Development of a validated glenoid trabecular density-modulus relationship

Incorporating subject-specific mechanical properties derived from clinical-resolution computed tomography data increases the accuracy of finite element models. Site-specific relationships between density and modulus are required due to variations in trabecular architecture and tissue density by anatomic location. Equations have been developed for many anatomic locations and have been shown to have excellent statistical agreement with empirical results; however, a shoulder-specific density-modulus relationship does not currently exist. This study used micro-finite element cores of glenoid trabecular bone and co-registered quantitative computed tomography finite element models to develop a validated glenoid trabecular density-modulus relationship. Micro finite element model tissue density was considered as either homogeneous or heterogeneous, scaled by CT-intensity. When heterogeneous tissue density was considered, near absolute statistical agreement was predicted in the co-registered QCT-derived finite element models. The validated relationships have also been adapted for use in whole bone scapular models and have the potential to dramatically increase the accuracy of clinical-resolution CT-derived shoulder finite element studies.