Ultrasonography as a reliable diagnostic tool in old quadriceps tendon ruptures: a prospective multicentre study.

Quadriceps tendon rupture is an uncommon injury. In the majority of cases, predispositions as recurrent microtrauma or degenerative changes are present. The diagnosis of acute quadriceps tendon ruptures can usually be made by clinical examination. Ultrasonography has been shown as a reliable, inexpensive and easily available diagnostic tool to confirm the diagnosis. In this study, we evaluated the clinical value of ultrasonography for establishing diagnosis of old quadriceps tendon ruptures. In the prospective time period of 6 years (01/1998-12/2003), the delayed diagnosis of quadriceps tendon rupture was established in six patients with seven cases of old ruptures (one bilateral rupture). The mean age was 50.2 (SD+/-16.9) years in one woman and five men. The mean interval from trauma until diagnosis was 15.2 (SD+/-7.1; range 8-24) weeks. In all cases, ultrasonography represented a reliable and sensitive tool for establishing diagnosis of old quadriceps tendon rupture. We therefore recommend the use of ultrasonography in the diagnostic work up of cases with knee trauma and potential involvement of tendon injuries.