Fixation Stability of Olecranon Osteotomies

Abstract

Eighteen pairs of fresh frozen human upper extremities were selected and each randomized to 2 of 3 olecranon osteotomy and fixation technique groups: (1) transverse osteotomy with 0.062 Kirschner wire and tension band fixation; (2) chevron osteotomy with 6.5-mm cancellous lag screw and tension band fixation; and (3) oblique intraarticular osteotomy with 3.5-mm cortical lag screw and tension band fixation. The arms were mounted with the elbow at 90 degrees flexion and the wrist constrained; a dual linear displacement transducer across the osteotomy was used to determine angulation, translational displacement, and the total gap size. First the brachialis and then the triceps were incrementally loaded to 10 kg using a pulley and cable system to control force direction; the muscle load versus osteotomy displacement was recorded. Cycling with 10 kg was repeated 20 times with the brachialis and triceps alternately loaded and the osteotomy displacement remeasured. There were no statistically significant differences between the amounts of displacement for the 3 osteotomy and fixation techniques caused by either muscle action. The total displacement caused by the brachialis load for all techniques was appreciably greater than that of the triceps load. No significant increase in displacements occurred after 20 load cycles. These results suggest all 3 olecranon osteotomy and fixation techniques offer comparable stability, so the choice of technique should be left to the surgeon's preference.