Locking versus non-locking plates in fixation of extra-articular distal humerus fracture: a randomized controlled study

Introduction Studies have shown that the use of nonlocking (reconstruction) plates in fixing distal humerus fractures may not yield stable fixation which therefore requires long immobilization and suboptimal functional results. There are reports showing that locking plates are biomechanically superior to nonlocking plates. The aim of this study was to compare elbow functional outcomes between locking and nonlocking plates in fixation of distal humerus fractures. Methods A single-centre, randomized control study was conducted at an academic level 1 trauma centre. A total of 60 patients with type 13-A fracture (AO/OTA classification) were randomized into two equal groups, locking plates group, and nonlocking plates group. The primary outcome measure was the Mayo elbow performance score (MEPS) at one year. Secondary outcomes measures were elbow flexion/extension arc, union, operative time, and complications (e.g., infection, heterotrophic ossification). Results The Mayo Elbow Performance Score (MEPS) at one year was 88 +/- 10.1 in locking plates group and 75.8 +/- 12.8 in nonlocking plates group. The difference was found to be statically significant (Pvalue = 0.01). Elbow flexion/extension arc of motion at one year was 116 degrees +/- 15 degrees in locking plates group and 113 degrees +/- 28 degrees in nonlocking plates. The difference was not found to be statistically significant (Pvalue = 0.17). Conclusion Both implants yield similar results, with locking plates showing slightly better clinical scores.