The functional consequence of syndesmotic joint malreduction at a minimum 2-year follow-up.

OBJECTIVE:
To examine the correlation between syndesmotic malreduction and functional outcome.

DESIGN:
Prospective evaluation of bilateral computed tomography scans and functional outcome scores.

SETTING:
Level I regional trauma center.

MATERIALS AND METHODS:
From January 1, 2004, to December 31, 2006, 107 of 681 operatively treated ankle fractures (15.7%) had associated syndesmotic injuries requiring reduction and fixation. All patients available at a minimum of 2 years postindex procedure underwent clinical and radiographic examination, computed tomographic (CT) scanning of both ankles (injured and uninjured), and functional outcome scoring using the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires.

RESULTS:
Sixty-eight of 107 (63.5%) syndesmotic injuries in 68 patients were available for follow-up. Twenty-seven (39%) were malreduced (rotational or translational asymmetry) when compared with the contralateral uninjured syndesmotic joint. Fifteen percent of the open syndesmotic reductions were malreduced on postoperative CT scans, whereas 44% (A/B) of the closed syndesmotic reductions were malreduced on postoperative CT scan (P = 0.11). Patients with a malreduced syndesmosis recorded significantly worse functional outcome scores (P < 0.05) on both the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires when compared with those patients whose syndesmosis had healed in anatomic alignment.

CONCLUSIONS:
At a minimum of 2 years follow-up, patients with malreduced syndesmotic injuries demonstrated significantly worse functional outcome using the Short Form Musculoskeletal Assessment and Olerud/Molander questionnaires. Open reduction of the syndesmosis resulted in a substantially lower rate of malreduction when evaluated by postoperative CT scan. Based on these findings, we recommend that surgeons not only perform a direct, open visualization of the syndesmosis during the reduction maneuver, but obtain a postoperative CT scan with comparison to the contralateral extremity as well. If the syndesmosis is found to be malreduced, consideration must be given to revising the osteosynthesis.

LEVEL OF EVIDENCE:
Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.