Plantar soft tissue deformability and diabetic foot ulceration: Is there a link?

Abstract

Background: Ultrasound elastography is getting popular in the area of musculo-skeletal assessment (Lin et al., 2015), with some preliminary studies demonstrating its use in differentiating between the deformability of plantar soft tissue of diabetic and non-diabetic patients (Matteoli et al., 2015). Whilemechanical trauma has been recognised as a cause of foot ulceration in diabetic neuropathic patients, there has been no study comparing the mechanical properties of the plantar soft tissue in ulcerated vs non-ulcerated feet. Aims: The aim of this study was to determine if a significant difference exist between the plantar soft tissue in the ulcerated vs non-ulcerated feet. Methods: 69 patients with diabetic neuropathy volunteered to participate in this study. 11 out of the total 138 feet tested had an active ulcer at the forefoot. Realtime elastography (Esaote S.p.A., IT) using a linear probe attached to a stand-off interface material was used to enable comparison of deformability between different trials. The relative deformability of plantar soft tissue was measured at the forefoot and rear-foot, this was also normalised over the maximum deformation of the stand-off to account for the effect of loading magnitude. Results: Independent sample T-test showed significantly higher deformability (t(138) = 2.26, p = 0.044, x = 0.036) and normalised deformability (t(138) = 2.553, p = 0.025, x = 0.046) at the heel in the ulcerated feet. Summary/conclusions: The observed difference in deformability at the heel between the ulcerated and non-ulcerated feet clearly indicates a link between tissue mechanics and ulceration.