Overtightening of the syndesmosis revisited and the effect of syndesmotic malreduction on ankle dorsiflexion

Effect of Ankle Position on Tibiotalar Motion With Screw Fixation of the Distal Tibiofibular Syndesmosis in a Fracture Model

“…As mentioned by Gonzalez et al, 6 several methodological shortcomings to the study performed by Tornetta et al 21 may have an effect within our study. As there was no description of how the force application to achieve maximal dorsiflexion was measured or any method to ensure the accuracy of said application, there is potential for error in achieving both accuracy and precision with repeated measurements.…”

“…By adding a PER-4 fracture and testing both isolated syndesmosis fixation and proximal fracture fixation with syndesmotic fixation, we aimed to find any differences in dorsiflexion following fixation. The findings of Tornetta et al 21 and Gonzalez et al 6 were again validated, and no significant motion limitations were found with performing syndesmotic fixation in equinus vs dorsiflexion within a cadaveric fracture model.…”

“…A 4.5-mm lag screw with washer (Synthes, Paoli, PA) was then inserted in a lag by technique fashion, first drilling both the fibula and tibia with a 3.2-mm drill bit, followed by drilling both cortices of the fibula with a 4.5-mm drill bit to prevent screw engagement of the fibula. Each lag screw was tightened by a single examiner by hand to "2-finger tight" as described in previous works 6,21 and was performed with the ankle in gravity equinus, or a resting position. Range-of-motion measurements were then repeated and the change in maximal dorsiflexion evaluated for a statistically significant difference.…”

“…The methods used by Tornetta et al 21 have recently been replicated in another cadaveric model demonstrating that mal-reducing the syndesmosis with compression fixation also does not impede range of motion. 6 Both studies found that ankle position is not vitally important in avoiding overcompression of the syndesmosis during fixation; however, neither used a fracture model, which would represent the most common scenario requiring such fixation. The interplay of the presence of a fracture on distal fibular mobility may allow overcompression in a scenario that an intact fibula may not.…”

Effect of Syndesmotic Implant Removal on Dorsiflexion

“…Previously published work by the senior author examining syndesmotic screw fixation in a cadaveric model used a preload methodology of 25 lb to ensure ankle specimens would be taken through a full dorsiflexion range of motion. 17 Additionally, in vivo pilot tests were performed before the initiation of this study that demonstrated this amount of force to be sufficient to cause maximal ankle dorsiflexion. Torque applied in other studies examining ankle motion varied from 10 Nm (DiGiovanni, Weaver, and Meyer), 11,24,31 12 Nm (Moseley), 26 15 Nm (Assal), 3 16.1 Nm (Scharfbillig), 27 to 20 Nm (Greisberg).…”