MRI OF ANTERIOR CRUCIATE LIGAMENT HEALING

Objective: The purpose of this study was to evaluate using MRI the nat ural healing of the anterior cruciate ligament (ACL) when treated cons ervatively by early protective motion. Materials and Methods: Consecut ive acute complete intraligamentous ruptures of the ACL in 50 cases th at were allowed to heal without surgery were evaluated before and afte r 3 month treatment by MRI, arthroscopy, and stress radiographs. Twent y-nine of the 50 patients were also reevaluated 11 months from the ini tial injury, of which 7 were reevaluated again 24 months from the init ial injury by MRI. The MR appearance of the treated ACL was categorize d into four grades depending on homogeneity, straight band, and size. Results: MR assessment of the ACL after 3 month treatment demonstrated a well defined normal-sized straight band in 37 cases (74%). There wa s a significant relationship between the 3 and 11 month MR evaluations (r(s) = 0.801, p < 0.0001). There were also significant relationships between the MR and arthroscopic evaluations (r(s) = 0.455, p < 0.005) and between the MR and stress radiographic evaluations (r(s) = 0.348, p < 0.025) after the 3 month treatment. Conclusion: MRI can demonstra te ACL healing when treated conservatively with early protective mobil ization.