Biomechanical Analysis of Internal Fixation Methods for Distal Interphalangeal Joint Arthrodesis

Background: The biomechanical performance of distal interphalangeal joint (DIPJ) fixation techniques in response to cyclic and load-to-failure bending loads is generally unknown. The purpose of this study is to assess the performance of 4 commonly used techniques for DIP arthrodesis. Methods: Phalanges were fixed by one of the following techniques: (1) 2 parallel Kirschner wires (K-wires), (2) 1 longitudinal K-wire and 1 oblique K-wire, (3) an Acutrak® 2 Micro headless compression screw, or (4) 90-90 wiring. The phalanges were loaded in cantilever bending on the palmar side of the phalange for 3000 cycles, then loaded-to-failure. Results: The 90-90 wiring was significantly worse than the other 3 methods in 9 of 10 parameters analyzed. Both K-wire methods and the screw produced similar results in nearly all parameters. Conclusions: Given the lack of difference in biomechanical performance between K-wires and compression screws, consideration should be given to other factors such as cost and complication profiles when choosing an implant for DIPJ fusion.