Double-contrast CT arthrography of the cruciate ligaments

The value of computed tomography (CT) in evaluating the cruciate ligaments was assessed by studying an amputated knee in order to find the most suitable position for detecting minimal defects of the ligaments. The anterior cruciate ligament (ACL) or the posterior cruciate ligament (PCL), or both, of 60 patients (61 knees) were then examined by CT and the findings were compared with those of arthroscopy. Defects 3 mm in length were shown by CT. A sufficient quantity of air and an adequate amount of positive contrast medium were required to obtain an accurate picture of the ligaments. For the ACL, the sensitivity of CT was 96.6%, specificity was 95.5%, and accuracy was 96.1%. For the PCL, sensitivity was 78.6%, specificity was 91.7%, and accuracy was 84.6%. Ruptures of the cruciate ligaments shown by CT were classified into four types. Their CT images coincided significantly with their arthroscopic findings. This study shows double-contrast CT arthrography to be a valuable method for evaluating the cruciate ligaments, and especially the ACL. (author)