What is the incidence of total elbow arthroplasty after intra-articular versus extra-articular distal humerus open reduction and internal fixation?

Introduction Distal humerus fractures are rare but technically challenging. Intra-articular patterns may predispose patients to post-traumatic osteoarthritis, potentially requiring total elbow arthroplasty (TEA). This study compared TEA incidence after intra- versus extra-articular distal humerus fracture fixation across age groups. Methods The TriNetX database (2006–2026) was queried for patients undergoing open reduction and internal fixation (ORIF) of distal humerus fractures. Patients were stratified into younger (10–40 years) and older (>50 years) cohorts and classified as extra-articular (current procedural terminology (CPT) 24545) or intra-articular (CPT 24546, 24586, 24579). Cohorts were 1:1 propensity-matched for demographics and comorbidities. Younger patients were analyzed as a combined cohort. Kaplan–Meier analysis estimated TEA incidence at 1, 3, 5, and 10 years. Results In the older cohort (2181 patients/group; mean age ∼70 years), intra-articular fractures demonstrated significantly higher TEA conversion at 1 year (3.9% vs. 1.6%), 3 years (4.3% vs. 2.1%), 5 years (4.3% vs. 2.1%), and 10 years (4.4% vs. 2.2%) (all p s < 0.05; odds ratio: 2.02–2.46). Kaplan–Meier analysis confirmed lower TEA-free survival in intra-articular patients ( p < 0.001). TEA conversion remained rare in younger patients (1.04% at 10 years). Conclusion TEA conversion after distal humerus ORIF is uncommon overall but varies by age and fracture pattern, supporting individualized counseling. Level of evidence Level III, Prognostic