Anterior cruciate ligament reconstruction: the diagnostic value of MRI.

A prospective study was carried out in order to evaluate the predictive value of MRI in the early postoperative course after cruciate ligament replacement. Twenty patients who had undergone anterior cruciate ligament reconstruction using autologous patellar tendon/bone grafts were examined clinically and with contrast enhanced MRI at 2, 12 and 24 weeks, and 1 and 2 years after operation. The clinical findings were evaluated according to the scores established by Lysholm, OAK and IKDC. The MRI scans (SP 63, 1.5 Tesla) were assessed in terms of the quality and signal intensity of the reconstructed ligaments. During the first postoperative year there was a significant increase of signal intensity and in homogeneity of the neoligament on in the MRI. Seventeen patients had an average value for signal/noise of 1.1 at two weeks after surgery, which had increased to 7.1 at 1 year. In 14 patients the reconstructed ligament could not be evaluated in MRI scans after 1 year but clinical instability was not suspected in any of these patients. Two years after operation the MRI signal, intensity of the neoligament was again decreasing.