The radiographic diagnosis of the anterior cruciate ligament deficient knee.

Various radiologic procedures are used in the evaluation of the cruciate deficient knee, including routine roentgenography, arthrography, and computed tomography (CT). Routine roentgenograms can document a joint effusion, an avulsion fracture with or without complete anterior cruciate ligament (ACL) description, and other osseous abnormalities, e.g., degenerative joint changes. Double-contrast arthrography can determine the integrity f the ACL. When correctly performed and carefully interpreted, more than 90% accuracy is possible in diagnosing if the ligament is present and intact, torn, or absent. The condition of the medial and lateral menisci, the articular cartilages, and the synovium can be evaluated by the same arthrographic study. In those instances in which the arthrographic diagnosis is equivocal of the ACL has been repaired or can not be examined arthrographically, the CT examination may be useful. Unfortunately, because the CT examination is expensive and correct interpretations are sometimes difficult, its use is accordingly limited.