The objective of this research is to determine if advances in technology, namely digital methods to capture residual limb shape, can meet the well-fitting prosthetic socket standard-of-care with the added benefits of improved access and service delivery. The current standard of care for prosthetic provision requires multiple, in-person clinical visits between the Veteran and their prosthetist. Separate visits for residual limb shape capture, check socket fitting, and definitive socket delivery are required every time a new socket is needed. For Veterans who live in rural communities far from VA facilities, the challenges associated with attending these clinical visits can be a significant burden. This research seeks to determine if the residual limb shape capture visit can be performed remotely with the assistance of a study helper using digital methods.
Of paramount concern when providing a prosthesis to a Veteran with a lower limb amputation is obtaining a good fit. Prosthetic sockets that fit poorly are either worn sparingly or not at all. Obtaining a good fit is a process. Veterans know it when they wear a well-fitting prosthesis and prosthetists know it when they see it (lack of reactive hyperemia). Patient reported outcomes play an important role whereby the prosthetist solicits feedback from the patient about how the check socket feels and the location of any perceived discomfort. This informal approach is infrequently supplemented with qualitative survey instruments. Reducing or eliminating excessive distal end pressure is also essential as the distal end tissues of the residual limb can rarely support body weight loads without discomfort or injury. However, no instrument to directly measure distal end residual limb pressures is commercially available.
The investigators propose to determine if a prosthetic socket, whose shape is captured remotely by a study helper using a digital scanner, fits at least as well as a prosthetic socket whose shape is captured in-person by a prosthetist using traditional hand casting methods. If it does, then rural Veterans with a helper could forgo a clinical visit. To make this determination, the investigators propose to perform a between-subject experiment with two specific aims.
Specific Aim 1: Determine if patient reported outcomes, reported by a group of individuals fit with a prosthetic socket whose shape was captured with study helper assistance using digital methods, are at least as good as those reported by a different group of individuals fit with a prosthetic socket whose shape was captured by a prosthetist using traditional methods. The investigators propose to recruit ambulatory Veterans with unilateral transtibial amputation (n=20) and their study helpers (n=20) to participate in a between-subject experiment. Participants will be randomly assigned and fit with either a prosthesis made with study helper assistance and digital methods, or one made wholly by a prosthetist using traditional methods. Patient reported outcome metrics will be collected while the subject is still wearing their as-prescribed socket (baseline) at the beginning of the study, and again after wearing the study prosthesis for two weeks.
Specific Aim 2: Determine if distal end residual limb pressure, measured from a group of individuals fit with a prosthetic socket whose shape was captured with study helper assistance using digital methods, are no worse than those measured from a group of individuals fit with a prosthetic socket whose shape was captured by a prosthetist using traditional methods. In addition to the human subject procedures of Specific Aim 1, the investigators further propose to fabricate two duplicate prosthetic sockets for each subject: one duplicate of the subject's as-prescribed socket and one duplicate of the study socket randomly assigned to the subject in Specific Aim 1. Embedded in the distal end of these duplicate sockets will be a novel pressure sensor. Distal end residual limb pressure while standing and walking will be measured while the subject is still wearing their as-prescribed socket (baseline), and again after wearing the study prosthesis for two weeks.
The proposed research will discover if it is possible to forgo one of the clinical visits needed to fabricate a well-fitting prosthesis. It is the investigators' hope that this research will advance the use of technology in the provisioning of prostheses, particularly to Veterans who live in rural communities far from VA Medical Centers or alternative service providers.
