Reverse Total Shoulder Arthroplasty for Proximal Humerus Fractures Using the Biomet Comprehensive Shoulder System:...

Reverse total shoulder arthroplasty (rTSA) is an established treatment for complex proximal humerus fractures in elderly patients, providing reliable pain relief and functional improvement. Outcomes are well described at one and two years, but whether changes observed between these timepoints are clinically meaningful remains unclear.

We conducted a retrospective analysis of prospectively collected data on 64 patients who underwent reverse total shoulder arthroplasty using the Comprehensive Shoulder System (Biomet, Warsaw, IN, USA) for acute proximal humerus fractures with two-year follow-up. Patient-reported outcome measures included the Visual Analog Scale (VAS), Single Assessment Numeric Evaluation (SANE), and American Shoulder and Elbow Surgeons (ASES) score. Range of motion (ROM) was assessed using forward flexion and external rotation. Paired t-tests compared mean outcomes between one and two years. Patient acceptable symptom state (PASS) threshold achievement was assessed at each timepoint, while minimal clinically important difference (MCID) achievement between one and two years was evaluated at the individual patient level. Regression analysis identified factors associated with interval changes.

Pain relief was achieved by one year (VAS 1.4±0.7) and remained stable at two years (1.3±0.8, P = .672), with >95% of patients meeting PASS thresholds at both timepoints. Statistically significant improvements were observed in SANE (73.8±9.1 to 75.4±8.6, P < .001), ASES (74.3±5.6 to 75.7±6.2, P = .005), and external rotation (15±7° to 16±7°, P = .019). PASS threshold achievement increased slightly for SANE (64.1% to 68.8%), ASES (46.9% to 56.3%), and external rotation (39.1% to 51.6%). Individual MCID improvement between one and two years was observed in 23.4% of patients for VAS, 9.4% for SANE, 3.1% for ASES, and 10.9% for external rotation. Regression analysis identified BMI, fracture complexity, and dominant-side involvement as correlates of pain outcomes, while cement use and anatomic healing were associated with functional improvements.

RTSA for proximal humerus fractures provides predictable pain relief and substantial functional recovery by one year. Although average improvements between one and two years were modest, clinically meaningful improvement continued in a subset of patients, particularly for pain (23.4%) and external rotation (10.9%). These findings suggest that one-year PROMs adequately capture recovery for most patients while recognizing continued improvement in selected individuals.

Level IV, Case Series, Treatment Study.