Morphometry-based design and finite element assessment of primary stability in glenoid baseplate fixation for reverse shoulder arthroplasty for the Indian population.

Introduction: The geometrical and morphological parameters of the glenoid vary across ethnic groups, affecting the fixation of the baseplates in reverse shoulder arthroplasty. Studies have shown that using larger baseplates for smaller glenoids may not facilitate a better biomechanical outcome, and therefore a population-based investigation plays a crucial role in selecting an appropriate implant. Methods: This work investigates finite element analysis of a pear-shaped glenoid baseplate, designed based on the morphometric parameters of the Indian glenoid. A percentile-based method was used to select the representative glenoid to select small, middle and large glenoid variations within the Indian population. Nine glenoid-baseplate assemblies were assembled from three different glenoid dimensions and three baseplate sizes. This baseplate-scapula construct was subjected to finite element analysis under specified loading conditions for various abduction angles to investigate mechanical load sharing and primary stability. Results: These findings indicated that the fixation outcomes changed based on the baseplate-glenoid assembly, showing that the biomechanical performance did not depend on the baseplate size alone. Discussion: Smaller baseplates and intermediate baseplates showed better primary stability in the Indian glenoid, supporting morphometry-guided baseplate selection based on implant-glenoid dimensional compatibility.