• ABSTRACT
    • Anatomic total shoulder arthroplasty (aTSA) and reverse shoulder arthroplasty (RSA) are increasingly common, with volume projected to increase over 90% by the year 2025. Therefore, it is critical to understand the expected longevity of aTSA using modern implants and techniques, rates of conversion to RSA, and most common indications for conversion if surgeons are to properly diagnose and treat patients. A retrospective review was conducted of 800 patients who had undergone aTSA, RSA, or hemiarthroplasty (HA) between 2015 and 2019 at a tertiary-care academic medical center. All patients who had undergone primary aTSA were included. Patients who had undergone primary HA, primary RSA, or had had primary surgery at an outside hospital were excluded. Primary outcomes were indications for and time to conversion from aTSA to RSA. Secondary outcomes were indications for primary aTSA and preliminary survivorship data of modern implants. Between 2015 and 2019, 235 patients underwent primary aTSA, with a mean time to follow-up of 3.43 years (0.07-5.24 years). Mean time to conversion from aTSA to RSA was 15.6 months, with a 2.13% conversion rate (5 patients). Eighty percent of the conversions (4 patients) were due to rotator cuff tear. We found that 2.13% of primary aTSA patients at our institution were converted to RSA at a mean of 15.6 months after the primary procedure. Rotator cuff tears were the indication for 80% of these. Since conversions occurred relatively soon after primary surgery, the authors recommend use of MRI without contrast prior to surgery to possibly reduce the risk of such failures. This study was a Level 3 retrospective database review.