A comparison of trans-tibial amputee suction and vacuum socket conditions

Abstract

Daily volume loss of the stump leads to a poor fit of the prosthetic socket. A method of preventing this volume loss and maintaining a good fit was developed. A vacuum (-78 kPa) was drawn on the expulsion port of a total surface-bearing suction socket to hold the liner tightly against the socket. Stump volume of 10 trans-tibial amputees was measured prior to and immediately after a 30 minute walk with normal and vacuum socket conditions. Under the normal condition, the limb lost an average of 6.5% of its volume during the walk. In contrast, with the liner held tightly by vacuum, the limb gained an average of 3.7% in volume. It is believed that the difference observed between conditions resulted from a greater negative pressure developed during the swing phase of gait with the vacuum condition. X-rays revealed that the limb and tibia pistoned 4 mm and 7 mm less, respectively, under the vacuum condition. The combination of reduced pistoning and maintenance of volume is thought to account for the more symmetrical gait observed with the vacuum.

Transfemoral sockets with vacuum-assisted suspension comparison of hip kinematics, socket position, contact pressure, and preference: Ischial containment versus brimless

“…Enhanced suspension creates a more solid connection to the socket, which potentially creates less motion during swing, resulting in the perception of greater control and less prosthetic weight for the person with amputation [9][10]. Vacuum-assisted suspension (VAS) offers the person with amputation a dynamic form of suspension in that it can actively suspend through a manual or electronic pump.…”

“…Vacuum-assisted suspension (VAS) offers the person with amputation a dynamic form of suspension in that it can actively suspend through a manual or electronic pump. This dynamic suspension may provide a more positive link to the prosthesis and reduce prosthetic migration and socket movement (pistoning and lateral shifting) during gait and other activities such as sitting [9][10]. Reduced motion could increase control in swing and stance by establishing a more stable and healthy environment for the femur and thigh [9][10][11].…”

Elevated vacuum suspension preserves residual-limb skin health in people with lower-limb amputation: Randomized clinical trial

“…This outcome raises the possibility that EVS enables a stable environment for adaptive vascular remodeling to occur in the residual limb over time. This hypothesis is indirectly supported by research on the biomechanical effects of EVS in attenuating pistoning [5,[9][10][11] and contact pressure [33], where authors suggest that putative physiological benefits of EVS stem from a superior and more stable connection between person and prosthesis. Results here from hyperspectral imaging and quantification of reactive hyperemia further support this view.…”

“…Furthermore, EVS preserved skin barrier function of the residual limb as compared to SoC after 16 wk of use. These findings suggest that in addition to improved fit and performance benefits [5][6][7][8] ascribed to EVS, long-term use may also impart physiological benefits to residual-limb health in people with lower-limb amputation.…”

“…EVS sockets continue to grow in popularity on the basis of improved fit and function [5][6][7][8] through a reduction of pistoning [5,[9][10][11] and residual-limb volume management [5,[12][13]. A recent systematic review of EVS studies [14] identified only two peer-reviewed journal publication related to the effects of EVS on residual-limb physiology [5,15] and underscores the need for more evidence-based research in this underserved field. The lack of objective data on the physiological effects of EVS represents a critical barrier to develop the overall clinical significance of the socket platform on residual-limb health.…”