An MRI Analysis of the Site of Acute Achilles Tendon Rupture: Is the Most Common Site 2–6 Cm from the Calcaneal Insertion?

CATEGORY: Sports, Ankle INTRODUCTION/PURPOSE: No previous study has performed a quantitative analysis of the site of acute Achilles tendon rupture. The purpose of this study was to investigate the site of acute Achilles tendon rupture via magnetic resonance imaging (MRI). METHODS: The medical records and MRIs of 201 patients with acute Achilles tendon rupture were retrospectively reviewed. The rupture site was measured as the distance from the calcaneal insertion of the Achilles tendon to the proximal end of the distal stump. The relationship between the site of the rupture and patient demographics was analyzed, and the intra- and interobserver reliability scores of the measurements were assessed using intraclass correlation coefficients. RESULTS: The rupture site had a mean size of 6.1 cm with a standard deviation of 1.6. The median was 6.3 cm, and the range of the 10th–90th percentile was 5.0–8.1 cm. There was no significant difference in rupture site according to patient demographics. All of the intra- and interobserver reliability scores of the measurements of the rupture site were excellent. CONCLUSION: Most acute Achilles tendon ruptures that were visible on MRI occurred 5–8 cm above the calcaneal insertion, which is greater than the previously reported 2–6 cm location.