Article

Elevated vacuum suspension systems use a pump to draw air from the
socket with the intent of reducing bone-socket motion as compared to passive
suction systems. However, it remains unknown if elevated vacuum suspension
systems decrease limb displacement uniformly during transitions from unloaded to
full-body-weight support. OBJECTIVES: To compare limb-socket motion between
elevated vacuum and passive suction suspension sockets using a controlled loading
paradigm. STUDY DESIGN: Comparative analysis. METHODS: Persons with transtibial
amputation were assessed while wearing either an elevated vacuum or passive
suction suspension socket. Digital video fluoroscopy was used to measure axial
bone-socket motion while the limb was loaded in 20% body-weight increments. An
analysis of variance model was used to compare between suspension types. RESULTS:
Total axial displacement (0%-100% body weight) was significantly lower using the
elevated vacuum (vacuum: 1.3 cm, passive suction: 1.8 cm; p < 0.0001). Total
displacement decreased primarily due to decreased motion during initial loading
(0%-20%; p < 0.0001). Other body-weight intervals were not significantly
different between systems. CONCLUSION: Elevated vacuum suspension reduced axial
limb-socket motion by maintaining position of the limb within the socket during
unloaded conditions. Elevated vacuum provided no meaningful improvement in
limb-socket motion past initial loading. CLINICAL RELEVANCE: Excessive
bone-socket motion contributes to poor residual limb health. Our results suggest
elevated vacuum suspensions can reduce this axial displacement. Visual assessment
of the images suggests that this occurs through the reduction or elimination of
the air pocket between the liner and socket wall while the limb is unloaded.
CI - (c) The International Society for Prosthetics and Orthotics 2015.

Langue : ANGLAIS