User opinions about connected pressure detection systems to prevent wheelchair-related pressure injuries: An exploratory cross-sectional survey.

About 1% of the world's population uses a wheelchair. Wheelchair use is a well-known risk of pressure injury. A connected pressure detection system could help to prevent this complication that is linked to long durations of sitting, provided that user expectations are understood. The aim of this study was to explore the needs of wheelchair users (WU) regarding connected pressure detection systems to prevent pressure injury. A cross-section survey-based study of WU was conducted, using an anonymous electronic questionnaire posted from July 2019 to June 2020. Eighty-eight people responded. The majority were power wheelchair users (72.7%); one third (33.0%) had already sustained a pressure injury; only 17.0% knew of the existence of pressure detection systems, nevertheless 78.4% believed that they could be useful in daily life. The feature that received the highest rating was a pressure warning alarm (4.2/5 points). The majority (71.6%) preferred reminder-alerts to be set according to their habits and not according to medical guidelines. In conclusion, pressure detecting systems were perceived as useful to prevent pressure injuries by both manual and power wheelchair users. Work is needed to inform potential users of the existence of such systems.

Cross-cultural adaptation and reliability of the Foot Posture Index (FPI-6) - French version.

PURPOSE: The 6-item Foot Posture Index (FPI-6) is a reliable tool for the evaluation of foot deformities. Our aim was to translate and cross-culturally validate the FPI-6 for use in French-speaking countries and to determine the intra-rater and inter-rater reliability of the French version. METHODS: Cross-cultural adaptation was performed according to guidelines. Two clinicians assessed the FPI-6 in 52 asymptomatic individuals. We evaluated intra- and inter-rater reliability with the intraclass correlation coefficients (ICC), correlations (p-value < 0.05) and Bland-Altman plots. Standard error of measurement (SEM) and minimum detectable change (MDC95) were determined. RESULTS: For the cross-cultural adaptation, we modified several items of the FPI-6 user guide and added footnotes to ensure correct interpretation. ICC of the total FPI-6 scores were 0.94 to 0.96 for the intra- and inter-rater reliability for dominant and non-dominant lower limb. Correlations were significant (p < 0.001); r 0.88 to 0.92. Total score SEM was 0.68 to 0.78 and MDC95 was 1.58 to 1.82. CONCLUSIONS: Intra- and inter-rater reliability of this French version of the FPI-6 was excellent for the total score and good to excellent for each item. The French FPI-6 can be used in French-speaking countries. The identification of SEM and MDC scores is useful for clinical interpretation.

The French version of the 6-item Foot Posture Index (FPI-6) can be used in clinical practice in French-speaking countriesIntra- and inter-rater reliability of total FPI score are excellentWe provide minimal detectable change value for clinical interpretation (1.58 to 1.82).

Finite Element Tissue Strains Computation to Evaluate the Mechanical Protection Provided by a New Bilayer Dressing for Heel Pressure Injuries.

OBJECTIVE: Pressure injuries (PIs) result in an extended duration of care and increased risks of complications for patients. When treating a PI, the aim is to hinder further PI development and speed up the healing time. Urgo RID recently developed a new bilayer dressing to improve the healing of stages 2 and 3 heel PIs. This study aims to numerically investigate the efficiency of this new bilayer dressing to reduce strains around the PI site. METHODS: The researchers designed three finite element models based on the same heel data set to compare the Green-Lagrange compressive and maximal shear strains in models without a PI, with a stage 2 PI, and with a stage 3 PI. Simulations with and without the dressing were computed. Analysis of the results was performed in terms of strain clusters, defined as volumes of tissues with high shear and compressive strains. RESULTS: Decreases in the peak and mean values of strains were low in all three models, between 0% and 20%. However, reduction of the strain cluster volumes was high and ranged from 55% to 68%. CONCLUSIONS: The cluster analysis enables the robust quantitative comparison of finite element analysis. Results suggest that use of the new bilayer dressing may reduce strain around the PI site and that this dressing could also be used in a prophylactic manner. Results should be extended to a larger cohort of participants.

Use of the SINBAD score as a predicting tool for major adverse foot events in patients with diabetic foot ulcer: A French multicentre study.

OBJECTIVE: To assess the relationship between the site, ischaemia, neuropathy, bacterial infection, area, depth (SINBAD) score and major adverse foot events in patients with diabetes and foot ulcers. METHODS: For this retrospective ancillary study, patients (n = 537) followed for a diabetic foot ulcer (DFU) in six French hospitals were included between 1 February 2019 and 17 March 2019, and between 1 February 2020 and 17 March 2020. The SINBAD score was assessed at inclusion. The frequency of a composite outcome consisting of eight major adverse foot events (MAFE) was assessed after 5-6 months of follow-up: hospitalisation for DFU, septic surgery, revascularisation, minor amputation, major amputation, death, secondary infection and ulcer recurrence. A logistical regression explored the link between the SINBAD score and MAFE and each of its component. RESULTS: A low SINBAD score (from 0 to 3) was observed in 61% of patients and a high (from 4 to 6) in 39%. MAFE occurred in, respectively, 24% and 28% of these patients. Multivariate analyses showed a significant relationship between the SINBAD score and MAFE, with the continuous SINBAD score: odds ratio (OR) 1.72 [95% CI (1.51-1.97)] or dichotomic SINBAD score (values: 0-3 and 4-6): OR 3.71 [95% CI (2.54-5.42)]. The SINBAD score (continuous or dichotomic) at inclusion was also significantly associated with six out of the eight components of the MAFE. CONCLUSIONS: The SINBAD score is a useful tool for predicting major adverse foot events.

Relationship between care pathway features and use or non-use of orthotic devices by individuals with Charcot-Marie-Tooth disease: a cross-sectional, exploratory study.

PURPOSE: Orthotic devices may be prescribed for the management of foot and ankle deformities caused by Charcot-Marie-Tooth disease (CMT). However, the actual use of these devices is variable. No studies have evaluated the impact of prescription, delivery and follow-up of orthotic devices on their use.We aimed to describe the relationship between the pathways followed by individuals with CMT and orthotic device use. MATERIALS AND METHODS: Exploratory, cross-sectional, 35-item survey of orthotic device management. Individuals with CMT were recruited from CMT-France Association. RESULTS: Of the 940 respondents, 795 were included, mean age of 52.9 (SD 16.9) years. Rate of orthotic device use was 49.2% (391/795). The most frequent reason for non-use was a poor fit. Non-use was related to the orthotic device type, the health professionals consulted, and the severity of the CMT-related impairments. Follow-up visits (38.7%), re-evaluation of orthotic devices (25.3%) and consultations with the Physical and Rehabilitation Medicine physician were infrequent (28.3%). CONCLUSIONS: Orthotic devices are massively underused. Follow-up and re-evaluation are infrequent. Care pathways, prescription and delivery of orthotic devices must be optimized to meet the expectations of people with CMT. Device fitting, individual needs, and changes in the clinical state must be re-evaluated regularly by specialists to improve orthotic device use.Implications for rehabilitationFoot deformities and foot drop contribute to disability in people with Charcot Marie Tooth Disease but use of orthotic devices is poor.To improve orthotic device use, regular multidisciplinary consultations and regular re-evaluation of the device by specialists in neuro-orthopaedics are important.The device fit should be regularly re-evaluated by the prescribing doctor or the practitioner who made the device.Regular multimodal evaluation of foot deformity, including muscle strength and length, and the individual's needs and expectations is also important to improve orthotic device use.

Intraspecific variation in reproductive barriers between two closely related Arabidopsis sister species.

Reproductive isolation (RI) is a critical component of speciation and varies strongly in timing and strength among different sister taxa, depending on, for example the geography of speciation and divergence time. However, these factors may also produce variation in timing and strength among populations within species. Here we tested for variation in the expression of RI among replicate population pairs between the sister taxa Arabidopsis lyrata subsp. lyrata and A. arenicola. While the former is predominantly outcrossing, the latter is predominantly selfing. We focused on intrinsic prezygotic and postzygotic RI as both species occur largely in allopatry. We assessed RI by performing within-population crosses and interspecific between-population crosses, and by raising offspring. RI was generally high between all interspecific population pairs, but it varied in timing and strength depending on population history. Prezygotic isolation was strongest between the closest-related population pair, while early postzygotic isolation was high for all other population pairs. Furthermore, the timing and strength of RI depended strongly on cross direction. Our study provides empirical support that reproductive barriers between species are highly variable among population pairs and asymmetric within population pairs, and this variation seems to follow patterns typically described across species pairs.

MR-based quantitative measurement of human soft tissue internal strains for pressure ulcer prevention.

Pressure ulcers are a severe disease affecting patients that are bedridden or in a wheelchair bound for long periods of time. These wounds can develop in the deep layers of the skin of specific parts of the body, mostly on heels or sacrum, making them hard to detect in their early stages. Strain levels have been identified as a direct danger indicator for triggering pressure ulcers. Prevention could be possible with the implementation of subject-specific Finite Element (FE) models. However, generation and validation of such FE models is a complex task, and the current implemented techniques offer only a partial solution of the entire problem considering only external displacements and pressures, or cadaveric samples. In this paper, we propose an in vivo solution based on the 3D non-rigid registration between two Magnetic Resonance (MR) images, one in an unloaded configuration and the other deformed by means of a plate or an indenter. From the results of the image registration, the displacement field and subsequent strain maps for the soft tissues were computed. An extensive study, considering different cases (on heel pad and sacrum regions) was performed to evaluate the reproducibility and accuracy of the results obtained with this methodology. The implemented technique can give insight for several applications. It adds a useful tool for better understanding the propagation of deformations in the heel soft tissues that could generate pressure ulcers. This methodology can be used to obtain data on the material properties of the soft tissues to define constitutive laws for FE simulations and finally it offers a promising technique for validating FE models.

Development of a preoperative questionnaire to improve satisfaction with hallux valgus repair: A Delphi study.

BACKGROUND: Satisfaction with hallux valgus repair is often poor, despite good surgical outcomes. Many tools have been developed to assess the outcome of the procedure; however none evaluate the association between the initial motive for repair and the reasons for post-surgical dissatisfaction. The aim of this study was to develop a new tool to analyse the subjective and objective expectations of individuals during a pre-operative consultation for hallux valgus repair in order to improve post-surgical satisfaction. METHODS: We first collected the reasons for dissatisfaction with repair from the medical files of dissatisfied individuals. Then, a steering committee of 4 French experts in the management of hallux valgus designed a questionnaire based on the reasons for dissatisfaction. We then used the DELPHI method to validate the questionnaire: we submitted the questionnaire to a panel of 34 francophone experts in hallux valgus repair for rating in 4 rounds. RESULTS: The medical files of 853 individuals were reviewed and a 52-item questionnaire relating to expectations from hallux valgus surgery was drafted. After the 4 rounds, a final 44 item questionnaire reached consensus. Thirteen items related to clinical and psychological profile, 5 to pain, 9 to physical activity, 4 to aesthetics and 13 to footwear. CONCLUSION: This tool should facilitate gathering of individuals' expectations from hallux valgus repair to ensure realistic goals and reduce post-surgical dissatisfaction.

New pressure ulcers dressings to alleviate human soft tissues: A finite element study.

Pressure Ulcers (PU) are real burdens for patients in healthcare systems, affecting their quality of life. External devices such as prophylactic dressings may be used to prevent the onset of PU. A new type of dressing was designed to alleviate soft tissue under pressure, with the objective to prevent PU and to improve the healing conditions of category-1 and category-2 wounds. The mechanical interactions of this dressing with a generic model of human skin/hypodermal soft tissue was simulated using the Finite Element (FE) method. Different cases with intact skin tissues and injured tissues with a category-2 PU, with and without dressings in place, were modeled. The tissues were deformed under compressive load; internal strains were computed. The results showed a clear benefit from the use of the dressing to reduce the peak internal strains both in the intact and injured tissues models by 17-25%, respectively. The intact soft tissues model was evaluated via sacral pressure measurements performed on one healthy volunteer. Results showed a good agreement between pressure measurements and estimations both with and without the dressing in place; particularly under the bony prominence and in surrounding tissues. As a conclusion, the importance of dressings to maintain a proper biochemical environment for the healing of PU is incontestable. Yet, new concepts of dressings may be developed to prevent the onset of PU, but also to provide local stress and strain reliefs and create mechanical conditions as less damaging as possible for the tissues.

Biomechanical lower limb model to predict patellar position alteration after medial open wedge high tibial osteotomy.

Medial open-wedge high tibial osteotomy is a surgical treatment for patients with a varus deformity and early-stage medial knee osteoarthritis. Observations suggest that this surgery can negatively affect the patellofemoral joint and change the patellofemoral kinematics. However, what causes these effects and how the correction angle can change the surgery's impact on the patellofemoral joint has not been investigated before. The objective of this study was to develop a biomechanical model that can predict the surgery's impact on the patellar position and find the correlation between the opening angles and the patellar position after the surgery. A combined finite element and multibody model of the lower limb was developed. The model's capabilities for predicting the patellofemoral kinematics were evaluated by performing a passive deep flexion simulation of the native knee and comparing the outcomes with magnetic resonance images of the study subject at various flexion angles. The model at a fixed knee flexion angle was then used to simulate the high tibial osteotomy surgery virtually. The results showed a correlation between the wedge opening angles and the patellar position in various degrees of freedom. These results indicate that larger wedge openings result in increased values of patellar distalization, lateral patellar shift, patellar rotation, and patellar internal tilt. The developed model in this study can be used in future studies to monitor the stress distribution on the patellar cartilage and connecting tissues to investigate their relationship with observations of pain and cartilage injury due to post-operative altered patellar kinematics.

Environment dependence of the expression of mutational load and species' range limits.

Theoretical and empirical research on the causes of species' range limits suggest the contribution of several intrinsic and extrinsic factors, with potentially complex interactions among them. An intrinsic factor proposed by recent theory is mutational load increasing towards range edges because of genetic drift. Furthermore, environmental quality may decline towards range edges and enhance the expression of load. Here, we tested whether the expression of mutational load associated with range limits in the North American plant Arabidopsis lyrata was enhanced under stressful environmental conditions by comparing the performance of within- versus between-population crosses at common garden sites across the species' distribution and beyond. Heterosis, reflecting the expression of load, increased with heightened estimates of genomic load and with environmental stress caused by warming, but the interaction was not significant. We conclude that range-edge populations suffer from a twofold genetic Allee effect caused by increased mutational load and stress-dependent load linked to general heterozygote deficiency, but there is no synergistic effect between them.

Bench testing of tracheostomy tube-related insults using an instrumented manikin.

PURPOSE: Choosing the right tracheal tube for the right patient is a daily preoccupation for intensivists and emergency physicians. Tracheal tubes can generate severe complications, which are chiefly due to the pressures applied by the tube to the trachea. We designed a bench study to assess the frequency of pressure levels likely to cause tracheal injury. METHODS: We tested the pressure applied on the trachea by 17 tube models of a given size range. To this end, we added a pressure sensor to the posterior tracheal wall of a standardized manikin. RESULTS: Only 2 of the 17 tubes generated pressures under the threshold likely to induce tracheal injury (30 mmHg/3.99 kPa). The force exerted on the posterior wall of the trachea varied widely across tube models. CONCLUSION: Most models of tracheal tubes resulted in forces applied to the trachea that are usually considered capable of causing tracheal tissue injury. LEVEL OF EVIDENCE: Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence: How common is the problem?: step 1; Is this diagnostic or monitoring test accurate? (Diagnosis) step 5; What will happen if we do not add a therapy? (Prognosis) n/a; Does this intervention help? (Treatment Benefits) step 5; What are the COMMON harms?(Treatment Harms) step 5; What are the RARE harms? (Treatment Harms) step 5; Is this (early detection) test worthwhile? (Screening) step 5.

MR-compatible loading device for assessment of heel pad internal tissue displacements under shearing load.

In the last decade, the role of shearing loads has been increasingly suspected to play a determinant impact in the formation of deep pressure ulcers. In vivo observations of such deformations are complex to obtain. Previous studies only provide global measurements of such deformations without getting the quantitative values of the loads that generate these deformations. To study the role that shearing loads have in the etiology of heel pressure ulcers, an MR-compatible device for the application of shearing and normal loads was designed. Magnetic resonance imaging is a key feature that allows to monitor deformations of soft tissues after loading in a non-invasive way. Measuring applied forces in an MR-environment is challenging due to the impossibility to use magnetic materials. In our device, forces are applied through the compression of springs made of polylactide. Shearing and normal loads were applied on the plantar skin of the human heel through a flat plate while acquiring MR images. The device materials did not introduce any imaging artifact and allowed for high quality MR deformation measurements of the internal components of the heel. The obtained subject-specific results are an original data set that can be used in validations for Finite Element analysis and therefore contribute to a better understanding of the factors involved in pressure ulcer development.

A Systematic Review on Selected Complications of Open-Wedge High Tibial Osteotomy from Clinical and Biomechanical Perspectives.

BACKGROUND: The wedge opened during high tibial osteotomy defines the alignment correction in different body planes and alters soft tissue insertions. Although multiple complications of the surgery can be correlated to this, there is still a lack of consensus on the occurrence of those complications and their cause. The current study is aimed at clarifying this problem using a combined medical and biomechanical perspective. METHODS: We conducted a systematic review of the literature on selective complications of the surgery correlated with the angles of the opened wedge. Search topics covered tibial slope alteration, patellar height alteration, medial collateral ligament release, and model-based biomechanical simulations related to surgical planning or complications. Findings. The selection process with the defined inclusion/exclusion criteria led to the collection of qualitative and quantitative data from 38 articles. Medial collateral ligament tightness can be a valid complication of this surgery; however, further information about its preoperative condition seems required for better interpreting the results. The posterior tibial slope significantly increases, and the patellar height (using the Blackburne-Peel ratio) significantly decreases in the majority of the selected studies. Model-based biomechanical studies targeting surgical planning are mostly focused on the lower-limb alignment principles and tibiofemoral contact balancing rather than surgical complications. Interpretation. Increased posterior tibial slope, patellar height decrease, and medial collateral ligament tightness can occur due to alterations in different body planes and in soft tissue insertions after wedge opening. This study clarified that information about preoperative alignment in all body planes and soft-tissue conditions should be considered in order to avoid and anticipate these complications and to improve per surgery wedge adaptation. The findings and perspective of this review can contribute to improving the design of future clinical and biomechanical studies.

Expressed mutational load increases toward the edge of a species' geographic range.

There is no general explanation for why species have restricted geographic distributions. One hypothesis posits that range expansion or increasing scarcity of suitable habitat results in accumulation of mutational load due to enhanced genetic drift, which constrains population performance toward range limits and further expansion. We tested this hypothesis in the North American plant, Arabidopsis lyrata. We experimentally assessed mutational load by crossing plants of 20 populations from across the entire species range and by raising the offspring of within- and between-population crosses at five common garden sites within and beyond the range. Offspring performance was tracked over three growing seasons. The heterosis effect, depicting expressed mutational load, was increased in populations with heightened genomic estimates of load, longer expansion distance or long-term isolation, and a selfing mating system. The decline in performance of within-population crosses amounted to 80%. Mutation accumulation due to past range expansion and long-term isolation of populations in the area of range margins is therefore a strong determinant of population-mean performance, and the magnitude of effect may be sufficient to cause range limits.

Three-Dimensional Reconstruction of Foot in the Weightbearing Position From Biplanar Radiographs: Evaluation of Accuracy and Reliability.

The initial assessment and postoperative monitoring of patients with various abnormalities of the foot in clinical routine practice is primarily based on the analysis of radiographs taken in the weightbearing position. Conventional x-ray imaging, however, only provides a 2-dimensional projection of 3-dimensional (3D) bony structures, and the clinical parameters assessed from these images can be affected by projection biases. In the present work, we addressed this issue by proposing an accurate 3D reconstruction method of the foot in the weightbearing position from low-dose biplanar radiographs with clinical index measurement assessment for clinical routine practice. The accuracy of the proposed reconstruction method was evaluated for both shape and clinical indexes by comparing 3D reconstructions of 6 cadaveric adult feet from computed tomographic images and from biplanar radiographs. For the reproducibility study, 3D reconstructions from the biplanar radiographs of the foot of 6 able-bodied subjects were considered, with 2 observers repeating each measurement of anatomic landmarks 3 times. Baseline assessment of important 3D clinical parameters was performed on 17 subjects (34 feet; mean age 27.7, range 20 to 52 years). The average point to surface distance between the 3D stereoradiographic reconstruction and the computed tomographic scan-based reconstruction was 1 mm (range 0mm to 6mm). The selected radiographic landmarks were highly reproducible (95% confidence interval <2.0 mm). The greatest interindividual variability for the clinical parameters was observed for the twisting angle (mean 87°, range 73° to 100°). Such an approach opens the way for routine 3D quantitative analysis of the foot in the weightbearing position.