Evaluation of anterior cruciate ligament grafts with MRI

This study was performed to know whether or not anterior cruciate ligament (ACL) graft can be qualitatively evaluated by MRI. Subjects were 96 knees of 96 patients aging 23.4 y in a mean. Materials were autografts in 80 cases and allografts in the remainders. Reconstructive surgery was carried out arthroscopically. MRI was performed with GE Signa 1.5 T superconducting apparatus with T1-weighted conditions for the sagittal image of 3 mm thick slice at 1.5, 3, 6, 9, 12 and 24 months after surgery. Correlations of signal intensities of reconstructed ACL were examined with graft materials, stage of MRI after surgery, and knee laxity. MRI well imaged reconstructed ACL and was useful to evaluate the position of the graft, its thickness and tension. No difference of the images was found in ACL graft materials. Signal intensity of the brightness did not change definitely with time. Thus MRI was found to be inappropriate for evaluating quality or process of reconstructed ACL. (H.O.)