Nine-year outcome after anatomic stemless shoulder prosthesis: clinical and radiologic results

Background: Several stemless shoulder implants are available on the market, but only a few studies have presented results with sufficient mid-to long-term follow-up. The present study evaluated clinical and radiologic outcomes 9 years after anatomic stemless shoulder replacement. Methods: This is a prospective cohort study evaluating the stemless shoulder prosthesis since 2005. Anatomic stemless shoulder replacement using a single prosthesis was performed in 49 shoulders; 17 underwent total shoulder replacement, and 32 underwent hemiarthroplasty. Forty-three patients were clinically and radiologically monitored after a mean of 9 years (range, 90-127 months; follow-up rate, 88%). The indications for shoulder replacement were primary osteoarthritis in 7 shoulders, post-traumatic in 24, instability in 7, cuff tear arthropathy in 2, postinfectious arthritis in 1, and revision arthroplasty in 2. Results: The Constant-Murley Score improved significantly from 52% to 79% (P < .0001). The active range of motion also increased significantly for flexion from 101 degrees to 118 degrees (P = .022), for abduction from 79 degrees to 105 degrees (P = .02), and for external rotation from 21 degrees to 43 degrees (P < .0001). Radiologic evaluation revealed incomplete radiolucency in 1 patient without clinical significance or further intervention. No revision caused by loosening or countersinking of the humeral implant was observed. Conclusions: The 9-year outcome after stemless shoulder replacement is comparable to that of third-and fourth-generation standard shoulder arthroplasty. (C) 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.