Abstract
Magnetic resonance (MR) images of 40 knees with chronic anterior cruciate ligament (ACL) injuries were retrospectively evaluated. They were defined as chronic if symptoms persisted at the follow-up examination than 6 months after injury. The 15 men, and 25 women patients ranged in age from 16 to 49 years (mean, 30 years). The MR imaging features of the ACL in sagittal images were classified into three types by one orthopedist : continuous low intensity band (8%), non-continuous band (58%) and non-visualized (34%). Posterior cruciate ligament (PCL) buckling was observed in 11 knees (28%) and anterior shift of the tibia was observed in 11 knees (28%). Disrupted femoral attachment of the ACL was observed in 38 knees (95%) in coronal images. The MR images of the knee with chronic ACL injuries were very variable and may occasionally be difficult to distinguish from an intact ACL.
