short-term results of a convertible diaphyseal-fit anatomic shoulder arthroplasty system

Background: the purpose of this analysis is to present a two-year follow-up of patient-reported outcomes, revision rate, and notable radiographic features of a convertible, diaphyseal-fit anatomic total shoulder arthroplasty system (atsa).methods: from june 2012 to june 2015, 100 shoulders were treated with atsa using a convertible, diaphyseal-fit stem. functional outcomes and radiographic findings were assessed preoperatively and at 6 months, 1 year, and 2 years postoperatively. complications and reoperations were also determined.results: ninety-three shoulders were analyzed in this study. patients were 47.3% male and had an average age of 67.3±8.1-years-old (range 44.7-89.1). two-year clinical outcomes show a revision rate of 4.3%. average preoperative ases was 37.1±18.9 (6.7-86.7), sst (77.4%) was 3.1±2.4 yes responses (0-9), and sane (88.2) was 25.4±21.5% (0-85.0%). at two years post-operative average (75% follow-up) ases was 89.3±15.1 (37.0-100), sst was 10.0±2.5 yes responses (0-12), and sane was 85.6%±17.0% (33.0-100%). radiographic analysis at two years identified 2 shoulders (4%) with glenoid radiolucency (both lazarus grade 1), 5 shoulders with at least one humeral radiolucent line (10%), and 9 shoulders (18%) with stress-shielding. there were 12 shoulders (24%) with distal pedestal formation. this finding was associated with the presence of radiolucent lines (p=0.002).conclusion: this two-year analysis identified improvement in ases, sst, and sane scores and a low revision rate. presence presence of a distal pedestal was associated with increased rates of radiolucent lines. further analysis with longer-term and more robust follow-up will improve our understanding of the risks and benefits of this shoulder system.