ABSTRACT
The purpose of this study was to analyse the magnetic resonance (MR) appearance of the patellar tendon autograft for anterior cruciate ligament injury. Among 35 patients of ACL reconstructions with central 1/3 of the patellar tendon autograft and interference screw fixation, 13 patients underwent MRI examination. All examination were performed on 1.5 T magnet(Signa;GE medical system). T1WI, PDI, T2WI Sagittal and coronal images were obtained together with T2WI MPGR and oblique sagittal images. A four-level grading system based on the MR appearance of the ACL graft was developed. A grade I was indiscernible in graft course, Grade II; incomplete in its course, grade III; complete but thin and grade IV; complete and thick. 2 out of 13 patients showed grade I, 3; grade II, 4; grade III and 4 grade IV. Five patients of grade I and II had a finding of roof impingement. However, only one out of 8 grade III and IV revealed such finding. In summary reconstructed ACL had various appearance in MRI, which was considered to be closely related with roof impingement.