In recent years, use of anatomic stemless total shoulder arthroplasty (AsTSA) has increased. Despite evidence to suggest good mid-term results at 2-year follow-up there is a paucity of evidence for longer term follow-up. This study aimed to investigate outcomes at a minimum of 5 years post-operatively following primary AsTSA.

This study is a retrospective case series of all patients who underwent a Mathys Affinis AsTSA from July 2010 (first case) to August 2018 (to allow minimum 5-year follow-up). Clinical outcomes included revision rate, range of motion and patient reported outcomes (Oxford Shoulder Score and Numerical Satisfaction Score). Radiological outcome was assessment of radiolucent lines for Lazarus grading.

A total of 105 stemless TSAs were implanted. Five patients underwent revision (4.8%). Seventy-five AsTSA's were included in the final study for analysis of 5-year outcomes. Median follow-up time was 6.1 years. Median age was 69 years old and 81% were female. Oxford shoulder score showed a range of 18 to 48, with a median score of 47. Satisfied or very Satisfied was selected in 94.37%. Median range of motion assessments showed forward elevation 160°, abduction 150°, external rotation 40°, and mode internal rotation was to the lumbar spine. No glenoid lucency was present in 79.7%. There were 9.5% with Lazarus Grade 1 lucency, 5.4% with Lazarus Grade 2, and 5.4% Lazarus Grade 3. No humeral lucency was observed.

This cohort study demonstrates promising clinical and radiological outcomes for the Mathys Affinis Stemless TSA at minimum 5 years post-operatively.