Sonography of the Patellar Tendon and Adjacent Structures in Pediatric and Adult Patients

Abstract

1535 he patellar tendon and its adjacent soft tissue and bony structures may be affected by a number of conditions, most of which are thought to be related to trauma. The patellar tendon is readily seen on sonography because of its superficial location. Patellar tendon abnormalities have been given a number of different labels with a confusing overlap in terminology. This pictorial essay illustrates both normal and abnormal appearances of the patellar tendon on sonography and describes the more common conditions affecting it. Sonographic Technique The patellar tendon is readily examined on sonography with high-frequency linear array transducers. Transducers up to 20 MHz are now available and may be desirable to achieve high spatial resolution. However, acoustic penetration may be limited, and these transducers are expensive and not widely available. In practice, excellent patellar tendon sonography can be performed with 7to 10-MHz transducers. The knee is examined in a flexed or semiflexed position, and comparison may be made with the contralateral side. Longitudinal and transverse images of the tendon are obtained with electronic focusing at the appropriate depth [1]. An acoustic standoff pad can be used to help visualize more superficial structures in greater detail and can also facilitate direct palpation during real-time scanning. Power Doppler sonography can be used to examine for increased tissue blood flow associated with patellar tendon abnormality [2].