The design and fabrication study of custom-made metacarpophalangeal joint prosthesis made of titanium alloy

Abstract

Objective To explore the method of design and fabrication of custom-made joint prosthesis using computer assisted design (CAD) and rapid prototyping (RP) technique and provide a new prosthesis for metacarpophalangeal (MP) joint replacement.Methods3D contour image was reconstructed from 2D CT scans of the MP joint using 3DMSR software.Custom-made joint prosthesis and intramedullary stem were designed with Surface 9.0 image processing software.After being convened into STL data format,the computer-assisted design was imported into the FS-320QZ rapid prototyping machine,and the resin prototype was made.The RP model was used as a positive mould to build a silicon negative mould,and the negative mould was sent to the factory to manufacture Ti-6A1-4V alloy MP joint prosthesis through ordinary mould-melted founding process.Results Individualized prototype of MP joint prosthesis was obtained by 3D reconstruction of 2D spiral CT scans of the MP joint and CAD technique.The joint surface of the prosthesis was smooth and the intramedullary stem matched the intramedullary cavity shape and size.The dataset was converted into STL data format.After a series of molding,melting and founding processes,custom -made MP joint prosthesis made of titanium alloy was manufactured.ConclusionIndividualized MP joint prosthesis can be made using CAD and rapid prototyping technique based on 3D reconstruction of CT seam of the MP joint of interest. Key words: Custom-made; Metacurpophalangeal joint; Rapid prototyping