The Accuracy of Ultrasonographic Examination of Injured Posterior Cruciate Ligament

The purpose of this retrospective study was to define the accuracy of sonographic examination compared with magnetic resonance imaging (MRI) in detecting tears of the posterior cruciate ligament (PCL). Thirty-five patients with traumatic knee injuries fulfilling all the criteria were selected from 531 patients referred for sonographic examinations during 2003 to 2005 in the university hospital. The presence or absence of PCL injury was determined by MRI. Torn PCL was indicated when a PCL diameter (anterior-posterior dimension) greater than 10 mm, or a wavy or indistinct posterior PCL margin was found on sonographic examination. Among the 35 patients, 13 were found to have PCL tears on sonographic examination. Ten of these tears were also diagnosed by MRI. Two of 22 patients with normal PCL on sonographic examination were found to have PCL tears following MRI. There was significant agreement between MRI and sonography. We found that sonographic examination could accurately detect tears of the PCL and can be utilized as the first choice of imaging modality for patients with PCL injuries.