Greater tuberosity fragment volume does not predict clinical outcomes or tuberosity healing after reverse shoulder arthroplasty for proximal humerus fractures: a retrospective cohort study.

Abstract

Purpose: Greater tuberosity (GT) fragment healing has been associated with improved outcomes following reverse total shoulder arthroplasty (RTSA) for proximal humerus fractures, yet the relationship between pre-operative GT fragment volume and clinical outcomes remains largely unexplored. We hypothesised that larger GT volumes would be associated with improved outcomes and larger anatomical dimensions.

Methods: We retrospectively studied 153 patients who underwent RTSA for proximal humerus fracture. GT fragment volume was measured on pre-operative computed tomography (CT). Clinical outcomes included forward flexion, abduction, external and internal rotation, visual analogue scale (VAS) pain score, Quick Disabilities of the Arm, Shoulder and Hand (Quick DASH) score, and Subjective Shoulder Value (SSV). Anatomical parameters and patient sex were also evaluated. Associations were assessed using Spearman and point-biserial correlations.

Results: GT fragment volume showed no significant correlation with any clinical outcome measure (all p ≥ 0.15) or with radiographic tuberosity healing (r =  - 0.135, p = 0.15); this persisted in 91 patients with confirmed healing. In contrast, it correlated with maximal tuberosity length on radiographs (r = 0.54) and CT (r = 0.52), glenoid surface area (r = 0.35), and male sex (r = 0.32), all significant after Bonferroni correction; a weak correlation with humeral head diameter (r = 0.18) did not survive correction.

Conclusion: GT fragment volume correlates with anatomical shoulder dimensions and reflects overall skeletal size but does not predict clinical outcomes or tuberosity healing following RTSA. Surgeons should not rely on it to predict outcomes, healing potential, or to guide surgical decision-making.