Increased signal intensity within the anteromedial or posterolateral bundles of a double-bundle ACL reconstruction is frequently associated with a partial tear, noted the researchers from Minia University.
"MRI can evaluate the integrity of the graft as regarding its continuity and detect any other complications such as impingement, arthrofibrosis, tear, ganglion cyst, etc.," said lead study author Dr. Mohammed Amin, an assistant professor of radiology. The modality "helps in preoperative planning, if necessary."
In the study, 45 patients underwent double-bundle ACL reconstruction on one knee between June 2008 and May 2011. All 45 patients subsequently received a postoperative MRI exam at a mean of 26 months after reconstruction to assess graft integrity and signal intensity. Only 10 of the 45 patients were symptomatic.
Partial tears of the anteromedial graft were discovered in four patients, and partial tears of the posterolateral graft were seen in six patients. Complete tears of the anteromedial graft were evident in three patients, and complete tears of the posteromedial graft were seen in five. Both grafts were completely torn in three individuals.
Signal intensity within the grafts was increased in four patients (80%) with a partial tear of the anteromedial graft, and it was increased in 12 patients (30%) with an intact anteromedial graft. Signal intensity was also increased in six patients (80%) with a partial rupture of the posterolateral graft and in 12 patients (41%) with an intact posterolateral graft.
Amin and colleagues plan to continue their research with dynamic MRI to correlate findings with arthroscopy and/or surgery.