Ultrasound and MRI in the assessment of Achilles tendon rupture: are both necessary?

Background: This prospective observational study aims to evaluate the accuracy of ultrasound, compared with MRI, in assessing the ATr features, to safely plan the surgical treatment. Material and Methods: Patients surgically managed at our Institution for ATr were prospectively recruited. All the patients underwent clinical examination, ultrasound and MRI. These examinations were performed in a blind manner by different authors, who were unaware of the results of the complementary imaging technique. Results: 34 patients (32 males; 2 females; mean age: 47) were included in the present study. Both ultrasound and MRI showed no significant differences, compared with intraoperative measurement, in assessing the gap between the two stumps (MRI: p=0.13; US: p=0.26) and the distance between the ATr and the tendon calcaneal insertion (MRI: p = 0.23; US: p = 0.51). All the partial Achilles tendon ruptures intraoperatively identified, 4 out of 34 (11.76%), were correctly classified in ultrasound, whereas one ATr classified as partial on MRI appeared intraoperatively complete. Conclusions: The present study showsultrasound, when performed by an experienced sonographer, is accurate in defining the main features of acute Achilles tendon rupture. Hence, this cheap imaging technique is useful in decision making and to plan the surgical management of the tendon injury.