[Diagnosis of calcification of the patellar tendon. Echo-radiographic comparison]

Real-time sonography was compared to low-kilovoltage radiographs in the diagnosis of intra-tendinous calcifications in 10 patients with chronic patellar tendonitis. In these patients sonography demonstrated thickening (100% of cases) and hypoechogenicity (90% of cases) of the patellar tendon. Ultrasound disclosed all calcifications displayed on radiographs showing hyperechoic foci. The associated acoustic shadow was absent in one case of a calcification less than one millimeter in diameter. Real-time ultrasound appears highly reliable in the diagnosis of even minute intra-tendinous calcifications. It also provides an accurate three-dimensional localization of the calcific deposits in the tendons.