Plantar tissue thickness is related to peak plantar pressure in the high-risk diabetic foot

Foot Plantar Pressure Abnormalities in Near Adulthood Patients with Type 1 Diabetes

Increased ulcer risk diminishes the quality of life in diabetes. This study assessed abnormalities in foot plantar pressure distribution in adolescents with T1D to detect early signs of ulcer risk. A total of 102 T1D patients, without diabetic neuropathy, were included (mean age 17.8 years, mean diabetes duration 7.4 year). Pedography was captured using Novel emed. Data from the study group were compared with reference data. The study revealed a statistically significant reduced foot contact area in both feet in the entire foot and under the head of the fifth metatarsal bone and the second toe. In both feet, the peak pressure was increased under the entire foot, hindfoot, midfoot, first metatarsal head, big toe, and second toe. There was no statistically significant difference in peak pressure. The mean plantar pressure rating was statistically significantly increased in both feet across the entire sole, in the hindfoot, midfoot, and first metatarsal head. T1D patients of age near adulthood without neuropathy have increased values in mean pressure and reduced contact area, pointing to the need of monitoring and preventive measures. These results point to the need of further research and analysis which should include various risk factor such as foot anatomy, body posture, or certain metabolic factors.

The effectiveness of a thermography-driven preventive foot care protocol on the recurrence of diabetic foot ulcers in low-medical resource settings: An open-labeled randomized controlled trial

BACKGROUND

Plantar temperature monitoring, along with a comprehensive preventive foot care approach, is utilized to prevent recurrence of diabetic foot ulcers. However, there is a lack of standardized protocols for individuals with diabetic foot ulcer history in low-medical resource countries.

OBJECTIVE

This study investigated the efficacy of nurse-led, thermographic-evaluation-guided foot care in preventing diabetic foot ulcer recurrence in a low-medical resource country.

DESIGN

Single-blind, 1:1 allocation randomized controlled trial.

SETTINGS

Two wound care facilities with wound care nurse specialists in Indonesia.

PARTICIPANTS

120 patients with a diabetic foot ulcer history.

INTERVENTION

In the intervention group, baseline risk assessment including smartphone thermography evaluation was performed. Personalized foot care and education were conducted monthly for participants whose thermographs showed increased foot lesion temperature at baseline risk assessment. The control group received usual care and education using a booklet at baseline. The follow-up period was six months.

MAIN OUTCOME

Time to recurrence was evaluated using Kaplan-Meier survival analysis, and between-group comparisons were performed using the log-rank test. Potential risk factors were incorporated into the multivariate Cox regression model. Secondary outcomes included quality of life (European Quality of Life 5 Dimensions 3 Level Version) and foot care behavior, were analyzed using Mixed Models for Repeated Measures at baseline, third, and sixth follow-up (3 and 6 months from baseline).

RESULTS

120 participants (intervention 60, control 60) were randomized. The intervention group had a significantly lower recurrence rate than the control group (15% vs. 35%, p = 0.011) and a significant difference in time to ulceration (log-rank test, p = 0.009) after a 6-month follow-up period. Intervention care reduced the risk of diabetic foot ulcer recurrence by 59% (Hazard ratio 0.41, 95% confidence interval 0.18, 0.96, p = 0.039) in multivariate Cox regression analysis. On the third follow-up, total diabetic foot care behavior score (p < 0.001) was significantly improved by the intervention. On the sixth follow-up, mobility (p = 0.020), self-care (p = 0.023), pain/discomfort (p < 0.001), anxiety/depression (p = 0.016), EuroQol Visual Analogue Scale score (p = 0.002), and total diabetic foot care behavior score (p < 0.001) showed significant improvements in the intervention group.

CONCLUSIONS

Foot care and personalized education delivered at a frequency based on the risk level assessed by thermography effectively reduced diabetic foot ulcer recurrence, and improved quality of life and foot care behaviors.

REGISTRATION NUMBER

UMIN000039012.

TWEETABLE ABSTRACT

Nurse-led diabetic foot care and education reduced diabetic foot ulcer recurrence in Indonesia.

Evaluation of in-shoe plantar pressure and shear during walking for diabetic foot ulcer prevention

OBJECTIVE

To investigate reliability and changes of in-shoe plantar pressure and shear during walking at three cadences with two insole designs. This was a precursor to the investigation of plantar loading in people with diabetes for potential foot ulcer prevention.

METHOD

A sensorised insole system, capable of measuring plantar pressure and shear at the heel, fifth metatarsal head (5MH), first metatarsal head (1MH) and hallux, was tested with ten healthy participants during level walking. Reliability was evaluated, using intra-class correlation coefficient (ICC), while varying the cadences and insole types. Percentage changes in pressure and shear relative to values obtained at self-selected cadence with a flat insole design were investigated.

RESULTS

Mean±standard deviation of maximum pressure, medial-lateral and anterior-posterior shear of up to 380±24kPa, 46±2kPa and -71±4kPa, respectively, were measured. The ICC in ranges of 0.762-0.973, 0.758-0.987 and 0.800-0.980 were obtained for pressure, anterior-posterior and medial-lateral shear, respectively. Opposite anterior-posterior shear directions between 5MH and 1MH (stretching), and between 1MH and hallux (pinching) were observed for some participants. Increasing cadence increased pressure and anterior-posterior shear (by up to +77%) but reduced medial-lateral shear at the heel and hallux (by up to -34%). Slower cadence increased anterior-posterior shear (+114%) but decreased medial-lateral shear (-46%) at the hallux. The use of a flexible contoured insole resulted in pressure reduction at the heel and 5MH but an increase in anterior-posterior shear at the heel (+69%) and hallux (+75%).

CONCLUSION

The insole system demonstrated good reliability and is comparable to reported pressure-only systems. Pressure measurements were sensitive to changes in cadence and insole designs in ways that were consistent with the literature. However, our plantar shear showed localised shear changes with cadences and insoles for the first time, as well as stretching and pinching effects on plantar tissue. This opens new possibilities to investigate plantar tissue viability, loading characteristics and orthotic designs aimed towards foot ulcer prevention.

Plantar fascia stiffness in patients with type 2 diabetes mellitus: Stiffness effect on fall risk and gait speed

AIMS

The primary objective was to compare patients with type 2 diabetes mellitus (T2DM) and healthy peers in terms of plantar fascia (PF) stiffness, fall risk, and gait speed. The second objective was to examine the relationship between stiffness of PF and fall risk, gait speed.

METHODS

Fifty patients diagnosed with T2DM (mean duration = 10.74 ± 7.07 years) were included. Myotonometer was used to evaluate the stiffness of PF. To assess the risk of falling, and gait speed, the International Fall Efficiency Scale (FES-I) and the 4-Meter Gait Speed Test (4mGST) were used, respectively.

RESULTS

Compared to healthy controls, PF stiffness (right foot mean difference = 148.99 N/m, left foot mean difference = 113.13 N/m p < .001) was higher in the T2DM group. The FES-I and 4mGST scores were worse in the group with T2DM (p < .05). 12.8 % of FES-I and 23.4 % of 4mGST variance were explained by stiffness of PF.

CONCLUSIONS

The results of the study showed that the stiffness of PF changed in patients with T2DM. There was a decrease in gait speed and an increase in the risk of falling as PF stiffness increased.

Ultrasound and Clinical Alterations in the Foot of Children with Obesity and Diabetes

BACKGROUND

Alterations in plantar soft tissues are often reported in adults with diabetes, whereas data on children are conflicting. Also, the extent of foot damage caused by excess body fat in children has not been fully characterized yet. This study aimed to address the relationship between body mass and structural changes of the foot in children and adolescents with and without diabetes.

METHODS

In a case-control study, 43 participants (age 13 ± 2.6 years) were recruited, 29 (67%) with type 1 diabetes (T1D) and 14 (33%) controls. Anthropometric parameters [body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR)], foot posture index-6 (FPI-6) for static foot posture, and navicular drop test (NDT) for medial longitudinal arch height (MLA) were measured in all participants. The thickness of the midfoot plantar fascia (MPF) and medial midfoot fat pad (MMFP) were quantified using ultrasound.

RESULTS

No differences in clinical and ultrasonographical parameters were observed between the study groups. MMFP thickness was correlated with MPF thickness (p = 0.027). MMFP and MPF thicknesses were positively associated with BMI (p < 0.001 and p = 0.013, respectively), WC (p < 0.001 and p = 0.013), and WHtR (p < 0.001 and p = 0.026). The NDT measured on the right and left foot correlated with WHtR (p = 0.038 and p = 0.009, respectively), but not with WC and BMI.

CONCLUSIONS

Children with T1D show structural alterations of plantar soft tissues which seem related to body mass increase rather than diabetes pathology. Ultrasound is a valuable tool to assess early structural changes of the foot in young people with an elevated BMI.

Factors Associated with the Local Increase of Skin Temperature, 'Hotspot,' of Callus in Diabetic Foot: A Cross-Sectional Study

BACKGROUND

Increased local skin temperature (hotspot) on a callus site as detected by thermography is a well-known precursor of diabetic foot ulcers. This study aimed to determine the factors associated with callus hotspots in order to predict the risk of callus hotspots and then provide information for specific interventions.

METHODS

In this cross-sectional study, 1,007 patients' data from a diabetic foot prevention clinic between April 2008 and March 2020 were used. Data regarding patients' characteristics, foot calluses, and callus hotspots were collected and analyzed. Callus and callus hotspot were confirmed from foot photos and thermographs, respectively. A callus hotspot was defined as a relative increase in temperature compared to the skin surrounding the callus on the thermograph. Plantar pressure was measured with a pressure distribution measurement system. A generalized linear mixed model was used to identify the factors associated with callus hotspots.

RESULTS

Among the 2,014 feet, 28.5% had calluses, and 18.5% of feet with calluses had callus hotspots. The factors associated with callus hotspots were number of calluses (Adjusted odds ratio (aOR): 1.540, P = .003), static forefoot peak plantar pressure (SFPPP) (aOR: 1.008, P = .001), and body mass index (aOR: 0.912, P = .029).

CONCLUSIONS

Patients with a higher SFPPP were more likely to have callus hotspots suggesting that SFPPP might contribute to callus inflammation. SFPPP has the potential to be a useful predictor of callus hotspots in people with diabetes and at the same time provide information for off-loading interventions to prevent callus hotspots.

Characteristics of Plantar Pressure Distribution in Diabetes with or without Diabetic Peripheral Neuropathy and Peripheral Arterial Disease

Background. Excessive plantar pressure leads to increased risk of diabetic foot ulcers. Diabetic peripheral neuropathy (DPN) and peripheral arterial disease (PAD) have been considered to be associated with alterations in gait and plantar pressure in diabetic patients. However, few studies have differentiated the effects with each of them. Objective. To investigate the plantar pressure distribution in diabetic patients, with DPN and PAD as independent or combined factors. Methods. 112 subjects were recruited: 24 diabetic patients with both DPN and PAD (DPN-PAD group), 12 diabetic patients with DPN without PAD (DPN group), 10 diabetic patients with PAD without DPN (PAD group), 23 diabetic patients without DPN or PAD, and 43 nondiabetic healthy controls (HC group). The in-shoe plantar pressure during natural walking was measured. Differences in peak pressure, contact area, proportion of high pressure area (%HP), and anterior/posterior position of centre of pressure (COP) were analysed. Results. Compared with HC group, in DPN-PAD group and DPN group, the peak pressures in all three forefoot regions increased significantly; in PAD group, the peak pressure in lateral forefoot increased significantly. The contact area of midfoot in the DPN-PAD group decreased significantly. PAD group had larger HP% of lateral forefoot, DPN group had larger HP% of inner forefoot, and DPN-PAD group had larger HP% of total plantar area. There was a significant tendency of the anterior displacement of COP in the DPN-PAD group and DPN group. No significant differences were observed between the D group and HC group. Conclusion. DPN or PAD could affect the plantar pressure distribution in diabetic patients independently or synergistically, resulting in increased forefoot pressure and the area at risk of ulcers. DPN has a more pronounced effect on peak pressure than PAD. The synergistic effect of them could significantly reduce the plantar contact area of midfoot.

Relationship Between Plantar Tissue Hardness and Plantar Pressure Distributions in People With Diabetic Peripheral Neuropathy

Objective: People with diabetic peripheral neuropathy (DPN) are usually accompanied with increased plantar pressure. Such high plantar loading during daily activities may cause changes in the biomechanical properties of plantar soft tissue, whose viability is critical to the development of foot ulcers. This study aimed to investigate the relationship between plantar tissue hardness and plantar pressure in people with and without DPN, and preliminarily explore the influence of plantar loading patterns on the plantar pressure and tissue hardness.

Methods: The study was conducted on 14 people with DPN and 14 diabetic people without DPN. The Shore durometer and MatScan System were used to measure the plantar tissue hardness and plantar pressure, respectively. The plantar loading level was evaluated by the duration of daily weight-bearing activity and was used to group diabetic participants with and without DPN into two subgroups (lower loading group and higher loading group).

Results: The plantar tissue hardness was significantly correlated with static peak plantar pressure (PPP, p < 0.05) and dynamic pressure-time integral (PTI, p < 0.05) in the forefoot region in people with DPN. Results of variance analysis showed a significant interaction effect between peripheral neuropathy and plantar loading on tissue hardness (p < 0.05), but not plantar pressure. For people with DPN, significant differences in tissue hardness between the higher loading group and lower loading group were observed in the forefoot, midfoot and hindfoot regions. In the higher loading group, people with DPN had significantly greater tissue hardness than that in people without DPN in the toes, forefoot, midfoot and hindfoot regions (p < 0.05).

Conclusions: There is a significant correlation between tissue hardness and PPP, and between tissue hardness and PTI in people with DPN. Plantar loading associated with daily activities plays a significant role on the plantar tissue hardness in people with DPN. The findings of this study contribute to further understand the relationship between increased plantar tissue hardness and high plantar pressure in people with diabetic peripheral neuropathy.

Tissue Oxygenation Measurements to Aid Scalpel Debridement Removal in Patients With Diabetes

BACKGROUND

Callus formation in the diabetic foot increases the risk of ulcer onset. It is standard procedure to remove these dead tissue layers to reduce rising pressures. In a surgical procedure known as scalpel debridement, or chiropody the callus tissue is removed up to the epidermal layer. Factors may influence the outcome of this surgical process such as clinician inexperience. In an effort to standardize the debridement process, tissue oxygenation (TO) measurements are obtained before and after to study the effect of debridement on callus tissue.

METHODS

Fifteen debridement cases were analyzed using near infrared (NIR) imaging to study changes in TO. The NIR-based device used in this study estimates effective changes in TO in terms of oxy-, deoxy-, total hemoglobin, and oxygen saturation. Weber contrasts between callus tissue and the surrounding normal tissue were compared following debridement for all TO parameters. In a secondary analysis, callus tissue was segmented into quadrants and a percent of significance (in terms of total TO change) was calculated using a t-test.

RESULTS

Results show majority of cases displayed greater than 80% as the significant change in TO following debridement, except in cases with the presence of blood clot (a common precursor for ulceration). In cases where incomplete debridement was suspected, a significant change in TO was still observed.

CONCLUSIONS

With extensive systematic studies in the future, NIR imaging technique to measure changes in TO may be implemented as a low-cost hand-held imaging device useful for objectively assessing the effectiveness of the scalpel debridement process.

An intelligent insole system with personalised digital feedback reduces foot pressures during daily life: An 18-month randomised controlled trial

AIMS

High plantar pressure is a major risk factor in the development of diabetic foot ulcers (DFUs) and recent evidence shows plantar pressure feedback reduces DFU recurrence. This study investigated whether continued use of an intelligent insole system by patients at high-risk of DFUs causes a reduction in plantar pressures.

METHODS

Forty-six patients with diabetic peripheral neuropathy and previous DFU were randomised to intervention (IG) or control groups (CG). Patients received an intelligent insole system, consisting of pressure-sensing insoles and digital watch. Patients wore the device during all daily activity for 18-months or until ulceration, and integrated pressure was recorded continuously. The device provided high-pressure feedback to IG only via audio-visual-vibrational alerts. High-pressure parameters at the whole foot, forefoot and rearfoot were compared between groups, with multilevel binary logistic regression analysis.

RESULTS

CG experienced more high-pressure bouts over time than IG across all areas of the foot (P < 0.05). Differences between groups became apparent >16 weeks of wearing the device.

CONCLUSIONS

Continuous plantar pressure feedback via an intelligent insole system reduces number of bouts of high-pressure in patients at high-risk of DFU. These findings suggest that patients were learning which activities generated high-pressure, and pre-emptively offloading to avoid further alerts.

Unsupervised Generative Adversarial Network for Plantar Pressure Image-to-Image Translation

Analyzing human gait from plantar pressure is critical for human health. The majority of works focus on classifying the healthy plantar pattern from unhealthy ones. Different from previous works, we adopt a generative adversarial network to produce healthy plantar pressure image for individual patients. In this work, we do not have pairs of images for training thus we cast the problem as an unsupervised generative adversarial learning task. Our network benefits from multiple components: an encoder-decoder generator, a convolution-based discriminator, a convolution-based evaluation network, and a new term in the loss function to preserve the person's gait style. Our method achieves high performance (99.8%) on the CAD WALK databases which have patients with hallux valgus disease.

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.

The Mechanoreceptor's Role in Plantar Skin Changes in Individuals with Diabetes Mellitus

Mechanical skin properties (MSPs) and vibration perception thresholds (VPTs) show no relationship in healthy subjects. Similar results were expected when comparing MSP and VPT in individuals with diabetes mellitus (DM) and with diabetic (peripheral-)neuropathy (DPN). A healthy control group (33 CG), 20 DM and 13 DPN participated in this cross-sectional study. DM and DPN were classified by using a fuzzy decision support system. VPTs (in µm) were measured with a modified vibration exciter at two different frequencies (30 and 200 Hz) and locations (heel, first metatarsal head). Skin hardness (durometer readings) and thickness (ultrasound) were measured at the same locations. DPN showed the highest VPTs compared to DM and CG at both frequencies and locations. Skin was harder in DPN compared to CG (heel). No differences were observed in skin thickness. VPTs at 30 and 200 Hz correlated negatively with skin hardness for DPN and with skin thickness for DM, respectively. This means, the harder or thicker the skin, the better the perception of 30 or 200 Hz vibrations. Changes in MSP may compensate the loss of sensitivity up to a certain progression of the disease. However, the influence seems rather small when considering other parameters, such as age.

Comparison of Clinical Tests for Peripheral Diabetic Neuropathy in a Type 1 Diabetes Cohort

OBJECTIVE

To examine the performance and agreement of 5 modalities for testing sensory neuropathy against a neurothesiometer among Hispanic patients with type 1 diabetes (T1D) in an outpatient setting.

METHODS

A cross-sectional study was conducted at a tertiary reference center in Mexico City. Sensitivity, specificity, predictive values, and likelihood ratios were calculated using a VibraTip device, 128 Hz tuning fork, and the Semmes-Weinstein 5.07/10 g monofilament test, Ipswich touch test (IpTT), and pinprick test (PPT). The VPT obtained using a neurothesiometer was used as the standard. Agreement between tests was calculated using kappa coefficients.

RESULTS

Our study included 78 patients (156 examinations), of whom 56.4% were females. The mean age was 38.2 ± 13.0 years, and the mean body mass index was 24.6 ± 4.8 kg/m². The best sensitivity was found for IpTT and VibraTip (89.7% and 79.3%, respectively), while the PPT and IpTT had the highest positive predictive values (94.4% and 92.9%, respectively). The highest kappa coefficients were obtained for the IpTT vs neurothesiometer (kappa coefficient [κ] = 0.893, P < .001), followed by VibraTip vs neurothesiometer (κ = 0.782, P < .001). The VibraTip vs IpTT also had a substantial agreement (κ= 0.713, P < .001).

CONCLUSION

Our findings demonstrated that the IpTT had the best diagnostic performance and agreement compared with the standard in this cohort of Hispanic patients with T1D. The IpTT is a useful, simple test for diabetic neuropathy screening. These findings support its inclusion in future guidelines for diabetic foot examination.

Using Bidimensional Multiscale Entropy Analysis of Ultrasound Images to Assess the Effect of Various Walking Intensities on Plantar Soft Tissues

Walking performance is usually assessed by linear analysis of walking outcome measures. However, human movements consist of both linear and nonlinear complexity components. The purpose of this study was to use bidimensional multiscale entropy analysis of ultrasound images to evaluate the effects of various walking intensities on plantar soft tissues. Twelve participants were recruited to perform six walking protocols, consisting of three speeds (slow at 1.8 mph, moderate at 3.6 mph, and fast at 5.4 mph) for two durations (10 and 20 min). A B-mode ultrasound was used to assess plantar soft tissues before and after six walking protocols. Bidimensional multiscale entropy (MSE_2D) and the Complexity Index (CI) were used to quantify the changes in irregularity of the ultrasound images of the plantar soft tissues. The results showed that the CI of ultrasound images after 20 min walking increased when compared to before walking (CI₄: 0.39 vs. 0.35; CI₅: 0.48 vs. 0.43, p < 0.05). When comparing 20 and 10 min walking protocols at 3.6 mph, the CI was higher after 20 min walking than after 10 min walking (CI₄: 0.39 vs. 0.36, p < 0.05; and CI₅: 0.48 vs. 0.44, p < 0.05). This is the first study to use bidimensional multiscale entropy analysis of ultrasound images to assess plantar soft tissues after various walking intensities.

Ultrasound in the Modern Management of the Diabetic Foot Syndrome: A Multipurpose Versatile Toolkit

Ultrasound (US) is a noninvasive and versatile technology that in recent years found acceptance in almost all the medical specialties, with diagnostic and interventional applications. In the diabetic foot syndrome (DFS), US found specific indications mainly in the screening, quantification, and follow-up of the vascular component of the pathology, but also in the study of the deformities and structural modifications induced by neuropathy and in the diagnosis and surgical management of infections, especially those that induce anatomical changes, like abscesses and fasciitis. This review will summarize all these application of US, giving special attention to the vascular aspects, and on the predominant role that US gained in recent times to guide the indication to revascularization, on the new standardized approach to the study of the arterial tree of the limb and the foot, the so-called duplex ultrasound arterial mapping, which significantly increased the utilization of US to plan the revascularizations in this complex pathology. Outside the vascular fields, the diagnosis of neuropathy and infection and the intraoperative use of US in the surgical management of abscesses and fasciitis will be discussed, leaving the last part to the new and interesting applications of US in the management of DFU, a field that is still in evolution, offering new possibilities to the health care professionals involved in the management of these chronic wounds. The variety of applications both in diagnostic and operative fields makes US a rather versatile technology-a toolkit-that should have a special place among those at reach of the specialists of DFS care.

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.

Differences in the Sub-Metatarsal Fat Pad Atrophy Symptoms between Patients with Metatarsal Head Resection and Those without Metatarsal Head Resection: A Cross-Sectional Study

We aimed to evaluate the differences in the sub-metatarsal skin and fat pad atrophy between patients at a high risk of ulceration with and without previous metatarsal head resection. A cross-sectional study was performed in a diabetic foot unit involving 19 participants with a history of metatarsal head resection (experimental group) and 19 (control group) without a history of metatarsal head resection but with an ulcer in other locations in the metatarsal head. No participants had active ulcerations at study inclusion. Sub-metatarsal skin thickness and fat pad thickness in the first and second metatarsals were evaluated by an ultrasound transducer. The experimental group showed sub-metatarsal fat pad atrophy (3.74 ± 1.18 mm and 2.52 ± 1.04 mm for first and second metatarsal, respectively) compared with the control group (5.44 ± 1.12 mm and 4.73 ± 1.59 mm) (p < 0.001, confidence interval: (CI): 0.943-2.457 and p < 0.001, CI: 1.143-3.270 for first and second metatarsal, respectively); however, sub-metatarsal skin thickness was not different between groups (experimental 2.47 ± 0.47 mm vs. control 2.80 ± 0.58 mm (p = 0.063, CI: -0.019-0.672) and 2.24 ± 0.60 mm vs. 2.62 ± 0.50 mm (p = 0.066, CI: -0.027-0.786) for first and second metatarsal, respectively). Patients with previous metatarsal head resection showed sub-metatarsal fat pad atrophy, which could be associated with the risk of reulceration in the metatarsal head.

A Method to Analyze Plantar Stiffness Variation in Diabetes Using Myotonometric Measurements

Diabetes mellitus is a group of metabolic disease, which has become globally prevalent, and affects a large population in socio-economically backward countries in Asian continent. Chronic diabetes can lead to ulceration in the plantar region and may result in amputation. Assessment of mechanical properties of plantar tissues can aid in early diagnosis of ulceration. Myotonometry, a technique to measure dynamic stiffness, is preferred due to its noninvasiveness, easy employability, and rapid investigation. In this study, an attempt has been made to analyze the changes in biomechanical properties of plantar soft tissue in diabetes. MyotonPro, a handheld device, is used for this purpose. 43 diabetic subjects with varied duration of diabetes are recruited. Site-specific mechanical properties of the plantar region for both the feet are acquired and statistical analysis is performed. Results show that the MyotonPro is able to differentiate the stages of diabetes. It is seen that there is a spatial variability in the mechanical properties of the plantar. Additionally, it is observed that there is a significant increment in the plantar stiffness value in the group with higher diabetic age (p &lt; 0.05). Further, significant changes in dynamic mechanical properties are also observed in submetatarsal region. Additionally, a right–left asymmetry has been observed in frequency and stiffness values for later stages of diabetes. This study demonstrated the feasibility of MyotonPro in discriminating the stages of diabetic period. Thus, the proposed approach could be useful in early diagnosis of foot ulceration for various clinical conditions.

Gait changes in persons with diabetes: Early risk marker for diabetic foot ulcer

Background Increasing prevalence of diabetic foot ulcer (DFU) and subsequent foot amputation in persons with type 2 diabetic neuropathy is a well known fact. The present study was aimed to identify the initial risk marker for DFU. Methods Dynamic plantar pressure analysis was done for persons with type 2 diabetes mellitus (T2DM) without neuropathy (D), patients with diabetic neuropathy (DN) with normal foot profile and healthy persons with normal foot profile (C). Results The data showed a significant difference in dynamic peak plantar pressure between C and DN (P = 0.035) and no significant difference between D and DN (P = 0.997). The dynamic segmental peak plantar pressure results showed significant difference only in the medial heel region (P = 0.009) among the three groups. Conclusions Gait variations and restrictions in subtalar and first metatarsophalangeal joint are found in persons with diabetic neuropathy even before the onset of foot deformity.

Volumetric Analysis in Autologous Fat Grafting to the Foot

BACKGROUND

Pedal fat grafting is a safe, minimally invasive approach to treat pedal fat pad atrophy. Prior randomized controlled trials demonstrate that the fat as measured directly under the metatarsal heads disappears between 2 and 6 months after fat grafting, despite patients having relief for 2 years. The authors aim to use magnetic resonance imaging to further assess three-dimensional volume of fat in the foot after autologous fat grafting to help explain the mechanism for improved pain.

METHODS

A prospective study was performed using magnetic resonance imaging before and at 6 months after pedal fat grafting to assess changes in the three-dimensional morphology of the fat.

RESULTS

Seventeen patients (six men and 11 women) underwent injections with a mean volume of 5.8 cc per foot. At 6 months, patients demonstrated increased tissue thickness (p = 0.008) and volume (p = 0.04). Improvements were seen in pain (p < 0.05) and activity (p < 0.05). Foot pressures and forces were significantly decreased and positively correlated with increased fat pad volume (p < 0.05).

CONCLUSIONS

Pedal fat grafting significantly increases metatarsal fat pad volume. The distribution of the fat may contribute to lasting clinical relief in these patients.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Index of Plantar Pressure Alters with Prolonged Diabetes Duration

INTRODUCTION

Diabetic foot ulcers develop with deviations in the distribution of plantar pressure. It is difficult to interpret any alteration in plantar pressure under different conditions of type 2 diabetes mellitus (T2DM). The aim of this study was to gain a better insight into the variations in plantar pressure with increased duration of diabetes.

METHODS

Plantar pressure was examined in 1196 participants with or without T2DM. Subjects with normal glucose tolerance (NGT) and impaired glucose tolerance (IGT) were assigned to control groups, and those with T2DM were divided into five groups according to diabetes duration (< 2 years, 2-5 years, 5-10 years, 10-15 years, and > 15 years). The clinical characteristics, plantar peak pressure, and pressure-time integral (PTI) were compared among the seven study groups, and factors associated with peak pressure and the PTI were analyzed.

RESULTS

At the hallux, peak pressure exhibited an upward trend in patients with T2DM within 5 years of diabetes duration, followed by a distinct downward slope with further progression of the disease (trend analysis, p  < 0.05). An uneven distribution of peak pressure was found at other locations, but this unevenness was ultimately lower than that in the two control groups (p  < 0.05). No obvious trend was noted for PTI among patients with different diabetes duration; however, those with diabetes for > 10 years manifested a significantly sharper increase in the PTI at the metatarsus (11.63 Ns/cm², p  < 0.05) and heel (14.12 Ns/cm², p  < 0.05) than at the hallux (8.76 Ns/cm²). A fluctuation in the PTI was also detected at the hallux and midfoot of diabetes patients, which was broadly flat when compared with that of the two control groups. The stepwise multiple regression analysis revealed that the variation in plantar pressure was independently associated with age, body mass index, and vibration perception threshold (VPT) (p  < 0.05).

CONCLUSIONS

There would appear to be an association between longer diabetes duration and decreased peak pressure for the hallux, suggesting that individuals with diabetes for > 10 years will have an increased PTI for the metatarsus and heel. The reduced pressure on the hallux is believed to be transferred to the metatarsus. Age, BMI, and VPT are distinct risk factors of abnormal plantar pressure.

Current Therapeutic Strategies in Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are the fastest growing chronic complication of diabetes mellitus, with more than 400 million people diagnosed globally, and the condition is responsible for lower extremity amputation in 85% of people affected, leading to high-cost hospital care and increased mortality risk. Neuropathy and peripheral arterial disease trigger deformities or trauma, and aggravating factors such as infection and edema are the etiological factors for the development of DFUs. DFUs require identifying the etiology and assessing the co-morbidities to provide the correct therapeutic approach, essential to reducing lower-extremity amputation risk. This review focuses on the current treatment strategies for DFUs with a special emphasis on tissue engineering techniques and regenerative medicine that collectively target all components of chronic wound pathology.

Innovative intelligent insole system reduces diabetic foot ulcer recurrence at plantar sites: a prospective, randomised, proof-of-concept study

BACKGROUND

Prevention of diabetic foot ulcer recurrence in high risk patients, using current standard of care methods, remains a challenge. We hypothesised that an innovative intelligent insole system would be effective in reducing diabetic foot ulcer recurrence in such patients.

METHODS

In this prospective, randomised, proof-of-concept study, patients with diabetes, and with peripheral neuropathy and a recent history of plantar foot ulceration were recruited from two multidisciplinary outpatient diabetic foot clinics in the UK, and were randomly assigned to either intervention or control. All patients received an insole system, which measured plantar pressure continuously during daily life. The intervention group received audiovisual alerts via a smartwatch linked to the insole system and offloading instructions when aberrant pressures were detected; the control group did not receive any alerts. The primary outcome was plantar foot ulcer occurrence within 18 months. This trial is registered with ISRCTN, ISRCTN05585501, and is closed to accrual and complete.

FINDINGS

Between March 18, 2014, and Dec 20, 2016, 90 patients were recruited and consented to the study, and 58 completed the study. At follow-up, ten ulcers from 8638 person-days were recorded in the control group and four ulcers from 11 835 person-days in the intervention group: a 71% reduction in ulcer incidence in the intervention group compared with the control group (incidence rate ratio 0·29, 95% CI, 0·09-0·93; p=0·037). The number of patients who ulcerated was similar between groups (six of 26 [control group] vs four of 32 [intervention group]; p=0·29); however, individual plantar sites ulcerated more often in the control group (ten of 416) than in the intervention group (four of 512; p=0·047). In an exploratory analysis of good compliers (n=40), ulcer incidence was reduced by 86% in the intervention group versus control group (incidence rate ratio 0·14, 95% CI 0·03-0·63; p=0·011). In the exploratory analysis, plantar callus severity (change from baseline to 6 months) was greater in re-ulcerating patients (6·5, IQR 4·0-8·3) than non-re-ulcerating patients (2·0, 0·0-4·8; p=0·040).

INTERPRETATION

To our knowledge, this study is the first to show that continuous plantar pressure monitoring and dynamic offloading guidance, provided by an innovative intelligent insole system, can lead to a reduction in diabetic foot ulcer site recurrence.

FUNDING

Diabetes UK and Orpyx Medical Technologies.

Foot callus thickness does not trade off protection for tactile sensitivity during walking

Until relatively recently, humans, similar to other animals, were habitually barefoot. Therefore, the soles of our feet were the only direct contact between the body and the ground when walking. There is indirect evidence that footwear such as sandals and moccasins were first invented within the past 40 thousand years¹, the oldest recovered footwear dates to eight thousand years ago² and inexpensive shoes with cushioned heels were not developed until the Industrial Revolution³. Because calluses-thickened and hardened areas of the epidermal layer of the skin-are the evolutionary solution to protecting the foot, we wondered whether they differ from shoes in maintaining tactile sensitivity during walking, especially at initial foot contact, to improve safety on surfaces that can be slippery, abrasive or otherwise injurious or uncomfortable. Here we show that, as expected, people from Kenya and the United States who frequently walk barefoot have thicker and harder calluses than those who typically use footwear. However, in contrast to shoes, callus thickness does not trade-off protection, measured as hardness and stiffness, for the ability to perceive tactile stimuli at frequencies experienced during walking. Additionally, unlike cushioned footwear, callus thickness does not affect how hard the feet strike the ground during walking, as indicated by impact forces. Along with providing protection and comfort at the cost of tactile sensitivity, cushioned footwear also lowers rates of loading at impact but increases force impulses, with unknown effects on the skeleton that merit future study.

Plantar pressure distribution in diverse stages of diabetic neuropathy

Background

Diabetic Foot Ulceration in patients with diabetes could be associated with high plantar pressure caused by diabetes neuropathy. Therefore, it seems that one of the ways of identifying high-risk legs in diabetic patients with neuropathy would be characterization of elevated plantar pressure distributions.

Objective

Comparing the plantar pressure distribution in diabetic patients who suffered neuropathy with those without neuropathy.

Methods and materials

Plantar pressure distribution was recorded in the following categories: 38 diabetic patients without neuropathy, 30, 40 and 34 patients with mild neuropathy, moderate and severe neuropathy respectively.

Results

Patients suffered from severe neuropathy suggested higher maximum peak plantar pressure at midfoot, heel, and medial forefoot. The peak pressure of midfoot was significantly different in the following categories as well: patient without neuropathy (32.3 ± 17.9 kPa), mild neuropathic (24.0 ± 17.9 kPa), moderate neuropathic (21.5 ± 12.6 kPa), and severe neuropathic (22.9 ± 10.7 kPa) groups (p = 0.02).

Conclusion

The progression of diabetic neuropathy would have been increased followed by the peak plantar pressure.

Fat Grafting for Pedal Fat Pad Atrophy in a 2-Year, Prospective, Randomized, Crossover, Single-Center Clinical Trial

BACKGROUND

By age 60, 30 percent of Americans suffer from fat pad atrophy of the foot. Forefoot fat pad atrophy results from long-term aggressive activity, genetically dictated foot type, multiple forefoot steroid injections, surgery, and foot trauma.

METHODS

The authors present data from a 2-year, prospective, randomized crossover study performed to assess pain and disability indexes, fat pad thickness, forces, and pressures of stance and gait. Group 1 underwent fat grafting with 2 years of follow-up, and group 2 underwent conservative management for 1 year, then underwent fat grafting with 1 year of follow-up.

RESULTS

Eighteen subjects (14 women and four men) constituted group 1. Thirteen subjects (nine women and four men) constituted group 2. Group 1 reported the worst pain at baseline and group 2 experienced the worst pain at 6- and 12-month standard-of-care visits; pain for both groups improved immediately following fat grafting and lasted through study follow-up (p < 0.05). Group 1 demonstrated functional improvements at 12, 18, and 24 months postoperatively (p < 0.05), whereas group 2 demonstrated the highest function at 12 months postoperatively (p < 0.05). Pedal fat pad thickness of subjects in group 1 increased postoperatively and returned to baseline thickness at 2 months postoperatively; subjects in group 2 experienced return to baseline thickness at 6 months postoperatively (p < 0.01). Forces and pressures of stance and gait increased over the 2 years of follow-up for group 1 (p < 0.05).

CONCLUSION

Pedal fat grafting provides long-lasting improvements in pain and function, and prevents against worsening from conservative management.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

The Influence of Fat Grafting on Skin Quality in Cosmetic Foot Grafting: A Randomized, Cross-Over Clinical Trial

BACKGROUND

Pedal fat grafting is a cosmetic procedure to treat the functional and aesthetic sequelae of pedal fat pad atrophy. Fat grafting has been found to mitigate these symptoms, but the exact mechanism is unknown.

OBJECTIVES

The authors hypothesized that pedal fat grafting may improve skin quality, accounting for prolonged symptomatic improvement despite loss of grafted fat.

METHODS

Patients with pedal atrophy were enrolled in a randomized crossover clinical trial. Group 1 underwent fat grafting upon enrollment with 2-year follow-up. Group 2 was managed conservatively for 1 year then placed into the fat grafting group with 1-year follow-up. Patients underwent pedal ultrasounds to determine thicknesses of the fat pad and dermis, and photographs were taken to assess skin quality.

RESULTS

Three men and 20 women with an average age of 63 ± 6 years and an average BMI of 26.0 ± 4.6 kg/m2 were enrolled in the study. Twenty-six feet were injected in Group 1 and 17 were injected in Group 2. Group 1 dermal thickness increased at 6 months post-injection (P < 0.05). This increase persisted through 24 months. Group 2 dermal thickness decreased prior to injection (P < 0.05) but returned to baseline after injection and through 12-month follow-up (P < 0.05). Fat pad thickness returned to baseline by study completion in both groups (P < 0.05).

CONCLUSIONS

Pedal fat grafting yielded a significant, sustained increase in dermal thickness, though grafted fat was not retained. Fat grafting may improve skin quality, which could contribute to improved clinical outcomes despite loss of grafted fat.

LEVEL OF EVIDENCE: 2

Selected RANKL/RANK/OPG system genetic variants in diabetic foot patients

Purpose

Diabetic foot is a complication of long-lasting diabetes mellitus affecting up to 15% of patients, both in type 1 and type 2 diabetes. Osteoprotegerin is involved in osteogenesis and calcification. The aim of the study was to assess the role of selected osteoprotegerin gene variants in diabetes patients with diabetic foot.

Methods

The study involved 300 patients with diabetes and diabetic foot and 968 healthy controls. The study group was formed by 243 patients with diabetic foot of neuropathic origin, 102 with diabetic foot of neuroischemic origin and 77 with Charcot neuroarthropathy.

Results

Compared to controls, rs1872426 and rs1485286 showed correlation with diabetic foot in diabetes subjects. Significant associations between rs2073618, rs1872426, rs7464496 and rs1485286 in men were reported. The aforementioned correlations were also present in type 2 diabetes patient subgroup. Variant rs1485286 was associated to diabetic foot of neuropathic origin. Sex-specificity for females was present for rs6993813 in patients with diabetic foot of neuropathic origin and type 1 diabetes. Variants rs1872426, rs2073617 and rs1485286 were correlated with CN. We found that age, body weight, body mass index, waist circumference, hip circumference and waist-hip ratio were among the basic risk factors of diabetic foot.

Conclusions

The following variants TNFRSF11B (rs2073618, rs2073617, rs1872426, rs1032128, rs7464496, rs11573829 and rs1485286), COLEC10 (rs6993813, rs3134069) and TNFSF11 (rs9533156) present differences in allele frequencies in diabetic foot patients and show correlation with gender, diabetes type and diabetic foot etiology.

Novel insole design for diabetic foot ulcer management

Around the world, over 400 million people suffer from diabetes. In a chronic diabetic condition, the skin underneath the foot often becomes extremely soft and brittle, resulting in the development of foot ulcers. In literature, a plethora of footwear designs have been developed to reduce the induced stresses on a diabetic foot and to consequently prevent the incidences of foot ulcers. However, to date, no insole design exists which can handle post-ulcer diabetic foot conditions without hindering the mobility of the patients. In the current work, a novel custom insole design with arch support and ulcer isolations was tested for effective stress reduction in a diabetic foot with ulcers using finite element modeling. A full-scale model of the foot was developed with ulcers of different geometries and sizes at the heel and metatarsal regions of the foot. The stresses at the ulcer locations were quantified for standing and walking with and without the novel custom insole model. The effect of material properties of the insole on the ulcer stress reduction was quantified extensively. Also, the effectivity of a novel synthetic skin material as the insole material was tested for stress offloading at the ulcers and the rest of the foot. From the analyses, peak stress reductions were observed at the ulcers up to 91.5% due to the ulcer isolation in the novel custom insole design and the skin-like material. Specifically, the ulcer isolation feature in the insole was found to be approximately 25% more effective in peak stress reduction for commonly occurring ulcers with irregular geometry, over the tested regular circular ulcer geometry. Also, a threshold material stiffness was found for the custom insole, below which the peak stresses at the ulcers did not decrease any further. Based on this information, a working prototype of the custom insole was developed with custom ulcer isolations, which will be subjected to further testing. The results of this study would inform better custom insole designing and material selection for post-ulcer diabetic conditions, with effective stress reduction at the ulcers, and the possibilities of preventing further ulceration.

Peak pressure data and pressure-time integral in the contralateral limb in patients with diabetes and a trans-tibial prosthesis

BACKGROUND

Clinicians currently rely on observational clinical data pertaining to the biomechanics of the diabetic foot. However, advances in technology can objectively describe this. A thorough understanding of the functional and mechanical consequences following trans-tibial amputations is lacking.

RESEARCH QUESTION

Does a trans-tibial prostheses significantly increase peak plantar pressures and pressure time integrals in the intact foot of patients with type-2 diabetes and neuropathy?

METHODS

A prospective quantitative matched-subject design was employed. Twenty participants living with diabetes and peripheral sensory neuropathy were recruited. Ten participants presented with a trans-tibial amputation and 10 had intact feet. Participants were matched for gender, age, foot type and BMI. Peak plantar pressure and pressure time integral data were recorded using the Tekscan HR™ pressure mat system, using the two-step gait protocol. The Shapiro-Wilk test was used to determine normality of data. The Independent Samples t-test and the Mann Whitney U test were carried out to reject the null hypothesis.

RESULTS

Although no significant differences (p < 0.05) in mean peak plantar pressures were observed in all the foot masks analysed between the amputee and the control group, a significant difference (p = 0.002) in mean pressure time integrals was recorded with highest pressure time integral (PTI) values under the 2nd-4th metatarsophalangeal joint (MTP joint) for the trans-tibial amputee group.

SIGNIFICANCE

Cumulative exposure of both pressure and time can lead to tissue damage. PTI could be considered as an important contributory factor in determining ulcer formation. Elevated PTI under the 2nd-4th MTP joints sustained in the intact contralateral limb in patients using below knee prosthesis could possibly be due to gait alterations in this population. The preservation of the contralateral limb is of great concern and importance as this might impact patient's mobility and quality of life.

Can ultrasound measures of intrinsic foot muscles and plantar soft tissues predict future diabetes-related foot disease? A systematic review

Introduction

Diabetes mellitus (DM) is associated with hyperglycaemia and advanced glycosylation end-products. In the foot, the consequences of chronic or uncontrolled diabetes are micro and macrovascular disease, neuropathy, reduced joint mobility and structural and soft tissue changes that increase the risk of ulcer development and amputation. Diabetes foot assessment currently includes a comprehensive history, neurological and vascular assessments and examination focussed on dermatological and musculoskeletal abnormalities. Whilst these assessments are helpful for predicting ulceration risk, direct identifiers that enable early therapeutic intervention are lacking. The intention of this review was to ascertain if B-mode ultrasound could be clinically applied to identify structural change in the diabetic foot and be utilised as an early predictor of ulceration risk.

Methods

Primary databases and grey literature sources were systematically searched. Selection criteria were that the study included a diabetic sample and used B-mode ultrasound to assess soft tissue structures of the foot (plantar skin, plantar fat pad or intrinsic muscles).

Results

Fifteen studies were identified for inclusion (combined diabetic sample of 773). Ultrasound demonstrated reductions in tissue thickness in diabetics compared to non-diabetics under first (p = 0.01) and second (p = 0.03) metatarsal heads, but not the third (p = 0.24). Statistical heterogeneity was high for ultrasound thickness measures under metatarsal heads four/five (I² 65%, 81%) and very high for plantar skin (I² 98%), heel pad (I² 76%) and intrinsic muscles (I² 91%, 81%). Extensor digitorum brevis (EDB) ultrasound measures were significantly thinner in diabetics for all dimension measures compared to healthy controls except one study, which reported no significant differences in EDB thickness.

Conclusions

No direct evidence was found to indicate B-mode ultrasound measures can predict soft tissue changes in the plantar foot in diabetes, although low level studies indicate ultrasound has the potential to identify structural change. Clinical, methodological and statistical heterogeneity limit result applicability. This review highlights the need for robust prospective longitudinal research to examine the predictive validity of this method.

Concordance in diabetic foot ulceration: a cross-sectional study of agreement between wound swabbing and tissue sampling in infected ulcers

BACKGROUND

There is inadequate evidence to advise clinicians on the relative merits of swabbing versus tissue sampling of infected diabetic foot ulcers (DFUs).

OBJECTIVES

To determine (1) concordance between culture results from wound swabs and tissue samples from the same ulcer; (2) whether or not differences in bacterial profiles from swabs and tissue samples are clinically relevant; (3) concordance between results from conventional culture versus polymerase chain reaction (PCR); and (4) prognosis for patients with an infected DFU at 12 months' follow-up.

METHODS

This was a cross-sectional, multicentre study involving patients with diabetes and a foot ulcer that was deemed to be infected by their clinician. Microbiology specimens for culture were taken contemporaneously by swab and by tissue sampling from the same wound. In a substudy, specimens were also processed by PCR. A virtual 'blinded' clinical review compared the appropriateness of patients' initial antibiotic regimens based on the results of swab and tissue specimens. Patients' case notes were reviewed at 12 months to assess prognosis.

RESULTS

The main study recruited 400 patients, with 247 patients in the clinical review. There were 12 patients in the PCR study and 299 patients in the prognosis study. Patients' median age was 63 years (range 26-99 years), their diabetes duration was 15 years (range 2 weeks-57 years), and their index ulcer duration was 1.8 months (range 3 days-12 years). Half of the ulcers were neuropathic and the remainder were ischaemic/neuroischaemic. Tissue results reported more than one pathogen in significantly more specimens than swabs {86.1% vs. 70.1% of patients, 15.9% difference [95% confidence interval (CI) 11.8% to 20.1%], McNemar's p-value < 0.0001}. The two sampling techniques reported a difference in the identity of pathogens for 58% of patients. The number of pathogens differed in 50.4% of patients. In the clinical review study, clinicians agreed on the need for a change in therapy for 73.3% of patients (considering swab and tissue results separately), but significantly more tissue than swab samples required a change in therapy. Compared with traditional culture, the PCR technique reported additional pathogens for both swab and tissue samples in six (50%) patients and reported the same pathogens in four (33.3%) patients and different pathogens in two (16.7%) patients. The estimated healing rate was 44.5% (95% CI 38.9% to 50.1%). At 12 months post sampling, 45 (15.1%) patients had died, 52 (17.4%) patients had a lower-extremity ipsilateral amputation and 18 (6.0%) patients had revascularisation surgery.

LIMITATIONS

We did not investigate the potential impact of microbiological information on care. We cannot determine if the improved information yield from tissue sampling is attributable to sample collection, sample handling, processing or reporting.

CONCLUSIONS

Tissue sampling reported both more pathogens and more organisms overall than swabbing. Both techniques missed some organisms, with tissue sampling missing fewer than swabbing. Results from tissue sampling more frequently led to a (virtual) recommended change in therapy. Long-term prognosis for patients with an infected foot ulcer was poor.

FUTURE WORK

Research is needed to determine the effect of sampling/processing techniques on clinical outcomes and antibiotic stewardship.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

NUMERICAL ANALYSIS OF THE FOOT IN HEALTHY AND DEGENERATIVE CONDITIONS

The aim of this work is the development of a 3D numerical model of the foot that allows evaluating the influence of degenerative phenomena on the foot mechanical functionality. Such degenerative phenomena induce histo-morphological alterations and significant modification of the plantar soft tissue mechanical properties, as stiffening and lower damping capabilities. The finite element model of the foot is developed starting from the analysis of biomedical images. Different constitutive models define the mechanical response of the biological tissues. Because of the major role of plantar soft tissue in the here proposed analysis, a specific visco-hyperelastic constitutive formulation is provided considering the typical features of the tissue mechanics, as geometric and material non linearity, almost incompressible behavior and time-dependent phenomena. Constitutive parameters are identified by the analysis of experimental data from in vitro and in vivo mechanical tests, leading to the identification of a range of constitutive parameters for healthy and degenerative conditions. Numerical analyses are developed to investigate the influence of the progression of the degeneration on the distribution of stress and of strain within foot tissues during static standing. Numerical results show the increase of stress values with the appearance of degenerative conditions, showing the typical stiffening phenomenon. The mechanical response of the plantar soft tissue during specific loading condition and the influence of degenerative phenomena on foot mechanics can be evaluated with numerical analysis.

High-Frequency Ultrasound: Description of Sacral Tissue Characteristics in Healthy Adults

OBJECTIVES

The purpose of this study was to describe selected sacral tissue characteristics in a convenience sample of healthy volunteer subjects.

DESIGN

Descriptive.

SAMPLE AND SETTING

Fifty healthy volunteers in a clinical learning center in a school of nursing.

METHODS

Sacral scans were obtained using a 20-MHz ultrasound scanning system in 3 positions: prone and 60° and 90° side-lying from the back. The images were analyzed by software in the ultrasound program using quantitative parameters of dermal thickness and density (dermal median intensity and derived number of low-echogenic pixels to total pixels [LEP:TP] ratio).

RESULTS

In general, average values were as follows: dermal thickness between 2.32 and 2.65 mm; median pixel intensity between 102 and 112; and the LEP:TP ratio between 0.39 and 0.56. There were significant differences in sacral tissue characteristics between measures of thickness and dermal density (median intensity and LEP:TP ratio) by subject side-lying position (60° and 90°) versus prone position, with all P values less than .0001.

CONCLUSIONS

Overall, the ranges were consistent across measures of thickness and dermal density except for systematic differences between side-lying and prone positions. When comparing thickness, median intensity, or LEP:TP ratio, it is important to report subject position. To best recognize tissue inflammation indicative of pressure injuries before surface changes are seen, it is useful to understand healthy high-frequency ultrasound sacral tissue characteristics. It is anticipated that quantitative assessment of dermal thickness, density, and LEP:TP ratio could help identify individuals with incipient pressure injury.

Autologous Fat Grafting for Pedal Fat Pad Atrophy: A Prospective Randomized Clinical Trial

BACKGROUND

Pedal fat pad atrophy is associated with pain, decreased tissue thickness, and increased foot pressures. To date, no objective studies investigating the use of fat grafting to the forefoot have been performed. The authors hypothesize that pedal fat grafting can reduce pain, increase tissue thickness, and decrease pedal pressures.

METHODS

A prospective randomized study was performed to assess tissue thickness, pain, and foot pressures. Group 1 underwent fat grafting immediately with 1-year follow-up, and group 2 underwent conservative management for 1 year.

RESULTS

Thirteen patients (two men and 11 women) constituted group 1 and 12 patients (four men and eight women) constituted group 2. Ten patients in group 1 underwent bilateral injections with a mean volume of 4.8 cc per foot. Mean follow-up time was 11.1 ± 5.4 months for group 1 and 13.8 ± 4.2 months for group 2. At 1 year, group 1 demonstrated improved foot function (p = 0.022), pain (p = 0.022), and work/leisure activities (p = 0.021). Group 1 had no change in tissue thickness, whereas in group 2, the right third metatarsal tissue thickness decreased significantly (p = 0.036). Foot pressures in group 1 did not improve; however, group 2 had a significant increase in left foot pressure (p = 0.011). When comparing the groups at 1 year, group 2 had significantly higher foot pressures and forces than group 1 (p < 0.05).

CONCLUSIONS

Pedal fat grafting significantly improves pain and disability outcomes, and prevents against worsening foot pressures. Future analysis will reveal whether fat grafting has lasting efficacy.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Repeatability and agreement of ultrasonography with computed tomography for evaluating forefoot structure in the coronal plane

Background

Forefoot structure is important to understand some foot problems such as hallux valgus and metatarsalgia. Ultrasonography (US) is a highly portable, noninvasive, low cost, and fast imaging method, especially when compared to magnetic resonance imaging (MRI), computed tomography (CT), and radiography. As the use of US for evaluating forefoot bony structure has not been validated, except for the presence of synovitis, erosions and bursitis within the forefoot in people with inflammatory arthritis, the purpose of this study was to determine whether US is a reliable method for evaluating forefoot structure.

Methods

Sixty feet (30 women, age = 40.1 ± 11.8 years) were examined by US and CT to assess agreement with CT and repeatability of US evaluation of the 2nd metatarsal head height, length between the medial sesamoid bone and 5th metatarsal head, transverse arch height, transverse arch index, sesamoid rotation angle, and area under the transverse arch. The measurement data were evaluated for agreement with CT using the intra-class correlation coefficient (ICC)_{3, 1}, Pearson correlation coefficient, and Bland-Altman plot, and with ICC_{1, 1} for repeatability.

Results

The ICC_{3, 1} values of 0.78–0.89, Pearson correlation coefficient of 0.78–0.90, and Bland-Altman plots showed almost perfect agreements between the US and CT method for all parameters, except the area under the transverse arch (AUTA). The ICC_{1, 1} also showed perfect agreements (0.84–0.92) between two sets of US measurements in all parameters.

Conclusions

The US evaluation of forefoot structure in the coronal plane showed good agreement with CT and repeatability of two ultrasonograms in adult women. This reliable evaluation method of forefoot structure can contribute to a quick clinical assessment screening for risk factors of foot problems such as hallux valgus and metatarsalgia. However, because of some limitations such as a lack of inter-observer reliability, more research is needed to validate US evaluation of forefoot structure.

Trial registration

The current study (trial registration number: R0297) was approved by the Ethical Committee for Human Experiments of Kyoto University (http://www.ec.med.kyoto-u.ac.jp) on December 3, 2015. The first participant in this study was enrolled on November 17, 2015 and retrospectively registered.

Weight-Bearing Exercise and Foot Health in Native Americans

Diabetes contributes to sensory peripheral neuropathy, which has been linked to lower limb abnormalities that raise the risk for foot ulcers and amputations. Because amputations are a reason for pain and hospitalization in those with diabetes, it is of critical importance to gain insight about prevention of ulcer development in this population. Although the American Diabetes Association (ADA) now recommends that individuals with neuropathy can engage in moderate-intensity weight-bearing activity (WBA), they must wear appropriate footwear and inspect their feet daily. The physical forces and inflammatory processes from WBA may contribute to plantar characteristics that lead to ulcers. The purpose of this study was to compare neuropathic status and foot characteristics in Native Americans according to WBA classification. The t tests for unequal sample sizes found that exercisers had more difficulty sensing baseline temperature than nonexercisers, except at the right foot (all p values < .05). By dividing groups into no/low risk and high risk for ulcer, a majority showed no/low risk according to touch and vibration sense. Exercisers demonstrated higher surface skin temperature gradients at the first metatarsal head, a plantar site where wounds tend to form. The more consistently exercisers performed, the higher the plan-tar pressures were at the right second (r = .24, p = .02) and third metatarsal heads (r = .26, p = .01). Findings from this investigation do not refute current ADA recommendations and further intervention studies are needed that are longitudinal and measures WBA more accurately.

The effects of short foot exercises and arch support insoles on improvement in the medial longitudinal arch and dynamic balance of flexible flatfoot patients

[Purpose] The purpose of the present study is to apply short foot exercises and arch support insoles in order to improve the medial longitudinal arch of flatfoot and compare the results to identify the effects of the foregoing exercises on the dynamic balance of the feet and the lower limbs. [Subjects and Methods] Fourteen university students with flexible flatfoot were selected by conducting navicular drop tests and randomly assigned to a short foot exercise group of seven subjects and an arch support insoles group of seven subjects. The intervention in the experiment was implemented for 30 minutes per time, three times per week for five weeks in total. [Results] In inter-group comparison conducted through navicular drop tests and Y-balance tests, the short foot exercise group showed significant differences. Among intra-group comparisons, in navicular drop tests, the short foot exercise group showed significant decreases. In Y-balance tests, both the short foot exercise group and the arch support insoles group showed significant increases. [Conclusion] In the present study, it could be seen that to improve flatfoot, applying short foot exercises was more effective than applying arch support insoles in terms of medial longitudinal arch improvement and dynamic balance ability.

Benefits, Challenges, and Potential Utility of a Gait Database for Diabetes Patients

Gait analysis is a useful tool in understanding movement impairments, which impact on patient well-being. The use of gait analysis in patients with diabetes has led to improvements in health care including the treatment and prevention of ulceration and development of targeted exercise interventions. The current convention when analyzing gait is to address specific complications of diabetes, controlling for potential influencing conditions within a study sample to understand the effects of the few specific complications chosen for analysis. Databases allow for the storage of data in a structured format, allowing easy access to large quantities of data in a consistent, comparable manner. A database of gait analyses of patients with diabetes has the potential to include far greater sample sizes for statistical analyses, allowing multiple influencing factors to be assessed simultaneously, and relationships identified between multiple influencing factors. However, a database of this type would encounter ethical and methodological challenges in its implementation, which are discussed. This article introduces some of the potential benefits, challenges, and utility of a gait database for diabetes patients. We highlight that, whereas the creation of a database within this clinical population would be a complex process both ethically and practically, huge potential benefits could be gained, overcoming some of the limitations faced by traditional isolated gait analysis studies.

A Review of the Biomechanics of the Diabetic Foot

In general, diabetic foot ulcers result from abnormal mechanical loading of the foot, such as repetitive moderate pressure applied to the plantar aspect of the foot while walking. Diabetic peripheral neuropathy causes changes in foot structure, affecting foot function and subsequently leading to increased plantar foot pressure, which is a predictive risk factor for the development of diabetic foot ulceration. Prevention of diabetic foot ulceration is possible by early identification of the insensitive foot, therefore a foot “at risk,” and by protecting the foot from abnormal biomechanical loading. Abnormal foot pressures can be reduced using several different approaches, including callus debridement, prescription of special footwear, injection of liquid silicone, Achilles tendon lengthening, and so forth. Off-loading of the diabetic wound is a key factor in successful wound healing, as it is associated with reduced inflammatory and accelerated repair processes. Pressure relief can be achieved using various off-loading modalities including accommodative dressing, walking splints, ankle-foot orthosis, total contact cast, and removable and irremovable cast walkers.

The Role of Skin Hardness, Thickness, and Sensory Loss on Standing Foot Power in the Development of Plantar Ulcers in Patients with Diabetes Mellitus—A Preliminary Study

This article presents the results of a study on patients with diabetic neuropathy to find the relationships between the foot pressures characterized by power ratio (PR), foot sole hardness (Shore values), and foot sole soft tissue thickness. The results showed that the increase in PR values for diabetic patients in the upper sensation loss levels (S = 7.5 to 10 g) compared to the corresponding increase in lower sensation loss (S=3 to 4.5 g)were of the order of 5 times in the lateralheel and big toe, respectively, and 4 times in the first metatarsal head regions. The increase in PR values for diabetic patients in the upper Shore value regions (30 to 40) compared to the corresponding increase in lower Shore value regions (20 to 30) were of the order of 3.4 times in lateral heel and 2.4, 2.0, and 2.3 times in the first, second, and lateral metatarsal head regions, respectively. At sites contiguous to frank ulcers for foot sole hardness (Shore values of 50) at sensation level > 10 g PR was as high as 59, and foot sole thickness values were also greater than the corresponding normal values. The study shows all measured parameters may play a part in the development of plantar ulcers.

Foot deformities, function in the lower extremities, and plantar pressure in patients with diabetes at high risk to develop foot ulcers

Objective

Foot deformities, neuropathy, and dysfunction in the lower extremities are known risk factors that increase plantar peak pressure (PP) and, as a result, the risk of developing foot ulcers in patients with diabetes. However, knowledge about the prevalence of these factors is still limited. The aim of the present study was to describe the prevalence of risk factors observed in patients with diabetes without foot ulcers and to explore possible connections between the risk factors and high plantar pressure.

Patients and methods

Patients diagnosed with type 1 (n=27) or type 2 (n=47) diabetes (mean age 60.0±15.0 years) were included in this cross-sectional study. Assessments included the registration of foot deformities; test of gross function at the hip, knee, and ankle joints; a stratification of the risk of developing foot ulcers according to the Swedish National Diabetes Register; a walking test; and self-reported questionnaires including the SF-36 health survey. In-shoe PP was measured in seven regions of interests on the sole of the foot using F-Scan^®. An exploratory analysis of the association of risk factors with PP was performed.

Results

Neuropathy was present in 28 (38%), and 39 (53%) had callosities in the heel region. Low forefoot arch was present in 57 (77%). Gait-related parameters, such as the ability to walk on the forefoot or heel, were normal in all patients. Eighty percent had normal function at the hip and ankle joints. Gait velocity was 1.2±0.2 m/s. All patients were stratified to risk group 3. Hallux valgus and hallux rigidus were associated with an increase in the PP in the medial forefoot. A higher body mass index (BMI) was found to increase the PP at metatarsal heads 4 and 5. Pes planus was associated with a decrease in PP at metatarsal head 1. Neuropathy did not have a high association with PP.

Conclusions

This study identified several potential risk factors for the onset of diabetic foot ulcers (DFU). Hallux valgus and hallux rigidus appeared to increase the PP under the medial forefoot and a high BMI appeared to increase the PP under the lateral forefoot. There is a need to construct a simple, valid, and reliable assessment routine to detect potential risk factors for the onset of DFU.

Predictors of barefoot plantar pressure during walking in patients with diabetes, peripheral neuropathy and a history of ulceration

Objective

Elevated dynamic plantar foot pressures significantly increase the risk of foot ulceration in diabetes mellitus. The aim was to determine which factors predict plantar pressures in a population of diabetic patients who are at high-risk of foot ulceration.

Methods

Patients with diabetes, peripheral neuropathy and a history of ulceration were eligible for inclusion in this cross sectional study. Demographic data, foot structure and function, and disease-related factors were recorded and used as potential predictor variables in the analyses. Barefoot peak pressures during walking were calculated for the heel, midfoot, forefoot, lesser toes, and hallux regions. Potential predictors were investigated using multivariate linear regression analyses. 167 participants with mean age of 63 years contributed 329 feet to the analyses.

Results

The regression models were able to predict between 6% (heel) and 41% (midfoot) of the variation in peak plantar pressures. The largest contributing factor in the heel model was glycosylated haemoglobin concentration, in the midfoot Charcot deformity, in the forefoot prominent metatarsal heads, in the lesser toes hammer toe deformity and in the hallux previous ulceration. Variables with local effects (e.g. foot deformity) were stronger predictors of plantar pressure than global features (e.g. body mass, age, gender, or diabetes duration).

Conclusion

The presence of local deformity was the largest contributing factor to barefoot dynamic plantar pressure in high-risk diabetic patients and should therefore be adequately managed to reduce plantar pressure and ulcer risk. However, a significant amount of variance is unexplained by the models, which advocates the quantitative measurement of plantar pressures in the clinical risk assessment of the patient.

Pedobarography in diagnosis and clinical application

Introduction:

Pedobarography as a new diagnostic tool enables measuring the pressure between the foot and the floor during dynamic loading. Dynamic analysis of the foot shows advantage over static analysis due to its capabilities for detecting high load points in certain diseases and in certain phases of walking. Pedobarography as a new method in the context of rehabilitation include wide range of clinical entities.

Goal:

To show the advantages of pedobarography as new diagnostic and rehabilitation method in prevention programs.

Material and methods:

A prospective study included 100 patients with diabetes mellitus type 2. Research was conducted in the Primary Health Care Center of the Sarajevo Canton and the Center for Physical Medicine and Rehabilitation. The test parameters were: Test of balance–symmetric load for the test, the number of comorbidity, clinical examination of foot deformity, test with 10 g monofilament, HbA1c. From the total sample 45 patients (Group I) were selected, aged 50-65 years, which underwent pedobarography (on the appliance Novel Inc., Munich with EMED™ platform) and robotic fabrication of individual orthopedic insoles, followed by control pedobarography. Plantar pressure was determined using standard pedobarography, computer recorded parameters: peak pressure (kPa), force (Ns), area (cm).

Results:

The average age of the respondents was 59.4±11.38 years; altered results on the balance test were present in 34% of patients; 61% of respondents have ≤2 comorbidity. In the total sample, the average number of foot deformity was 2.84. Flat feet have 66% of respondents, and valgus position 57%. The average HbA1c values were 7.783±1.58% (min.5–max.15.0). All subjects (45) after the first, and after the second measurement of peak pressure, have values above 200 kPa, or are in the designated zone of peak pressure that needs to be corrected. In a study was determined the correlation between the number of deformities and peak pressure, the number of deformities and the area upon which plantar pressure act, test with 10g monofilament and peak pressure.

Conclusion:

Within the framework of prevention programs early diagnosis, detection of sensitivity disorders, adequate treatment and taking load from the feet with the help of pedobarography, are of great importance for the patient suffering from diabetes

Assessment of diabetic polyneuropathy and plantar pressure in patients with diabetes mellitus in prevention of diabetic foot

Introduction:

Risk assessment for development foot ulcer in diabetics is a key aspect in any plan and program for prevention of non-traumatic amputation of lower extremities.

Material and methods:

In the prospective research to assessed diabetic neuropathy in diabetic patients, to determined the dynamic function of the foot (plantar pressure), by using pedobarography (Group I), and after the use of orthopedic insoles with help of pedobarography, to determined the connection between the risk factors: deformity of the foot, limited joint movements, diabetic polyneuropathy, plantar pressure in effort preventing changes in the diabetic foot.

Results:

Out of 1806 patients, who are registered in one Team of family medicine examined 100 patients with diabetes mellitus Type 2. The average age of subjects was 59.4, SD11.38. The average HbA1c was 7.78% SD1.58. Combining monofilament and tuning fork tests, the diagnosis of polyneuropathy have 65% of patients. Comparing Test Symptom Score individual parameters between the first and second measurement, using pedobarography, in Group I, statistically significant difference was found for all of the assessed parameters: pain, burning sensation, paresthesia and insensitivity (p<0,05). The measurements of peak pressure, both first and the second measurement, for all of the subjects in Group I(45) show values above 200kPa. That’s a level of pressure that needs to be corrected. The study finds correlation between the foot deformation, diabetic polyneuropathy and plantar pressure (p>0,05).

Conclusion:

A detail clinical exam of diabetic food in a family doctor office equipped with pedobarography (plantar pressure measurements), use of orthopedic insoles, significantly reduces clinical symptoms of diabetic polyneuropathy in patients with diabetes.

An innovative ultrasound foot scanner system for measuring the change in biomechanical properties of plantar tissue from sitting to standing

The present study investigated the reliability of an innovative ultrasound foot scanner system in assessing the thickness and stiffness of plantar soft tissue and the comparison of stiffness and thickness in sitting and standing. Fifteen young healthy individuals were examined. The target sites on the foot sole for investigation included the heel pad, the fifth metatarsal head, the second metatarsal head, the first metatarsal head, and the pulp of the hallux. The test (day 1) and retest (day 2) were performed 1 week apart at the exact time with humidity and temperature of the assessment room under control. The thickness and stiffness of the plantar soft tissue obtained in sitting and standing positions on day 1 were used for comparison. The results showed significant test-retest reliability [intraclass correlation coefficient(3,2)>0.90, P<0.001] at all five sites in both sitting and standing positions. When changing from sitting to standing, the plantar soft tissue became significantly thinner (with decrease ranging from 10 to 14% at various sites) and stiffer (with increase ranging from 123 to 164% at various sites, all P<0.05). The present innovative system is a reliable device for the measurement of the thickness and stiffness of plantar soft tissue in either the sitting or the standing position. The change in positions from sitting to standing resulted in a significant thinning and stiffening of plantar soft tissues. This system could be a potential clinical device to monitor the biomechanical properties of plantar tissue in the elderly or in patients with diseases such as diabetes to estimate the risk of developing foot ulcer or other foot complications.