THE IMPACT OF REDUCTION ON SURVIVORSHIP AND OUTCOMES FOLLOWING LOCKED PLATE FIXATION OF PROXIMAL HUMERUS FRACTURES

Proximal humerus fracture management remains controversial. There is evidence to suggest that open reduction and internal fixation (ORIF) with locked plating can lead to excellent outcomes. However, mixed results have been reported in some studies. Variables that impact outcome following locked plate fixation, including fracture reduction, require further elucidation. The objectives of this study were to evaluate survivorship and outcomes in a large series of proximal humerus fractures treated with locked plating and to discern the association between fracture reduction and outcome. This retrospective study included 147 patients from a single institution treated with locked plate fixation for unstable proximal humerus fractures during the period of 2008–2018. Fracture pattern, reduction, fixation characteristics, maintenance of reduction, and failure were evaluated on radiography. Follow-up data were collected from charts. Surveys were used to collect patient-reported outcome measures (PROMs). Signs of radiographic failure (new changes suggestive of osteonecrosis, arthritis, nonunion, fixation failure, hardware fracture, instability, and screw penetration) and history of re-operation were documented. Analysis was performed on 134 patients with ≥12 months follow-up. Survivorship free from revision surgery was calculated using the Kaplan-Meier method. Independent t-tests and chi-squared tests were used to evaluate the association of variables with radiographic failure. Mean age was 58±15 years and 97 were female (66%). Baseline patient and fracture characteristics are outlined in Table 1. Following ORIF, coronal alignment was 135.5±9.84°; 133 fractures were fixed with adequate coronal alignment of 120–150° (90%) and 83 fractures were fixed with neutral coronal alignment of 130–140° (56%). Sagittal reduction was neutral in 138 (88%) and the head was noted to be tilted posteriorly in 9 (6%). The medial column was restored in 114 (78%). Mean follow-up duration was 5±3 years. Survivorship free from revision surgery was 95% at 1 year, 93% at 2 years, and 89% at 5 years. Revision surgery for failure was performed in 14 patients (10%) including arthroplasty for arthritis or osteonecrosis in 8 (5%), screw removal for joint penetration in 3 (2%), repair nonunion in 2 (1%), and Latarjet procedure for instability in 1 (1%). Radiographic evidence of failure included avascular necrosis in 11 (7%), arthritis in 10 (7%), nonunion in 3 (2%), screw penetration in 3 (2%), failure of fixation in 2 (1%), and instability in 1 (1%). Pre-operative factors associated with post-operative failure included female gender, fracture with head split, and fracture-dislocation (p Survivorship and outcomes following locked plate fixation of proximal humerus fractures were very good in this large series of proximal humerus fractures. Factors associated with failure included fracture pattern (fracture-dislocation and head-splitting fractures) and reduction (sagittal alignment). Locked plate fixation continues to be a viable option for management of unstable proximal humerus fractures. For any figures or tables, please contact the authors directly.