Magnetic resonance imaging of reconstructed anterior cruciate ligament

After anterior cruciate ligament reconstruction with autologous patellar te ndon, 23 patients who had clinically stable knees were studied prospectivel y with sequential magnetic resonance imaging 1, 2, 3, 6, and 12 months afte r surgery. The images of the anterior cruciate ligament were obtained with a 1.5 tesla magnetic resonance scanner in the oblique sagittal, coronal, an d oblique axial planes. The cross-sectional area and signal intensity on th e reconstructed anterior cruciate ligament were measured in an oblique axia l image. The usefulness of the oblique axial image in evaluating the integr ity of the reconstructed anterior cruciate ligament was seen. The result sh owed that the diameter of the graft increased by 70% of its initial size an d the signal intensity of the reconstructed graft also showed a tendency to increase. In three patients, there was discontinuity in the graft directio n on the oblique sagittal image, but on the oblique axial image there was n o evidence of reconstructed anterior cruciate ligament rupture in the seque ntial images. This shows the value of the oblique axial image in evaluating the integrity of the reconstructed anterior cruciate ligament. Also, suffi cient notchplasty in anterior cruciate ligament reconstruction may be neede d to prevent graft impingement.