Mitigation of Triceps Avulsion Fracture After Proximal Ulna Plate Fixation

Triceps avulsion fractures have become an increasingly common postoperative complication of olecranon fracture repair with proximal ulna plate (PUP) fixation. The purpose of this study is to create an efficient, reproducible mechanism to mitigate this issue.

Ten matched pair cadaveric specimens underwent a complete transverse osteotomy to simulate an olecranon fracture, followed by fracture reduction with a PUP. One arm from each pair underwent an additional augmented suture repair, where the triceps tendon was sutured directly to the plate. A custom jig was used to hold the specimen in position and apply a tensile force on the triceps until mechanical failure.

All control specimens (without augmented suture repair) failed through a full-thickness triceps avulsion fracture at an average force of 967.7 N. The augmented suture-repaired specimens failed at an average force of 1204.3 N through partial avulsion fractures, widening of the osteotomy site, and triceps ruptures.

Our study demonstrated that an augmented suture repair of PUP fixation for olecranon fractures is a simple and effective way to significantly increase fixation strength and change the potential failure mechanism.