Elevated Vacuum Suspension Influence on Lower Limb Amputee's Residual Limb Volume at Different Vacuum Pressure Settings

Abstract

In Brief Lower limb amputees continue to contend with residual limb volume fluctuations. The stabilization of residual limb volume has the ability to increase comfort, reduce tissue breakdown, and improve daily function. Clinical evidence on elevated vacuum suspension has demonstrated the potential to maintain residual limb volume; however, the effect of different vacuum pressure settings has not been quantified. The purpose of this research is to gain outcome knowledge regarding elevated vacuum suspension and to investigate the effects of different vacuum pressure settings on lower limb amputee's residual limb volume. This single subject study focused on a K2 transtibial amputee new to elevated vacuum suspension with a history of residual limb volume fluctuations. The patient was fitted with a 0-ply total surface bearing socket that used the LimbLogic® VS. The percent change in volume was measured using the OMEGA® Tracer® volume feature at three treatment levels: absence of elevated vacuum (suction), vacuum (negative pressure) at 10 in Hg, and vacuum (negative pressure) at 15 in Hg. The results indicated a significantly less volume fluctuation with vacuum (0.8%) compared with suction (4.9%). Vacuum settings at 10 and 15 in Hg generated similar absolute percent changes in volume; however, 15 in Hg demonstrated a decreasing rate of change potentially suggesting a physiological alteration in the residual limb. During the duration of the study (3.5 months), an improvement was seen in volume retention with the length of vacuum suspension usage. In addition, the progressive healing of a distal wound was observed. As lower limb amputees continue to contend with residual limb volume fluctuations, it is important to understand the benefits the elevated vacuum can provide. Future research is necessary to investigate any physiological changes to the residual limb because of vacuum pressure settings. Vacuum suspension significantly improved volume retention compared with suction. Volume retention improved with the length of vacuum suspension usage, along with progressive healing of a distal wound. The authors believe future research is needed to investigate any physiological changes to the residual limb because of vacuum pressure settings and to fully understand the mechanisms associated with the ability to retain residual limb volume with elevated vacuum suspension.