NEW ORLEANS — The use of elevated vacuum suspension has positive, quantitative effects on residual limb health and circulation, according to a presenter here at the American Academy of Orthotists and Prosthetists Annual Meeting and Scientific Symposium.
Matthew Wernke, PhD, research engineer at WillowWood, presented his findings as part of the Thranhardt Lecture Series, here.
Past studies of the effect of elevated vacuum suspension (EVS) have concentrated on qualitative results, Wernke said.
“What is lacking from the literature is an understanding of physiological changes to the residual limb that are making these benefits possible,” he said. “So with that in mind, the goal of our team was to quantitatively assess changes in residual limb skin health and circulation in response to elevated vacuum suspension.”
Wernke and colleagues examined a group of five transtibial amputees and five transfemoral amputees using a randomized crossover design with half of participants using an EVS and half using a non-EVS. All participants had used either a suction or pinlocking socket suspension before the study. The researchers collected data at three points: a baseline, a midline of 8 weeks and a final point at 16 weeks. Their results come from a combination of skin health measurements, circulation imaging and in-socket probe measurement. Data was collected before, during and after activity, with static poses followed by treadmill walking and then static poses again.
The results showed a reduction in transepidermal water loss when using EVS as compared to non-EVS for most cases, which Wernke said indicates perseveration of epidermal barrier function. Additionally, long-term use of EVS significantly attenuated reactive hyperemia as compared with non-EVS conditions. Results also suggested that long-term use of EVS improves the dynamic response of blood flow to activity and reduces the transcutaneous oxygen pressure as compared to suction.
“Taken together these outcomes suggest that long-term use of vacuum suspension preserves skin health and improves perfusion of the limb,” he said. – by Amanda Alexander
Wernke M. Quantification of residual limb skin health and circulation in response to elevated vacuum suspension. Presented at: American Academy of Orthotists and Prosthetists Annual Meeting and Scientific Symposium; Feb. 18-21, 2015; New Orleans.
Disclosure: A grant and support for Wernke’s research was provided by the Department of Veterans Affairs Center for Innovation.