Relationship between foot type, foot deformity, and ulcer occurrence in the high-risk diabetic foot

Improving Physical, Physiological, and Psychological Health Outcomes in Patients with Diabetic Foot Ulcers - State of the Art

Diabetic foot disease is a complex and challenging complication of diabetes mellitus, which imposes a significant burden of disease on patients, their carers, and the wider health systems. Recurrence rates are high, and current evidence indicates a high mortality associated with it. While management algorithms have primarily focused on the physical aspects of healing, there is increasing recognition of the critical role played by psychological and biomechanical factors in the development and resolution of diabetic foot disease. Therefore, in this paper, we aim to explore how diabetic foot outcomes can be improved by addressing not only the physical but also the psychological and biomechanical aspects that are integral to the development of this condition and its optimal resolution. We explore new technologies that allow for non-invasive objective assessment of the diabetic foot at risk, and we also explore the role of understanding biomechanics, which is essential to determining risk of foot disease, but also the potential for recurrence. In addition, we discuss the evidence linking depression and cognitive impairment to diabetic foot disease and offer our insight on the research direction required before implementing novel information into front-line clinics.

[Technical Orthopedics - Chronic Diabetic Foot Wounds]

Technical Orthopedics - Chronic Diabetic Foot Wounds Abstract: Chronic foot wounds are a very common and a growing problem. This review focuses on the treatment and the prophylaxis of diabetic foot ulcers from the perspective of technical orthopedics. Diabetic foot ulcers are of great importance for those affected, in particular because of the risk of infections and resulting amputations. With a good prophylaxis and consistent treatment, these complications can often be avoided.

Ulcer occurrence on adjacent toes and hallux valgus deformity after amputation of the second toe in diabetic patients

BACKGROUND

Amputation of the second toe is associated with destabilization of the first toe. Possible consequences are hallux valgus deformity and subsequent pressure ulcers on the lateral side of the first or on the medial side of the third toe. The aim of this study was to investigate the incidence and possible influencing factors of interdigital ulcer development and hallux valgus deformity after second toe amputation.

METHODS

Twenty-four cases of amputation of the second toe between 2004 and 2020 (mean age 68 ± 12 years; 79% males) were included with a mean follow-up of 36 ± 15 months. Ulcer development on the first, third, or fourth toe after amputation, the body mass index (BMI) and the amputation level (toe exarticulation versus transmetatarsal amputation) were recorded. Pre- and postoperative foot radiographs were evaluated for the shape of the first metatarsal head (round, flat, chevron-type), the hallux valgus angle, the first-second intermetatarsal angle, the distal metatarsal articular angle and the hallux valgus interphalangeal angle by two orthopedic surgeons for interobserver reliability.

RESULTS

After amputation of the second toe, the interdigital ulcer rate on the adjacent toes was 50% and the postoperative hallux valgus rate was 71%. Neither the presence of hallux valgus deformity itself (r = .19, p = .37), nor the BMI (r = .09, p = .68), the shape of the first metatarsal head (r = - .09, p = .67), or the amputation level (r = .09, p = .69) was significantly correlated with ulcer development. The interobserver reliability of radiographic measurements was high, oscillating between 0.978 (p = .01) and 0.999 (p = .01).

CONCLUSIONS

The interdigital ulcer rate on the first or third toe after second toe amputation was 50% and hallux valgus development was high. To date, evidence on influencing factors is lacking and this study could not identify parameters such as the BMI, the shape of the first metatarsal head or the amputation level as risk factors for the development of either hallux valgus deformity or ulcer occurrence after second toe amputation.

TRIAL REGISTRATION

BASEC-Nr. 2019-01791.

A Novel Classification for Diabetic Foot Ulcers of the First Ray

OBJECTIVE

Diabetic foot ulcers of the first ray result from several distinct biomechanical mechanisms related to anatomical deformities, which must be addressed if surgical offloading is contemplated. The objective of this study was to create a classification of the anatomical deformities of first-ray ulcers that could lead to better standardization of treatment and reporting.

METHODS

The authors performed a file review of patients with diabetic neuropathy diagnosed with first-ray ulcers over a period of 3 years in an outpatient setting. Anatomical deformities were diagnosed clinically and reported with ulcer location. The primary classification was the metatarsophalangeal joint, the interphalangeal joint, and the distal phalanx.

RESULTS

Records for 59 patients (mean age, 62 years) with University of Texas A1 and A2 ulcers were reviewed. Mean ulcer duration was 2 months. The more common deformities were hallux valgus (41%), hallux valgus interphalangeus (14%), and hallux malleus (20%), and these were primarily associated with metatarsophalangeal, interphalangeal joint, and tip-of-toe ulcers, respectively (P < .0001).

CONCLUSIONS

By classifying ulcer locations, the relevant corrective surgery may be chosen. Although some prophylactic procedures may be safe and effective, prophylactic hallux valgus correction in the diabetic foot requires further study.

Parámetros biomecánicos de la función del pie medidos en el consultorio del especialista en Ortopedia y Traumatología

Introducción: Los estudios dinámicos de la función del pie habitualmente se realizan en laboratorios de marcha de gran complejidad. El objetivo de este estudio fue analizar parámetros funcionales utilizando una plataforma de fuerza en una serie de pacientes asintomáticos evaluados en consultorios externos. Materiales y Métodos: Estudio de corte transversal que incluyó una serie consecutiva de pacientes asintomáticos voluntarios a quienes se les realizó una medición con una plataforma de fuerza (TekScan MatScan®, Boston, MA, EE.UU.) entre 2014 y 2020, en la Ciudad Autónoma de Buenos Aires, Argentina. Resultados: Se incluyeron 316 registros de 158 pacientes con mediciones bilaterales. La mayoría eran mujeres (66,5%) y el promedio de la edad era de 47 años (DE 16.1). Se evaluaron 14 variables, correspondientes a parámetros de fuerza, trayectoria y tiempo de contacto de la fuerza. El tiempo de contacto total fue de 0,79 segundos (DE 0,09), el CoF time según la región del pie fue del 20% en el talón, 26% en el mediopié y 46% en el antepié. El CPEI (center of pressure excursion index) fue del 16,55% (DE 7,14). Conclusiones: Se comunican los parámetros funcionales del pie en pacientes asintomáticos. Se midieronel tiempo de contacto del pie en el suelo, la fuerza (en talón, mediopié y antepié) y la trayectoria de la fuerza con una plataforma de fuerza. No se utilizaron radiaciones ionizantes. Estos hallazgos podrían ser utilizados como valores de referencia para detectar marchas patológicas. Nivel de Evidencia: II  

Flexor Tendon Tenotomy Treatment of the Diabetic Foot: A Multicenter Randomized Controlled Trial

OBJECTIVE

The aim of this study was to evaluate the effects of needle flexor tendon tenotomy treatment of the diabetic hammertoe deformity.

RESEARCH DESIGN AND METHODS

A multicenter randomized controlled trial of individuals with diabetes and ulcers or impending ulcers associated with hammertoes was performed between 1 November 2019 and 31 March 2021. Participants were stratified by the presence of ulcers or impending ulcers. Participants were randomly assigned to tenotomy and standard nonsurgical treatment or to standard nonsurgical treatment alone. Primary outcomes were time to ulcer healing and progression from impending ulcer to active ulcer.

RESULTS

Of 224 screened participants with diabetes, 95 (59.0% men) were included. The mean follow-up was 291 ± 70 days, 28 (29.5%) had type 1 diabetes, mean diabetes (presented with 25-75% quartile) duration was 20 (13-26) years, and mean age was 67.7 ± 9.8 years. Of the included participants, 16 had ulcers, of whom 8 were randomly assigned to intervention. Of the remaining 79 with impending ulcers, 39 were randomly assigned to intervention. For participants with ulcers, healing rates favored tenotomy (100% vs. 37.5%, P = 0.026) as did time to ulcer healing (P = 0.04). For those with impending ulcers, incidence of progression to an active ulcer was lower (1 vs. 7, P = 0.028) and the number of ulcer-free days higher (P = 0.043) in the tenotomy group. No serious adverse events were recorded.

CONCLUSIONS

This randomized study showed that the simple procedure of needle flexor tendon tenotomy was effective and safe when treating and preventing ulcers associated with the diabetic hammertoe deformity.

Biomechanical and musculoskeletal changes after flexor tenotomy to reduce the risk of diabetic neuropathic toe ulcer recurrence

OBJECTIVE

To assess the effect of flexor tenotomy in patients with diabetes on barefoot plantar pressure, toe joint angles and ulcer recurrence during patient follow-up.

METHODS

Patients with a history of ulceration on the toe apex were included. They underwent minimally invasive needle flexor tenotomy by an experienced musculoskeletal surgeon. Dynamic barefoot plantar pressure measurements and static weight-bearing radiographs were taken before and 2-4 weeks after the procedure.

RESULTS

A total of 14 patients underwent flexor tenotomy on 50 toes in 19 feet. There was a mean follow-up time of 11.4 months. No ulcer recurrence occurred during follow-up. Mean barefoot plantar pressure was assessed on 34 toes and decreased significantly after the procedure by a mean 279 kPa (95% CI: 204-353; p < 0.001). Metatarsophalangeal, proximal interphalangeal and distal interphalangeal joint angles were assessed on nine toes and all decreased significantly (by 7° [95% CI: 4-9; p < 0.001], 19° [95% CI: 11-26; p < 0.001] and 28° [95% CI: 13-44; p = 0.003], respectively).

CONCLUSION

These observations show a beneficial effect of flexor tenotomy on biomechanical and musculoskeletal outcomes in the toes, without ulcer recurrence.

Diabetic foot ulcer in Southern Jordan: A cross-sectional Study of Clinical and Microbiological Aspects

Background

Materials and methods

Results

Conclusion

•

Diabetic foot ulcer is a common complication of diabetes.

•

This study is first of its kind in southern Jordan that combined clinical and microbiological aspects of diabetic foot ulcer.

•

The most frequent bacterial isolates from diabetic foot ulcers are gram negative bacteria.

•

Inappropriate previous use of antibiotics is the main determinant of multi-drug resistant isolates.

•

High rates of multi-drug resistant isolates in this study reflect the loose implementation of antibiotics dispensing regulations in Jordan.

Thai version of the Questionnaire for Diabetes-Related Foot Disease (Thai Q-DFD): validity and reliability

Aims

To reduce diabetic foot complications, an annual screening of diabetes-related foot disease (DRFD) should be promoted. The screening tool as the Thai translated Questionnaire for Diabetes-related Foot Disease, Thai Q-DFD, has been established. The study was designed to assess the validity and reliability of the Thai Q-DFD before practical use in the community.

Methods

One hundred and thirty-nine persons with diabetes volunteered in a concurrent validity testing for agreement in diagnosis between the Thai Q-DFD and the standard clinical examinations. The test-retest reliability (a stability of a tool over time between three days apart) was assessed in 50 volunteers. The agreement in either validity or reliability test was evaluated using kappa coefficient.

Results

The screening diagnosis as DRFD by the Thai Q-DFD substantially agreed with that by the standard clinical examinations (kappa = 0.71). The Thai Q-DFD also showed high sensitivity (0.92) and specificity (0.78). Additionally, the Thai Q-DFD presented good test-retest reliability for DRFD diagnosis (kappa = 0.74).

Conclusions

The Thai Q-DFD is comparable to the original English version in terms of concurrent validity and test-retest reliability. Therefore, it can be used for a screening of DRFD in Thai people.

A new application of the Rotterdam Diabetic Foot Study Test Battery: grading pedal sensory loss to predict the risk of foot ulceration

AIMS

To assess the relationship between the degree of loss of foot sensation at baseline and incidence of foot ulceration (DFU).

METHODS

Diabetic patients (n = 416) participating in the observational Rotterdam Diabetic Foot (RDF) Study were followed prospectively (median 955.5 days (IQR, 841.5-1121)). Subjects underwent sensory testing of the feet (39-item RDF Study Test Battery) at baseline and were assessed regarding incident DFU. Seven groups of incremental degree of sensory loss were distinguished, according to the RDF-39 sum score. Kaplan-Meier and regression analyses were used to determine the independent hazard of baseline variables for new DFU.

RESULTS

40 participants developed DFUs. The mean incident rate of new-onset ulceration from study start was 4.5 (95%CI: 3.3 to 6.1) per 100 person-years, which increased significantly from 0 to 67.70 in the seven groups (p < 0.0005). Predictors for DFUs were higher RDF-39 score (aHR: 1.173, p < 0.0005) and kidney function (aHR: 1.022, p = 0.016). Prior DFU suggests increased mortality risk.

CONCLUSIONS

The degree of sensory loss at baseline was associated with progression to DFU during follow-up. Grading the loss of sensation using the RDF Study Test Battery may result in a more precise risk stratification compared to the use of the 10 g monofilament according to current guidelines.

Diabetic foot off loading and ulcer remission: Exploring surgical off-loading

INTRODUCTION

Diabetic peripheral neuropathy leads to foot deformity, soft tissues damage, and gait imbalance, all of which can increase the mechanical stress imposed on the foot and give rise to Charcot neuroarthropathy. The current International Working Group of the Diabetic Foot International Guidelines on offloading focus on managing neuropathic foot ulcers related to pressure: only 2 of their 9 recommendations deal with surgical interventions. We assess the role of surgical techniques in off-loading to heal and possibly prevent diabetic foot ulceration.

METHODS

We systematically analysed published data from January 2000 to November 2020 to assess methods of surgical offloading and associated outcomes for the surgical reconstruction. We tried to identify healing, remission-rates, return to ambulation, complications and limitations.

RESULTS

Five discrete categories of surgical offloading are used in recalcitrant ulcers: 1. Lesser toe tenotomies; 2. Metatarsal head resection ± Achilles tendon release; 3. Hallux procedures; 4. Bony off-loading procedures in the form of exostectomy; and 5. Complex surgical foot reconstruction. Adjuvant modalities including surgically placed antibiotic delivery systems show promise, but further studies are required to clarify their role and effect on systemic antibiotic requirements.

CONCLUSIONS AND IMPLICATIONS

Surgery is important to mechanically stabilise and harmonise the foot for long term off-loading and foot-protection. Surgery should not be reserved for recalcitrant cases only, but extended to ulcer prevention and remission. Further comparative studies will benefit surgical decision making to avoid recurrence and define time point when surgical off-loading could protect against irretrievable tissue loss/re-ulceration.

Diabetic Foot Infections: The Diagnostic Challenges

Diabetic foot infections (DFIs) are severe complications of long-standing diabetes, and they represent a diagnostic challenge, since the differentiation between osteomyelitis (OM), soft tissue infection (STI), and Charcot’s osteoarthropathy is very difficult to achieve. Nevertheless, such differential diagnosis is mandatory in order to plan the most appropriate treatment for the patient. The isolation of the pathogen from bone or soft tissues is still the gold standard for diagnosis; however, it would be desirable to have a non-invasive test that is able to detect, localize, and evaluate the extent of the infection with high accuracy. A multidisciplinary approach is the key for the correct management of diabetic patients dealing with infective complications, but at the moment, no definite diagnostic flow charts still exist. This review aims at providing an overview on multimodality imaging for the diagnosis of DFI and to address evidence-based answers to the clinicians when they appeal to radiologists or nuclear medicine (NM) physicians for studying their patients.

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.

Surgery for the diabetic foot: A key component of care

Surgery for acute and chronic diabetic foot problems has long been an integral component of care. While partial foot amputations remain as important diabetic limb-salvaging operations, foot-sparing reconstructive procedures have become equally important strategies to preserve the functional anatomy of the foot while addressing infection, chronic deformities, and ulcerations. A classification of types of diabetic foot surgery is discussed in accordance with the soft tissue status and acuity of the presenting foot problem. This brief overview from the Association for Diabetic Foot Surgeons describes common conditions best treated by surgical interventions, as well as specific indications. While techniques and indications continue to evolve, effective surgical management of the diabetic foot remains an integral component of care as well as for the prevention of recurrent ulceration.

Limb Salvage and Prevention of Ulcer Recurrence in a Chronic Refractory Diabetic Foot Osteomyelitis

Biomechanical changes caused by structural foot deformities predispose patients to plantar ulceration. Plantar ulcer recurrence often leads to osteomyelitis, which is more commonly observed in patients with diabetes. Once the infection of diabetic foot ulcer (DFU) spreads and is complicated by osteomyelitis, treatment becomes more complicated and difficult. Osteomyelitis treatment remains challenging because of low drug concentration within the tissue caused by poor circulation and inadequate localized nutrition. Moreover, tissues around plantar ulcers are fewer and are thin, making the formation of granulation tissues difficult due to elevated plantar pressure. Furthermore, the skin around the wound is excessively keratinized, and the epidermis is hard to regenerate. Meanwhile, skin grafting at that site is often not successful due to poor blood circulation. Therefore, it is technically challenging to manage diabetic pressure plantar ulcer with osteomyelitis and prevent its recurrence. Here, we present a case of chronic DFU complicated by osteomyelitis due to foot deformity. The ulcer was successfully healed using advanced wound repair technology comprising of surgical bone resection, vancomycin-loaded bone cement implant, negative-pressure wound therapy, and autologous platelet-rich gel. Subsequently, preventive foot care with custom-made offloading footwear was prescribed. The plantar ulcer did not recur and improvement in biomechanical parameters was observed after the intervention. This case represents an effective and comprehensive management strategy for limb salvage and prevention in patients with complicated foot conditions.

Can a combination of lifestyle and clinical characteristics explain the presence of foot ulcer in patients with diabetes?

AIMS

The aim of this study was to identify the biomechanical, neurological and clinical parameters along with other demographics and lifestyle risk factors that could explain the presence of foot ulcer in patients with diabetes in Africa.

METHODS

A total of 1270 (M/F:696/574) patients; 77(M/F:53/24) with ulcerated vs 1193 (M/F: 643/550) with non-ulcerated feet; participated in this study. A set of 28 parameters were collected and compared between the participants with and without active foot ulcers. Multivariate logistic regression was utilised to develop an explanatory model for foot ulceration.

RESULTS

Foot swelling (χ2(1,n = 1270) = 265.9,P = 0.000,Phi = 0.464) and impaired sensation to monofilament (χ2(2,n = 1270) = 114.2,P = 0.000,Cramer'sV = 0.300) showed strong association with presence of ulceration. A lower Temperature sensitivity to cold stimuli and limited ankle joint mobility were observed to be significant (P < 0.05) contributors to ulceration. The logistic regression model can justify the presence of foot ulceration with 95.3% diagnostic accuracy, 99.1% specificity and 37.3% sensitivity.

CONCLUSION

Participants with ulcerated foot show distinct characteristics in few foot related parameters. Swollen foot, limited ankle mobility, and peripheral sensory neuropathy were significant characteristics of patients with diabetic foot ulcer. One out of three patients with ulcerated foot showed common characteristics that could be justified by the model.

An educational intervention on foot self-care behaviour among diabetic retinopathy patients with visual disability and their primary caregivers

AIMS AND OBJECTIVES

To assess the effectiveness of a 12-week educational intervention on foot self-care behaviour among diabetic retinopathy patients with visual disability and their primary caregivers in China.

BACKGROUND

Diabetes with the coexistence of diabetic retinopathy and foot problems complicating diabetes not only represents a personal disaster, but also becomes a serious burden to public health in China. A foot self-care educational intervention is both cost-effective and feasible even in a health resource-limited setting, which should be developed and evaluated.

DESIGN

Quasi-experimental.

METHODS

From July-September 2017, we enrolled 80 eligible hospitalised diabetic retinopathy patients and their primary caregivers by convenient sampling method in a first-class comprehensive hospital in Nantong, in China. Before and after the educational intervention that is in accordance with the TREND statement (for details, see the "Supplementary File 1"), researchers and subjects filled out the self-designed questionnaire on foot problems complicating diabetes and the Diabetic Foot Self-care Behavior Scale, respectively.

RESULTS

Scores of foot self-care behaviour among the subjects significantly improved from 54.19 ± 8.01-75.85 ± 5.04. The number of patients with fasting blood glucoses <7.0 mmol/L improved from 43 (53.75%)-80 (100%). The results of incidence of foot problems complicating diabetes were not statistically significant. The complete execution of each item in Diabetic Foot Self-care Behavior Scale of subjects was apparently higher.

CONCLUSIONS

This educational intervention can facilitate positive foot self-care behaviours among the diabetic retinopathy patients with visual disability and their primary caregivers in China.

RELEVANCE TO CLINICAL PRACTICE

This study adds to the evidence of the effectiveness of an educational intervention to foster positive foot self-care behaviours. This educational intervention appears to be prospective in promoting diabetic home-based self-management in China, and the delivery method of the intervention may be applied to other chronic diseases.

Hind- and midfoot bone morphology varies with foot type and sex

Foot type has been associated with pain, injury, and altered gait mechanics. Morphological variations in foot bones due to foot type variation may impact surgical and therapeutic treatments. The purpose of this study was to utilize principal component analysis (PCA) to determine how morphology of the hind- and midfoot bones differs among foot types and sex. The calcaneus, talus, navicular, and cuboid were segmented using previously obtained computed tomography (CT) scans and converted to surface models. The CTs were sorted into four foot types-cavus, neutrally aligned, asymptomatic planus, and symptomatic planus. Morphometric shape analysis software (Geomorph) was used to perform a PCA to determine which components varied between foot types and between sexes. The calcaneus showed planus feet of both types to have calcanei that have decreased height and increased length compared to neutrally aligned feet. The talus demonstrated increased posterior mass for cavus feet compared to neutrally aligned feet. For the navicular, symptomatic planus had a more posteriorly positioned tuberosity and were wider than asymptomatic planus feet. The cuboid did not exhibit any differences between foot types. Sex differences, found only at the talus and navicular, were subtle. PCA is an objective technique that helped elucidate differences in bone morphology between foot types and sex without needing to determine the features of interest before comparing groups. Understanding these variations can help inform diagnosis of foot pathologies and surgical protocols as well as improve computer models of the foot. Published 2018. This article is a U.S. Government work and is in the public domain in the USA. J Orthop Res 9999:1-16, 2019.

Predictors of Diabetic Foot Reulceration beneath the Hallux

AIMS

To evaluate the factors that predict reulceration beneath the hallux in people with a history of diabetic foot ulceration.

METHODS

A prospective study conducted between January 2012 and December 2014 was performed in a diabetic foot unit to assess the risk factors associated with hallux reulceration. Sixty patients with diabetic neuropathy and a history of previous ulcer were consecutively included. Sociodemographic factors and comorbidities plus the biomechanical and radiographic factors were obtained. Follow-up on participants was conducted every month, and they wore offloading therapeutic footwear and custom-made insoles. Hallux reulceration during the follow-up period was assessed as the main outcome measure in the study.

RESULTS

Patients were followed up during 29 (14.2-64.4) months. Twenty-nine patients (52%) developed a new ulceration: 9 patients (31%) in the hallux and 20 (69%) in other locations. Functional hallux limitus (p = 0.005, 95% CI (2.097-73.128), HR 12.384) and increased body mass index (p = 0.044, 95% CI (1.003-1.272), HR 1.129) were associated with the hallux ulceration-free survival time in the multivariate Cox model.

CONCLUSIONS

Obesity and the presence of functional hallux limitus increase the probability of developing hallux reulceration in patients with diabetic neuropathy and a history of ulcers.

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.

Novel In-Shoe Exoskeleton for Offloading of Forefoot Pressure for Individuals With Diabetic Foot Pathology

INTRODUCTION

Infected diabetic foot ulcers are the leading cause of lower limb amputation. This study evaluated the ability of in-shoe exoskeletons to redirect forces outside of body and through an exoskeleton as an effective means of offloading plantar pressure, the major contributing factor of ulceration.

METHODS

We compared pressure in the forefoot and hind-foot of participants (n = 5) shod with novel exoskeleton footwear. Plantar pressure readings were taken during a 6-m walk at participant's self-selected speed, and five strides were averaged. Results were taken with Achilles exotendon springs disengaged as a baseline, followed by measurements taken with the springs engaged.

RESULTS

When springs were engaged, all participants demonstrated a decrease in forefoot pressure, averaging a 22% reduction ( P < .050). Patient feedback was universally positive, preferring the exotendon springs to be engaged and active.

CONCLUSIONS

Offloading is standard of care for reducing harmful plantar pressure, which may lead to foot ulcers. However, current offloading modalities are limited and have issues. This proof-of-concept study proposed a novel offloading approach based on an exoskeleton solution. Results suggest that when the novel exoskeletons were deployed in footwear and exotendon springs engaged, force was successfully transferred from the lower leg through the exoskeleton-enabled shoe to ground, reducing load on the forefoot. The results need to be confirmed in a larger sample. Another study is warranted to examine the effectiveness of this offloading to prevent diabetic foot ulcer, while minimizing gait alteration in daily physical activities.

Smarter Sole Survival: Will Neuropathic Patients at High Risk for Ulceration Use a Smart Insole-Based Foot Protection System?

OBJECTIVE

This study examined adherence to alert-based cues for plantar pressure offloading in patients with diabetic foot disease.

METHOD AND DESIGN

Participants (n = 17) with in diabetic foot remission (history of neuropathic ulceration) were instructed to wear a smart insole system (the SurroSense Rx, Orpyx Medical Technologies Inc, Calgary, Canada) over a three-month period. This device is designed to cue offloading to manage unprotected sustained plantar pressures in an effort to prevent foot ulceration. A successful response to an alert was defined as pressure offloading, which occurred within 20 minutes of the alert onset. Patient adherence, defined as daily hours of device wear, was determined using sensor data and patient questionnaires. Changes in these parameters were assessed monthly.

RESULTS

Patients demonstrating increased adherence over the course of the study received more alerts (0.82 ± 0.31 alerts/hour) than patients whose adherence did not improve (0.36 ± 0.46 alerts/hour, P = .156). By the final stages of the study, participants who had received at least one alert every two hours were more adherent with offloading than participants who received fewer alerts (52.5 ± 4.1% vs 24.7 ± 22.4%, P = .043). Furthermore, duration of time from alert generation to successful offloading was significantly greater in the group receiving fewer alerts. This was measured in the third month with an effect size Cohen's d = 1.739, P = .043.

CONCLUSION

The results suggest a minimum number of alerts (one every two hours) is required for patients with diabetic neuropathy to optimally respond to offloading cues from a smart insole system.

5th Congress of WUWHS Abstract book Florence, Italy September 25–29 2016

The abstract book contains the abstracts of keynote lectures, focus sessions, symposia, workshops, AIUC annual meeting, AISLEC annual meeting, EPUAP annual meeting, ETRS special session, sponsor symposia, oral presentations, poster presentations and the subject index.

Plantar pressures are higher in cases with diabetic foot ulcers compared to controls despite a longer stance phase duration

BACKGROUND

Current international guidelines advocate achieving at least a 30 % reduction in maximum plantar pressure to reduce the risk of foot ulcers in people with diabetes. However, whether plantar pressures differ in cases with foot ulcers to controls without ulcers is not clear. The aim of this study was to assess if plantar pressures were higher in patients with active plantar diabetic foot ulcers (cases) compared to patients with diabetes without a foot ulcer history (diabetes controls) and people without diabetes or a foot ulcer history (healthy controls).

METHODS

Twenty-one cases with diabetic foot ulcers, 69 diabetes controls and 56 healthy controls were recruited for this case-control study. Plantar pressures at ten sites on both feet and stance phase duration were measured using a pre-established protocol. Primary outcomes were mean peak plantar pressure, pressure-time integral and stance phase duration. Non-parametric analyses were used with Holm's correction to correct for multiple testing. Binary logistic regression models were used to adjust outcomes for age, sex and body mass index. Median differences with 95 % confidence intervals and Cohen's d values (standardised mean difference) were reported for all significant outcomes.

RESULTS

The majority of ulcers were located on the plantar surface of the hallux and toes. When adjusted for age, sex and body mass index, the mean peak plantar pressure and pressure-time integral of toes and the mid-foot were significantly higher in cases compared to diabetes and healthy controls (p < 0.05). The stance phase duration was also significantly higher in cases compared to both control groups (p < 0.05). The main limitations of the study were the small number of cases studied and the inability to adjust analyses for multiple factors.

CONCLUSIONS

This study shows that plantar pressures are higher in cases with active diabetic foot ulcers despite having a longer stance phase duration which would be expected to lower plantar pressure. Whether plantar pressure changes can predict ulcer healing should be the focus of future research. These results highlight the importance of offloading feet during active ulceration in addition to before ulceration.

A Critical Evaluation of Existing Diabetic Foot Screening Guidelines

AIM

To evaluate critically the current guidelines for foot screening in patients with diabetes, and to examine their relevance in terms of advancement in clinical practice, improvement in technology, and change in socio-cultural structure.

METHODS

A structured literature search was conducted in Pubmed/Medline, CINAHL, Cochrane Register of Controlled Trials, and Google between January 2011 and January 2015 using the keywords '(Diabetes) AND (Foot Screening) AND (Guidelines)'.

RESULTS

Ten complete diabetes foot screening guidelines were identified and selected for analysis. Six of them included the full-process guidelines recommended by the International Diabetes Federation. Evaluation of the existing diabetes foot screening guidelines showed substantial variability in terms of different evidence-based methods and grading systems to achieve targets, making it difficult to compare the guidelines. In some of the guidelines, it is unclear how the authors have derived the recommendations, i.e. on which study results they are based, making it difficult for the users to understand them.

CONCLUSIONS

Limitations of currently available guidelines and lack of evidence on which the guidelines are based are responsible for the current gaps between guidelines, standard clinical practice, and development of complications. For the development of standard recommendations and everyday clinical practice, it will be necessary to pay more attention to both the limitations of guidelines and the underlying evidence.

Towards the generation of a parametric foot model using principal component analysis: A pilot study

There have been many recent developments in patient-specific models with their potential to provide more information on the human pathophysiology and the increase in computational power. However they are not yet successfully applied in a clinical setting. One of the main challenges is the time required for mesh creation, which is difficult to automate. The development of parametric models by means of the Principle Component Analysis (PCA) represents an appealing solution. In this study PCA has been applied to the feet of a small cohort of diabetic and healthy subjects, in order to evaluate the possibility of developing parametric foot models, and to use them to identify variations and similarities between the two populations. Both the skin and the first metatarsal bones have been examined. Besides the reduced sample of subjects considered in the analysis, results demonstrated that the method adopted herein constitutes a first step towards the realization of a parametric foot models for biomechanical analysis. Furthermore the study showed that the methodology can successfully describe features in the foot, and evaluate differences in the shape of healthy and diabetic subjects.

Forefoot ulcer risk is associated with foot type in patients with diabetes and neuropathy

AIMS

To stratify the ulceration risk according to the foot morphology in people with diabetes and a history of forefoot neuropathic ulceration.

METHODS

A cross-sectional study was performed on 139 neuropathic individuals with diabetes and previous forefoot ulcers between January 2012 and February 2014. Foot position of the participants was evaluated by using the foot-posture index. A multivariate analysis adjusted for confounding variables was performed with the ulceration risk factors that were found in the univariate analysis.

RESULTS

Two hundred and fifty-eight feet were analysed, 104 (40.3%) feet had a history of ulceration on the forefoot and 154 (59.7%) feet had no previous ulceration. Two positive tests of neuropathy (p<0.001; CI[1.961-6.249] OR 3.500), presence of deformities (p=0.043; CI[1.020-3.599] OR 1.916) and foot type (p=0.039) showed an association with ulceration risk in multivariate analyses. Pronated feet showed a higher risk of ulceration than supinated feet (p=0.011; CI[1.253-5.708] OR 2.675), while significant differences between neutral and supinated feet were not found (p=0.221; CI[0.719-2.753] OR 1.476).

CONCLUSIONS

A pronated foot has a higher risk of ulceration on the forefoot in neuropathic people with deformities and diabetes mellitus. Foot type should be evaluated in people at risk of ulceration.

Risk factors for foot ulceration in adults with end-stage renal disease on dialysis: study protocol for a prospective observational cohort study

BACKGROUND

Adults with end-stage renal disease treated with dialysis experience a high burden of foot ulceration and lower extremity amputation. However, the risk factors for foot ulceration in the dialysis population are incompletely understood due to the lack of high-quality prospective evidence. This article outlines the design of a prospective observational cohort study, which aims to investigate the risk factors for foot ulceration in adults on dialysis.

METHODS/DESIGN

This study will recruit 430 participants with end-stage renal disease on dialysis from satellite and home-therapy dialysis units across multiple health organisations in Melbourne, Victoria, Australia. Data collection at baseline will include a participant interview, medical record review, completion of a health-status questionnaire and a non-invasive foot assessment. Twenty participants will also be recruited to a reliability study to evaluate the reproducibility of testing procedures. Primary outcome data includes: new foot ulcer(s). Secondary outcome data includes: number of new foot ulcers, time to onset of new foot ulcer(s), new lower extremity amputation(s), episodes of infection of the foot or lower extremity, episodes of osteomyelitis, foot-related hospitalisations, revascularisation procedure(s) of the lower extremity, new podiatry interventions, kidney transplantation, and mortality. Participants will be assessed at baseline, and at 12 months they will be evaluated for the primary and secondary outcomes. Multivariate Cox proportional hazards models will be used to assess predictors of new foot ulceration and time to event secondary outcomes. Logistic regression will be used for binary outcomes including prevalence of foot ulcerations.

DISCUSSION

This is the first multi-centre prospective observational cohort study to investigate risk factors for foot ulceration in adults with end-stage renal disease on dialysis. This study will improve on prior studies by using prospective methods, multi-centre recruitment, statistical methods to control for confounding variables, and a pre-specified sample size estimation. The findings can inform the design of future trials evaluating the effectiveness of clinical interventions, which may lead to improved patient outcomes in the dialysis setting.

An 'Importance' Map of Signs and Symptoms to Classify Diabetic Polyneuropathy: An Exploratory Data Analysis

Aims/Hypothesis

Early diagnosis of diabetic polyneuropathy (DPN) is critical for a good prognosis. We aimed to identify different groups of patients, based on the various common clinical signs and symptoms of DPN, that represent a progressive worsening of the disease before the onset of plantar ulceration or amputation. We also sought to identify the most important DPN-related variables that can discriminate between groups, thus representing the most informative variables for early detection.

Methods

In 193 diabetic patients, we assessed 16 DPN-related signs, symptoms, and foot characteristics, based on the literature and the International Consensus on the Diabetic Foot. We used multiple correspondence analysis and the Kohonen algorithm to group the variables into micro and macro-classes and to identify clusters of patients that represent different DPN conditions.

Results

Four distinct groups were observed. One group showed no indication of DPN. The remaining groups were characterized by a progressive loss of the vibration perception, without a worsening of symptoms or tactile perception. The 2 intermediate groups presented different aspects of DPN: one showed mostly DPN symptoms and the other showed the incipient vibration impairment, callus and crack formation, and foot arch alteration. The fourth group showed more severe foot and DPN conditions, including ulceration and amputation, absence of vibration and tactile perception (irrespective of how many compromised foot areas), and worse foot deformities and callus and crack formation.

Conclusion

Vibration perception was more informative than tactile sensitivity in discriminating early DPN onset because its impairment was evident in more groups. Symptoms and callus and cracks did not discriminate the severity status and should be interpreted in association with other clinical variables. Reconsideration of the current screening techniques is needed to clinically determine the early onset of neuropathy using tactile perception.

Diabetic foot complications and their risk factors from a large retrospective cohort study

Background

Foot complications are considered to be a serious consequence of diabetes mellitus, posing a major medical and economical threat. Identifying the extent of this problem and its risk factors will enable health providers to set up better prevention programs. Saudi National Diabetes Registry (SNDR), being a large database source, would be the best tool to evaluate this problem.

Methods

This is a cross-sectional study of a cohort of 62,681 patients aged ≥25 years from SNDR database, selected for studying foot complications associated with diabetes and related risk factors.

Results

The overall prevalence of diabetic foot complications was 3.3% with 95% confidence interval (95% CI) of (3.16%–3.44%), whilst the prevalences of foot ulcer, gangrene, and amputations were 2.05% (1.94%–2.16%), 0.19% (0.16%–0.22%), and 1.06% (0.98%–1.14%), respectively. The prevalence of foot complications increased with age and diabetes duration predominantly amongst the male patients. Diabetic foot is more commonly seen among type 2 patients, although it is more prevalent among type 1 diabetic patients. The Univariate analysis showed Charcot joints, peripheral vascular disease (PVD), neuropathy, diabetes duration ≥10 years, insulin use, retinopathy, nephropathy, age ≥45 years, cerebral vascular disease (CVD), poor glycemic control, coronary artery disease (CAD), male gender, smoking, and hypertension to be significant risk factors with odds ratio and 95% CI at 42.53 (18.16–99.62), 14.47 (8.99–23.31), 12.06 (10.54–13.80), 7.22 (6.10–8.55), 4.69 (4.28–5.14), 4.45 (4.05–4.89), 2.88 (2.43–3.40), 2.81 (2.31–3.43), 2.24 (1.98–2.45), 2.02 (1.84–2.22), 1.54 (1.29–1.83), and 1.51 (1.38–1.65), respectively.

Conclusions

Risk factors for diabetic foot complications are highly prevalent; they have put these complications at a higher rate and warrant primary and secondary prevention programs to minimize morbidity and mortality in addition to economic impact of the complications. Other measurements, such as decompression of lower extremity nerves, should be considered among diabetic patients.

A comparison of two methods of foot health education: the Fremantle Diabetes Study Phase II

AIMS

To compare the effectiveness of two different methods of education on foot health, behaviours and attitudes in patients with type 2 diabetes.

METHODS

Community-based patients were consecutively allocated to written education (Group A) or an interactive educator-led session (Group B). A quantitative Foot Score (maximum 90 points score based on severity of treatable pathology), the Nottingham Assessment of Functional Foot Care (NAFFC) survey score (maximum 30 points reflecting frequency of foot care behaviours) and a 6-question survey of attitudes to foot complications were administered at baseline and 3 months.

RESULTS

154 patients (mean±SD age 68±10 years, 59.7% males, median [interquartile range] diabetes duration 11.5 [5.6-18.9] years) were recruited. There was a greater change (Δ) in Foot Score from baseline to 3 months in Group A (8.3±3.6, Δ-1.8 (95% CI: -2.4 to -1.2) vs Group B (6.8±2.6, Δ-0.1 (-0.7 to 0.4); P<0.001), but no change in NAFFC survey score in either group (P=0.13). In the attitudes survey, Group B felt they better understood how to prevent foot complications than Group A after education (P=0.031).

CONCLUSIONS

Written information was more effective at improving foot health while interactive education improved confidence in undertaking preventive measures, suggesting that the most effective foot care education should include both components.

Kinematic foot types in youth with equinovarus secondary to hemiplegia

BACKGROUND

Elevated kinematic variability of the foot and ankle segments exists during gait among individuals with equinovarus secondary to hemiplegic cerebral palsy (CP). Clinicians have previously addressed such variability by developing classification schemes to identify subgroups of individuals based on their kinematics.

OBJECTIVE

To identify kinematic subgroups among youth with equinovarus secondary to CP using 3-dimensional multi-segment foot and ankle kinematics during locomotion as inputs for principal component analysis (PCA), and K-means cluster analysis.

METHODS

In a single assessment session, multi-segment foot and ankle kinematics using the Milwaukee Foot Model (MFM) were collected in 24 children/adolescents with equinovarus and 20 typically developing children/adolescents.

RESULTS

PCA was used as a data reduction technique on 40 variables. K-means cluster analysis was performed on the first six principal components (PCs) which accounted for 92% of the variance of the dataset. The PCs described the location and plane of involvement in the foot and ankle. Five distinct kinematic subgroups were identified using K-means clustering. Participants with equinovarus presented with variable involvement ranging from primary hindfoot or forefoot deviations to deformtiy that included both segments in multiple planes.

CONCLUSION

This study provides further evidence of the variability in foot characteristics associated with equinovarus secondary to hemiplegic CP. These findings would not have been detected using a single segment foot model. The identification of multiple kinematic subgroups with unique foot and ankle characteristics has the potential to improve treatment since similar patients within a subgroup are likely to benefit from the same intervention(s).

Self-awareness of foot health status in patients with Type 2 diabetes: the Fremantle Diabetes Study Phase II

AIMS

To determine self-awareness of diabetes-related foot problems and its associates in a community-based cohort of people with Type 2 diabetes.

METHODS

A survey concerning diabetic foot problems was administered to 358 consecutive patients with Type 2 diabetes [mean ± SD age 67.4 ± 10.8 years, 56.1% males, median (interquartile range) diabetes duration 9.0 (3.9-16.8) years] attending for detailed clinical, biochemical and questionnaire assessment as part of the longitudinal observational Fremantle Diabetes Study Phase II.

RESULTS

Compared with the 213 patients (59.5%) who considered their feet to be normal, the 145 (40.5%) who considered their feet to be abnormal were older, had longer diabetes duration and were more likely to have sensory neuropathic symptoms and self-reported poor circulation (P < 0.001). In those who considered their feet to be normal, 67.9% had peripheral sensory neuropathy (score >2/8 on the Michigan Neuropathy Screening Instrument clinical portion), 9.9% had an ankle-brachial index < 0.9, 6.1% had both peripheral sensory neuropathy and an ankle-brachial index < 0.90, and 86.9% had one or more features on inspection, such as deformity, dry skin, callus and fissures that could facilitate more serious complications, despite the majority having had at least one foot examination by a healthcare professional in the previous year.

CONCLUSIONS

Self-assessment of diabetes-related foot problems by patients in the Fremantle Diabetes Study Phase II was unreliable. The present data suggest that self-perceived foot health should be assessed together with foot examination findings. Intensive education and monitoring may be necessary in those who consider their feet to be normal but who have neurovascular, structural and/or other precursors of serious foot pathology.

A comparison of hallux valgus angles assessed with computerised plantar pressure measurements, clinical examination and radiography in patients with diabetes

BACKGROUND

Hallux valgus deformity is a common musculoskeletal foot disorder with a prevalence of 3.5% in adolescents to 35.7% in adults aged over 65 years. Radiographic measurements of hallux valgus angles (HVA) are considered to be the most reproducible and accurate assessment of HVA. However, in European countries, many podiatrists do not have direct access to radiographic facilities. Therefore, alternative measurements are desired. Such measurements are computerised plantar pressure measurement and clinical goniometry. The purpose of this study was to establish the agreement of these techniques and radiographic assessments.

METHODS

HVA was determined in one hundred and eighty six participants suffering from diabetes. Radiographic measurements of HVA were performed with standardised static weight bearing dorsoplantar foot radiographs. The clinical goniometry for HVA was measured with a universal goniometer. Computerised plantar pressure measurement for HVA was executed with the EMED SF-4® pressure platform and Novel-Ortho-Geometry software. The intra-class correlation coefficients (ICC) and levels of agreement were analysed using Bland & Altman plots.

RESULTS

Comparison of radiographic measurements to clinical goniometry for HVA showed an intraclass correlation coefficient (ICC) of 0.81 (95% confidence interval, 0.76 to 0.86; p<0.001). Radiographic measurement versus computerised plantar pressure measurement showed an ICC of 0.59 (95% confidence interval, 0.49 to 0.68; p<0.001). In addition, clinical goniometry versus computerised plantar pressure measurement showed an ICC of 0.77 (95% confidence interval, 0.70 to 0.82; p<0.001). The systematic difference of the computerised plantar pressure measurement compared with radiographic measurement and clinical goniometry was 7.0 degrees (SD 6.8) and 5.2 degrees (SD 5.0), respectively. The systemic difference of radiographic measurements compared with clinical goniometry was 1.8 degrees (SD 5.0).

CONCLUSIONS

The agreement of computerised plantar pressure measurement and clinical goniometry for HVA compared to radiographic measurement of HVA is unsatisfactory. Radiographic measurements of HVA and clinical goniometry for HVA yield better agreement compared to radiographic measurements and computerised plantar pressure measurement. The traditional radiographic measurement techniques are strongly recommended for the assessment of HVA.

Complications of the diabetic foot

The diabetic foot is at high risk for complications because of its role in ambulation. Peripheral neuropathy and peripheral vascular disease can lead to chronic foot ulcers, which are at high risk for infection, in part attributable to areas of high pressure caused by lack of tolerance of the soft tissue and bone and joint deformity. If left untreated, infection and ischemia lead to tissue death, culminating in amputation. Treatment strategies include antibiosis, topical therapies, offloading, debridement, and surgery. A multidisciplinary team approach is necessary in the prevention and treatment of complications of the diabetic foot.

The role of foot morphology on foot function in diabetic subjects with or without neuropathy

The aim of this study was to investigate the role of foot morphology, related with respect to diabetes and peripheral neuropathy in altering foot kinematics and plantar pressure during gait. Healthy and diabetic subjects with or without neuropathy with different foot types were analyzed. Three dimensional multisegment foot kinematics and plantar pressures were assessed on 120 feet: 40 feet (24 cavus, 20 with valgus heel and 11 with hallux valgus) in the control group, 80 feet in the diabetic (25 cavus 13 with valgus heel and 13 with hallux valgus) and the neuropathic groups (28 cavus, 24 with valgus heel and 18 with hallux valgus). Subjects were classified according to their foot morphology allowing further comparisons among the subgroups with the same foot morphology. When comparing neuropathic subjects with cavus foot, valgus heel with controls with the same foot morphology, important differences were noticed: increased dorsiflexion and peak plantar pressure on the forefoot (P<0.05), decreased contact surface on the hindfoot (P<0.03). While results indicated the important role of foot morphology in altering both kinematics and plantar pressure in diabetic subjects, diabetes appeared to further contribute in altering foot biomechanics. Surprisingly, all the diabetic subjects with normal foot arch or with valgus hallux were no more likely to display significant differences in biomechanics parameters than controls. This data could be considered a valuable support for future research on diabetic foot function, and in planning preventive interventions.

The importance of clinical biomechanical assessment of foot deformity and joint mobility in people living with type-2 diabetes within a primary care setting

AIMS

The aim of the study was to assess foot morphology and document foot deformities and joint mobility in a cohort of subjects living with type-2 diabetes mellitus in Malta in a Primary Care setting.

METHODS

A retrospective observational study was conducted on 243 subjects who participated in a local pilot diabetes foot screening project. Assessments included hammer/claw toes, hallux valgus, hallux limitus, prominent metatarsal heads, bony prominences, Charcot deformity, plantar callus, foot type and ankle and hallux mobility. The clinical assessments used during this screening program were based on validated and previously published tools.

RESULTS

Upon clinical examination 38% of the sample was found to have developed some form of corns or callosities in their feet. Hallux valgus deformity was present in 49.4% of the sample, whilst 39% of the sample had hammer toes. Prominent metatarsal heads (24%), other bony prominences (44%) and limited joint mobility were also reported. Furthermore, 56% of the sample presented with unsuitable footwear and upon clinical biomechanical examination a further 28% of the sample required prescription orthosis.

CONCLUSIONS/INTERPRETATION

A significant proportion of participants living with type-2 diabetes presented with foot deformities which are known to be predictive of foot ulceration in this high risk population. This research conducted in a primary care setting highlights the importance of increased vigilance coupled with strengthening of existing screening structures and introducing clinical guidelines with regards to biomechanical assessment of the feet in a primary care setting in order to reduce the incidence of diabetes foot complications.

Foot type biomechanics part 1: structure and function of the asymptomatic foot

BACKGROUND

Differences in foot structure are thought to be associated with differences in foot function during movement. Many foot pathologies are of a biomechanical nature and often associated with foot type. Fundamental to the understanding of foot pathomechanics is the question: do different foot types have distinctly different structure and function?

AIM

To determine if objective measures of foot structure and function differ between planus, rectus and cavus foot types in asymptomatic individuals.

METHODS

Sixty-one asymptomatic healthy adults between 18 and 77 years old, that had the same foot type bilaterally (44 planus feet, 54 rectus feet, and 24 cavus feet), were recruited. Structural and functional measurements were taken using custom equipment, an emed-x plantar pressure measuring device, a GaitMat II gait pattern measurement system, and a goniometer. Generalized Estimation Equation modeling was employed to determine if each dependent variable of foot structure and function was significantly different across foot type while accounting for potential dependencies between sides. Post hoc testing was performed to assess pair wise comparisons.

RESULTS

Several measures of foot structure (malleolar valgus index and arch height index) were significantly different between foot types. Gait pattern parameters were invariant across foot types. Peak pressure, maximum force, pressure-time-integral, force-time-integral and contact area were significantly different in several medial forefoot and arch locations between foot types. Planus feet exhibited significantly different center of pressure excursion indices compared to rectus and cavus feet.

CONCLUSIONS

Planus, rectus and cavus feet exhibited significantly different measures of foot structure and function.

Foot Type Biomechanics Part 2: are structure and anthropometrics related to function?

BACKGROUND

Many foot pathologies are associated with specific foot types. If foot structure and function are related, measurement of either could assist with differential diagnosis of pedal pathologies.

HYPOTHESIS

Biomechanical measures of foot structure and function are related in asymptomatic healthy individuals.

METHODS

Sixty-one healthy subjects' left feet were stratified into cavus (n=12), rectus (n=27) and planus (n=22) foot types. Foot structure was assessed by malleolar valgus index, arch height index, and arch height flexibility. Anthropometrics (height and weight), age, and walking speed were measured. Foot function was assessed by center of pressure excursion index, peak plantar pressure, maximum force, and gait pattern parameters. Foot structure and anthropometric variables were entered into stepwise linear regression models to identify predictors of function.

RESULTS

Measures of foot structure and anthropometrics explained 10-37% of the model variance (adjusted R(2)) for gait pattern parameters. When walking speed was included, the adjusted R(2) increased to 45-77% but foot structure was no longer a factor. Foot structure and anthropometrics predicted 7-47% of the model variance for plantar pressure and 16-64% for maximum force parameters. All multivariate models were significant (p<0.05), supporting acceptance of the hypothesis.

DISCUSSION AND CONCLUSION

Foot structure and function are related in asymptomatic healthy individuals. The structural parameters employed are basic measurements that do not require ionizing radiation and could be used in a clinical setting. Further research is needed to identify additional predictive parameters (plantar soft tissue characteristics, skeletal alignment, and neuromuscular control) and to include individuals with pathology.

Predictive factors for diabetic foot ulceration: a systematic review

Improving ability to predict and prevent diabetic foot ulceration is imperative because of the high personal and financial costs of this complication. We therefore conducted a systematic review in order to identify all studies of factors associated with DFU and assess whether available DFU risk stratification systems incorporate those factors of highest potential value. We performed a search in PubMed for studies published through April 2011 that analysed the association between independent variables and DFU. Articles were selected by two investigators-independently and blind to each other. Divergences were solved by a third investigator. A total of 71 studies were included that evaluated the association between diabetic foot ulceration and more than 100 independent variables. The variables most frequently assessed were age, gender, diabetes duration, BMI, HbA(1c) and neuropathy. Diabetic foot ulceration prevalence varied greatly among studies. The majority of the identified variables were assessed by only two or fewer studies. Diabetic neuropathy, peripheral vascular disease, foot deformity and previous diabetic foot ulceration or lower extremity amputation - which are the most common variables included in risk stratification systems - were consistently associated with diabetic foot ulceration development. Existing diabetic foot ulceration risk stratification systems often include variables shown repeatedly in the literature to be strongly predictive of this outcome. Improvement of these risk classification systems though is impaired because of deficiencies noted, including a great lack of standardization in outcome definition and variable selection and measurement.

Is calcaneal inclination higher in patients with insertional Achilles tendinosis? A case-controlled, cross-sectional study

Insertional Achilles tendinosis is a condition where a patient complains of isolated pain at the Achilles tendon insertion site due to intratendinous degeneration. It has been suggested that this condition is associated with cavus foot deformity. However, to our knowledge, there is no study that has confirmed this observation. We carried out a cross-sectional, case-controlled study to explore the association of increased calcaneal inclination-a surgically important characteristic of cavus foot deformity-with insertional Achilles tendinosis. Patients with Achilles tendinosis and matched controls without the pathology were compared. Although a statistically significant difference was detected in calcaneal inclination angle between these 2 groups (p = .038), we felt that the difference was not clinically significant (calcaneal inclination angle = 20.9 vs. 18.9, respectively). Within the limitations of the study, we conclude that there is no clinically significant difference in calcaneal inclination between those with or without insertional Achilles tendinosis.

Anatomy of the varus foot and ankle

In summary, varus deformity of the foot and ankle encompasses a spectrum of deformities from mild to severe. The cause of this deformity may be bone, muscle imbalance, or a combination of both. Surgical intervention should be planned only after the patient's anatomy is understood. Uncorrected symptomatic varus deformities may have significant consequences on gait kinematics and foot biomechanics.

The Characteristics and Clinical Significance of Plantar Pressure Distribution in Patients with Diabetic Toe Deformity: A Dynamic Plantar Pressure Analysis

This study evaluated plantar pressure distribution and its clinical significance in patients with diabetic foot toe deformities. Patients with diabetic claw or hammer toe deformities (patient group; n = 30) and healthy subjects without toe deformities (control group; n = 30) were recruited into the study. Plantar pressures in different regions of the foot were measured using the F-scan® in-shoe plantar pressure dynamic analysis system. Peak pressures in the hallux and first to fifth metatarsal heads were significantly higher in the patient group compared with the control group. In the midfoot there was no significant difference between the two groups. Hindfoot peak plantar pressures were significantly lower in the patient group compared with the control group. The results indicated that toe deformities in patients with diabetes increased forefoot plantar pressures to abnormally high levels. If plantar pressure is regularly monitored in patients with diabetic foot, toe deformities might be detected earlier and ulceration prevented.

Significant J-shaped association between body mass index (BMI) and diabetic foot ulcers

BACKGROUND

Disagreement exists regarding the relationship between body weight and foot ulceration risk among diabetic persons.

METHODS

We used a nested case-control design to estimate the association between body mass index (BMI) and 1-year and 5-year foot ulceration risk. We obtained data on all diabetic patients < 60 years of age who were treated in the US Department of Veterans Affairs healthcare system in 2003. Patient characteristics and co-morbidities were obtained at baseline. For each individual with an incident foot ulcer (case), up to four individuals were randomly selected who matched the case on age, sex, race, marital status, and calendar time.

RESULTS

Crude 1-year and 5-year incidence rates were 1.35 and 6.22% after a mean follow-up of 11.8 ± 1.2 months and 55.5 ± 12.8 months, respectively. Compared with individuals with BMI 25-29.9 kg/m(2) , those with BMI 40-44.9 kg/m(2) and those with BMI ≥ 45 kg/m(2) had 25% [adjusted odds ratio (AOR) = 1.25; 95% confidence interval (CI), 1-1.56] and 83% (AOR = 1.83; 95% CI, 1.44-2.32) higher 1-year risk and 1.4 (AOR = 1.39; 95% CI, 1.26-1.54) and 2.1 (AOR = 2.08; 95% CI, 1.86-2.32) times higher 5-year risk. BMI < 25 kg/m(2) was associated with 30% higher risk at both 1 year (AOR = 1.28; 95% CI, 1.04-1.58) and 5 years (AOR = 1.27; 95% CI, 1.15-1.40).

CONCLUSIONS

Our data suggest a significant J-shaped association between BMI and diabetic foot ulcers.

Characteristics of diabetic patients visiting a podiatry practice in Germany

OBJECTIVE

To describe the foot characteristics of diabetic patients attending a podiatry practice for their first consultation. The objective was to determine how effectively diabetic foot ulcers are being prevented in primary care.

METHOD

All diabetic patients who presented at a podiatry practice between 2006 and 2008 for their first consultation were analysed. Anonymous data were obtained from the standard patient anamnesis sheet completed by the podiatrist. These included results of patient interviews and examinations.

RESULTS

A total of 230 diabetic patients (93.9% had type 2 diabetes mellitus and 6.1% had type 1) were analysed. The mean age was 67.7 years (+/- 10.8). Just under half (47.4%) were female. The mean duration of diabetes was 12.6 years (+/- 10.5) years. 70.4% of the patients had diabetic neuropathy (confidence intervals: 64.5-76.3), of whom 73.2% already had resting foot pain or strain foot pain while walking. 58.3% of the patients had toenail mycosis, and of these 38.1% had the infection in all 10 toenails. Most of the patients had at least one foot deformities (89.6% splayfoot and 37.0% flatfoot). 40.2% had no sensation to microfilament testing on either their right or left foot toes. The overall mean vibration sensation test threshold was 3.7 (+/- 2.3).

CONCLUSION

While there is a structure and strategy for the primary and secondary prevention of the diabetic foot ulcers, its delivery is often ineffective. This audit shows that, in Germany, the detection and prevention of diabetic foot problems in podiatric practices happens far too late.