Can MR appearance performed a few days after injury predict the morphological recovery of the anterior cruciate ligament treated by early protective motion?

The aim of this study was to determine whether early MRI after anterior cruciate ligament (ACL) injury can predict the morphological recovery of the torn ACL treated by early protective motion. Consecutive acute ruptures of the ACL in 35 patients (mean age; 27.2 years) who were allowed to be healed without surgery were evaluated by repeated MRI. MR images were compared for a few days after injury (initial MRI), approximately one month after treatment (second MRI), and at an average follow-up of 8.5 months (follow-up MRI). The average time from injury to the initial MRI was 7.3 days. The initial MR appearance of the torn ligament was classified into five types of visualized ligament contours. The emergence of restoration signs such as straight band and/or verticalization was examined in the second MRI. The follow-up MR appearance of the treated ACL was categorized into four grades depending on homogeneity, straight band, and size. Relationships between the initial MRI and the follow-up MRI, the restoration signs on the second MRI and the follow-up MRI were analyzed using the Spearman rank correlation coefficient. As a result, the contour of the initial MRI was found to correlate with morphological recovery on the follow-up MRI (rs=0.565, p<0.001). There was no correlation between the emergence of restoration signs on the second MRI and morphological recovery on the follow-up MRI. (author)