Evaluating trunnionosis in modular anatomic shoulder arthroplasties: a retrieval study

• Published in: Journal of shoulder and elbow surgery 2023-10, Vol.32 (10), p.1999-2007
• Main Authors: Maxwell, Michael, Tooley, Trevor, Penvose, Ian, Gehrke, Corinn, Koueiter, Denise, Wiater, Brett, Baker, Erin, Wiater, J. Michael
• Format: Article
• Language: English
• Subjects: corrosion; fretting; shoulder hemiarthroplasty; standard damage; Total shoulder arthroplasty; trunnion wear
• ISSN: 1058-2746; 1532-6500
• DOI: 10.1016/j.jse.2023.04.001

Shoulder arthroplasty procedures are widely indicated, and the number of shoulder arthroplasty procedures has drastically increased over the years. Rapid expansion of the utilization of reverse total shoulder arthroplasty has outpaced the more modest growth of anatomic total shoulder arthroplasty (aTSA) while shoulder hemiarthroplasty (HA) has trended down. Recently, shoulder prostheses have transitioned to increasingly modular systems offering more individualized options with the potential for decreased pain and increased range of motion. However, increased primary procedures has resulted in increased revision surgeries, with one potential cause being fretting and corrosion damage within these modular systems. Following institutional review board approval, 130 retrieved aTSA and 135 HA explants were identified through database query. Humeral stem and head components were included in all 265 explants, whereas 108 included polyethylene glenoid liner components. All explanted components were macroscopically evaluated for standard damage modes, and taper junctions were microscopically examined for fretting/corrosion using a modified Goldberg-Cusick classification system that was 4-quadrant graded for both the male and female component. Medical records were reviewed for patient demographics and surgical information. In this series, 158 of explants were from female patients (male = 107), and 162 explants were from the right shoulder. Average age at implantation was 61 years (range: 24-83), average age at explanation was 66 years (range, 32-90), and average duration of implantation was 61.4 months (range, 0.5-240). Scratching, edge deformation, and burnishing were the most commonly observed standard damage modes. Of the 265 explants, 146 had a male stem component vs. 118 with a female stem component. Average summed fretting grades on male and female stem components were 8.3 and 5.9, respectively (P