Fracture-Dislocation of the Proximal Humerus: A Marker of Poor Outcome.

Abstract

The purpose of this study was to evaluate the effect that associated glenohumeral dislocations have on outcomes following surgical treatment of proximal humerus fractures. This IRB-approved study reports on 301 patients, who underwent operative treatment for proximal humerus fractures at an academic medical center from January 2006 to January 2023. Fractures were classified according to the Neer system. Patients were separated into two cohorts based on whether a glenohumeral dislocation was present at the time of initial injury. Outcomes measured included the Disabilities of the Arm, Shoulder, and Hand (DASH) score, shoulder range of motion (forward elevation, external rotation, internal rotation), readmission rates, complications, hardware removal, and need for revision surgery. Independent samples t-tests and chi-squared analysis were used for continuous and categorical variables, respectively. A binary logistic regression was performed to analyze the influence of these factors on complication rate. 230 patients sustained an isolated fracture (PHF) and 71 sustained a fracture-dislocation (FD). Significant differences were observed between the FD and PHF groups in all measured outcomes. The FD group had a poorer DASH score (24.38 ± 19.09 vs 10.54 ± 13.67; P < 0.001) and reduced range of shoulder motion in forward elevation (114° ± 40° vs 162° ± 19°; P < 0.001), external rotation (40° ± 19° vs 66° ± 19°; P < 0.001), and internal rotation (57° ± 26° vs 82° ± 21°; P < 0.001). Readmission rates were higher in the FD group (0.28 ± 0.85 vs 0.05 ± 0.28; P < 0.001). The FD cohort also had a higher rate of complications (25.35% vs 6.52%; P < 0.001), need for removal of hardware (14.08% vs 3.04%; P = 0.002), and overall revision surgery (11.27% vs 1.30%; P < 0.001). The FD cohort demonstrated a greater incidence of AVN (12.68% vs 4.35%; P = 0.012). No significant difference was observed regarding rates of fracture healing and recurrent dislocation. Multivariate analysis in the form of binary logistic regression indicated that fracture-dislocation significantly increased the complication risk (OR = 3.310, 95% CI = 1.42-7.70; P = 0.005). Proximal humerus fracture-dislocations are associated with worse functional outcomes and higher complication rates compared to those without dislocations. These findings highlight the potential need for specialized treatment strategies to mitigate the impact of dislocation on recovery.