Chronic tibiofibular syndesmosis injury: the diagnostic efficiency of magnetic resonance imaging and comparative analysis of operative treatment.

Background: The purpose of this study was to determine the sensitivity and specificity of MRI in chronic syndesmosis injury by comparing the arthroscopic findings with MRI findings and to suggest therapeutic guidelines of syndesmotic fixation.
Methods: Between January, 2003, and January, 2004, 20 patients were diagnosed with chronic syndesmosis injury according to syndesmosis widening (>2 mm) on arthroscopic examination. The average age of the patients was 32 years. The minimum followup was 22 (22 to 30) months. MRI was obtained in all patients. For evaluating the therapeutic role of syndesmotic fixation, we separated the patients into two groups (with and without transfixation) and compared preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores and patient satisfaction.
Results: The sensitivity, specificity, and accuracy of MRI were 90.0%, 94.8%, and 93.4%, respectively. In group I with syndesmotic fixation, the AOFAS ankle-hindfoot scale improved from 52 to 87, and in group II without syndesmotic fixation the score improved from 63 to 90 at last followup, which showed no statistically significant difference (p = 0.6453). Also, patient satisfaction showed no difference between the two groups.
Conclusions: MRI showed high sensitivity, specificity, and accuracy under the criteria we proposed, and we recommend it as the main diagnostic tool for diagnosing a chronic syndesmosis injury. These findings might suggest that pain is mainly caused by hypertrophy and impingement of the soft tissue in the distal tibiofibular joint. Arthroscopic debridement alone can be recommended if the distal tibiofibular chronic syndesmosis injury is not combined with medial ankle instability and lateral displacement of the talus.