Morphologic Changes Occur Over First Two Years Post-ACL Injury
Cartilage thinning seen in trochlea of femur, thickening in central medial aspect of femur
TUESDAY, June 28 (HealthDay News) -- Significant changes are seen in cartilage thickness two years after acute injury of the anterior cruciate ligament (ACL), and these changes are associated with age at the time of injury, according to research published in the June 15 issue of The Journal of Bone & Joint Surgery.
Richard B. Frobell, Ph.D., from Lund University Hospital in Sweden, used magnetic resonance imaging (MRI) to evaluate the two-year changes in cartilage thickness, bone marrow lesions, and joint fluid of knees in 61 individuals with acute ACL injury treated surgically or nonsurgically. MRI was conducted at baseline, and at three, six, 12, and 24 months following the injury. All patients were treated with rehabilitation; 34 received early ACL reconstruction (average of 44.5 days after injury) and 11 received delayed ACL reconstruction (408 days after injury).
The investigators found that significant cartilage thinning occurred in the trochlea of the femur, and significant cartilage thickening occurred in the central medial aspect of the femur after 24 months. Older age at injury was associated with cartilage thinning, and younger age with cartilage thickening. Treatment of the torn ACL, activity level, and osteochondral fracture at baseline did not affect these changes. Most post-traumatic bone lesions of the tibia and femur resolved completely, but 30 new lesions developed in the lateral aspect of 21 knees over two years.
"Significant cartilage thickening occurs in the central medial aspect of the femur two years after an acute ACL injury and that significant cartilage thinning occurs in the femoral trochlea. Older age at the time of injury and male sex were found to be independent risk factors for these changes," the authors write.