Diagnosing AITFL Injuries in Patients with Lateral Ankle Ligament Injuries: The Utility of MRI and Physical Exam

Research Type: Level 4 – Case series Introduction/Purpose: Diagnosis of syndesmotic injuries is notoriously difficult in the setting of lateral ankle ligament injury. In this study, consecutive patients that underwent isolated lateral ankle ligament repair were included to assess whether MRI interpretation by radiologists or foot and ankle surgeons and physical exam were predictive of AITFL injury. Methods: Patients that underwent lateral ankle ligament reconstruction and had a preoperative MRI were retrospectively included in this study. A 2.5mm or 3.0mm probe was used to assess the integrity of the AITFL with injury noted if the probe passed through the ligament; the AITFL was repaired if probe test was positive. MRI images were assessed by a fellowship-trained foot and ankle surgeon and a radiologist for impression of AITFL injury. Squeeze test was also recorded preoperatively as an indicator of AITFL injury. Results: Forty-eight patients with recalcitrant lateral ankle pain were assessed with preoperative MRI. Each patient underwent lateral ankle ligament reconstruction and ankle arthroscopy. Median time to surgery from injury was 238 days. Thirty-one patients were found to have an AITFL tear during arthroscopy. Thirteen patients (27%) had MRI reports with radiology noting AITFL injuries whereas 39 patients (81%) were suspected to have AITFL injuries based on an orthopedic surgeon’s interpretation. Squeeze test was positive in 83% of patients. Of the 31 patients with AITFL tears diagnosed on arthroscopy, 27 (87%) had MRI interpretations by orthopedic surgeons that were suspected to be positive versus 11 (35%) that had a diagnosis by a radiologist. Squeeze test was positive in 74% of patients. Conclusion: In this study, the correlation between positive arthroscopic evidence of AITFL tear and orthopedic surgeon’s MRI interpretation was high compared to radiologist report. This highlights the need for independent image interpretation in those with recalcitrant pain after suspected lateral ankle ligament sprain to avoid a missed AITFL injury.