A New Method for Reduction and Stabilization of the Distal Tibiofibular Syndesmosis

Abstract

Category: Ankle; Trauma Introduction/Purpose: Fixation strategies for distal tibiofibular syndesmotic injuries are associated with risk of malreduction. We describe a new method of reduction and fixation of the syndesmosis with two suture buttons placed through a single sagittal tunnel through the fibula and across the tibia at the attachment sites of the anterior and posterior-inferior tibiofibular ligaments. Methods: Eighteen frozen cadaveric lower leg specimens were divided in two groups of nine and subjected to syndesmotic injury followed by reduction and fixation. Nine were repaired with the new method and 9 with the conventional method. Post-reduction CT images were obtained and compared to pre-injury CT images to assess quality of reduction. Specimens were then tested on an MTS machine and loaded between +\-5Nm at 0.5Hz of internal and external rotation for 500 cycles. Cyclic loading was paused at 0, 100, and 500 cycles to assess torsional resistance, fibular rotation, and fibular translation with the foot first internally rotated 10 degrees and then externally rotated 15 degrees. Peak torque and translation of the fibula was measured. Results: A statistically significant difference was detected between groups, with the new method of fixation showing less lateral translation of the fibula. Data that did not reach statistical significance showed a trend towards decreased post reduction translation in the sagittal plane and improved rotational alignment with the new method. Decreased fibular rotation that reached statistical significance was noted in the new technique with internal rotation at 0, 100 and 500 cycles and during external rotation at 100 and 500 cycles. No differences were noted for torsional resistance or fibular translation between groups. Conclusion: The new method of syndesmotic fixation facilitated reduction of the syndesmosis that resulted in improved alignment, and better rotational stability compared with the conventional technique. This may be a reliable alternative to current methods of syndesmosis reduction and fixation.