Locking and Non-locking Constructs Achieve Similar Radiographic and Clinical Outcomes for Internal Fixation of Intra-articular Distal Humerus Fractures

Background: Locking plates have been used increasingly for the management of distal humerus fractures. Studies that compare patient-centered outcomes between locking and non-locking fixation for distal humerus fractures are lacking. Questions/Purposes: The purposes of this study were to (1) determine whether locking plates offered superior fixation compared with non-locking plates for distal humerus fractures, (2) determine whether the use of locking plates was associated with fewer complications, and (3) determine whether locking plate use resulted in superior radiographic outcome compared with non-locking plates. Lastly, another aim was to determine the average cost difference associated with locking plate use versus non-locking plate use for distal humerus fracture fixation. Patients and Method: Demographic, clinical, and radiographic data including loss of fixation, range of motion, rate of infection, nonunion and reoperation, as well as measures of fixation were collected retrospectively and compared on 96 patients with surgically treated AO type 13C distal humerus fractures (65 locking, 31 non-locking) at 6-week and 6-month follow-up. Average costs of locking and non-locking constructs were calculated and compared. Results: Three in 96 (3.1%) of all cases experienced loss of fixation, with no difference between the two groups. There was no difference between locking and non-locking groups with regard to the rate of nonunion, infection, and reoperation at 6 weeks and 6 months. On average, locking plate constructs were 348% more expensive than non-locking constructs. Conclusion: While there are some significant differences in radiographic parameters and cost between locking and non-locking constructs for internal fixation of intra-articular distal humerus fractures, there were no statistically significant differences in clinical outcome.