Many surgeons and orthopaedic references recommend that fixation
of a disrupted distal tibiofibular syndesmosis be performed with
the ankle in dorsiflexion to avoid overtightening and subsequent restriction
of ankle dorsiflexion. This recommendation is based in large part
on one cadaveric study without clinical correlation. The purpose
of the present study was to examine whether overtightening of the
syndesmosis limits maximal ankle dorsiflexion.
Nineteen cadaveric ankles were used for the study. Each ankle
was tested for the initial range of motion after release of the
Achilles tendon proximal to the ankle joint. All capsular and ligamentous structures
remained intact. Kirschner wires were placed in the tibia and talus.
The angle between the wires with the ankle maximally dorsiflexed
was measured before and after syndesmotic compression. Syndesmotic
compression was achieved with a 4.5-mm lag screw with the ankle
in plantar flexion.
There was no difference between the values for maximal dorsiflexion
before and after syndesmotic compression.
Syndesmotic compression in and of itself does not diminish ankle
dorsiflexion in a cadaveric model.
Maximal dorsiflexion of the ankle during syndesmotic fixation
is not required in order to avoid loss of dorsiflexion. It is likely
that the most important aspect of syndesmotic fixation is anatomic
reduction of the syndesmosis and that the degree of ankle dorsiflexion
during fixation is not important.