LONG-TERM CLINICAL AND RADIOLOGICAL OUTCOMES OF STEMLESS SHOULDER ARTHROPLASTY

The first stemless shoulder arthroplasty implant was introduced into the market in 2004. Despite an exponential increase in the use of stemless implants, only short- and mid-term results are available. Long-term studies that could further our understanding of the longevity and survivorship of stemless implants are lacking. The purpose of this study was to examine the clinical and radiographic outcomes of patients who have undergone stemless shoulder arthroplasty between 2004- 2015. This study involved clinical and radiological assessment of patients who had undergone anatomic total shoulder arthroplasty (TSA) and hemiarthroplasty (HA) with a stemless humeral component (Biomet Total Evolutive Shoulder System [TESS] or Comprehensive Nano Stemless Shoulder) at a mean of 10-years. All patients had complete pre-operative data. The clinical follow-up was conducted by an advanced practice physiotherapist. Radiographic assessment was performed by two fellowship trained orthopedic surgeons with a subspecialty in shoulder arthroplasty. Patient-reported outcome measures examined included pain, the American Shoulder and Elbow Surgery (ASES) score, and the Western Ontario Osteoarthritis of the Shoulder (WOOS) index. Successful radiological criteria were summarized in five categories. A total of 30 patients with a mean age of 78 ± 7 years including 16 females (53%) who underwent TSA (25) or HA (five) with a Nano (10) or TESS (20) component were included. Preliminary analysis demonstrated that at a mean of 10 years (range: 8 to 15 years), patients continued to have significant relief of pain (P=0.004), and functional improvement as measured by the WOOS (P=0.0007) and ASES (P 2 mm around the entire glenoid component, and among those seven patients, three (12%) had progressive lucency around the humeral component >2 mm in two or more contiguous zones. There was no evidence of lucency around the remainder of humeral components, which were all well fixed at final follow-up. There were no revisions or reoperations performed among the patients included in the current review. The first generation of stemless components have demonstrated excellent long-term survivorship and patient-reported functional outcomes. Humeral component lucency was only observed among patients with glenoid loosening, which may be attributed to polyethylene debris particles, rather than stemless implantation. Overall, stemless shoulder arthroplasty has been found to be a reliable humeral bone-preserving option at a mean of 10 years.