Prevention and healing of diabetic foot ulcers is important to reduce the burden of diabetic foot disease. To solve barriers in current treatment strategies, we propose a paradigm shift from stratified healthcare towards personalised medicine for diabetic foot disease. Personalised medicine aims to deliver the right treatment to the right patient at the right time, based on individual diagnostics. Different treatment strategies should be available for different patients, delivered in an integrated, objective, quantitative and evidence-based approach.

To deliver personalised medicine, individual diagnostics should focus on modifiable risk factors for ulcer development or healing, more than on the classical risk factors of peripheral neuropathy and peripheral artery disease (in case of ulcer prevention) or only ulcer-related characteristics (in case of ulcer healing), and beyond single ulcer episodes. This includes structured biomechanical and behavioural profiling, while new research with (big) data science may identify additional risk factors, such as geographical or temporal patterns in ulceration. Industry involvement can drive the development of wearable instruments and assessment tools, to facilitate large-scale individual diagnostics.

For a paradigm shift towards personalised medicine in prevention, large-scale collaborations between stakeholders are needed. As each ulcer episode not prevented costs about €10,000 in medical costs alone, and each amputation not prevented costs €25.000; therefore, investments towards personalised medicine can be cost-effective.

We hope to see more discussions around this paradigm shift, and increasing investments of energy and money in diabetic foot ulcer prevention in research and clinical practice.

Discussion Points:

• Prevention and healing should both take place in one multidisciplinary team, or we will never look beyond single ulcer episodes
• The current medical model in ulcer prevention and healing is harmful
• Care for diabetic foot disease needs professionals outside medicine and allied health

Guidelines recommend non-removable knee-high offloading devices as the first line treatment of plantar diabetic foot ulcers [1]. However, most studies do not take into account that these devices hinder daily activities, thus reducing patients’ acceptance of treatment. This talk will discuss promises and challenges of future research on non-removable ankle-high devices, including non-removable therapeutic footwear [3], being less restrictive to daily activities than knee-high devices.

Furthermore, guidelines recommend people at high risk of developing foot ulcers to wear therapeutic footwear to prevent ulcers [2]. However, patient adherence to wearing therapeutic footwear is low. Studies are inconclusive on what factors and patient characteristics that are associated with low adherence, and only single pilot studies have investigated interventions to improve adherence. This talk will summarize adherence research up to date and discuss future research directions, including potential interventions and methodological issues.

References

1. Bus, et al. IWGDF Guideline on offloading foot ulcers. Diabetes Metab Res Rev 2019, (in press).

Bus, et al. IWGDF Guideline on the prevention of foot ulcers in persons with diabetes. Diabetes Metab Res Rev 2019, (in press).

Jarl and Tranberg. An innovative sealed shoe to off-load and heal diabetic forefoot ulcers – a feasibility study. Diabetic Foot & Ankle 2017, 8:1348178.

Discussion points

• Is there a role for non-removable ankle-high offloading devices and therapeutic footwear in the treatment of diabetic foot ulcers?
• How can we improve adherence to wearing therapeutic footwear to prevent foot ulcers
• What knowledge gaps should future research address?

Diabetic foot ulcer (DFU) is a general expression of severe vascular and neurological complications in the in the lower limbs at later stage of diabetic patients. The incidence DFU was around 6~15%.  Severe DFU usually accompanies with a series of local complications, such as gangrene, deep and large ulcer, osteomyelitis, infective and chronic wounds. Patients may also suffer other systemic diseases, such as heart conditions, sepsis or renal failure.  Amputation is the most common choice for severe DFU treatment.  At present, 90% of DFU patients with severity at Wagner III or above will end up amputation.  For those whose ulcers healed through conventional treatment, the recurrence rate is 40% within 1 year, 60% and 65% respectively within 3 and 5-years.  Therefore, new treatments to promote DFU healing and limb salvage rate are in great need.

Since 2011, clinical scientists in China launched a novel strategy for the treatment of severe DFU (Wagner III and above) by using transverse tibial transport technique (TTT).  First, the diabetic patients must receive systemic treatment to control their blood glucose level and other systemic symptoms.  Second, the TTT is applied in addition to the conventional treatment of debridement and dressing changes for the wound management.  It was noted that after TTT, the ulcer wound management became much more responsive and effective.  With a review of 93 cases of severe DFU cases treated with TTT in China, the wound healing rate and limb salvage rate was over 95% for Wagner III DFU, and 1-year and 3-year recurrence rate of DFU was 7.2% and 8.6 % respectively, in contrast, the conventional management the 1-year and 3-year recurrence rate of DFU was 40% and 60% respectively.

The possible underlying mechanisms for the TTL surgery are: (1) Decompress the marrow cavity and promote angiogenesis in the distal limb. (2) Systemic factors released to promote stem cells mobilization. (3) Transverse lengthening promotes macrophages transformation from M1 to M2 phase. (4) Other possible mechanisms included improve the sympathetic never function or lymphatic microcirculation.  More research is still needed to understand the underlying biological mechanisms for TTT treatment of DFU and other peripheral avascular diseases.

Hence TTT may be a novel, simple and cost-effective surgical method to promote DFU healing, especially for severe DUF cases with high successful rate of limb salvage and low incidence of recurrence rate.

The toes play an important role in gait to stabilise the foot and assist in forward propulsion. Current diabetic foot screening guidelines do not include an examination of foot muscle strength, even though structural changes in the forefoot and atrophy of the intrinsic foot muscles, which has implications for foot function, are evident in the neuropathic diabetic foot. The paper grip test (1) was developed by W. J. Theuvenet and P. W. Roche in Nepal, in 1990. It was used as a screening tool for identifying muscle weakness in people with leprosy. It offers a quick assessment of muscle strength and does not require specialist or expensive equipment. This presentation will explore the research completed within the Centre for Biomechanics and Rehabilitation Technologies at Staffordshire University, UK on the use of the paper grip test for people with diabetes mellitus. Exploring the validity of the paper grip test as a clinical tool for assessing plantar flexion strength of the hallux in people with diabetic neuropathy (2). Furthermore, examining the relationship between the paper grip test, the strength of the foot-ankle muscles and falls risk (3).

References:

1. de Win MM, Theuvenet WJ, Roche PW, de Bie RA, van Mameren H. The paper grip test for screening on intrinsic muscle paralysis in the foot of leprosy patients. Int J Lepr Other Mycobact Dis. 2002;70(1):16–24.
2. Healy A, Naemi R, Sundar L, Chatzistergos P, Ramachandran A, Chockalingam N. Hallux plantar flexor strength in people with diabetic neuropathy: Validation of a simple clinical test. Diabetes Res Clin Pract [Internet]. 2018;144:1–9.
3. Chatzistergos P, Healy A, Naemi R, Sundar L, Ramachandran A, Chockalingam N. The relationship between hallux grip force and balance in people with diabetes. Gait Posture. 2019;70:109–15.

Discussion Points

• Could the paper grip test add value to current foot examination procedures for people with diabetes mellitus?
• Could the paper grip test be used to identify people at risk of falling?
• Is it possible to improve the grip ability of the toes?

In a healthy blood vessel, endothelial cells dynamically integrate biomechanical and biochemical signals from the flowing blood at their apical surface and the basement membrane at their basolateral surface. In metabolic diseases, changes in the biochemical environment may disturb endothelial cell response to mechanical forces, and the mechanical environment may affect biochemical kinetics. Over the past decade, we showed that changes in blood glucose, which are experienced by people with diabetes, disturb endothelial biomechanical response. We are now reversing the research question to investigate how the mechanical environment impacts the way vascular cells metabolize glucose. Our data show that steady laminar but not oscillating disturbed flow decreases endothelial glucose metabolism, which in turn affects critical endothelial functions such as nitric oxide production. We are currently developing computational models to predict endothelial metabolic changes with pharmaceutical therapies, as well as 3D in vitro models to study how endothelial cells metabolically interact with parenchymal tissue. This research has translational applications in macrovascular disease such as atherosclerosis and microvascular disease such as wound healing.

Discussion Points

• How could manipulation of cellular metabolism impact wound healing?
• In what way do altered metabolites in diabetic wounds impact endothelial migration and proliferation?
• Would enhanced blood flow to the wound compensate for the metabolic effects on cells?

Shortcomings in achieving effective revascularization are a major bottleneck for large scale tissue engineering and tissue regeneration. This is potentiated in diabetes, where the vasculature is significantly affected and angiogenesis is impaired. Motivated by the need to generate alternative therapeutic avenues to treat cardiovascular diseases, my lab is 1) developing vascularization strategies for regenerative medicine applications, and 2) generating human tissue mimics as surrogate for cell biology studies and drug screening purposes. This talk will cover our recent efforts in vascular regeneration and tissue engineering therapies in type I diabetes. Our comprehensive analysis of the potential impact of diabetes has shown that Type I diabetes affects not only the angiogenic sprouting, as described for years, but also affects graft perfusion and maturation into vessels of specific subtypes (i.e. arterial, venous). Moreover, we show that there is no memory effect as microvessels from diabetic animals will undergo normal sprouting, perfusion and maturation if transplanted into healthy hosts, instead of diabetic ones. This indicates the environment is driving the cell responses and highlights the importance of controlling blood glucose effectively.

Discussion points:

• Tissue engineering
• Neovascularization
• Arterio-venous differentiation

From the perspective of three different devices we will explore what makes a good medical device for prevention and treatment.  Medical device performance for prevention and treatment require features and characteristics that are specific to the intended application.  Cross over devices leave either the prevention or the treatment lacking in relation to the optimal potential device performance.  Looking at prophylactic /wound treatment-dressings life based on protective performance and protective endurance test results allows us to look at the resultant impact on the tissues.  Heel boots are often applied as a checklist item and the patient’s wellbeing is left to the device and its application without consideration of the interactions of design features with the characteristics of the materials of construction.  This leaves the patient unwilling to be compliant with the prescription due to discomfort, lack of function or interference with activities and treatments.  Compression wraps are applied independent of the life of the wrap cycle.  Selection of the wrap based on intended extent of compression fails to consider either the life of the wraps application, is it rewrapped daily, bi-weekly or even bi-monthly.  Is the patient capable of maintain proper function in the periods that are outside the life of the wrap cycle?

Discussion Points:

• Performance of a device may not last as long as it’s ‘good looks’
• Proper tissue protection is built from the ground up, it is feature interactive, for example moisture vapor transmission and heat exchange are not just dependent on fabric of construction or product fill (batting vs air), architecture and designed air wash exchange play critical roles, and often feature interdependent (ie: loosing one features performance challenges other features ability to protect tissue).
• Normal application for one clinician, will not be protective for another. Low stretch compression wraps applied by a clinician that sees the patient on a 3 day/4 day rotation will perform differently than those applied by a clinician that sees the patient once every 7-10 days.  This is even true when wrap life is considered in selection of no stretch vs elastic compression products.