The use of a large diameter glenosphere in Reverse Shoulder Arthroplasty for proximal humeral fractures in elderly patients undergoing tuberosity removal.

Background and aim: Prosthetic replacement with reverse shoulder arthroplasty (RSA) is commonly indicated for complex proximal humerus fractures (PHFs) in elderly patients. Aim of this study was to evalu-ate the clinical and radiological outcomes of RSA performed for comminuted PHFs, without periprosthetic reconstruction of the tuberosities. Our hypothesis was that a large diameter glenosphere could ensure satisfac-tory RSA mobility and stability, regardless of tuberosity removal. Methods: We selected 32 patients (4 men, 28 women) with comminuted PHFs who underwent RSA with tuberosity excision and implantation of a 44-mm glenosphere between 2009 and 2015. Active range of motion (ROM), stability, Constant-Murley Score (CMS) (1) and Subjective Shoulder Value (SSV ) (2) were assessed one year and four years after surgery. Results: Clinical and radiological information were collected for 23 patients (72%). At one-year follow-up, active anterior elevation (AE) was 96±28 degrees, external rotation with adducted arm (ER1) 9±7 degrees, external rotation with abducted arm (ER2) 14±10 degrees, internal rotation (IR) to L4; CMS was 56±10 and SSV 65±22. Clinical assessment at 4-year follow up showed a decrease in active ROM (AE was 88±20 degrees, ER1 8±2 degrees, ER2 12±10 degrees, IR to L4), CMS (52±9) and SSV (62±8). No RSA dislocation occurred during the study. In 4 patients, grade I glenoid notching without any sign of component loosening was observed 4 years after surgery. Conclusions: A large diameter glenosphere does not ensure results com-parable to those achieved after RSA with tuberosity reconstruction. However, the 44-mm glenosphere was effective in preventing RSA instability. (www.actabiomedica.it)