Daniel Kuo1, Alekos A. Theologis1,2, Radu I. Bolbos1, Julio Carballido-Gamio1, ChunBong Benjamin Ma3, Xiaojuan Li1
1Musculoskeletal Quantitative Imaging Research (MQIR), Department of Radiology, University of California, San Francisco, San Francisco, CA, USA; 2School of Medicine, University of California, San Francisco, San Francisco, CA, USA; 3Department of Orthopaedic Surgery, University of California, San Francisco, San Francisco, CA, USA
Patients with ACL injuries have a high risk of developing osteoarthritis (OA) despite ACL reconstruction. However, the mechanism of OA development in ACL-injured knees remains elusive. Nine ACL-injured patients were studied over 2 years to evaluate changes in bone marrow edema-like lesions (BMEL) and cartilage degeneration. Degenerative changes were evaluated using MR T1ρ relaxation time quantification and laminar analysis. Although BMEL resolved significantly over time, T1ρ values in BMEL-overlying cartilage were elevated at both baseline and follow-ups, suggesting irreversible damage in those regions. T1ρ values were also elevated in superficial layers of the weight-bearing cartilage sub-compartments of the medial knee.