Background: Diabetes mellitus is one of the most common diseases worldwide and the number of patients is expected to increase dramatically in future. Plantar ulceration is partly caused by high plantar pressures and a major complication in diabetic patients.
Purpose: The aim of this study was to investigate the pressure-relieving effects of two vacuum orthoses in patients with diabetes mellitus.
Methods: Twenty patients with diabetes mellitus were included. They presented with plantar callosities but no ulceration. Exclusion criteria included the use of walking aids and other systemic diseases. Plantar pressure distribution was measured with sensor insoles (Pedar-X, Novel GmbH) during walking in two vacuum orthoses, a post-operative shoe and an off-the-shelf shoe as reference condition. Statistical analysis was conducted using Friedman and Wilcoxon signed-rank tests.
Results: Significant differences in plantar pressure distribution were found between the four walking conditions. The contact area increased in the midfoot with the vacuum orthoses. Maximum force and peak pressures showed a significant decrease under the rearfoot and forefoot and increased in the midfoot area during walking with both vacuum orthoses. The high-cut vacuum orthosis revealed equal pressure relief under the forefoot and significantly lower rearfoot pressures compared to the post-operative shoe.
Conclusions: The vacuum orthoses demonstrated a comparable pressure-relieving efficacy under the forefoot to post-operative shoes. Using vacuum orthosis significantly benefited re-distribution of plantar pressure and the roll-over process. Clinical significance of the pressure-relieving efficacy could not be confirmed in this investigation and has to be addressed in further studies.