Overtightening of the ankle syndesmosis: is it really possible?

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.