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> Residual Limb Volume Fluctuation
> Advanced Socket Fabrication
> Interface Materials
> Compartment Syndrome
Purpose/objectives: The purpose of this project is to assess fabrication quality of computer- manufactured prosthetic sockets and positive models, and to determine to what degree too large a socket impacts the health and quality of life of individuals with transtibial amputation using prosthetic limbs.
Findings to date: We found considerable variability in the quality of computer-manufactured sockets [#5] and models [#3] made by the central fabrication industry in prosthetics. Some central fabrication facilities (~40%) consistently demonstrated very low manufacturing error while others were less consistent. These findings led us to publish an evaluation strategy for central fabrication facilities to test their equipment [#2]. The strategy may also be useful to companies who manufature fabrication equipment as well as clinics who have fabrication facilities in house. We also offer testing services to clinics, companies, and individuals as part of our laboratory's services through a not-for-profit cost center. The intent is to provide a detailed report of the manufacturing quality of the models/sockets made using the computer-manufacturing suite of equipment.

We are currently investigating how much size and shaping error cause a clinically detectable change in prosthetic fit. If we discover clear metrics that correlate with the user's quality of fit then those metrics may be useful towards creating outcome assessment criteria for clinical care.

We gratefully acknowledge funding from the National Institutes of Health, R01HD-069387.
Advanced Socket Fabrication
Peer-reviewed publications:
#1. Sanders JE, Severance MR, Allyn KJ. Computer-socket manufacturing error: How much before it is clinically apparent? J Rehabil Res Dev. 2012; 49(4):567-582. PMID.
#2. Sanders JE, Severance MR. Assessment technique for computer-aided manufactured sockets. J Rehabil Res Dev. 2011; 48(7): 763-74. PMID: 21938663.
#3. Sanders JE, Severance MR, Myers TR, Ciol MA. Central fabrication: carved positive assessment. Prosthet Orthot Int. 2011 Mar; 35(1): 81-9. PMID: 21515893.
#4. Sanders JE, Severance MR. Measuring foam model shapes with a contact digitizer. Prosthet Orthot Int. 2011 Jun; 35(2): 242-5. PMID:21515900.
#5. Sanders JE, Rogers EL, Sorenson EA, Lee GS, Abrahamson DC. CAD/CAM transtibial prosthetic sockets from central fabrication facilities: how accurate are they? J Rehabil Res Dev. 2007; 44(3): 395-405. PMID:18247236.
#6. Zachariah SG, Sorenson E, Sanders JE. A method for aligning trans-tibial residual limb shapes so as to identify regions of shape change. IEEE Trans Neural Syst Rehabil Eng. 2005 Dec; 13(4): 551-7. PMID:16425837.
#7. Sanders JE, Mitchell SB, Zachariah SG, Wu K. A digitizer with exceptional accuracy for use in prosthetics research: a technical note. J Rehabil Res Dev. 2003 Mar-Apr; 40(2): 191-5. PMID:15077643.

Recent meetings presentations:
A. CAD/CAM sockets: clinical assessment of fit vs. socket shape error. American Academy of Orthotists and Prosthetists 37th Academy Annual Meeting and Scientific Symposium, Orlando, Florida, 2011
B. How accurate are carved positives made by central fabrication facilities? Thranhardt Award Winner, American Academy of Orthotists and Prosthetists 36th Academy Annual Meeting and Scientific Symposium, Chicago, Illinois, 2010