Long-term clinical, radiological, and patient-oriented outcomes of the TESS and Nano stemless shoulder arthroplasty systems.

Abstract

The first stemless shoulder arthroplasty implant was introduced in 2004. Despite an exponential increase in the use of stemless implants, only short- and mid-term results are available. Long-term studies of stemless implants are lacking. The purpose of this study was to examine the long-term clinical and radiographic outcomes of patients who have undergone stemless shoulder arthroplasty. 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 [Nano]). Patient-reported outcome measures examined included pain, the American Shoulder and Elbow Surgeons score, and the Western Ontario Osteoarthritis of the Shoulder Index. Successful radiological criteria were summarized into 5 categories for the TSA: (1) no migration of the humeral component <5 mm, 2) no progressive lucency around the humeral component >2 mm in 2 or more contiguous zones, 3) no migration of the glenoid component <5 mm, and 5) no progressive lucency >2 mm around the entire glenoid component. Successful radiological criteria were summarized in the first 3 categories for the HA group. Overall, 47 stemless arthroplasties in 39 patients with a mean age of 78 years at follow-up were analyzed. There were 29 females (62%) in the cohort. Of 47 arthroplasties, 37 were TSA and 10 were HA, with 17 Nano and 30 TESS components. The mean follow-up was 10 years (range: 8 to 15 years). On average, there was a statistically significant improvement in range of motion, pain relief, and function as measured by the Western Ontario Osteoarthritis of the Shoulder Index and American Shoulder and Elbow Surgeons scores. In the TSA group, 7 (15%) patients had radiographic evidence of progressive lucency >2 mm around the glenoid component, with 3 having signs of glenoid migration. Four patients (11%) had progressive lucency around the humeral component >2 mm in 2 or more contiguous zones. Ten patients had superior migration of the humeral head due to cuff deficiency, and 7 had subsidence with concomitant medial calcar stress shielding. In the HA group, 3 joints had superior migration of the humeral head due to cuff deficiency. Overall, there were 2 cases of revision among the entire cohort. In the present study, both the TESS and Nano stemless shoulder arthroplasty implants were found to provide a reliable humeral bone-preserving option with excellent survivorship at a mean of 10 years.