Does the IOFIX improve compression in ankle fusion?

BackgroundThe new IOFIX is an intra-osseous fixation device comprising an “X-post” through which a lag screw passes to apparently improve force distribution across an arthrodesis.We conducted a novel human cadaveric study. Our null hypothesis was no difference in force exists in an ankle arthrodesis model stabilized with the IOFIX or a conventional single lag screw.MethodIn ten cadaver ankles a pressure transducer was compressed as an IOFIX and standard single lag screws were alternately compared.ResultsThe median average force created by the IOFIX was 3.95 kg and 2.4 kg for the single conventional lag screw (p ⩽ 0.01). The IOFIX improved contact area across the arthrodesis with a median average of 3.41 cm2 compared with 2.42 cm2 in the lag screw group (p ⩽ 0.03).ConclusionOur results suggest an IOFIX improves force distribution across an ankle arthrodesis compared with a single conventional lag screw.