Comparison of Ultrasound and MRI with Intraoperative Findings in the Diagnosis of Peroneal Tendinopathy, Tears, and Subluxation

CATEGORY: Ankle INTRODUCTION/PURPOSE: Suspected peroneal tendinopathy, tears, and subluxation are often confirmed using magnetic resonance imaging (MRI) or diagnostic ultrasound (US). The choice between these two imaging modalities is commonly based on surgeon preference as the accuracy of these tests for the diagnosis of peroneal tendinopathy, tears, and subluxation is not known. The purpose of this study was to compare MRI and US to the intraoperative findings in patients who underwent surgery for the treatment of suspected peroneal tendinopathy, tears, and subluxations to determine the diagnostic accuracy of each imaging modality. METHODS: The operative records and diagnostic images for 21 patients who underwent surgery for suspected peroneal tendinopathy, tears, or subluxation were retrospectively reviewed. Two fellowship trained musculoskeletal radiologists conducted a systematic blinded review of the stored MRI and US images. The results of this review were compared with the intraoperative findings to yield the sensitivity and specificity for each imaging modality. RESULTS: For the diagnosis of peroneus brevis tears, both MRI and ultrasound were equally good at detecting tears. In the diagnosis of peroneus brevis tears, MRI was marginally better with a sensitivity and specificity of 100% versus ultrasound, which had a sensitivity of 90% and specificity of 100%. In the diagnosis of peroneal subluxation, ultrasound had a sensitivity of 100% and a specificity of 100% compared to MRI, which had a sensitivity of 33% and specificity of 100%. CONCLUSION: In comparing MRI and US to intraoperative findings for the diagnosis of peroneal tendinosis, tears and subluxation, we found ultrasound to be more effective at diagnosing peroneal tendinopathy and subluxation, while MRI was found to be slightly more accurate in the diagnosis of peroneus brevis tendon tears. Both MRI and ultrasound were effective for the diagnosis of peroneus longus tears.