The evidence base of elevated vacuum and pin-lock suspension system in transtibial prosthetic users: A literature review with a systematic approach

Abstract: Aim: This review aims to describe the existing evidence base for using elevated vacuum suspension and pin-lock suspension systems in regards to fluctuations of limb volume, balance, effect on gait (spatial and temporal, kinematic, and kinetic data), and in-socket movement (pistoning and transverse forces). Background: There is a growing population with a TT amputation thus there is an increased demand for TT prosthetic solutions. There are a multitude of different suspension methods with different drawbacks and benefits. This review investigates elevated vacuum suspension (EVS) and pin-lock suspension systems. Method: A systematic search was conducted in Medline, PubMed, and Scopus, and included or excluded articles per the eligibility criteria. The chosen studies will be carefully read and critically appraised for their quality of evidence. Results: 13 articles were found that matched the eligibility criteria and aim, 5 articles included pin-lock suspension systems and 9 included EVS systems. 3 looked at limb volume fluctuation, 1 at balance, 4 at in-socket movement (transverse forces and pistoning), and 8 at the quality of gait (temporal and spatial, kinematic, and kinetic). Conclusion: Several of the articles included in this review indicate that EVS results in better performance on balance tests, higher velocity, and a more stable residual limb volume than other suspension systems. Furthermore, it was shown that prosthetic users with an EVS had more normal values in their ROM during gait and less in-socket movement.