Diabetic foot ulcer incidence in relation to plantar pressure magnitude and measurement location

A cross sectional pilot study utilising STrain Analysis and Mapping of the Plantar Surface (STAMPS) to measure plantar load characteristics within a healthy population

BACKGROUND

No in-shoe systems, measuring both components of plantar load (plantar pressure and shear stress) are available for use in patients with diabetes. The STAMPS (STrain Analysis and Mapping of the Plantar Surface) system utilises digital image correlation (DIC) to determine the strain sustained by a deformable insole, providing a more complete understanding of plantar shear load at the foot-surface interface.

RESEARCH QUESTIONS

What is the normal range and pattern of strain at the foot-surface interface within a healthy population as measured by the STAMPS system? Is STAMPS a valid tool to measure the effects of plantar load?

METHODS

A cross-sectional study of healthy participants was undertaken. Healthy adults without foot pathology or diabetes were included. Participants walked 20 steps with the STAMPS insole in a standardised shoe. Participants also walked 10 m with the Novel Pedar® plantar pressure measurement insole within the standardised shoe. Both measurements were repeated three times. Outcomes of interest were global and regional values for peak resultant strain (SMAG) and peak plantar pressure (PPP).

RESULTS

In 18 participants, median peak SMAG and PPP were 35.01 % and 410.6kPa respectively. The regions of the hallux and heel sustained the highest SMAG (29.31 % (IQR 24.56-31.39) and 20.50 % (IQR 15.59-24.12) respectively) and PPP (344.8kPa (IQR 268.3 - 452.5) and 279.3kPa (IQR 231.3-302.1) respectively). SMAG was moderately correlated with PPP (r= 0.65, p < 0.001). Peak SMAG was located at the hallux in 55.6 % of participants, at the 1st metatarsal head (MTH) in 16.7 %, the heel in 16.7 %, toes 3-5 in 11.1 % and the MTH2 in 5.6 %.

SIGNIFICANCE

The results demonstrate the STAMPS system is a valid tool to measure plantar strain. Further studies are required to investigate the effects of elevated strain and the relationship with diabetic foot ulcer formation.

Evaluating plantar biomechanics while descending a single step with different heights

Objective

This study aims to investigate the plantar biomechanics of healthy young males as they descend a single transition step from varying heights.

Methods

Thirty healthy young males participated the experiment using the F-scan insole plantar pressure system in which participants made single transition steps descent from four step heights (5, 15, 25, and 35 cm), leading with their dominant or non-dominant foot. Plantar pressure data were collected for 5 s during the period between landing touchdown and standing on the ground. Landing at each step height was repeated three times, with a five-minute rest between different height trials.

Results

At 5 cm and 15 cm steps, participants demonstrated a rearfoot landing strategy on both sides. However, forefoot contact was observed at heights of 25 cm and 35 cm. Parameters related to center of plantar pressure (COP) of the leading foot were significantly larger compared to the trailing foot (P < 0.001), increased with higher step heights. Vertical ground reaction forces for the biped, leading and trailing feet decreased with increasing step height (all P < 0.05). The leading foot had a higher proportion of overall and forefoot loads, and a lower proportion of rearfoot load compared to the trailing foot (P < 0.001). The overall load on the dominant side was lower than that on the non-dominant side for both the leading and trailing feet (P < 0.001). For the trailing foot, forefoot load on the dominant side was lower than that on the non-dominant side, however, the opposite result appeared in rearfoot load (P < 0.001). Upon the leading foot landing, forefoot load exceeded the rearfoot load for the dominant (P < 0.001) and non-dominant sides (P < 0.001). Upon the trailing foot landing, forefoot load was lower than the rearfoot load for the dominant (P < 0.001) and non-dominant sides (P = 0.019).

Conclusion

When the characteristics of biomechanical stability are compromised by step height, landing foot, and footedness factors - due to altered foot landing strategies, changing COP, or uneven force distribution - ability to control motion efficiently and respond adaptively to the forces experienced during movement is challenged, increasing the likelihood of loss of dynamic balance, with a consequent increased risk of ankle sprains and falls.

Exploration of predictive risk factors for diabetic foot in patients with diabetes in Beijing: analysis of 5-year follow-up data of patients with diabetes mellitus in a single center in Beijing

Background

Large-scale prospective cohort studies on diabetic foot ulcers risk factor screening in China are limited. Therefore, this prospective cohort study aimed to explore the predictive risk factors for diabetic foot ulcers to provide clinicians with concise and effective clinical indicators for identifying a high-risk diabetic foot and guiding the prevention of diabetic foot ulcers.

Methods

Patients with diabetes who visited the Department of Endocrinology of Peking University First Hospital from October 2017 to December 2018 were selected as research participants by convenience sampling. A total of 968 patients were included. After enrollment, a dedicated person collected and recorded all baseline data. A dedicated telephone follow-up was conducted every 12-24 months to evaluate whether the endpoint event had occurred. All patients were followed up for an average of 61 (57-71) months, with 95% of them followed up for more than 60 months. According to the occurrence of endpoint events, they were divided into the DFU and non-DFU groups. The data between the two groups were analyzed using independent-sample t-test, Wilcoxon rank sum test, and chi square test. We used univariate and multivariate logistic regression analysis to analyze the factors that affected the occurrence of diabetic foot ulcers.

Results and conclusions

After the 5-year follow-up, the incidence of diabetic foot was 25.83%. Multivariate logistic regression analysis revealed that body mass index (odds ratio: 1.046; 95% confidence interval: 1.001-1.093), abnormal pinprick sensation (odds ratio: 4.138; 95% confidence interval: 1.292-13.255), history of fungal foot infection (odds ratio: 2.287; 95% confidence interval: 1.517-3.448), abnormal 128-Hz tuning fork test (odds ratio: 2.628; 95% confidence interval: 1.098-6.294), and HbA1c≥ 8% (odds ratio: 1.522; 95% confidence interval: 1.014-2.284) were independent predictors of diabetic foot. Our study highlights clinically relevant indicators that may help to prevent the occurrence of diabetic foot and guide timely interventions.

Plantar pressure measurement in diabetic foot disease: A scoping review

AIMS/INTRODUCTION

Patients with a healed diabetic foot ulcer (DFU) have a 40% risk of ulcer recurrence within a year. New and effective measures to prevent DFU recurrence are essential. We aimed to highlight emerging trends and future research opportunities in the use of plantar pressure measurement to prevent DFU recurrence.

MATERIALS AND METHODS

Our scoping review protocol was drafted using the Preferred Reporting Items for Systematic Reviews and Meta-analysis - Scoping Review protocol. Peer-reviewed, English-language papers were included that addressed both plantar pressure measurement and diabetic foot disease, either as primary studies that have advanced the field or as review papers that provide summaries and/or opinion on the field as a whole, as well as specific papers that provide guidelines for future research and advancement in the field.

RESULTS

A total of 24 eligible publications were identified in a literature search using PubMed. A further 36 eligible studies were included after searching the references sections of these publications, leaving a total of 60 publications included in this scoping review.

CONCLUSIONS

Plantar pressure measurement can and will play a major role in the prevention of DFU. There is already a strong, albeit limited, evidence base in place to prove its benefit in reducing DFU recurrence. More research is required in larger populations, using remote monitoring in real-world settings, and with improved technology.

In-shoe plantar pressure measurement technologies for the diabetic foot: A systematic review

Introduction

Loss of cutaneous protective sensation and high plantar pressures increase the risk for diabetic foot patients. Trauma and ulceration are imminent threats, making assessment and monitoring essential. This systematic review aims to identify systems and technologies for measuring in-shoe plantar pressures, focusing on the at-risk diabetic foot population.

Methods

A systematic search was conducted across four electronic databases (Scopus, Web of Science, PubMed, Oxford Journals) using PRISMA methodology, covering articles published in English from 1979 to 2024. Only studies addressing systems or sensors exclusively measuring plantar pressures inside the shoe were included.

Results

A total of 87 studies using commercially available devices and 45 articles proposing new systems or sensors were reviewed. The prevailing market offerings consist mainly of instrumented insoles. Emerging technologies under development often feature configurations with four, six or eight resistive sensors strategically placed within removable insoles. Despite some variability due to the inherent heterogeneity of human gait, these devices assess plantar pressure, although they present significant differences between them in measurement results. Individuals with diabetic foot conditions appears exhibit elevated plantar pressures, with reported peak pressures reaching approximately 1000 kPa. The results also showed significant differences between the diabetic and non-diabetic groups.

Conclusion

Instrumented insoles, particularly those incorporating resistive sensor technology, dominate the field. Systems employing eight sensors at critical locations represent a pragmatic approach, although market options extend to systems with up to 960 sensors. Differences between devices can be a critical factor in measurement and highlights the importance of individualized patient assessment using consistent measurement devices.

White noise insole: an artificial evoked sensation device that can be expected to improve plantar sensation of diabetic foot

Diabetic foot is a common severe complication of diabetes, and its main symptom is diabetic foot ulcer. The production of plantar diabetic foot ulcers is usually affected by two factors, namely neuropathy or vascular disease. While previous studies proved that stochastic resonance (SR) could effectively enhance the plantar touch of patients with diabetic feet, the potential impact of SR on neural circuit feedback, especially on the input of the tactile nerves of the lower limbs, is less clear. This study aims to explore the potential impact on the tactile threshold of the human foot when using vibrating insoles. We study a white noise vibration insole based on SR mechanism. We compare and analyze the tactile threshold voltage (TTV) triggered by an electrical stimulation device in three main plantar pressure-bearing areas (the second metatarsal (M2), the fourth metatarsal (M4), and the heel (H) area) of 8 participants using EEG and self-developed vibration insole. Significance found in M2 and M4 areas, white noise signal (WNS) lowered the tactile threshold in these areas, and had a potentially positive impact on patients with diabetic feet, especially in the M4 area. The influence of WNS on the plantar heel area was still controversial. This study showed that WNS applied to the sole could improve the plantar tactile sensing ability of patients with diabetic feet, but it did not cover all areas. The application of WNS showed better benefits for the forefoot area than for the hindfoot area, which was speculated that may be related to the difference in the distribution density of blood vessels in plantar areas. Due to the impaired natural touch in participants with diabetic foot, using artificial evoked sensation WNS intervention, would be a feasible approach to improve plantar sensation.

A 2-Stage Approach in Managing Diabetic Forefoot Ulcers

BACKGROUND

Forefoot plantar ulcers in patients with diabetic neuropathy are considered to be primarily the result of increased shear forces applied over prominent plantar bony prominences. The purpose of this article is to describe a 2-stage treatment pathway utilizing an outpatient percutaneous tendon-Achilles lengthening (TAL) as the first stage procedure and subsequent proximal metatarsal osteotomy (MTO) as a second stage procedure for a persistent or recurrent ulcer.

METHODS

A consecutive 112 patients (146 feet), who presented to our Multidisciplinary Diabetic Foot Team clinics since February 2019 with plantar nonischemic forefoot ulcers were included in this study. Excluding the patients who died or were lost to follow-up, 96 feet were followed for a minimum 12 months (range 12-36 months). After TAL, patients were encouraged to walk in a walking cast for 6 weeks and were followed for a minimum 12 months. Patients with persistent or recurrent ulcers were investigated with magnetic resonance imaging scan, and based on intramedullary osteomyelitis and septic destruction of distal metatarsal, we describe a second-stage MTO with the 3 most common clinical presentations.

RESULTS

Of 96 feet, none had infection or wound-related problems following TAL. Complete transection of the tendon was noted in 4 patients (4%) and heel callosity in 1 patient. In 92 feet (96%), the ulcers healed within 10 weeks (±4 weeks) after TAL but, in 12 feet (10%), the ulcer failed to heal or recurred. At a minimum 12 months after the second-stage MTO, none in this subgroup had recurrence of ulcer or a transfer lesion.

CONCLUSION

TAL followed with a walking cast as an outpatient procedure was effective in healing forefoot ulcers in 96% of feet. Comparable to the widely practiced hand surgery Wide Awake Local Anesthesia No Tourniquet (WALANT) procedure, our approach involved active control of the degree of ankle dorsiflexion by the patient, and the procedure was proven to be safe and well tolerated. When the second-stage MTO was required to offload the forefoot, in our small cohort, patients had ulcer-free outcome for a minimum 12 months.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Dry needling of the flexor digitorum brevis muscle reduces postural control in standing: A pre-post stabilometric study

There are studies that show the better balance after dry needling in lumbar pain. However, the postural control effects after foot dry needling are unknown. Our objective was to check if dry needling reduces postural control. Eighteen subjects with flexor digitorum brevis (FDB) muscle Myofascial trigger point were evaluated pre- and post-deep dry needling. We measured stabilometric variables in a pre-post study. We have found significant differences in three stabilometric variables: surface with eyes closed (29.36-53.21 mm2 ) (p = 0.000), medium speed of the laterolateral displacement with eyes closed (1.42-1.64 mm/s) (p = 0.004), and medium speed of the anteroposterior displacement with eyes closed (1.30-1.53 mm/s) (p = 0.025). Dry needling therapy application in FDB muscle reduces standing postural control with eyes closed.

Evaluating the use of a novel low-cost measurement insole to characterise plantar foot strain during gait loading regimes

Introduction: Under plantar loading regimes, it is accepted that both pressure and shear strain biomechanically contribute to formation and deterioration of diabetic foot ulceration (DFU). Plantar foot strain characteristics in the at-risk diabetic foot are little researched due to lack of measurement devices. Plantar pressure comparatively, is widely quantified and used in the characterisation of diabetic foot ulceration risk, with a range of clinically implemented pressure measurement devices on the market. With the development of novel strain quantification methods in its infancy, feasibility testing and validation of these measurement devices for use is required. Initial studies centre on normal walking speed, reflecting common activities of daily living, but evaluating response to differing gait loading regimes is needed to support the use of such technologies for potential clinical translation. This study evaluates the effects of speed and inclination on stance time, strain location and strain response using a low-cost novel strain measurement insole. Methods: The STrain Analysis and Mapping of the Plantar Aspect (STAMPS) insole has been developed, and feasibility tested under self-selected normal walking speeds to characterise plantar foot strain, with testing beyond this limited regime required. A treadmill was implemented to standardise speed and inclination for a range of daily plantar loading conditions. A small cohort, comprising of five non-diabetic participants, were examined at slow (0.75 m/s), normal (1.25 m/s) and brisk (2 m/s) walking speeds and normal speed at inclination (10% gradient). Results: Plantar strain active regions were seen to increase with increasing speed across all participants. With inclination, it was seen that strain active regions reduce in the hindfoot and show a tendency to forefoot with discretionary changes to strain seen. Stance time decreases with increasing speed, as expected, with reduced stance time with inclination. Discussion: Comparison of the strain response and stance time should be considered when evaluating foot biomechanics in diabetic populations to assess strain time interval effects. This study supports the evaluation of the STAMPS insole to successfully track strain changes under differing plantar loading conditions and warrants further investigation of healthy and diabetic cohorts to assess the implications for use as a risk assessment tool for DFU.

Compensatory gait mechanics in person with multiple toe amputation: A single case report

This case highlights the biomechanical influence of toe amputation on contralateral limb force elevation, possibly through reduced ipsilateral plantar flexor torque production. These findings provide insight into toe amputation-related compensatory gait mechanics with greater inter-limb asymmetry, which may increase the risk of musculoskeletal comorbidities, including osteoarthritis in contralateral limb.

Novel 3D-printed foot orthoses with variable hardness: A comfort comparison to traditional orthoses

Custom foot orthoses are used to treat a variety of foot pathologies. However, orthotic production requires significant hands-on fabrication time and expertise to produce orthoses that are both comfortable and effective. This paper introduces a novel 3D printed orthosis and fabrication method that utilizes custom architectures to produce variable-hardness regions. These novel orthoses are compared to traditionally fabricated orthoses during a 2-week user comfort study. Twenty (n = 20) male volunteers underwent orthotic fitting for both traditional and 3D-printed foot orthoses prior to engaging in treadmill walking trials and 2 weeks of wear. Each participant undertook a regional comfort, acceptance, and comparison analysis of the orthoses at three time points throughout the study (0, 1, and 2 weeks). Both the 3D-printed and the traditionally fabricated foot orthoses demonstrated statistically significant increases in comfort when compared to the factory fabricated shoe insert. Additionally, the two orthosis groups were not significantly different from each other in comfort rankings both regionally and overall at any time point. The similar comfort achieved by the 3D-printed orthosis to the traditionally fabricated orthosis after 7 days and 14 days emphasizes the potential of the future use of the more reproducible and adaptable 3D-printed orthosis manufacturing methodology.

Accuracy of Foot Pressure Measurement on Predicting the Development of Foot Ulcer in Patients with Diabetes: A Systematic Review and Meta-Analysis

OBJECTIVE

Areas of the foot with diabetic ulcers have been observed to have greater plantar pressures compared to non-ulcerated. Pressures play an essential role in the mechanism of lesion, and their reduction is effective in prevention. We conducted a systematic review to evaluate pedobarography as a predictive tool for ulcer development, since there is still no consensus on this aspect.

METHODS

We searched PUBMED (MedLine), EMBASE, Scopus, Web of Science, CINAHL and Scielo for cohort studies that measured plantar pressure at baseline and verified ulcer development on follow-up. Pooled effects of accuracy, sensitivity, specificity and relative risk were calculated using the inverse variance method. Risk of bias was assessed using the QUADAS-2 tool.

RESULTS

Three studies (n = 2000) had enough information on accuracy to be included into a meta-analysis, and 4 (n = 2651) were analyzed using qualitative methods. Pooled sensitivity and specificity were found to be 0.63 (Confidence Interval (CI) 0.58-0.68) and 0.42 (CI 0.27-0.58), respectively. Pooled relative risk was 1.95 (CI 1.09-3.51). Risk of bias was low to uncertain.

CONCLUSIONS

Pedobarography in itself appears to have low accuracy in evaluating risk of ulceration. Several methodological heterogeneities were found, and the most optimal cut-off value is yet to be determined.

Radiographic Bone Healing in Minimally Invasive Floating Metatarsal Osteotomy for Neuropathic Plantar Metatarsal Head Ulcers - A Retrospective Cohort Study

Minimally invasive floating metatarsal osteotomy is an option for treating neuropathic ulcers under the metatarsal heads. This study presents the radiographic results of the floating metatarsal osteotomy. We reviewed files and radiographs at least 4 months after a floating metatarsal osteotomy in patients with diabetic neuropathy. In 71 osteotomies in 54 patients with late onset diabetes (mean age 61 ± 9, mean HbA1c 7.9 ± 1.9%), the primary ulcer healed within 3.5 ± 1.4 weeks. Of 66 osteotomies where radiographs were available 10 had non-union (15%, all asymptomatic), 15 (23%) had hypertrophic callus formation and 41 (62%) had normal union. One patient developed an ulcer under the hypertrophic callus. This necessitated callus resection. Asymptomatic non-union may happen in 15% of floating osteotomies, but the osteotomies appear to be relatively safe and effective for neuropathic plantar metatarsal head ulcers. Hypertropic callus causing local re-ulceration is rare and can be managed surgically.

Self-offloading therapeutic footwear using compliant snap-through arches

In diabetic peripheral neuropathy, offloading high-plantar-pressure areas using statically offloaded customized insoles or expensive sensors and actuators are commonly-followed treatment procedures. In this article, we propose the concept of dynamically self-offloading therapeutic footwear that operates mechanically without using sensors and actuators. We achieve this by using an array of snapping arches. When a load higher than a bespoke value is applied, these arches enter negative-stiffness regime and offload the high-pressure region by snapping to a different shape. They again return to their initial shape when the load disappears. Thus, they serve as both sensors and actuators that get actuated by person's body weight. We present an analytical method to compute the switching load and the switchback time of such arches and use them to customize the footwear according to the person's body weight, gait speed, and foot size. We identify the high-pressure regions from the clinical data and place the arches such that these high-pressure regions get dynamically offloaded, and the pressure gets redistributed to other regions. We considered 200 kPa as a limiting pressure to prevent the prolonged effects of high plantar pressure. To check the efficacy of the concept, a complete 3D-printed prototype made of thermoplastic polyurethane was tested and compared with barefoot and in-shoe plantar pressure for subjects recruited at a clinical facility. We notice that the self-offloading insole shows the plantar pressure reduction at all the foot regions, and significant offloading of 57% is observed at the forefoot region.

Knowledge and practice of diabetic foot care and the prevalence of diabetic foot ulcers among diabetic patients of selected hospitals in the Volta Region, Ghana

Diabetic foot ulcers (DFUs) are a common but serious complication of diabetes mellitus (DM). The factors distressing the worth of diabetic foot care (DFC) are knowledge and practice. Foot ulcers are the main cause of amputation and death in people suffering from DM. This study assessed the knowledge and practice of DFC and the prevalence of DFUs and its associated factors among diabetic patients of selected hospitals in the Volta Region, Ghana. A multihospital-based cross-sectional study was conducted among 473 patients with DM who were recruited using the systematic sampling method. Data were collected using a validated, pretested, and structured questionnaire, while medical variables were obtained from patient folders and analysed using SPSS version 23. All statistically significant parameters in bivariate analysis were incorporated in the multivariate logistic regression analysis. The results showed that 63% of diabetic patients had good knowledge of DFC, while 49% competently practiced it. A negative correlation was found between knowledge and practice levels of DFC (r = -0.15, P = <.01). The prevalence of DFUs was 8.7% among the studied diabetic patients. Male diabetic patients were 3.4 times more likely to develop DFUs than female diabetic patients (crude odd ratio [cOR] = 3.35; 95% confidence interval [CI] = 1.75-6.43; P = <.001). Type 1 diabetic patients were five times more likely to develop DFUs than those who had type 2 diabetes (cOR = 5.00; 95% CI = 2.50-10.00; P = <.001). Diabetic patients who had a family history of diabetes were 4.7 times more likely to develop DFUs than those without family history (adjusted odd ratio [aOR] = 4.66; 95% CI = 1.55-13.89; P = .006). Those who had diabetes for 5 to 10 years were 3.3 times more likely to develop DFUs than those who had diabetes for less than 5 years (aOR = 3.28; 95% CI = 1.40-7.67; P = .006). Diabetic patients who had comorbidity were 3.4 times more likely to develop DFUs than those without comorbidity (cOR = 3.35; 95% CI = 1.74-6.45; P = <.001). The study found that there was good knowledge but poor practices of DFC among patients. Health care providers are expected to better educate patients and emphasise self-care practices to patients. Health care providers should also give more attention to patients with associated risk factors to avoid further complications and reduce the occurrence of DFUs.

Site-Specific, Critical Threshold Barefoot Peak Plantar Pressure Associated with Diabetic Foot Ulcer History: A Novel Approach to Determine DFU Risk in the Clinical Setting

Background and Objectives: Barefoot peak plantar pressures (PPPs) are elevated in diabetes patients with neuropathic foot ulcer (DFU) history; however, there is limited reported evidence for a causative link between high barefoot PPP and DFU risk. We aimed to determine, using a simple mat-based methodology, the site-specific, barefoot PPP critical threshold that will identify a plantar site with a previous DFU. Materials and Methods: In a cross-sectional study, barefoot, site-specific PPPs were measured with normal gait for patients with DFU history (n = 21) and healthy controls (n = 12), using a validated carbon footprint system. For each participant, PPP was recorded at twelve distinct plantar sites (1st–5th toes, 1st–5th metatarsal heads (MTHs), midfoot and heel), per right and left foot, resulting in the analysis of n = 504 distinct plantar sites in the diabetes group, and n = 288 sites in the control group. Receiver operator characteristic curve analysis determined the optimal critical threshold for sites with DFU history. Results: Median PPPs for the groups were: diabetes sites with DFU history (n = 32) = 5.0 (3.25–7.5) kg/cm², diabetes sites without DFU history (n = 472) = 3.25 (2.0–5.0) kg/cm², control sites (n = 288) = 2.0 (2.0–3.25) kg/cm²; (p < 0.0001). Diabetes sites with elevated PPP (>6 kg/cm²) were six times more likely to have had DFU than diabetes sites with PPP ≤ 6 kg/cm² (OR = 6.4 (2.8–14.6, 95% CI), p < 0.0001). PPP > 4.1 kg/cm² was determined as the optimal critical threshold for identifying DFU at a specific plantar site, with sensitivity/specificity = 100%/79% at midfoot; 80%/65% at 5th metatarsal head; 73%/62% at combined midfoot/metatarsal head areas. Conclusions: We have demonstrated, for the first time, a strong, site-specific relationship between elevated barefoot PPP and previous DFU. We have determined a critical, highly-sensitive, barefoot PPP threshold value of >4.1 kg/cm², which may be easily used to identify sites of previous DFU occurrence and, therefore, increased risk of re-ulceration. This site-specific approach may have implications for how high PPPs should be investigated in future trials.

Split Anterior Tibial Tendon Transfer to Dorsal Lateral Foot for Cavovarus Deformities With Neuropathic Ulcerations: A Case Series

Cavovarus deformity leads to increased peak pressure on the plantar lateral foot, which can lead to ulceration, and can potentially progress to amputation. Techniques have been suggested in the treatment of cavovarus deformity, such as peroneus brevis or longus tendon transfer, anterior tibial tendon lengthening, posterior tibial tendon transfer, or boney resection. This case series shows split anterior tibial tendon transfer as a surgical reconstruction of cavovarus pedal deformity. Our technique of split anterior tibial tendon in-phase transfer to the dorsal lateral foot, restores the eversion and dorsiflexory pull necessary to offset peroneal attenuation. The procedure can be performed primarily or staged, in order to achieve infection temporization prior to the transfer. A total of 14 patients underwent split anterior tibial tendon transfer, 57.14% (8/14) of which had preoperative ulcerations, and 42.86% (6/14) of which had preoperative hyperkeratotic pre-ulcerative lesions. The preoperative ulcerations were present for an average of 67.89 weeks (range 2-232), with an average area of 6.09 ± 7.44 cm². The ulcerations healed in 75% (6/8) of the patients, at 19.67 weeks (range 1.57-76), with new ulceration occurrence in 7.14% (1/14) of patients, 7.14% (1/14) rate of ulceration recurrence. None of the patients went on to minor or major amputation. The goal of the tendon transfer is to decrease midfoot plantar pressures on the lateral foot and allow for resolution of pre-existing ulcerations and rebalancing the foot and ankle.

Plantar shear stress in the diabetic foot: A systematic review and meta-analysis

AIMS

Diabetic foot ulceration (DFU) is a multifactorial process involving undetected, repetitive trauma resulting in inflammation and tissue breakdown. Shear stress forms a major part of plantar load, the aim of this review is to determine whether elevated shear stress results in ulceration.

METHODS

A systematic review of the Ovid Medline, EMBASE, CINAHL and Cochrane library databases was performed. Studies involving patients with diabetes who underwent plantar shear stress assessment were included. The primary outcome was plantar shear stress in patients with diabetes who had a current/previous DFU compared with those with no prior ulceration. Meta-analysis was performed comparing shear stress between those with a current or previous DFU and those without, and those with diabetes and healthy controls.

RESULTS

The search strategy identified 1461 potentially relevant articles, 16 studies met the inclusion criteria, involving a total of 597 patients. Comparing shear stress between the current/previous DFU group and those without: Standardised mean difference (SMD) 0.62 (95% CI -0.01 to 1.25), in favour of greater shear stress within the DFU group, p = 0.05. Comparing shear stress between people with diabetes and healthy controls: 0.36 (95% CI -0.31 to 1.03), in favour of greater shear stress within the diabetes group, p = 0.29.

CONCLUSION

This review suggests that that patients with diabetes and a history of ulceration exhibit greater shear stress than their ulcer-free counterparts. This strengthens the premise that development of systems to measure shear stress may be helpful in DFU prediction and prevention.

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.

Impact of Asthma on Plantar Pressures in a Sample of Adult Patients: A Case-Control Study

Based on the high prevalence of asthma in the population, and its relationship with various musculoskeletal and postural disorders, the aim of this study was to evaluate the plantar pressures in asthmatic patients compared to a control group. A case-control study involving 90 participants was conducted, consisting of 45 asthma patients and 45 healthy paired controls. Static plantar pressure data were recorded using a portable pressure sensor platform. Statistically significant differences were shown in the body weight on the left heel (p = 0.031), and the right forefoot maximum peak pressure was lower in the case group (p = 0.042). The findings of this study show alterations in static plantar pressures in asthmatic patients compared to healthy individuals. Specifically, the subjects with asthma showed less maximum pressure in the right forefoot and less weight on the left heel, which appear to be associated with the asthma disease.

Clinical foot measurements as a proxy for plantar pressure testing in people with diabetes

Background

High plantar pressures are associated with increased foot ulcer risk in people with diabetes. Identification of high plantar pressures in people with diabetes is clinically challenging due to time and cost constraints of plantar pressure testing. Factors affecting foot biomechanics, including reduced joint range of motion and foot deformity, are implicated in the development of high plantar pressures and may provide a method to clinically identify those at risk of pressure related complications. The aim of this study was to investigate the contribution of joint range of motion and foot deformity measures on plantar pressures in a community dwelling group with diabetes.

Methods

Barefoot (Tekscan HR Mat™) and in-shoe (Novel Pedar-X®) plantar pressure variables, weight bearing ankle dorsiflexion, hallux range of motion, lesser toe deformities and hallux abductus (HAV) scale were assessed in 136 adults with diabetes (52.2% male; mean age 68.4 years). Multivariate multiple linear regression was used to assess the effect of the four biomechanical factors plus neuropathy and body mass index on plantar pressure variables. Non-parametric bootstrapping was employed to determine the difference in plantar pressure variables for participants with two or more foot biomechanical pathologies compared to those with less than two pathologies.

Results

Almost one third (32%) of the cohort had two or more foot biomechanical pathologies. Participants with two or more foot biomechanical pathologies displayed significant increases in all barefoot plantar pressure regions (except forefoot), compared to those with less than two pathologies. No significant changes were found for the in-shoe plantar pressure variables. The regression model explains between 9.9% (95%CI: 8.4 to 11.4%) and 29.6% (95% CI: 28.2 to 31%), and between 2.5% (1.0 to 4.0%) and 43.8% (95% CI: 42.5–44.9%), of the variance in the barefoot and in-shoe plantar pressure variables respectively.

Conclusions

Participants presenting with two or more factors affecting foot biomechanics displayed higher peak pressures and pressure time integrals in all foot regions compared to those with less than two factors. The tests used in this study could help clinicians detect elevated plantar pressures in people with diabetes and present an opportunity for early preventative interventions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13047-021-00494-4.

The Role of Cutaneous Microcirculatory Responses in Tissue Injury, Inflammation and Repair at the Foot in Diabetes

Diabetic foot syndrome is one of the most costly complications of diabetes. Damage to the soft tissue structure is one of the primary causes of diabetic foot ulcers and most of the current literature focuses on factors such as neuropathy and excessive load. Although the role of blood supply has been reported in the context of macro-circulation, soft tissue damage and its healing in the context of skin microcirculation have not been adequately investigated. Previous research suggested that certain microcirculatory responses protect the skin and their impairment may contribute to increased risk for occlusive and ischemic injuries to the foot. The purpose of this narrative review was to explore and establish the possible link between impairment in skin perfusion and the chain of events that leads to ulceration, considering the interaction with other more established ulceration factors. This review highlights some of the key skin microcirculatory functions in response to various stimuli. The microcirculatory responses observed in the form of altered skin blood flow are divided into three categories based on the type of stimuli including occlusion, pressure and temperature. Studies on the three categories were reviewed including: the microcirculatory response to occlusive ischemia or Post-Occlusive Reactive Hyperaemia (PORH); the microcirculatory response to locally applied pressure such as Pressure-Induced Vasodilation (PIV); and the interplay between microcirculation and skin temperature and the microcirculatory responses to thermal stimuli such as reduced/increased blood flow due to cooling/heating. This review highlights how microcirculatory responses protect the skin and the plantar soft tissues and their plausible dysfunction in people with diabetes. Whilst discussing the link between impairment in skin perfusion as a result of altered microcirculatory response, the review describes the chain of events that leads to ulceration. A thorough understanding of the microcirculatory function and its impaired reactive mechanisms is provided, which allows an understanding of the interaction between functional disturbances of microcirculation and other more established factors for foot ulceration.

Plantar Pressure Distribution Among Diabetes and Healthy Participants: A Cross-sectional Study

Background:

Plantar Pressure distribution refers to the distribution of force over the sole of the foot. Recently many studies indicate plantar pressure distribution assisted in determining and managing the impairment related to musculoskeletal disorders.

Methods:

This cross-sectional study was conducted with forty participants (20 diabetes type 2 patients +20 healthy) from Imam Abdulrahman bin Faisal University. All the measurements were taken in the morning session. To measure height and weight, participants took off their shoes and stood on the stadiometer. The body mass index determined with the help of a bioelectric impedance device to get the health level of the participants—Proclaimed diabetes type 2 patients selected for the data collection. Tekscan's Mobile Mat was used to determine the plantar pressure of healthy and diabetes participants.

Results:

The finding revealed that diabetes participants have more pressure in the mid-foot section, whereas healthy participants showed more pressure on the heel section. The metatarsal section showed similar types of pressure distribution in both participants. The result also revealed that diabetes participants have more peak pressures, time integral, and gradient than healthy participants. Significant differences between diabetes and healthy participants were existing.

Conclusions:

The findings highlight the importance of measuring plantar pressure distribution since these are known to incorporate in the main parts of the foot and thus provide a shred of constructive evidence for the total load exposer of a single leg static task.

Bare Foot and In-shoe Plantar Pressure in Diabetic Males and Females - Is There Difference?

Purpose

High plantar pressure is one of the factors associated with foot ulceration in diabetic patients. High-risk limbs could eventually be identified through this approach. The study was conducted to evaluate the difference in the barefoot and in-shoe plantar pressure among diabetic males and females.

Patients and Methods

A cross-sectional study was conducted and purposive sampling was employed for the recruitment of subjects in King Abdullah walking center. The dynamic plantar pressure generated by each subject was recorded using “novel footprint software” and up to five successful trials were collected for each subject of right and left foot.

Results

The mean age of female and male patients was 50.6 ± 13.4 and 46.07 ± 11.17, respectively. The mean difference between the weights was higher in males. The barefoot peak plantar pressure between gender in left limb was found significant. Moreover, the mean difference in plantar pressure at maximum concentration and maximum force of right and left limb between males and females was found statistically significant. The mean difference in in-shoe plantar pressure at maximum force of left limb between males and females was found statistically significant.

Conclusion

As the prevalence of diabetes is increasing, the risk of plantar pressure also increasing simultaneously. The difference in plantar pressure among diabetic males and females is critically important as our study indicated that the bare foot and in-shoe plantar pressure was found higher in males than females as males had higher weight than females. Further longitudinal studies are required to be conducted in this context.

Reliability of ultrasound in evaluating the plantar skin and fat pad of the foot in the setting of diabetes

Ultrasound can be used to assess injury and structural changes to the soft-tissue structure of the foot. It may be useful to assess the feet of people with diabetes who are at increased risk of plantar soft-tissue pathological changes. The aim of this study was to determine if ultrasound measurements of plantar soft-tissue thickness and assessments of tissue acoustic characteristics are reliable in people with and without diabetes mellitus. A repeated measures design was used to determine intra-observer reliability for ultrasound measurements of plantar skin and fat pad thickness and intra- and inter-observer reliability of plantar skin and fat pad tissue characterisation assessments made at foot sites which are at risk of tissue injury in people with diabetes. Thickness measurements and tissue characterisation assessments were obtained at the heel and forefoot in both the unloaded and compressed states and included discrete layers of the plantar tissues: skin, microchamber, horizontal fibrous band, macrochamber and total soft-tissue depth. At each site, relative intra-observer reliability was achieved for the measurement of at least one plantar tissue layer. The total soft-tissue thickness measured in the unloaded state (ICC 0.925-0.976) demonstrated intra-observer reliability and is the most sensitive for detecting small change on repeated measures. Intra-observer agreement was demonstrated for tissue characteristic assessments of the skin at the heel (k = 0.70), fat pad at the lateral sesamoid region (k = 0.70) and both skin and fat pad at the second (k = 0.80, k = 0.70 respectively) and third metatarsal heads (k = 0.90, k = 0.79 respectively). However, acceptable inter-observer agreement was not demonstrated for any tissue characteristic assessment, therefore the use of multiple observers should be avoided when making these assessments.

Causation Research on Diabetic Foot Complications-What I Learned From Roger Pecoraro: The 2021 Roger E. Pecoraro Award Lecture

Roger Pecoraro made important contributions to diabetic foot research and is primarily responsible for instilling in me an interest in these complications. Our collaboration in the final years of his life led to the development of the Seattle Diabetic Foot Study. At the time it began, the Seattle Diabetic Foot Study was perhaps unique in being a prospective study of diabetic foot ulcer conducted in a nonspecialty primary care population of patients with diabetes and without foot ulcer. Important findings from this research include the demonstration that neurovascular measurements, diabetes characteristics, past history of ulcer or amputation, body weight, and poor vision all significantly and independently predict foot ulcer risk. A prediction model from this research that included only readily available clinical information showed excellent ability to discriminate between patients who did and did not develop ulcer during follow-up (area under the receiver operating characteristic curve [AUROC] 0.81 at 1 year). Identification of limb-specific amputation risk factors showed considerable overlap with those risk factors identified for foot ulcer but suggested arterial perfusion as playing a more important role. Risk of foot ulcer in relation to peak plantar pressure estimated at the site of the pressure measurement showed a significant association over the metatarsal heads, but not other foot locations, suggesting that the association between pressure and this outcome may differ by foot location. The Seattle Diabetic Foot Study has helped to expand our knowledge base on risk factors and potential causes of foot complications. Translating this information into preventive interventions remains a continuing challenge.

Immediate Effect of Manual Therapy on Tibiotarsal Joint Mobility and Static Balance in Individuals With Diabetes

Objectives

The objective of this study was to evaluate the immediate effect of manual therapy on ankle joint mobility and static balance in patients with diabetes.

Methods

Forty patients, at a mean age of 59.35 ± 7.85, with type 2 diabetes mellitus and neurologic symptoms according to a Neuropathy Symptom Score protocol with amplitude, were included. The patients were divided into 2 groups: sham group and intervention group, which underwent manual manipulation intervention and 7-day follow-up. Joint range-of-motion analysis was performed using digital goniometry and static discharge of weights assessed by computerized baropodometry with open and closed eyes. The Shapiro-Wilk normality test was used to analyze the distribution. The data showed normal distribution, so the analysis of variance tests followed by Tukey's tests were used. SAS statistical software was used and the significance level was 5%.

Results

The results of the intervention group showed an increase in the variable ankle goniometry over time compared to the sham group. The dorsiflexion movement on the right side obtained major gains over time; in addition, plantar flexion increased.

Conclusion

Based on the participants evaluated in this study, manual therapy increased the ankle joint amplitude and improved the static balance in individuals with diabetes.

A Meta-Analysis of the Outcomes of Resection Arthroplasty for Resistant Hallucal Diabetic Ulcers

The standard medical care (SC) of non-infected diabetic foot ulcers (DFUs) has been reported to yield varying rates of wound healing with high recurrence rate in non-infected wounds. Conservative surgery has been advanced as an alternative to SC in treating resistant non-complicated and complicated DFUs. Studies reporting resection arthroplasty (RA) of the first metatarsal head stated high healing rates with less recurrence. The aim of this meta-analysis is to quantitatively assess the efficacy of the RA procedure. Based on 9 included studies (3 case-control and 6 case-series) with 225 patients (244 feet, 244 hallucal plantar ulcers) and a mean follow-up period was of 22.8 ±13.3 months, the weighted estimates of comparative studies (RA vs. SC) were as follows: healing rate (100% vs. 79.9%, p = .0001), time to heal (3.3 ±0.28 vs. 8.4 ±1.5 weeks, p = .002), recurrence rate (5.7% vs. 25.4%, p = .001) and transfer rate (4.5% vs. 1.4%, p = .1). Similar values were found when analyzing case-series of non-infected and infected wounds treated with RA. Based on the available evidence, resection arthroplasty of the first ray is to be considered an effective conservative surgery in treating resistant or complicated hallucal neuropathic ulcers. Further prospective controlled trials are warranted to validate the review findings.

The Concurrent Validity, Test-Retest Reliability and Usability of a New Foot Temperature Monitoring System for Persons with Diabetes at High Risk of Foot Ulceration

At-home foot temperature monitoring may be useful in the early recognition of imminent foot ulcers that occur through biomechanical loading in people with diabetes. We assessed the concurrent validity, test–retest reliability, and usability of a new plantar foot temperature monitoring device in 50 people with diabetes and peripheral neuropathy. We compared plantar foot temperature measurements with a platform system that consists of embedded temperature sensors with those from a handheld infrared thermometer that was used as a reference. Repeated platform assessments were compared for test–retest reliability. Usability was assessed in 15 participants who used both devices daily for two weeks at home, after which they completed a questionnaire. Agreement between devices was excellent for the metatarsal heads and heel (ICCs ≥ 0.98, LOA: −0.89 °C; 1.16 °C) and hallux and lateral midfoot (0.93 ≤ ICC ≤ 0.96, LOA: −2.87 °C; 2.2 °C), good for digits 2–5 (0.75 ≤ ICC ≤ 0.88, LOA: −5.04 °C; 2.76 °C), and poor for the medial midfoot (ICC = 0.19, LOA: −8.21 °C; −0.05 °C). Test–retest reliability was high (ICC = 0.99, LOA: −0.59 °C; 1.35 °C). Participants scored between 3.8 and 4.3 on a 5-point Likert scale for willingness to measure, ease of use, measurement comfort, and duration. In conclusion, the platform shows good concurrent validity in foot regions where most ulcers occur, good test–retest reliability, and good usability for measuring plantar foot temperature. Further research should assess the clinical validity of the platform to help prevent plantar diabetic foot ulcers.

Assessment of Outcomes of a Metatarsal Bone Ostectomy for Chronic Plantar Ulcers: A Preliminary Study

BACKGROUND

Clinical management of chronic plantar ulcers is a difficult issue in medical practice. Pressure overloading is a problem that needs to be resolved. Herein, we report a surgical method to reduce plantar pressure: a dorsal approach to a metatarsal ostectomy.

METHODS

From March 2011 to October 2016, 16 patients suffering from chronic plantar ulcers underwent ostectomy procedures at Taipei Wan-Fang Municipal Hospital (Taipei Medical University). A bone segment about 0.5 to 1 cm long was removed via a dorsal foot approach. The plantar wound was treated with debridement only or was simultaneously covered with a skin graft. In total, 16 patients with an average age of 57.81 (SD, 11.6) years (12 males and 4 females) were included; 15 patients (93.75%) had a diagnosis of type 2 diabetes for a mean of 20.66 years (range, 5-30 years). The mean glycated hemoglobin was 9.14 g/dL (range, 5.2-13.2 g/dL). The mean plantar wound size was 5.72 cm. Four patients (25%) needed to receive a skin graft with a mean skin graft size of 8.13 cm.

RESULTS

The mean follow-up time was 15.2 months. The plantar wounds completely healed in 14 patients (87.5%) in an average of 2.14 months. No plantar ulcer was complicated with recurrence, but transfer ulcers developed in 2 patients (12.5%) at an average of 7.5 months postoperatively.

CONCLUSIONS

Metatarsal ostectomy surgery via a dorsal foot approach is an efficient way to reduce pressure overloading of chronic plantar wounds. Our study provides an alternative method to treat this difficult problem with a high wound healing rate and less recurrence.

Monitoring of Dynamic Plantar Foot Temperatures in Diabetes with Personalised 3D-Printed Wearables

Diabetic foot ulcers (DFUs) are a life-changing complication of diabetes that can lead to amputation. There is increasing evidence that long-term management with wearables can reduce incidence and recurrence of this condition. Temperature asymmetry measurements can alert to DFU development, but measurements of dynamic information, such as rate of temperature change, are under investigated. We present a new wearable device for temperature monitoring at the foot that is personalised to account for anatomical variations at the foot. We validate this device on 13 participants with diabetes (no neuropathy) (group name D) and 12 control participants (group name C), during sitting and standing. We extract dynamic temperature parameters from four sites on each foot to compare the rate of temperature change. During sitting the time constant of temperature rise after shoe donning was significantly (p < 0.05) faster at the hallux (p = 0.032, 370.4 s (C), 279.1 s (D)) and 5th metatarsal head (p = 0.011, 481.9 s (C), 356.6 s (D)) in participants with diabetes compared to controls. No significant differences at the other sites or during standing were identified. These results suggest that temperature rise time is faster at parts of the foot in those who have developed diabetes. Elevated temperatures are known to be a risk factor of DFUs and measurement of time constants may provide information on their development. This work suggests that temperature rise time measured at the plantar surface may be an indicative biomarker for differences in soft tissue biomechanics and vascularisation during diabetes onset and progression.

A Meta-Analysis of the Outcomes of Metatarsal Head Resection for the Treatment of Neuropathic Diabetic Foot Ulcers

Significance: Diabetic foot ulcers (DFUs) are associated with high morbidity, mortality, and health costs. Standard care (SC) associated with nonsurgical offloading is the mainstay treatment for DFUs, but it has high recurrence and infection rates. Metatarsal head resection (MHR) has been proposed as an effective surgical offloading technique for the treatment of plantar neuropathic DFUs, but with no evidence synthesis yet. Recent Advances: Based on PRISMA guidelines, a meta-analysis was conducted to assess the efficacy of MHR. Four electronic databases were searched for. Eleven studies met the inclusion criteria with a total of 477 patients (494 feet and 593 neuropathic forefoot ulcers). The studies included three retrospective comparative studies and eight case series. Critical Issues: Meta-analytical results of comparative studies on recent noninfected DFUs showed MHR having significantly better rates of healing, time to healing, ulcer recurrence, and infection than SC. Failure to heal, recurrence, and infection rates were 4 times higher in the SC group than in the MHR group, and the amputation rate was two times higher in the SC group than in the MHR group. The outcomes of the meta-analysis of case series on chronic and recalcitrant ulcers treated with MHR were similar. Future Directions: Considering the natural history of DFUs treated conservatively and the satisfactory outcomes with a significantly low complication rate of MHR, physicians should consider the use of MHR more often and include this technique in the early management of DFUs. Scope and Significance: DFU impose great public health burden around the globe. Standard of care using in-office debridement and topical agents is the usual mainstay of treatment. However, such conservative care is known to result in high rates of ulcer recurrence and complications. In this systematic review, we quantitatively investigate the outcomes of a surgical off-loading technique, the MHR in the treatment of chronic plantar neuropathic wounds. Translational Relevance: Many biochemical factors are implicated in the complex process of wound healing. In the case of diabetic neuropathic ulcers of the forefoot, additional mechanical factors induced by the presence of diabetic neuropathy lead to high pressure loads of the metatarsal heads on the plantar skin. With time, such chronic loads could favor ulcer formation. Removal of the causal mechanical factor could alleviate the pressure and allow wound healing. Clinical Relevance: Neuropathic plantar ulcers are difficult-to-heal wounds and chronicity is associated to frequent hospitalizations, higher rates of amputation, and mortality. Early removal of the indirect causal agent, the resection of the metatarsal head, after failure of a well-conducted conservative standard of care could be a needed solution for wound healing and consequently a potential for reducing complications and costs.

Flexor Digitorum Brevis Muscle Dry Needling Changes Surface and Plantar Pressures: A Pre-Post Study

BACKGROUND

The effects of the dry needling technique and pain reduction have been demonstrated in numerous quality studies. However, the mechanical effects of dry needling are largely unknown.

METHODS

A total of 18 subjects with flexor digitorum brevis muscle myofascial trigger point were evaluated pre- and post-deep dry needling. We measured static footprint variables in a pre-post study.

MAIN FINDINGS

We found differences in rearfoot maximum pressure (119.22-111.63 KPa; p = 0.025), midfoot maximum pressure (13.68-17.26 KPa; p = 0.077), midfoot medium pressure (4.75-6.24 KPa; p = 0.035) and forefoot surface (86.58-81.75 cm²; p = 0.020). All variables with significant differences decrease, with the exception of forefoot surface which showed an increase.

CONCLUSIONS

After flexor digitorum brevis muscle dry needling, midfoot plantar pressures (maximum and medium) and forefoot surface were increased, and rearfoot maximum pressure was decreased.

The Role of Foot-Loading Factors and Their Associations with Ulcer Development and Ulcer Healing in People with Diabetes: A Systematic Review

We aimed to comprehensively and systematically review studies associating key foot-loading factors (i.e., plantar pressure, weight-bearing activity, adherence or a combination thereof) with ulcer development and ulcer healing in people with diabetes. A systematic literature search was performed in PubMed and EMBASE. We included studies if barefoot or in-shoe plantar pressure, weight-bearing activity or footwear or device adherence was measured and associated with either ulcer development or ulcer healing in people with diabetes. Out of 1954 records, 36 studies were included and qualitatively analyzed. We found low to moderate quality evidence that lower barefoot plantar pressure and higher footwear and device adherence associate with lower risk of ulcer development and shorter healing times. For the other foot-loading factors, we found low quality evidence with limited or contradictory results. For combined measures of foot-loading factors, we found low quality evidence suggesting that lower cumulative plantar tissue stress is associated with lower risk of ulcer development and higher ulcer healing incidence. We conclude that evidence for barefoot plantar pressure and adherence in association with ulcer outcome is present, but is limited for the other foot-loading factors. More comprehensive investigation in particularly the combination of foot-loading factors may improve the evidence and targeting preventative treatment.

Evaluating the effects of sedentary behaviour on plantar skin health in people with diabetes

BACKGROUND

Diabetes-Related Foot Ulcers (DRFUs) are a common and devastating consequence of Diabetes Mellitus and are associated with high morbidity, mortality, social and economic costs. Whilst peak plantar pressures during gait are implicated cited as a major contributory factor, DRFU occurrence has also been associated with increased periods of sedentary behaviour. The present study was designed aimed to assess the effects of sitting postures on plantar tissue health.

METHODS

After a period of acclimatisation, transcutaneous oxygen tensions (T_CPO₂) and inflammatory cytokines (IL-1α and IL-1RA) were measured at the dorsal and plantar aspects of the forefoot before, during and after a 20-min period of seated-weight-bearing in participants with diabetes (n = 11) and no diabetes (n = 10). Corresponding interface pressures at the plantar site were also measured.

RESULTS

During weight-bearing, participants with diabetes showed increases in tissue ischaemia which were linearly correlated proportional to plantar pressures (Pearson's r = 0.81; p < 0.05). Within the healthy group, no such correlation was evident (p > 0.05). There were also significant increases in post seated weight-bearing values for ratio for IL-1α and IL-1RA, normalised to total protein, post seated weight-bearing in participants with diabetes compared to healthy controls.

CONCLUSION

This study shows that prolonged sitting may be detrimental to plantar skin health. It highlights the need to further examine the effects of prolonged sitting in individuals, who may have a reduced tolerance to loading in the plantar skin and soft tissues.

Influence of type 1 diabetes on the postural control of women in the third gestational trimester

BACKGROUND

Diabetes can cause biomechanical alterations that may be responsible for additional changes to those existing in a regular gestational period. The way a maternal body responds when affected by diabetes has not been clearly understood. This study aimed to describe the influence of type 1 diabetes on pregnant women's postural control.

METHODS

Forty pregnant women in their third gestational trimester were allocated in two equal groups - the control group and the type 1 diabetic group. The variables related to postural control and balance were assessed using photogrammetry (head protrusion; cervical lordosis; thoracic kyphosis; lumbar lordosis; pelvic anteversion, knee flexion, tibiotarsal and foot inclination angles were measured), and baropodometry (anteroposterior and mediolateral distance trajectory of the center of pressure, amplitude and average speed of displacement of the center of pressure).

FINDINGS

The results of the type 1 diabetic group showed, in the postural analysis, lower head protrusion and pelvic anteversion angles, while there was higher cervical lordosis, thoracic kyphosis, and lumbar lordosis angles. In the baropodometry, the anteroposterior distance and the amplitude of the center of pressure displacement with eyes open and closed were higher.

INTERPRETATION

The findings suggest that type 1 diabetes mellitus in the third trimester of pregnancy is associated with postural changes, a decrease in the active ankle range of motion and increase in the anteroposterior oscillation of the center of pressure, with negative repercussions for postural control.

Surgery Versus Nonsurgical Methods in Treating Neuropathic Plantar Forefoot Ulcers: A Meta-Analysis of Comparative Studies

The treatment of diabetic foot ulcers (DFUs) is usually based on local debridement, topical agents, and nonsurgical off-loading. When compared with nonsurgical methods, a number of articles reported better results with surgery. The aim of this meta-analysis was to collate quantitative evidence on the outcomes of surgery versus nonsurgical treatment (NST) of DFUs. Databases were searched from inception to September 2019. PRISMA guidelines were followed, and the Joanna Briggs Institute critical appraisal tools were used to appraise studies' quality. Nine studies were included totalizing 436 ulcers (216 treated with surgery and 220 DFUs with NST). The primary outcome was the healing rate. The secondary outcomes were time to heal, recurrence rate, transfer rate, infection rate, and amputation/revision surgery rate. The risk differences (RDs) between the healing rates following surgery and NST for infected and noninfected ulcers were 17% (95% confidence interval [CI] = 0.012-0.328, P = .03) and 19.2% (95% CI = 0.050-0.334, P = .008), respectively, in favor of surgery. The amputation/revision surgery rate was significantly better following surgery for both types of ulcers. Noninfected ulcers demonstrated significantly lesser time to heal, recurrence, and infection rates following surgery. This meta-analysis demonstrated that surgery was superior to NST in treating infected and noninfected neuropathic plantar wounds.

The role of foot pressure measurement in the prediction and prevention of diabetic foot ulceration-A comprehensive review

The predominant risk factor of diabetic foot ulcers (DFU), peripheral neuropathy, results in loss of protective sensation and is associated with abnormally high plantar pressures. DFU prevention strategies strive to reduce these high plantar pressures. Nevertheless, several constraints should be acknowledged regarding the research supporting the link between plantar pressure and DFUs, which may explain the low prediction ability reported in prospective studies. The majority of studies assess vertical, rather than shear, barefoot plantar pressure in laboratory-based environments, rather than during daily activity. Few studies investigated previous DFU location-specific pressure. Previous studies focus predominantly on walking, although studies monitoring activity suggest that more time is spent on other weight-bearing activities, where a lower "peak" plantar pressure might be applied over a longer duration. Although further research is needed, this may indicate that an expression of cumulative pressure applied over time could be a more relevant parameter than peak pressure. Studies indicated that providing pressure feedback might reduce plantar pressures, with an emerging potential use of smart technology, however, further research is required. Further pressure analyses, across all weight-bearing activities, referring to location-specific pressures are required to improve our understanding of pressures resulting in DFUs and improve effectiveness of interventions.

Predicting the risk of future diabetic foot ulcer occurrence: a prospective cohort study of patients with diabetes in Tanzania

OBJECTIVES

The aim of this study was to identify the parameters that predict the risk of future foot ulcer occurrence in patients with diabetes.

RESEARCH DESIGN AND METHODS

1810 (male (M)/female (F): 1012/798) patients, with no foot ulcer at baseline, participated in this study. Data from a set of 28 parameters were collected at baseline. During follow-up, 123 (M/F: 68/55) patients ulcerated. Survival analyses together with logistic regression were used to identify the parameters that could predict the risk of future diabetic foot ulcer occurrence.

RESULTS

A number of parameters (HR (95% CI)) including neuropathy (2.525 (1.680 to 3.795)); history of ulceration (2.796 (1.029 to 7.598)); smoking history (1.686 (1.097 to 2.592)); presence of callus (1.474 (0.999 to 2.174)); nail ingrowth (5.653 (2.078 to 15.379)); foot swelling (3.345 (1.799 to 6.218)); dry skin (1.926 (1.273 to 2.914)); limited ankle (1.662 (1.365 to 2.022)) and metatarsophalangeal (MTP) joint (2.745 (1.853 to 4.067)) ranges of motion; and decreased (3.141 (2.102 to 4.693)), highly decreased (5.263 (1.266 to 21.878)), and absent (9.671 (5.179 to 18.059)) sensation to touch; age (1.026 (1.010 to 1.042)); vibration perception threshold (1.079 (1.060 to 1.099)); duration of diabetes (1.000 (1.000 to 1.000)); and plantar pressure at the first metatarsal head (1.003 (1.001 to 1.005)), temperature sensation (1.019 (1.004 to 1.035)) and temperature tolerance (1.523 (1.337 to 1.734)) thresholds to hot stimuli and blood sugar level (1.027 (1.006 to 1.048)) were all significantly associated with increased risk of ulceration. However, plantar pressure underneath the fifth toe (0.990 (0.983 to 0.998)) and temperature sensation (0.755 (0.688 to 0.829)) and temperature tolerance (0.668 (0.592 to 0.0754)) thresholds to cold stimuli showed to significantly decrease the risk of future ulcer occurrence. Multivariate survival model indicated that nail ingrowth (4.42 (1.38 to 14.07)); vibration perception threshold (1.07 (1.04 to 1.09)); dry skin status (4.48 (1.80 to 11.14)); and temperature tolerance threshold to warm stimuli (1.001 (1.000 to 1.002)) were significant predictors of foot ulceration risk in the final model. The mean time to ulceration was significantly (p<0.05) shorter for patients with: dry skin (χ²=11.015), nail ingrowth (χ²=14.688), neuropathy (χ²=21.284), or foot swelling (χ²=16.428).

CONCLUSION

Nail ingrowth and dry skin were found to be strong indicators of vulnerability of patients to diabetic foot ulceration. Results highlight that assessments of neuropathy in relation to both small and larger fiber impairment need to be considered for predicting the risk of diabetic foot ulceration.

A Biomechanical Examination of Prefabricated Total Contact Cast Kits: Relevance to Patients With Diabetic Neuropathy

The traditional Total Contact Cast (TCC) is considered the gold standard for treating plantar diabetic ulcers. A number of prefabricated TCC kits have been introduced, which offer a user-friendly casting process for health care providers. Our objective was to evaluate pressure reduction and gait characteristics after application of a TCC kit (TCC-EZ) and traditional TCC. Fifteen individuals (9 males, 6 females; median age of 51.5 years [range = 40.5-71.2 years]) completed 30-m walking trials while fitted with TCC-EZ and TCC in a randomized order. A pair of automated wireless photogate sensors captured time to traverse the distance and pedobarographic insoles measured and recorded plantar pressures. Paired t tests were used to compare peak pressure, gait speed, and cast weights across the 2 modalities. Peak pressure and cast weight were significantly lower in the TCC-EZ arm (169.6 ± 41.3 kPa vs 214.9 ± 63.2 kPa, P = .0048; and 1.79 ± 0.17 kg vs 2.11 ± 0.25 kg, P = .0004). Contact area and gait speed were not significantly different between the 2 modalities (140.4 ± 25.8 cm2 vs 126.9 ± 37.8 cm2, P = .0228, Cohen’s d = 0.40; and 0.94 ± 0.19 m/s vs 0.83 ± 0.26 m/s, P = .0532, Cohen’s d = .48). TCC-EZ was found to provide more favorable pressure distributions compared with TCC. TCC-EZ is also lighter and may be a preferred treatment modality for patients. More research is necessary to reveal the clinical effectiveness of prefabricated total contact kits.

A state-of-the-art review of foot pressure

The science of foot pressure studies the forces acting on the bottom and different regions of the foot along with the pressure exerted on the plantar surface with the interacting surface in contact. The information derived gave impact to human biomechanical assessment on body balance and ergonomics posture during gait. Various experiments designed at generating foot pressure data returns only with limited knowledge generated. Obviously, the procedure for experiment design needs to be properly understood from the foot morphology aspects; healthiness, footwear, surface in contact, load and forces impacts, and the foot sensitivity as well as the specification for the foot pressure. This paper reviews the proper preliminary experimental setups for foot pressure measurement analysis during static or dynamic gait. The strength and limitations of recent devices used and considerable variables are also discussed. The overall review explains that the comfortable natural gait in relation to the aspects of sensitivity, load, time duration, and stability are the standard considerations for plantar pressure experiments.

Prediction of Diabetic Foot Ulceration: The Value of Using Microclimate Sensor Arrays

BACKGROUND

Accurately predicting the risk of diabetic foot ulceration (DFU) could dramatically reduce the enormous burden of chronic wound management and amputation. Yet, the current prognostic models are unable to precisely predict DFU events. Typically, efforts have focused on individual factors like temperature, pressure, or shear rather than the overall foot microclimate.

METHODS

A systematic review was conducted by searching PubMed reports with no restrictions on start date covering the literature published until February 20, 2019 using relevant keywords, including temperature, pressure, shear, and relative humidity. We review the use of these variables as predictors of DFU, highlighting gaps in our current understanding and suggesting which specific features should be combined to develop a real-time microclimate prognostic model.

RESULTS

The current prognostic models rely either solely on contralateral temperature, pressure, or shear measurement; these parameters, however, rarely reach 50% specificity in relation to DFU. There is also considerable variation in methodological investigation, anatomical sensor configuration, and resting time prior to temperature measurements (5-20 minutes). Few studies have considered relative humidity and mean skin resistance.

CONCLUSION

Very limited evidence supports the use of single clinical parameters in predicting the risk of DFU. We suggest that the microclimate as a whole should be considered to predict DFU more effectively and suggest nine specific features which appear to be implicated for further investigation. Technology supports real-time in-shoe data collection and wireless transmission, providing a potentially rich source of data to better predict the risk of DFU.

Monitoring of external predisposing factors for Diabetic Foot: A literature review and physicians' perspectives

Background: Diabetic foot is one of the most important complications of diabetes caused by the existence of some destructive factors in different anatomical locations of feet. Management and monitoring of these factors are very important to decrease or avoid ulcerating lesions of the foot. The purpose of this study is to identify and introduce the predisposing factors and anatomical locations associated with these destructive factors. Methods: First, we conducted a comprehensive review of different databases to identify the factors and associated anatomical locations from the previous studies. Then, we designed a questionnaire and invited physicians and specialists to express their perspectives on these factors and locations. The data were analyzed using SPSS version 23. Frequency, percentage, mean and standard deviation of these variables were calculated. Results: Based on the literature review, four factors, including pressure, moisture and sweat, temperature, and acceleration were identified as factors destructive to the tissues of the diabetic foot and worsen ulcers. The view of specialists approved the results of the literature review. Besides, there was an insignificant difference between the results of the literature review and the specialists' view in terms of anatomical locations that need to be continuously monitored. Conclusion: Monitoring the pressure in heel, first metatarsal, and first metatarsal head; moisture and sweat under the fingers, hallux and heels as well as the temperature at the first metatarsal, first metatarsal head, and the third metatarsal head are important in preventing ulceration, destructing the foot tissue, and accelerating the treatment process.

Prediction of peak plantar pressure for diabetic foot: The regressional model

BACKGROUND

The increase in peak plantar pressure could be the most important etiological factor for pathogenesis of a diabetic foot. Thus the fate of a diabetic foot syndrome which is a clinical triad of neurological, vascular and musculoskeletal changes could be biomechanically predictive and preventive using clinical parameters. In the presence of peripheral neuropathy, certain clinical parameters could be severely altered resulting into increased peak plantar pressure. Therefore the aim of the study was to identify the most important clinical parameters for the prediction of peak plantar pressure between neuropathy and non-neuropathy type 2 diabetes mellitus participants.

METHODOLOGY

A total of 380 participants were recruited under the study and divided into two groups (190 each group). The cross-sectional study was conducted at Kasturba Hosipal, Manipal, India. Multiple regression analysis was performed to find the hyperplane of best fit. Stepwise regression was performed with (α entry=0.15 and α removal=0.2) to select the best subset of predictors.

RESULTS

Adjusted R2 of the final model which included the predictors showed 90.8% variability for the dependent variable.

CONCLUSION

The findings from the regression analysis suggested model was found to be strongly significant in predicting the peak plantar pressure between neuropathy and non-neuropathy type 2 diabetes mellitus participants. Since higher values of peak plantar pressure is strongly associated with risk for future diabetic foot complications, it could be suggested that these clinical parameters could be very useful to assess and should be used in routine clinical practice very effectively.

Soft Tissue Reconstruction with Diabetic Foot Tissue Loss

Although substantial advances have been made in treatment of diabetic foot disease with respect to patient education, preventative measures, early intervention, and prophylactic procedures, most surgical interventions for this condition are reactionary. Patients still primarily present to emergency departments with acute infections and tissue necrosis. The surgical intervention for this results in soft tissue deficit, often with partial foot amputation, through excisional debridement of pathologic tissue. Minimizing this initial soft tissue loss, with subsequent reconstruction of the defect, forms the focus of this article with a detailed anatomic assessment of structures at risk in the forefoot, midfoot and rearfoot.

Investigation of the relationship between localized cumulative stress and plantar tissue stiffness in healthy individuals using the in-vivo indentation technique

This study was conducted to determine whether prolonged and repetitive exercise stiffens the plantar soft tissue. Healthy female subjects in their early 20s with a similar body mass index but different majors (13 engineers (controls) and 13 ballet dancers) were recruited. Tissue thickness was measured using ultrasound, while peak stress, stress distribution, and center of pressure were obtained Zebris^® pressure mat. Stiffness was evaluated using a custom-made tissue indentation system. F-test and independent sample T-test were used to determine significant differences between the two groups. No significance was found in the thickness of the second sub-metatarsal head (MTH) and heel between the two groups. In the second sub-MTH, the ballet group showed higher peak stress, loading rate, and stiffness than the control group. Conversely, in the heel region, all the results were higher for the control group. The results of this study quantify the impact of exercise on the stiffness of plantar soft tissue and confirm that even healthy individuals who do prolonged and repetitive exercise have stiffer plantar soft tissue.

Reliability of peak foot pressure in patients with previous diabetic foot ulceration

BACKGROUND

Previous reliability studies on peak plantar pressure measurements in patients with previous diabetic foot ulceration (DFU) did not stratify their analyses according to whether the foot had a previous ulcer.

RESEARCH QUESTION

Does test-retest reliability of peak foot pressure measurements from the various foot regions differ between the ulcerated and non-ulcerated feet?

METHODS

Data from 23 participants with peripheral neuropathy and healed plantar DFU were analysed in this test-retest reliability comparison study. Plantar pressure was evaluated on two sessions using Pedar^®-X in-shoe system, with a mean of 7.2 days (SD = 1.6) between sessions.

RESULTS

The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were calculated for 10 foot regions. Overall, test-retest reliability was excellent (ICCs, 0.82 to 0.95) for all peak pressure variables. CV ranged between 6.3% and 18.3%, and exceeded 15% over the hallux and medial forefoot regions in the ulcer foot (18.3% and 16.4%, respectively). Hallux peak pressure CV was significantly higher over the ulcer foot than over the non-ulcer foot (5.7%, 95% CI, 1.7%-10.2%). Peak pressure CV over the forefoot also tended to be higher over the ulcer foot (medial forefoot: 6.1%, 95% CI, -0.5%-14.5%; lateral forefoot: 4.1%, 95%CI, -0.7%-11.1%).

SIGNIFICANCE

Peak plantar foot pressure may be useful to distinguish between groups of patients with peripheral neuropathy and healed plantar DFU. However, clinical decisions based on ulcer foot hallux and forefoot peak pressure measurements should be interpreted with caution.

Distribution of the Highest Plantar Pressure Regions in Patients with Diabetes and Its Association with Peripheral Neuropathy, Gender, Age, and BMI: One Centre Study

The abnormal plantar pressure distribution and value play a key role in the formation of plantar calluses and diabetic foot ulcer. The prevalence of the highest pressure different distribution and its association with various factors among patients with diabetes is not well known. The study purpose was to evaluate the prevalence of different regions for the highest pressure on the sole and its association with selected factors among patients with diabetes. Medical records of nonulcer patients were retrospectively analysed. The relationship between pressure patterns on the sole obtained during a pedobarographic test as a semiquantitative assessment with colourful print analysis and neuropathy, gender, age, and BMI was searched. The most common location of the highest pressure was the central part of the forefoot. No association was found between the different highest pressure regions and age, sensory neuropathy, calluses, and foot deformities. The highest pressure on the lateral part of the foot and midfoot was observed more often in females and in patients with a BMI ≥ 35. The prevalence of the highest pressure on the forefoot was more common in patients with a BMI < 35. Conclusions. The most frequent regions of the highest pressure on the sole in patients with diabetes were the central part of the forefoot (2-3 metatarsal heads) with no simple relationship to the assessed variables other than BMI < 35. Female gender and higher BMI seem to be responsible for shifting the place of the highest pressure to other places of the foot.

A Foreign Body Through the Shoe of a Person With Diabetic Peripheral Neuropathy Alters Contralateral Biomechanics: Captured Through Innovative Plantar Pressure Technology

High plantar pressure as a result of diabetic peripheral neuropathy is often reported as a major risk factor for ulceration. However, previous studies are confined to laboratories with equipment limited by cables, reducing the validity of measurements to daily life. The participant concerned in this case report was wearing an innovative plantar pressure feedback system as part of a wider study. The system allows for continuous plantar pressure monitoring and provides feedback throughout all activities of daily living. The participant concerned was a 59-year-old male with type 2 diabetes who presented with severe peripheral neuropathy. In addition, the right ankle had previously undergone fusion. Between monthly study appointments, the participant unknowingly had a screw embedded in his right shoe, while pressure was being recorded. Although no significant differences in pressure were present for the right foot with the embedded screw, the contralateral foot showed significantly higher pressure when the screw was embedded, compared with pre and post time periods. The increase in pressure on the contralateral foot is expected to result from the protrusion of the screw in the right shoe, causing a perturbation to balance and a shift in the center of pressure toward the contralateral side. This compensatory effect is likely to have been magnified by the limited mobility of the fused right ankle. These findings highlight the importance of checking both feet for ulcer risk, in the event of receiving high-pressure feedback. This innovative technology may improve our understanding of diabetic plantar foot ulcer development.