Abstract:

Objective To compare the application value of CT and magnetic resonance imaging (MRI) in the postoperative evaluation of anterior cruciate ligament (ACL) reconstruction and to explore the clinical application of new imaging technologies. Methods Fifteen patients who underwent ACL reconstruction by the autologous tendon were scanned by spiral CT, routine MRI, and MR diffusion tensor imaging. The grafts and surrounding structures were observed and scored by two evaluation methods by one radiologist and one orthopedist. Results The bone tunnel, screw, and interface were clearly and directly displayed by CT curve planar reconstruction. The multiple planar reconstruction was helpful for displaying the contour of the graft and the osterophyte of the inter-condylar notch. The volume render technique could display the relationship of tunnel aperture and intercondylar eminence at any angle. MRI clearly displayed the fiber bundle of graft and provided quantitative data. Scores of the continuity and density/signal uniformity of graft and articular cavity and surrounding structure of CT were lower than those of MRI (P=0.001). Scores of the position of tunnel aperture, screw, shape of inter-condylar notch, and surrounding bone mineral density of CT were higher than those of MRI (P=0.001). The difference of scores of bone tunnel diameter measurements of CT and MRI was not statistically significant (P=0.102). Conclusion CT 3D reconstruction technology is better than MRI for observing the position of tunnel aperture, measuring the internal diameter of tunnel, and evaluating surrounding bone mineral density, while MRI is more sensitive to the shape and internal pathological changes of the graft. The postoperative evaluation of ACL reconstruction can be more straightforward and objective by CT and MRI.

Key words: anterior cruciate ligament, reconstruction, CT, magnetic resonance imaging, comparison