Biomechanical Evaluation of 2 Common Approaches for Total Elbow Arthroplasty: Triceps Tongue Compared With Triceps Reflecting.

Abstract

We hypothesize that the triceps tongue approach will be equivalent in strength to the triceps reflecting approach in load to failure following a cyclic preload. Seven paired fresh-frozen cadaveric arms were dissected using the triceps reflecting approach or triceps tongue approach to the posterior elbow. The triceps was then repaired in each specimen, and the elbows were placed in a testing jig. Elbows were preloaded in a cyclic fashion at 5 lbs (2.3 kgf) for 200 cycles in flexion/extension, followed by load to failure. The stiffness and ultimate failure strength for each specimen were determined. We defined ultimate failure as gapping in the suture construct of 4 mm or suture breakage. One of the triceps tongue specimens was excluded due to a testing error, resulting in 6 elbows in this group. There were no tendon repair failures during the cyclic preload. The median ultimate failure of the reflecting group occurred at 65 pounds, compared to 115 pounds in the tongue group. This was significantly different. The reflecting approach consistently failed along the entire bone-tendon interface. The tongue approach failed at the proximal repair site in 4 of 6 specimens, while the longitudinal aspect of the tendon repair remained intact. Following a cyclic preload of 5 lbs for 200 cycles, the triceps tongue repair is stronger than triceps reflecting in ultimate failure. The mode of failure of triceps tongue repair may be superior to that of triceps reflecting. This study may help guide surgeons when choosing a "triceps off" approach to total elbow arthroplasty.