Magnetic resonance evaluation of anterior cruciate ligament repair using the patellar tendon double bone block technique.

The magnetic resonance (MR) appearance of the anterior cruciate ligament reconstruction was determined in 20 clinically stable and 2 clinically unstable knees for a total of 22 examinations. All patients studied had undergone knee reconstruction using the patellar tendon as graft material. The reconstructed anterior cruciate ligament varies in appearance. It appeared as a thick, well-defined, low signal band on T1- and T2-weighted sagittal and coronal images in 14 of 22 examinations. The remaining 8 knees showed a graft having one or more thin and attenuated, low signal intensity bands in the sagittal and/or coronal plane. In 3 of these cases, the grafts appeared thicker in the coronal plane. All cases, including the two clinically unstable knees, showed no break in graft continuity. Arthroscopy confirmed an intact but lax graft in the clinically unstable knees.