Biomechanical Comparison of Intramedullary Fibular Nail Versus Plate and Screw Fixation

Abstract

Background:

Clinical evidence has shown that percutaneous ankle fracture fixation using an intramedullary fibular nail results in good outcomes at 1 year and reduces postoperative wound complications in patients with vulnerable soft tissues. Confirmatory biomechanical evidence of its strength when used to secure a supination external rotation (SER) IV (AO/OTA 44B-type) fracture, compared with traditional plates and screws, is currently lacking.

Methods:

Twenty cadaveric lower limbs (10 cadavers) had a SER IV injury surgically created. One leg was randomly allocated to fixation with a fibular nail and the other a lag screw and neutralization plate. A mechanical testing apparatus subjected all lower limbs to an axially loaded supination external rotation force to failure.

Results:

Superior ultimate torque to failure was demonstrated with a trend toward increased energy absorption in the nail group (P = .28 and .07, respectively). No difference was demonstrated in angle at failure. All specimens in the plate group lost reduction at the bone-metal interface as a result of screw pullout. In contrast, all specimens in the nail group failed because of disruption of the lateral ligaments.

Conclusions:

This study demonstrated greater torque to failure and better maintenance of the fibular construct for the intramedullary fibular nail compared to standard plating.

Clinical Relevance:

These results suggest that the previously documented clinical benefits of the fibular nail are complemented by biomechanical properties that compare favorably to standard techniques.