Use of a Low Profile Ultra-High Molecular Weight Polyethylene Diaphyseal Humeral Cement Restrictor in Shoulder Arthroplasty.

Background: When implanting a cemented humeral stem, a reliable method to prevent inappropriate extension and enable pressurization of cement in the intramedullary canal is required. The aim was to assess the outcomes of a dedicated humeral diaphyseal cement restrictor. Methods: In total 218 shoulders (207 patients) were included in the study, all of whom underwent a cemented total shoulder arthroplasty and a retrospective review was performed. The primary outcomes of interest were device stability in the medullary canal, successful occlusion of the canal, cement extrusion and quality of cement mantle. Results: The majority of the cohort was female (63.3%) males and the average patient age was 71.7 years (SD 8.45). In 81.7% the device was deemed to be stable in the medullary canal. The device was significantly more stable in primary (84.2%) compared to revision cases (64.3%, p = 0.02). In 69.7% Barrack grade A mantle quality was achieved, this was higher in primary cases (74.2%) compared to revision cases (39.3%) (p = 0.00006). Discussion: We noted excellent cementation outcomes using a cement restrictor specifically designed for the diaphyseal humerus anatomy. However, this humeral specific restrictor was noted to be more stable in primary as compared to revision cases.