Altered heel-pad mechanical properties in patients with Type 2 diabetes mellitus

Aims: To compare the heel-pad mechanical properties in patients with Type 2 diabetes mellitus with forefoot ulceration, without forefoot ulceration and age-matched healthy subjects. Methods: Heel-pad mechanical properties in 40 heels of 20 healthy subjects (group I) age-matched with the other groups, 42 heels of 21 diabetic patients without forefoot ulceration (group II), and 14 heels of 12 diabetic patients with active forefoot ulceration (group III) were assessed using a selfconstructed loading-unloading device and a 10-MHz linear-array ultrasound transducer. Results: There were no differences in the unloaded heel-pad thickness, compressibility index and elastic modulus between the three groups. When compared with group I subjects (mean ± SD, 27.9 ± 6.1%), a significant increase (P < 0.001) was found in both group II (36.1 ± 8.7%) and group III patients (43.2 ± 6.6%) for the energy dissipation ratio. This ratio was also significantly different (P = 0.003) between groups II and III. Conclusions: The higher impact energy dissipated in the heel-pad may put patients with Type 2 diabetes at higher risk for developing foot ulceration.