Central fabrication: carved positive assessment.

Area of Science:

• Prosthetics and Orthotics
• Biomedical Engineering
• Manufacturing Technology

Background:

• Limited adoption of Computer-Aided Design/Computer-Aided Manufacturing (CAD/CAM) in prosthetics, with only 24% of practitioners using it regularly.
• Potential for socket manufacturing errors in central fabrication processes to hinder wider CAD/CAM adoption.

Purpose of the Study:

• To quantify shape discrepancies between computer-generated models and centrally fabricated carved models.
• To identify carving as a potential primary source of socket manufacturing errors in central fabrication.

Main Methods:

• Experimental mechanical assessment of three trans-tibial model shapes.
• Electronic transmission of models to 10 central fabrication facilities for foam model production.
• Utilized a custom mechanical digitizer and alignment algorithm to compare fabricated models with original electronic files.

Main Results:

• Volume differences between models and electronic files averaged -0.9%, with a range of -4.2% to 1.0%.
• Mean radial error averaged -0.3 mm, and inter-quartile range averaged 0.6 mm.
• Fabricated models were significantly smaller than original electronic files (p < 0.01), indicating dimensional changes during fabrication.

Conclusions:

• Demonstrated significant variability in model quality across different central fabrication facilities.
• Carving was identified as a contributing factor but not the sole source of socket fabrication errors.
• Varied quality suggests that expertise in model fabrication differs among facilities, impacting overall socket accuracy.