Abstract
Introduction
It is recommended that the ankle be held in dorsiflexion at the time of placement of syndesmosis screw. We assessed the validity of this recommendation.
Materials and methods
A two-part roentgenographic and computerised analysis of distal tibiofibular syndesmosis. The first part involved recruitment of 30 healthy adult volunteers. The second part involved 15 ankle fractures with syndesmotic injury requiring syndesmosis screw placement. In the first part individuals maximally dorsiflexed and plantarflexed their ankles in a specialised jig for standardisation. Mortice views were taken and intermalleolar distance measured. In the second part mortice views were taken in plantarflexion and dorsiflexion before and after the placement of syndesmosis screw in theatre. The intermalleolar distance was then measured.
Results
In both parts of the study we found the change in intermalleolar distance between the positions of plantarflexion and dorsiflexion was not more than 0.9 mm. This change is significantly less than the calculated difference between the anterior and posterior talar body width of 3-5 mm.
Conclusion
This study shows that the width of ankle mortice is independent of the position of the talus occupying it and hence dorsiflexion of the ankle at the time of syndesmosis screw placement is totally unwarranted.
