Longitudinal Changes to Patellar Cartilage UTE-T2* After Anterior Cruciate Ligament Reconstruction Associate with Improved Knee Pain

Motivation: Clinical evidence of symptomatic benefit concurrent with deep knee cartilage compositional improvement following ACL reconstruction (ACLR) is lacking. Goal(s): To evaluate relationships between deep cartilage UTE-T2* changes and concurrent symptomatic changes following ACLR. Approach: UTE-T2* maps and patient reported outcomes were acquired at 7-weeks and again 2-years after ACLR in 48 patients. Smallest detectable UTE-T2* difference was calculated from test-retest UTE-T2* maps in 10 uninjured controls. Results: On average, UTE-T2* in deep femoral cartilage increased over 2 years following ACLR, and patients reported substantial symptomatic improvements over this time. Greater reductions in patellar cartilage UTE-T2* associated with greater improvements in patients' knee pain. Impact: UTE-T2* qMRI evaluation shows that longitudinal changes to deep knee cartilage composition associate with concurrent clinically meaningful improvements in patient reported knee pain following ACL reconstruction.