Abstract
Model of proximal interphalangeal (PIP) joint is prepared and the stress state of PIP joint during hyperextension is analyzed by the finite element method. The concentrations of equivalent stress are found in the subchondral bone at the middle of articular surface, the volar plate near proximal phalanx and the attached portion of volar plate in the middle phalanx. The stress distributions of joints with same hyperextension angle are much alike, indicating that the distribution can be estimated by the hyperextension angle without knowing the conditions of applied load. The equivalent stress at the attached portion of volar plate in the middle phalanx is larger than that in the proximal phalanx, and the fracture is clinically observed in the middle phalanx.
