Glass Tracing Alignment Method: A Novel, Low-Cost Coronal and Sagittal Alignment Transfer Method for Lower-Limb Prostheses

IntroductionThere are numerous ways to transfer the alignment of a lower-limb prosthesis that have been used and adapted over the last several decades. The proposed glass tracing alignment method (GTAM) allows for a convenient and rapid transfer of prosthetic alignment in the coronal and sagittal planes with minimal equipment requirements.ObjectiveThe aim of this article is to share a novel method for coronal and sagittal plane prosthetic alignment transfer, which may be done with minimal time, materials, and expense.Materials and MethodsProsthetic alignment may be transferred in part or in whole by tracing the prosthesis in both the coronal and sagittal planes. The prosthesis must first be stabilized on a surface that allows for the prosthetic foot to be traced and is adjacent to a wall surface that allows for tracing of the prosthesis proximal to the foot. The line of progression (LOP) of the prosthesis should be parallel to the edge of the table it is traced upon and in a vertical orientation when tracing the entire prosthesis in the sagittal plane. When tracing the coronal plane alignment, the foot should be oriented vertically and placed in the LOP. Sagittal and coronal tracings should include as much of the prosthesis as possible to insure the most accurate alignment transfer of components. The GTAM was developed to be a clinical complement to traditional alignment transfer methods, which may include use a vertical or horizontal prosthetic alignment transfer jig.ResultsUse of the described alignment tracing technique allows for the rapid alignment transfer of prosthetic componentry for a variety of applications.ConclusionsThe GTAM proposed is an easy way for a busy practitioner to certify that alignment transfers have been performed correctly or to preserve alignment when replacing elements of a prosthesis for clinical and/or research applications.Clinical RelevanceIt is expected that the GTAM will improve the clinical control, versatility, and scope of procedures related to referenced prosthetic and/or orthotic alignment to enhance the quality and consistency of patient outcomes.