Developing a methodology for analysis and manufacturing of proximal interphalangeal (PIP) joint using rapid prototyping technique

The purpose of this paper is to design and analyze four proximal interphalangeal joint (PIP) prosthesis thorough finite element analysis (FEA) and fabricate them using rapid prototyping (RP) technique. Arthritis of the finger joints is an important pathology of the hand. Major complaints in arthritis are stiffness, deformity and severe pain. The pain is due to the inflammatory process that occurs due to pathology, which involves joint degeneration, synovial swelling and ligament and muscle stiffness. Among the surgical treatment of arthritis is Arthroplasty which involves replacing the diseased joint with an artificial joint.

In this paper, four proximal interphalangeal joint (PIP) prostheses are designed, analyzed using FEA and fabricated using rapid prototyping technique. Four different prostheses “BM”, “IMP”, “IMP2” and “FINS” are designed using CATIA software and tested by normal daily functions such as grasp, key pinch and tip pinch tests using FEA to analyze the results based on their stress and deformation. Finally, the prostheses are fabricated using electron beam melting technology.

This paper examined and analyzed the relative motion of PIP designs using FEA by applying varying loads to check the stability and range of motion of the PIP implant. The ANSYS summary results were analyzed depending on the minimal results of equivalent stress and deformation from the taken tests that have happened on the designed prosthesis. The results conclude that, in the grasp test, the minimal equivalent stress and deformation have happened on the “BM” and “IMP2” implants. Furthermore, in the key pinch test, minimal equivalent stress and deformation occurred on the “FINS” implant, and finally, in the tip pinch, minimal equivalent stress occurred on the “FINS” and minimal deformation has happened on the “IMP2” implant.

These results conclude that both “IMP2” and “FINS” share the minimum results in the taken tests, and this shows that these implants may be further studied brainstormed upon to aid innovation of a better implant design that shares both of these implants’ features and shape. Nevertheless, testing in an in vivo or in vitro model to prove more of the effectiveness of these implants should be taken into consideration, and to test how the prostheses will function in an actual environment, a simulated hand can be designed and made to discover the true forces and mechanics of the fingers and the hands with the prosthesis that is implanted, as well as to know if the hand works properly.

This paper examined and analyzed the relative motion of PIP designs using FEA by applying varying loads to check the stability and range of motion of the PIP implant.