['With the use of surgical findings as the reference standard, the purpose of this study was to describe the sonographic findings of partial-thickness and complete tears of the quadriceps tendon and to determine whether sonography can potentially aid diagnosis.', 'Three hundred eighty-nine consecutive sonographic reports (January 1996 to April 2001) of the knee/quadriceps tendon were reviewed retrospectively and assessed for subsequent surgery on the quadriceps tendon. Seven cases were thus identified. Findings at surgery (complete versus partial tears) were compared with the original sonography reports.', 'All 4 partial tears and 1 of 2 complete tears were diagnosed correctly on the basis of sonography. One complete tear was described as a partial tear on the basis of sonography. In a seventh case, complete disruption of the extensor mechanism with osseous avulsion of the superior pole of the patella was identified correctly. Dynamic scanning was essential in diagnosing a partial quadriceps tendon tear in 1 case.'] Do sonography of partial-thickness quadriceps tendon tears with surgical correlation?