Non-union of the greater tuberosity in patients undergoing reverse total shoulder arthroplasty for proximal humerus fracture: Is it associated with worse outcomes?

4-part proximal humerus fractures are complex injuries that are often associated with comminution of the greater tuberosity. The purpose of this study is to evaluate the functional outcomes of 4-part humerus fractures that are treated with reverse total shoulder arthroplasty (rTSA) and correlate these outcomes with the healing status of the greater tuberosity.

A retrospective observational study was performed including 65 patients who underwent rTSA following a 4-part proximal humerus fracture. These patients were categorized into 3 groups according to the healing status of the greater tuberosity: patients with healed greater tuberosity in an anatomical position (group A, n = 43), patients with non-union of the greater tuberosity but in anatomical position (group B, n = 14), and patients with resorption or non-union of the greater tuberosity not in anatomical position (group C, n = 8). The Constant-Murley score and range of motion were recorded for each patient at 12 months postoperatively. The clinical and radiographical outcomes of the 3 groups were compared.

Patients with healed greater tuberosity (group A) had higher range of motion compared to patients with greater tuberosity migration or reabsorption (group C) regarding forward flexion (130° vs 80°, p < 0.001), abduction (110° vs 65°, p < 0.001) and external rotation (20° vs 10°, p = 0.004). However, no significant changes regarding forward flexion (130° vs 125°, p = 0.67), abduction (110° vs 100°, p = 0.60) and external rotation (20° vs 25°, p = 0.37) were noted between patients with healed greater tuberosity (group A) and those with non-united greater tuberosity that remained attached to the humeral prosthesis (group B). Similarly, Constant- Murley score was similar between patients of group A and group B (65.0 vs 61.5, p = 0.53), while it was higher in patients of group A compared to those of group C (65.0 vs 39.0, p = 0.053).

The outcomes of this study indicate that reliable recovery regarding range of motion and functional status can be achieved in patients who undergo rTSA due to 4-part proximal humerus fractures, as long as the greater tuberosity remains in close proximity to the humeral prosthesis, even if it has signs of non-union with no continuity to the adjacent humerus.