Finite Element Analysis of the Wrist Arthroplasty in Rheumatoid Arthritis - Computational Biomechanics of the Wrist Joint - page 59

Chapter 6
Finite Element Analysis of the Wrist
Arthroplasty in Rheumatoid Arthritis
Abstract This chapter presents information on finite element analyses (FEA)
of stress distribution and contact pressure with the carpal articulation following
total wrist arthroplasty (TWA) for rheumatoid arthritis (RA) of the wrist. Results
from the previous analyses on the healthy and rheumatic wrist were used for
comparison. A TWA model was developed based on parameters of a wrist implant
named ReMotion TM total wrist system, and was then applied with the same
boundary condition (static hand grip action) as the other two models. FEA has
revealed that the contact pressure for the TWA model was five times lower than
the RA model. Despite this encouraging finding, small variations in the amount of
stress distribution were still present when compared to the healthy model. This
comes to a conclusion that the used of TWA could reduces the high contact
pressure induced in the RA model thus improving the diseased condition, however,
there are rooms for improvement for TWA procedure to restore the biomechanical
behaviour of the healthy wrist joint.
Keywords Wrist joint Rheumatoid arthritis Total wrist arthroplasty Contact
pressure Stress Finite element analysis
6.1 Total Wrist Arthroplasty
Total wrist arthroplasty (TWA) for a rheumatic wrist has been designed to preserve
motion of the joint, thus found to be a superior alternative to wrist arthrodesis
(bone fusion). Despite of this privilege, there were issues with regards to its success
rates. Based on literature reports on clinical studies, it was addressed that this wrist
replacement has higher failure rates as compared to hip and knee arthroplasty [ 1 - 7 ].
In total hip arthroplasty (THA) procedure where the affected areas at the femoral
head and neck are dissected, it was reported as the most reliable arthroplasty to