Ultrasonography: an imaging modality enabling the diagnosis of bipartite patella

Ultrasound was used to diagnose bipartite patella in seven adolescents with anterior knee pain, and the findings were compared to those from plain rad iography and to those of a group of asymptomatic subjects. In all affected individuals the quadriceps and patellar tendons appeared normal on ultrasou nd. Sonographic examination of the patella demonstrated an irregularity of the bony contour with occurrence of a cleft between the main part of the pa tellar body and the large superolateral accessory ossicle. The signal detec ted in the interface between bones was less echogenic than bone reflecting its fibrocartilaginous nature. The correlation with conventional radiograph y was absolute, as was the inter- and intraobserver reliability. Ultrasound is thus proposed as a simple and reliable imaging modality in bipartite pa tella. We do not believe that it should replace the initial radiographic, b ut it can be used to evaluate the contralateral. knee for bilaterality and as an adjunct to therapeutic procedures such as local injections to increas e the accuracy of treatment.