribute to increased intratendinous re sting and dynamic pressures,which can be explained by the associated increased volume and reduced permeability of the tendon matrix,respectively.HYAL degrades glycosaminoglycans sufficiently to lower intratendinous pressures and may,therefore,serve as a promising treatment.

Measuring the immeasurable? Operationalising social capital in health research

During the last decennia, social capital has been a popular topic in social sciences. However, the concept is often used as a “catch all” for divers social characteristics. Consensus on how the concept should be measured is lacking. This keeps health researchers from drawing firm conclusions on the influence of social capital on health and hampers the decision on which social capital indicators to use in health research. This study compares five ways to operationalise social capital (generalized trust, a social network index, an expanded social network index, bonding, bridging and linking social capital and a multidimensional social capital index) in their ability to explain self-rated health and pain. To evaluate the models’ capacity to explain health, two logistic regression models were built, resulting in Nagelkerke R2 measures. Data were collected in a cross-sectional study in eight neighbourhoods in the region of Ghent (Belgium) by randomly sampling 50 adult inhabitants per neighbourhood. Findings show that the explanation of the observed variance in health by the studied social capital models ranges from 1.9% to 23.1%, but is more pronounced for self-rated health than for pain. The multidimensional social capital index explains most of the variance in health, but poses an important strain on the respondents due to a large number of surveyquestions. With some prudence, we presume that the explanatory added value of the more extended social capital models is rather limited from a practical point of view as the addition in explained variance of the other models seems not in relation to the number of questions needed. Researchers should weigh up the pros and cons of different manners to measure social capital carefully, taking the goals and focus of their study into account.

Status of adult inpatient burn rehabilitation in Europe: are we neglecting metabolic outcomes?

Background:Hypermetabolism,muscle wasting and insulin resistance are challenging yet important rehabilitation targets in the management of burns.In the absence of concrete practice guidelines,however,it remains unclear how these metabolic targets are currently managed.This study aimed to describe the current practice of inpatient rehabilitation across Europe.Methods:An electronic survey was distributed by the European Burn Association to burn centres throughout Europe,comprising generic and profession-specific questions directed at therapists,medical doctors and dieticians.Questions concerned exercise prescription,metabolic management and treatment priorities,motivation and knowledge of burn-induced metabolic sequelae.Odds ratios were computed to analyse associations between data derived from the responses of treatment priorities and knowledge of burn-induced metabolic sequelae.Results:Fifty-nine clinicians with 12.3±9 years of professional experience in burns,representing 18 out of 91 burn centres(response rate,19.8%)across eight European countries responded.Resistance and aerobic exercises were only provided by 42%and 38%of therapists to intubated patients,87%and 65%once out-of-bed mobility was possible and 97%and 83%once patients were able to leave their hospital room,respectively.The assessment of resting energy expenditure by indirect calorimetry,muscle wasting and insulin resistance was carried out by only 40.7%,15.3%and 7.4%respondents,respectively,with large variability in employed frequency and methods.Not all clinicians changed their care in cases of hypermetabolism(59.3%),muscle wasting(70.4%)or insulin resistance(44.4%),and large variations in management strategies were reported.Significant interdisciplinary variation was present in treatment goal importance ratings,motivation and knowledge of burn-induced metabolic sequelae.The prevention of metabolic sequelae was regarded as the least important treatment goal,while the restoration of functional status was rated as the most important.Knowledge of burn-induced metabolic sequelae was linked to higher importance ratings of metabolic sequelae as a therapy goal(odds ratio,4.63;95%CI,1.50–14.25;p<0.01).Conclusion:This survey reveals considerable non-uniformity around multiple aspects of inpatient rehabilitation across European burn care,including,most notably,a potential neglect of metabolic outcomes.The results contribute to the necessary groundwork to formulate practice guidelines for inpatient burn rehabilitation.

The physical and physiological effects of vacuum massage on the different skin layers: a current status of the literature

Vacuum massage is a non-invasive mechanical massage technique performed with a mechanical device that lifts the skin by means of suction,creates a skin fold and mobilises that skin fold.In the late 1970s,this therapy was introduced to treat traumatic or burn scars.Although vacuum massage was invented to treat burns and scars,one can find very little literature on the effects of this intervention.Therefore,the aim of this review is to present an overview of the available literature on the physical and physiological effects of vacuum massage on epidermal and dermal skin structures in order to find the underlying working mechanisms that could benefit the healing of burns and scars.The discussion contains translational analysis of the results and provides recommendations for future research on the topic.An extended search for publications was performed using PubMed,Web of Science and Google Scholar.Two authors independently identified and checked each study against the inclusion criteria.Nineteen articles were included in the qualitative synthesis.The two most reported physical effects of vacuum massage were improvement of the tissue hardness and the elasticity of the skin.Besides physical effects,a variety of physiological effects are reported in literature,for example,an increased number of fibroblasts and collagen fibres accompanied by an alteration of fibroblast phenotype and collagen orientation.Little information was found on the decrease of pain and itch due to vacuum massage.Although vacuum massage initially had been developed for the treatment of burn scars,this literature review found little evidence for the efficacy of this treatment.Variations in duration,amplitude or frequency of the treatment have a substantial influence on collagen restructuring and reorientation,thus implying possible beneficial influences on the healing potential by mechanotransduction pathways.Vacuum massage may release the mechanical tension associated with scar retraction and thus induce apoptosis of myofibroblasts.Suggestions for future research include upscaling the study design,investigating the molecular pathways and dose dependency,comparing effects in different stages of repair,including evolutive parameters and the use of more objective assessment tools.

Short-term effects of vacuum massage on epidermal and dermal thickness and density in burn scars: an experimental study

Background:Vacuum massage is a non-invasive mechanical massage technique invented to treat burns and scars.To date,no effects of vacuum massage on thickness and density of human scar tissue have been reported.The process in which external stimuli are converted into biochemical responses in the cell is known as mechanotransduction.In the skin endothelial cells,fibroblasts and myofibroblasts embedded in the extracellular matrix(ECM)sense mechanical stimuli(created by vacuum massage)and may promote intracellular processes leading to matrix remodelling.Since mechanotransduction could be a plausible working mechanism for vacuum massage as an anti-scarring therapy,this study aims to investigate the short-term effects of vacuum massage on thickness and density of epidermis and dermis in burn scars in order to find proof of ECM remodelling.Methods:A one group experimental study was performed.Patients with burn scars on upper extremities,lower extremities,and trunk were recruited for participation in this study.The DUB?cutis 22 MHz ultrasound scanner was used to assess thickness and density of the epidermal and dermal skin layers.After baseline measurements,vacuum massage was performed according to a pre-defined protocol.Measurements were carried out at 5 min,30 min,1 h,and 2 h post-intervention.Results:Thirteen scar sites from 9 different patients were investigated.In 8 out of the 13 scar sites,a disruption of the epidermis was noticed after the vacuum massage.Five minutes after the intervention,epidermal density decreased statistically significantly(p=.022)and dermal thickness increased(p=.018).Both changes lasted for more than 1 h,but after 2 h,the changes were no longer statistically significant.Dermal density decreased significantly(p=.048)immediately after the intervention,and this decrease was still present after 2 h(p=.011).Conclusions:Preliminary results show that the disruption of the epidermis may indicate that vacuum massage could be able to actually breach the skin barrier.The statistically significant changes in the dermal layers could suggest an increased ECM production after vacuum massage.