Adjustable-Volume Prosthetic Interfaces: A Systematic Literature Review and Meta-Analysis of Clinical Outcomes

The prosthetic human-device interface is the most important part of a prosthesis. Adjustability has been desired by patients as a potential solution to socket fit issues for several years, but market penetration for adjustable-volume sockets has been limited. The purpose of this article is to identify, critically appraise, synthesize, and to perform a meta-analysis of the available evidence pertaining to adjustable-volume prosthetic interfaces. Searches of four electronic medical research databases including (1) PubMed, (2) Google Scholar, (3) the Cochrane Library of Systematic Reviews, and (4) the O&P IQ were performed. Twenty-six articles were included. The United Kingdom National Service Framework for Long-Term Conditions tool was used to critically appraise the articles. Nine empirical evidence statements (EESs) were synthesized and graded. One EES was supported by Grade “A” evidence: ‘Manipulation of the internal volume of adjustable-volume prosthetic interfaces has been shown to influence residual limb fluid volumes in prosthesis users with history of transtibial amputation.’ Adjustable-volume interfaces demonstrated maximum internal volume change ranges of 6.1% to 12.0%. Meta-analysis showed an increase of 3.13 in fit comfort, measured with the socket comfort score(SCS), and 4.57 in overall satisfaction, measured with the modified Prosthetic Evaluation Questionnaire(PEQm) with the adjustable-volume interfaces compared to legacy SoC interfaces, both exceeding published MDCs. These findings indicate the adjustable-volume interfaces have value as a prosthetic intervention especially in those individuals who lack comfort and/or satisfaction with their current interface or with frequent volume fluctuations in the residual limb.