Medium-term rates of radiolucency after primary total shoulder arthroplasty using a cementless metal-backed pegged polyethylene glenoid

Background Total shoulder arthroplasty is an established treatment with the commonest cause of failure loosening of the glenoid component. Hydroxyapatite metal-backed glenoid components could offer better survivorship due to improved fixation. The aim of this study was to investigate periprosthetic radiolucency rates associated with an uncemented, metal-backed polyethylene glenoid component with medium-term results.Methods A single centre retrospective study examining radiological outcomes of the Epoca metal-backed glenoid component. Radiographs were analysed for post-operative adequacy of glenoid seating and radiographs at follow-up assessed for periprosthetic lucencies and any revision procedures were recorded.Results Forty-one patients were followed up with a mean follow-up time of 5.5 years (3-8 years). Primary indication for total shoulder arthroplasty was osteoarthritis (80%). Mean age was 69 years (53-86 years). Ninety-five per cent of glenoid components were completely seated. At follow-up six patients had undergone revision (14.6%). Thirty of the remaining patients (86%) did not demonstrate any radiolucency on follow-up radiographs. Complete glenoid seating post-operatively was associated with lower rate of subsequent radiolucency and revision (P < 0.01).Conclusion Low rates of radiolucency at medium-term follow-up with an uncemented metal-backed glenoid, however significant rates of revision. Complete seating of the glenoid component was associated with lower rates of radiolucency and revision.