Orthotic intervention in patients with diabetic foot ulceration

Diabetic foot ulcers: Classification, risk factors and management

Diabetic foot ulceration is a devastating complication of diabetes that is associated with infection, amputation, and death, and is affecting increasing numbers of patients with diabetes mellitus. The pathogenesis of foot ulcers is complex, and different factors play major roles in different stages. The refractory nature of foot ulcer is reflected in that even after healing there is still a high recurrence rate and amputation rate, which means that management and nursing plans need to be considered carefully. The importance of establishment of measures for prevention and management of DFU has been emphasized. Therefore, a validated and appropriate DFU classification matching the progression is necessary for clinical diagnosis and management. In the first part of this review, we list several commonly used classification systems and describe their application conditions, scope, strengths, and limitations; in the second part, we briefly introduce the common risk factors for DFU, such as neuropathy, peripheral artery disease, foot deformities, diabetes complications, and obesity. Focusing on the relationship between the risk factors and DFU progression may facilitate prevention and timely management; in the last part, we emphasize the importance of preventive education, characterize several of the most frequently used management approaches, including glycemic control, exercise, offloading, and infection control, and call for taking into account and weighing the quality of life during the formulation of treatment plans. Multidisciplinary intervention and management of diabetic foot ulcers (DFUs) based on the effective and systematic combination of these three components will contribute to the prevention and treatment of DFUs, and improve their prognosis.

How effective is orthotic treatment in patients with recurrent diabetic foot ulcers?

BACKGROUND

We assessed the efficacy of customized foot orthotic therapy by comparing reulceration rates, minor amputation rates, and work and daily living activities before and after therapy. Peak plantar pressures and peak plantar impulses were compared with the patients not wearing and wearing their prescribed footwear.

METHODS

One hundred seventeen patients with diabetes were prescribed therapeutic insoles and footwear based on the results of a detailed biomechanical study and were followed for 2 years. All of the patients had a history of foot ulcers, but none had undergone previous orthotic therapy.

RESULTS

Before treatment, the reulceration rate was 79% and the amputation rate was 54%. Two years after the start of orthotic therapy, the reulceration rate was 15% and the amputation rate was 6%. Orthotic therapy reduced peak plantar pressures in patients with reulcerations and in those without (P < .05), although a significant decrease in peak plantar impulses was achieved only in patients not experiencing reulceration. Sick leave was reduced from 100% to 26%.

CONCLUSIONS

Personalized orthotic therapy targeted at reducing plantar pressures by off-loading protects high-risk patients against reulceration. Treatment reduced the reulceration rate and peak plantar pressures, leading to patients' return to work or other activities.

Epidemiology of diabetic foot infections in an eastern Caribbean population: a prospective study

INTRODUCTION

This study evaluates the epidemiology of diabetic foot infections in an Eastern Caribbean nation in order to direct public health preventive measures.

METHODS

We prospectively identified all patients with diabetic foot infections who were admitted to tertiary care hospitals across Trinidad and Tobago from July 2011 to June 2012. A questionnaire was used to collect data on demographics, patient knowledge, avoidance of risk factors for chronic diseases (a proxy to unhealthy lifestyles), and glycosylated hemoglobin measurements on admission as an index of blood glucose control. The data were analyzed with statistical software.

RESULTS

There were 446 patients with diabetic foot infections (mean age = 56.9 years, standard deviation = 12.4 years). Most patients had Type 2 diabetes (93.3%) and were of Indo-Trinidadian (49.1%) or Afro-Trinidadian (41.7%) descent. There were preexisting complications of diabetes in 82.9% of patients with Type 2 diabetes: foot infections requiring hospitalization (70.2%), ischemic heart disease (32.5%), renal impairment (13.7%), and retinopathy (22.1%). Despite most patients claiming compliance with treatment, 75% had glycosylated hemoglobin levels above 7.1% at presentation, and 49.3% continued unhealthy lifestyles. Despite the high prevalence of diabetic complications at admission, and despite 70% having had previous hospitalization for treatment of foot infections, only 57.4% of patients reported ever being counseled or taught about foot care by medical personnel.

CONCLUSIONS

There is room for improvement in public health strategies to prevent diabetic foot complications in this setting. Such strategies should focus on patient education with emphasis on lifestyle modification and compliance with medical therapy.

Secondary prevention of diabetic foot infections in a Caribbean nation: a call for improved patient education

Most countries have instituted measures to limit the complications of diabetes. We evaluate secondary prevention strategies for diabetic foot infections in a Caribbean country. We performed a prospective questionnaire study evaluating all patients admitted to tertiary care hospitals across Trinidad and Tobago from July 2011 to June 2012. Primary study end points were the number of patient-detected injuries and the time interval between injury and presentation. Secondary end points included the practice of regular foot inspection (≥2 foot examinations per week) for early detection and the use of self-directed nonmedical therapies to treat foot infections. There were 446 patients admitted with diabetic foot infections at an average age of 56.9 ± 12.4 years. Three hundred and fifty-six (80%) were previously hospitalized with foot infections and 226 (51%) had already sustained end organ injury from diabetes. There were 163 (36.6%) patients walking barefoot at the time of injury and 189 (42.4%) had footwear-related injuries. In 257 (57.6%) cases, patients identified their foot injury shortly after the event. Despite early detection, they presented to hospital after a mean interval of 6.2 ± 5.03 days, with 78 (30.4%) having tried some form of home therapy first. Overall, 190 (42.6%) patients did not practice regular foot examinations. There is room for improvement in secondary preventative measures for diabetic foot infections in this setting. Educational campaigns may be beneficial to educate diabetics on the dangers of walking barefoot, the importance of appropriate footwear, regular foot inspection, and the importance of seeking immediate medical attention instead of experimenting with home remedies.

Determination of the augmentation effects of hyaluronic acid on different heel structures in amputated lower limbs of diabetic patients using ultrasound elastography

This study measured tissue properties of different anatomies of heels in amputated lower limbs of diabetic patients before and after hyaluronic acid (HA) or normal saline (NS) injections. Seven amputated lower limbs from six diabetic patients constituted the experimental group and one amputated lower limb from a diabetic patient served as the control. The limbs were placed in a fixation platform. A 5-12 MHz linear-array ultrasound transducer controlled by a stepping motor was used to load and unload tested heels. The loading-unloading velocity was 6 mm/s and the maximum loading stress was 178 kPa. Loading-unloading tests were performed before and after 1 mL HA injections into heels in the experimental group. The control limb underwent the same test before and after 1 mL NS injection. The unloaded thickness and Young's modulus of the macrochambers, microchambers and heel pads were determined before and after the interventions. The unloaded thickness of the macrochambers and the heel pad increased significantly (p = 0.012) after HA injection. The Young's modulus of the macrochambers decreased nonsignificantly after HA injections. Similar thickness and tissue stiffness changes were observed in the control limb. The baseline heel-pad energy dissipation ratio (EDR(hp)) was 81.3 ± 1.3% and decreased significantly (p = 0.012) to 73.1 ± 1.7% after HA injections. The EDR(hp) in the control increased after NS injection. Histologic examinations revealed localized HA accumulation in the macrochambers with an extension into the adjacent fibrous septa. Injection of HA can increase tissue thickness and enhance heel-pad tissue resilience.

The diabetic foot

Diabetes is reaching epidemic proportions and with it carries the risk of complications. Disease of the foot is among one of the most feared complications of diabetes. The ultimate endpoint of diabetic foot disease is amputation, which is associated with significant morbidity and mortality, besides having immense social, psychological and financial consequences. As the majority of amputations are preceded by foot ulceration, it is crucial to identify those at an increased risk. Diabetic foot ulcers may develop as a result of neuropathy, ischaemia or both and when infection complicates a foot ulcer, the combination can become limb and life threatening. Structural abnormalities such as calluses, bunions, hammer toes, claw toes, flat foot and rocker bottom foot need to be identified and managed.

The physical characteristics of materials used in the manufacture of orthoses for patients with diabetes

BACKGROUND

Neuropathic diabetic foot ulceration may be prevented if the mechanical stress transmitted to the plantar tissues can be modified. Orthotic therapy is one practical method commonly used to maintain tissue integrity. Orthotic design must consider the materials chosen for use in fabrication and profile of the device because both aspects influence the performance and durability of the device. Published research evaluating the physical properties of materials commonly used in the manufacture of orthoses for patients with diabetes is limited. This study investigated the physical properties of materials used to fabricate orthoses designed for the prevention of neuropathic diabetic foot ulcers.

METHODS

Fifteen commonly used orthotic materials were selected for testing: four specifications of 6.4-mm Poron (Rogers Corp., Gent, Belgium), 3.2-mm Poron, three densities of 12-mm Ethylene Vinyl Acetate (EVA), 12-mm low-density plastazote, two depths (6.4-mm, 3.2-mm) of Cleron (Algeo Ltd., Liverpool, UK), Professional Protective Technology (PPT), and MaxaCane (Algeo Ltd, Liverpool, UK). The density, resilience, stiffness, static coefficient of friction, durability, and compression set of each material were tested, ranked, and allocated a performance indicator score.

RESULTS

The most clinically desirable dampening materials tested were Poron 96 (6-mm) and Poron 4000 (6-mm). High density EVA (Algeo Ltd., Liverpool, UK) and Lunacell Nora EVA (Freudenberg, Weinhein, Germany) possessed the properties most suitable to achieve motion control. The data present a simple and useful comparison and classification of the selected materials.

CONCLUSIONS

Although this information should not be used as a single indicator for assessing the suitability of an orthotic material, the results provide clinically relevant information relating to the physical properties of orthotic materials commonly used in the prevention of neuropathic diabetic foot ulcers.

An in-vitro study of the pressure-relieving properties of four wound dressings for foot ulcers

This in-vitro study reports on a selection of mechanical tests on four wound dressings: Allevyn (Smith and Nephew), Biatain (Coloplast), Lyofoam (Seton Scholl) and Tielle (Johnson and Johnson). The aim of the study was to investigate these dressings in the laboratory by subjecting them to dry and wet compression tests, shearing tests and a cyclical test. As predicted, all dressings performed differently in the range of tests, with Lyofoam deforming the most when subjected to compression testing (5.6 mm). During wet compression, differences in the physical properties of all the materials tested were identified. During shearing testin, Allevyn and Tielle withstood the greatest shear deflection before failure, but Biatain withstood the greatest force before failing. During the cyclical testing, Lyofoam only reduced by 1% of its original thickness, while Biatain reduced by 30%. No one dressing performed better in all the tests. However, as an all-round 'pressure-relieving' dressing, Allevyn consistently outperformed the others in the study.