Tuberosity healing in reverse shoulder arthroplasty for proximal humerus fractures with a diaphyseal press-fit humeral stem

Background

Reverse shoulder arthroplasty (RSA) is a viable option for proximal humerus fractures (PHFs) in the elderly, and cemented humeral fixation is the standard of care. This study evaluates the influence of a diaphyseal press-fit stem with a 142° humeral inclination on tuberosity healing (TH) and functional outcome in RSA for PHF.

Methods

Twenty-three patients received an RSA for PHF by a single surgeon at one center over a 2-year period. The humeral stem design was intended for diaphyseal press fit with a 142° humeral inclination. The tuberosities were repaired for each patient with bone graft and a standard suture technique. Patients’ clinical and radiographic outcomes were collected with a minimum 12-month follow-up.

Results

Nineteen of 23 patients (83%), with a mean age of 75 + years, were available for follow-up at an average of 14 months. Radiographic analysis showed 68% of patients had evidence of TH. Grade 1 scapular notching was found in 32% of patients. There was no implant loosening or subsidence noted. Average range of motion was 163° ± 15° degrees of forward flexion, 113° ± 24° of abduction, internal rotation to the waist, and an average external rotation of 7 ± 1.5 as measured by the Constant-Murley score. The average American Shoulder and Elbow Surgeons score was 81.8, and the average Constant-Murley score was 67.9. While not significant, those with TH trended toward better clinical outcomes. There was a 0% revision rate.

Conclusion

A press-fit stem designed for diaphyseal fixation provides consistent reliable results in RSA for PHF. A high percentage of TH was appreciated with a 142° humeral inclination, neutral glenosphere construct, and a standardized bone grafting, suture technique. TH is associated with improved patient outcomes.