Increased Reduction Clamp Force Associated With Syndesmotic Overcompression.

BACKGROUND

The distal tibiofibular syndesmosis is disrupted in up to 45% of operatively treated ankle fractures, and syndesmotic malreduction has historically been correlated with poor outcome. The purpose of this study was to quantify the clamp force used during syndesmotic reduction and to evaluate the effect of clamp force on fibular overmedialization (overcompression) at the level of the distal tibiofibular syndesmosis.

METHODS

A prospectively recruited cohort of 21 patients underwent operative syndesmotic reduction and fixation. A ball point periarticular reduction forceps that was modified to include a load cell in one tine was used for the reduction, and the clamp force required for reduction was measured. Patients underwent postoperative bilateral computed tomographic scans of the ankle and hindfoot to assess syndesmotic reduction. The uninjured extremity was used as a control. Side-to-side differences in fibular medialization, translation, and rotation within the tibial incisura were measured. These findings were correlated with the reduction clamp force utilized to obtain the reduction.

RESULTS

Syndesmotic overcompression (fibular medialization greater than 1.0 mm when compared with noninjured ankle) was seen in 11 of 21 patients (52%). Increased clamp force significantly correlated with syndesmotic overcompression. The mean reduction clamp forces were 88 N for the undercompressed group, 130 N for the adequately compressed group, and 163 N for the overcompressed group.

CONCLUSION

This study demonstrated a significant correlation between increased clamp forces and syndesmotic overcompression, and determined objective forces that lead to overcompression. Our results indicate that surgeons should be cognizant of the clamp force used for syndesmotic reduction.

LEVEL OF EVIDENCE: Level III, case-control series, in accordance with STROBE guidelines.