Socket Geometry and Clinical Outcomes of Manual vs Digital Sockets for Lower-limb Amputees

Summary

The most important aspect of a lower-limb prosthesis is the socket as the interface between the human and the mechanical prosthetic system. Proper fit of the socket to the residual limb is a critical factor in determining comfort, suspension, energy expenditure and ultimately the functional efficiency of the remaining prosthesis. Patients may not wear their prosthesis if they find the socket uncomfortable.

Traditional manufacturing of prosthetic sockets is a high-skill process involving several stages. Capturing the shape of the residual limb and modifying the mould is performed with a manual, hands-on approach. This leads to inconsistencies between clinicians, and increases the likelihood of human error. There is opportunity to improve this process with advanced computer-aided design (CAD) and manufacturing (CAM). 3D printing can be leveraged for its ability to effortlessly manufacture one-off, complex and organic shapes, such as prosthetic sockets. However, the digital method removes the tactile feedback that the clinician generally benefits from when manually designing the socket, thus leading to some uncertainty in how they are modifying the socket. Moreover, the difference in the learning curve may cause inconsistencies in modifications made by different clinicians.

While clinicians may be hesitant in their knowledge-transfer from a manual to digital method, sockets designed using CAD still produce successful outcomes. To facilitate wider-spread adoption of 3D printing as a standard tool in the clinic, more research is needed to better understand how the digital design process affects the geometry of the socket, and how this affects clinical outcomes for amputees.

The investigators hypothesize that (1) digitally-designed sockets and manually-designed sockets will have geometric differences, (2) the digitally-designed socket will result in better clinical outcomes compared to manually-designed sockets, and (3) improved clinical outcomes will correlate to geometric differences centred on particular regions of the socket. However, a feasibility study is needed to inform an effective protocol. This feasibility study aims to explore socket geometries and prosthetic outcomes compared between manually-designed and digitally-designed devices for lower-limb amputees. Findings will help in improving the current 3D printing techniques and exploring outcomes for the users.

Conditions

• Amputation

Interventions

DEVICE

3D-printed socket

During the shape-capturing in-patient appointment, participants will be measured for the prosthetic device through (1) manual casting using Plaster of Paris bandages and (2) scanning using a 3D scanner. The clinician will manually modify the positive plaster cast and digitally modify the scanned impression using OMEGA software. The manually-modified positive cast will be digitized by scanning the cast, then 3D-printed. The digitally-modified socket file will also be 3D printed. The research investigator will make a de-identified mark on each socket to differentiate between the two sockets after 3D printing, and will record the order in which the sockets are fit to the patient.

Sponsors & Collaborators

• West Park Healthcare Centre

  lead OTHER

Principal Investigators

• Winfried Heim, MSc, C.P.(c) · West Park Healthcare Centre

Study Design

Allocation

NA

Purpose

OTHER

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2021-11-10

Primary Completion

2023-11-30

Completion

2023-11-30

Countries

• Canada

Study Locations