Proximity of the posterior interosseous nerve during cortical button guidewire placement for distal biceps tendon reattachment.

Abstract

To assess the distance between the posterior interosseous nerve (PIN) and a distally and ulnarly directed guide pin for placement of a cortical button to reattach a distal biceps tendon. We used 10 fresh frozen cadaveric upper limbs without deformities and identified the PIN through a dorsal approach. We performed a single incision anterior surgical approach, detached the biceps tendon, and drilled a 1.6-mm K-wire from the base of the biceps tendon insertion in 3 different trajectories, sequentially, measuring the following drilling angles: 30° distal and 30° ulnar, 30° ulnar, and 30° distal. In each testing scenario, we measured the minimum distance in millimeters between the tip of the K-wire and the PIN using a digital caliper through the dorsal incision. The mean and median distances from the guide wire to the PIN in each testing trajectory were each significantly different from each other, with the 30° ulnar direction leading to the greatest distance from the nerve. We found that the 30° ulnar drilling direction resulted in a significantly greater distance from the guide wire to the PIN, in comparison with the distal-ulnar and the distal-only trajectories. This study helps define the safe trajectory for guide wire placement in bicortical fixation of distal biceps tendon injuries.