Different material properties of cancellous bone influence analysis of glenoid component loosening: A finite element study

Glenoid component loosening is one of common complications after total shoulder arthroplasty. In investigating the glenoid component loosening, the finite element study is one of methods that have been utilised by experts. Therefore, assigning material properties for all finite element models become crucial to avoid any misinterpretation which, later, lead to wrong prediction on the performance of glenoid implant. This study was conducted to achieve two objectives; (1) to analyse the effect of different bone properties towards micromotion and stress at implant and cement, and (2) to clarify simplification of bone properties in evaluating glenoid component loosening. A load of 750N was simulated at three different glenoid locations (centre – C, superior-anterior-SA, superior-posterior-SP) which imitate concentric and eccentric loadings for elderly people daily activities. Our result showed that large different in micromotion and stress at implant between orthotropic model and another two model (isotropic and full cortical) does not allow simplification for assigning material properties for bone. Thus, assigning cancellous bone as orthotropic material was a realistic material property to represent the real bone condition in evaluating glenoid implant loosening.