MRI FOLLOW-UP EXAMINATION OF THE KNEE AFT ER RECONSTRUCTION OF THE ANTERIOR CRUCIATE LIGAMENT WITH AN AUTOLOGOUS TENDON GRAFT

In a prospective study, 153 MRI examinations were performed on 74 pati ents following reconstruction of a ruptured anterior cruciate ligament with a semitendinous graft. MRI examinations were performed at three defined intervals (3 months, 4 to 12 months, and 1 to 2 years postoper atively), and the findings were compared to simultaneous clinical test s to define stability criteria. This permitted reliable assessment of the integrity of the ligament graft; in three cases we correctly diagn osed a ruptured graft. A well defined tendon graft with recognizable f ibrous structures correlated with a clinically stable ligament in 98 % of the cases. Due to physiological transformation occurring from thre e months to one year postoperatively, that graft temporarily appears l ess distinct. Complete integration of the graft with full stability of the knee is visualized in the MRI scan as a tendon with low signal in tensity. Postoperative complications and the desire to participate in sports activities are indications for MRI examination.