Finite Element Analysis of the Wrist Joint Affected by Rheumatoid Arthritis - Computational Biomechanics of the Wrist Joint - page 44

Fig. 5.2 Simulated loss of carpal height due to bone destruction (b). As compared to the healthy
model (a) (total carpal height of 32.45 mm), the simulated impaction in RA model was seen to
have total carpal height reduced to 22.35 mm
Fig. 5.3 The dislocated carpus towards ulna (a). The RA bones are in red and the transparent
bones represent the normal healthy wrist. Weakened ligaments were simulated by remaining one
link (b). The ligament in circle was the simulated loss of tension of the radiotriquetral ligament
rheumatic wrist, the occurrence of SLAC (stage 3), SLD and the weakened radio-
triquetrial ligaments has resulted in the dislocation of carpus towards ulnar
direction [ 2 ]. These situations induced greater load subjected to the lunate thus
ultimately destruct the capitolunate joint [ 5 ]. Figure 5.4 illustrates the simulated
palmar (2.76 mm) and ulnar dislocation (7.61 mm) of the proximal carpal bones.