Ulcer-risk classification and plantar pressure distribution in patients with diabetic polyneuropathy: an exploration of the factors that can lead to foot ulceration

Abstract

Plantar pressure is critical in the onset of neuropathic foot ulcers. However, no international risk classifications include it as a stratification parameter. Whether plantar pressure distribution affects ulcer-risk was investigated in a research context and in a clinics-oriented scenario.Totals of 134 and 83 patients from a research study and from a clinics-oriented study, respectively, were categorized by ulcer-risk using the guidelines of the International Working Group on the Diabetic Foot. Patients were divided into one non-neuropathic and three neuropathic groups. Pressure distribution was acquired during gait (Pedar-X System); contact time, peak pressure, maximum force, pressure-time integral, and contact area were assessed for the patients’ hindfoot, midfoot, forefoot and toes. Analyses of variance (P < 0.05) were conducted for all parameters and regions. Groups were also divided into two sub-groups: low or high BMI; the same statistical analysis was conducted on sub-groups as well.Pressure distribution changed with polyneuropathy even in the low-risk groups. Neuropathic patients’ risk classification corresponded poorly with pressure distribution (median p = 0.686 [0.374–0.828]). Pressure integral, contact time and contact area changed (median p = 0.048 [0.001–0.223]). BMI, age and walking speed influenced most parameters (p < 0.05) except for contact area and pressure integral and made the studies almost incomparable (2-way ANOVA factor A > 0.05). The only comparable parameter was PTI which, together with the above factors, may increase ulcer-risk stratification models’ predictive abilities, once stronger evidence is proved through standardized measurement investigations.