Stemless reverse shoulder arthroplasty: clinical and radiologic outcomes with minimum 2 years' follow-up.

Background: Recently, a stemless reverse shoulder arthroplasty (RSA) design was developed to preserve bone stock. Clinical and radiologic studies of this design in larger cohorts with >100 patients are not frequent. The purpose of this study was to present the clinical and radiologic results of a newly developed stemless RSA implant. The hypothesis was that this design would provide similar clinical and radiologic results to other stemless implants, as well as stemmed implants.

Methods: Between September 2015 and December 2019, all patients who underwent primary RSA with a stemless Easytech prosthesis were considered eligible for inclusion in this prospective multicenter study. The minimum follow-up period was 2 years. Clinical outcomes consisted of the Constant score, adjusted Constant score, QuickDASH (short version of Disabilities of the Arm, Shoulder and Hand questionnaire) score, Subjective Shoulder Value, and American Shoulder and Elbow Surgeons shoulder score. Radiographic parameters included radiolucency, loosening, scapular notching, and specific geometric parameters.

Results: Stemless RSA was performed in 115 patients (61 women and 54 men) at 6 different clinical centers. The average age at the time of surgery was 68.7 years. The average Constant score was 32.5 preoperatively and showed significant improvement to 61.8 at latest follow-up (P < .001). The Subjective Shoulder Value also demonstrated significant improvement postoperatively (from 27.0 to 77.5, P < .001). Scapular notching was observed in 28 patients (24.3%); humeral loosening, 5 (4.3%); and glenoid loosening, 4 (3.5%). The total complication rate was 17.4%. Eight patients (4 women and 4 men) underwent implant revision.

Conclusion: The clinical outcomes of the examined stemless RSA seem to be comparable to those of other humeral designs; however, the complication and revision rates are higher than those of historical controls. Surgeons should proceed with caution when using this implant until longer-term follow-up data are available.