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Project

An advanced clinical examination platform for the examination of the diabetic foot.

Diabetes mellitus is one of the most common non-communicable, metabolicdiseases; characterized by hyperglycaemia. Alterations in the neurological, vascular and musculoskeletal system caused by diabetes mellitus are frequent and may, among others, result in the well-known diabetic foot, leading to foot ulcers in about 12-25% of the patients. These ulcerscause substantial morbidity, impair quality of life, engender high treatment costs and imply the most important risk factor for lower-extremityamputation. Risk assessment plays a crucial role in diabetic foot management. This is usually performed by evaluating the presence of peripheral neuropathy, peripheral angiopathy, history of foot ulcer and musculoskeletal disorders. Even though the development of foot ulcers is, to an important degree, related to gait impairments, objective gait evaluation is not sufficiently incorporated in the clinical assessment and management. If applied, gait in patients with diabetes mellitus is commonly assessed through single method studies using either plantar pressure measurement or three dimensional motion analyses. Critical appraisal of such studies highlights the lack of objective data with respect to segmental foot kinematics through conventional 3D lower limb kinematic analysis and the lack of an integrated approach.
The combined assessment of multisegment foot kinematics and plantar pressure distribution during walking in patients with diabetes is assumed to address some of theaforementioned limitations. However, this is purely speculative as currently no adequate evidence is available in the literature. Thus, elaborating on these scientific challenges is of clinical interest as it carries the potential for optimization of conservative and non-conservative treatment algorithms in an at-risk population for lower limb amputation.
The aim of this doctoral project was therefore to elaborate, bothin a qualitative and quantitative way, on the potential value of the combined assessment of foot kinematics and plantar pressure distribution in patients with diabetes mellitus. To achieve this goal, we aimed at developing an advanced clinical examination platform (ACEP).
In the first part of this doctoral project we addressed a number of methodological aspects related to the development of the ACEP (methodological part,chapter 1-6). In the second part, the possible value of the ACEP in objectively increasing the clinical insight in foot biomechanics of PwDM was initiated (clinical part). In this clinical perspective, we investigated the segmental foot kinematics and forefoot plantar pressure pattern through respectively a pathophysiological approach and a biomechanical approach (chapter 7-8).
The first part of this doctoral thesis covered the creation of an advanced clinical examination platform. In collaboration with the department of mechanical engineering, temporal and spatial synchronization of plantar pressure measurement technology within existing three-dimensional motion analysis equipment was first established. Simultaneously, a systematic review on published three-dimensional multisegment foot models was performed (chapter 1). This review highlighted the presence of a multitude of 3D multisegment foot models with the majority characterized by moderate methodological quality and absence ofpsychometric quality indicators. In a second study, we reviewed the clinical approaches and diagnostic quantities in pedobarographic measurements (chapter 2). This review revealed that inferential analysis of 4D pedobarographic data is predominantly performed through the combination of a subsampling method and the selection of specific physical quantities (low resolution perspective). The systematic review from chapter 1 provided a rationale for measurements of foot segmental mobility in the advanced clinical examination platform within this doctoral project. The Rizzoli_3DMFM protocol developed by Leardini et al. (2007) was implementedand tested for its repeatability in 6 healthy adult persons (chapter 3). Results from a repeated measure design including two therapists (senior and junior) and 4 measurement sessions revealed: 1) a considerable higher variability for the absolute 3D rotations, 2) poorer repeatability in the junior therapist and questionable results for the absolute representation of planar angles. In presence of foot deformities, higher inter-trial variability in this population was observed on one hand, as well as a trend towards poorer repeatability in the determination of the anatomical reference frame of the midfoot (chapter 4). Chapter 5 elaborated on the optimization of the calcaneal marker placement protocol. This was based on findings from another research group reporting potential difficulties to determine the anatomical reference frame of the calcaneus. A Calcaneal Marker Device was developed and evaluated for its repeatability with respect to manual marker placement. Results suggested that variations in marker placement are reduced using the novel device, possibly towards the limits dictated by the fine motor skills of therapists and tissue artefacts. In chapter 6, we explored the potential advantage of semi-automatic total mapping and temporal force-time indices insummarizing and interpreting 4D pedobarographic data. Six temporal force-time indices were found to be consistent, repeatable and in good correspondence with existing knowledge from the literature.
The secondpart of this doctoral thesis explored the utility of the advanced clinical examination platform in objectively increasing the clinical insight of foot biomechanics in patients with diabetes. Chapter 7 investigated whether patients with diabetes with and without neuropathy differentiate from persons without diabetes on their segmental foot mobility duringgait. The mobility of different foot segments was affected both in diabetic patients with and without neuropathy. Furthermore, an alteration injoint coupling between the rearfoot and tibia was suggested. In a second clinical study, classification of both non-diabetics and patients withdiabetes was done on the basis of forefoot plantar pressure pattern similarity (biomechanical approach, chapter 8). Relative regional impulses at the five metatarsals and hallux of 33 non-diabetics and 97 patients with diabetes were determined using a semi-automatic total mapping method. Subsequently, a non-hierarchical clustering technique was used to provide unsupervised feedback of potential forefoot plantar pressure patterns. An optimal classification of all participants indicated the presence of four distinct groups. Three groups encompassed forefoot plantar pressure patterns of both non-diabetics as well as patients with diabetes;however, one group comprised diabetic feet only. The relevance of the reported clusters was supported by analysis of variance statistics on other parameters and, moreover, good face validity with foot ulcer history was observed. Interestingly, no correlation with pathophysiological characteristics could be found.
In conclusion, this doctoral project contributed to an enhanced biomechanical insight in the (patho)mechanicsof the diabetic foot by developing an advanced clinical examination platform. The information on psychometric qualities of both foot segmental kinematic analyses as well as plantar pressure measurements is valuable for future clinical reasoning and interpretation. Gaining clinical insight in the complex foot biomechanics through the advanced clinical examination platform can be approached from different perspectives. Findings of the clinical studies suggest that adopting solely the pathophysiological paradigm may considerably limit future explorations. Adopting a biomechanical approach in light of developing classification systems may become a state-of-the art methodological approach in future studies on the mechanical component of the diabetic foot and may form the basis for research in etiology, prediction and treatment of diabetic foot related pathological conditions.
 

Date:1 Sep 2009 →  31 Aug 2013
Keywords:Diabetic foot
Disciplines:Laboratory medicine, Palliative care and end-of-life care, Regenerative medicine, Other basic sciences, Other health sciences, Nursing, Other paramedical sciences, Other translational sciences, Other medical and health sciences