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

BACKGROUND

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.

MATERIAL AND METHODS

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.

RESULTS

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).

CONCLUSIONS

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.