Superior glenoid erosion of the shoulder joint is a result of humeral subluxation caused by rotator cuff tears, and can be addressed using implants, specifically reverse total shoulder arthroplasty. This thesis examined the regional variations of bone present in superiorly eroded glenoids, established a baseline for regular RTSA baseplate fixation in patients with this defect, and compared the effect of geometric baseplate differences on implant fixation. The superiorly eroded glenoids demonstrated similar regional bone density variations as normal glenoids, and the superior and inferior regions of the glenoid demonstrated the densest and least dense cancellous bone, respectively. These regions also resulted in the most and least amounts of micromotion, respectively. The full-wedge and half-wedge baseplates resulted in more tangential micromotion, while the 6mm lateralized baseplate performed the worst overall. While the standard baseplate resulted in the best fixation outcomes, surgical limitations need to be accounted for when selecting the type of implant to be used.