Does implant modularity affect radiographic outcome following anatomic shoulder arthroplasty?

Abstract

BackgroundModularity in shoulder implants is a feature that is thought to allow for better anatomical recreation and subsequently improve clinical outcomes. This hypothesis was tested by retrospectively comparing the radiographic outcomes of 2 patient groups that received either modular (adaptable) or nonmodular shoulder implants during arthroplasty. Methods: Radiographic variables were measured to provide a comprehensive analysis of recreated shoulder anatomy. ResultsThe modular group demonstrated significant changes in humeral head height, greater tuberosity height, the radiographic distance from humeral head to acromion and center of rotation difference. In contrast, the nonmodular group demonstrated significant changes to humeral head height. A higher frequency of humeral radiolucent lines was noted in the non-modular group compared to the modular group. ConclusionsImplant modularity may produce measurable differences in radiographic anatomy and a lower measure of implant loosening in anatomic shoulder arthroplasty. Level of EvidenceLevel III; Retrospective Cohort Comparative Study