Grammont versus lateralizing reverse shoulder arthroplasty for proximal humerus fracture: functional and radiographic outcomes

Purpose: The aim of this study is to retrospectively compare clinical and radiographic outcomes of patients treated with non-lateralizing reverse shoulder arthroplasty (RSA) and with humeral lateralizing RSA after proximal humerus fracture (PHF). Methods: In total, 32 patients (8 men and 24 women), with a mean age of 77.4 (67–92), have been reevaluated (follow-up of 14.3 months) and divided into Grammont group (G-group—16 patients, 2 men and 14 women, mean age 82.3) and lateralizing group (L-group—16 patients, 4 men and 12 women, mean age 72.5). The dominant side was affected in 21 patients. Pain, Constant–Murley score (CMS), range of motion accurately measured with inertial sensors (SHoWlder, NCSLab®) and complications. Anatomic tuberosity healing, signs of loosening or mobilization of the implants and scapular notching (according to Sirveaux classification) have been measured on standard X-ray series (antero-posterior view in neutral, external and internal rotation; axillary view; outlet view). Results: Similar CMS was recorded between the two groups (G-group: 61/100; L-group: 64/100). G-group had higher forward flexion (128° vs. 112°) and abduction (126° vs. 114°), L-group had higher external rotation in abduction (35° vs. 41°); similar internal rotation (sacrum) and rotation with elbow in adduction were measured (12° vs. 19°). No statistically significant differences emerged. Anatomic healing of the tuberosity was higher in G-group (87.5% vs. 50%); low-grade scapular notching was higher in L-group (18.25% grade 1–2 vs. 0). Anatomic healed tuberosity guaranteed highly statistically significant improved functional outcomes. No revisions of the implant were performed. Conclusions: RSA can be considered a valid solution for the treatment of PHF in elderly low-demanding population. Cuff conditions should be investigated before surgery for the indication of the adequate model.