SLR - September 2013 - Jacqueline Donovan
Reference: Miller A, Barei D, Iaquinto J, Ledoux W, Beingessner D. Journal of Orthopaedic Trauma. 27(2):100-106, February 2013.
Scientific Literature Review
Reviewed by: Jacqueline Donovan, DPM
Residency Program: Grant Medical Center, Columbus, Ohio
Podiatric Relevance: It is accepted throughout the literature that anatomic reduction and restoration of the syndesmosis as well as the ankle mortise is a significant predictor of functional outcome following syndesmotic injury. Malreduced ankle fractures have been demonstrated in the literature to lead to ankle arthritis, specifically malreduction of the syndesmosis. In 2006, Gardner et al quoted a 52 percent rate of syndesmotic malreduction as evaluated by CT.
Methods: Fourteen (seven matched pair) cadaveric specimens were used in this study with an average specimen donor age of 80 years. Utilizing fluoroscopy, a 0.035 Kirschner wire was placed in the tibia, four centimeters proximal to the ankle joint, perpendicular to a true lateral image of the ankle as a marker for zero degrees of angulation. Three additional Kirschner wires were then inserted in the tibia for subsequent measurements in the axial plane. A CT of the ankle was performed not only to assess the normal anatomic syndesmotic relationship of the fibula to tibia but also to accurately identify the location of clamp placement for a zero degree, 15 degree or 30 degree angle from the fibula.
The second part of the study consisted of dissection of the cadaveric specimens to create a complete syndesmotic disruption utilizing an anterior approach. Pilot holes for clamp application were made in each tibia two centimeters proximal to the ankle joint at zero degrees, 15 degrees and 30 degree angles using both the Kirschner wires placed before CT and the measurements made from the scans. A large modified quad reduction clamp was applied at zero degrees, 15 degrees and 30 degrees and each specimen had a CT scan performed.
The specimens were then randomized to zero degrees to 30 degrees anterior angulation and a 3.5-mm Synthes screw was then placed in each specimen from a lateral fibular starting point through four cortices at the assigned angle. Again, the cadaver ankles were evaluated with CT imaging.
Results: Significant displacement of the fibula was noted in external rotation when the reduction clamps were placed at 15 and 30 degrees as well as significant overcompression of the syndesmosis. When the 30-degree lateral screws were placed, significant anteromedial displacement, external rotation and overcompression of the syndesmosis were noted. Significant external rotation and overcompression of the syndesmosis was also noted with the placement of the 15 degree posterolateral screws.
Conclusions: This study demonstrates that intraoperative clamping and fixation may cause significant malreduction of the syndesmosis. Iatrogenic malreduction of the syndesmosis can be caused by the clinicians’ placement of both the reduction clamp as well as screw placement. Depending on the angle of application, clamp placement can affect the reduction of the syndesmosis. Although this is not evident on radiographic examination, it likely contributes to patient complaints of ankle stiffness with syndesmotic screw placement. In conclusion, both the clamp and screw reductions showed significant overcompression of the syndesmosis.