MRI-based ACL graft maturity does not predict clinical and functional outcomes during the first year after ACL reconstruction.

PURPOSE: To determine whether magnetic resonance image (MRI)-based graft maturity predicts clinical and functional scores during the first year after ACL reconstruction.

METHODS: Patients with unilateral ACL reconstruction were prospectively invited to participate in this study, and they were examined using a 3.0-T MRI scan at 3, 6, and 12 months after the operation. Clinical examinations were performed on the same day, including subjective functional examinations, physical examinations and the KT-1000 test. MRI measurements were focused on the graft signal intensity of the ACL graft using the signal/noise quotient value from a region of interest analysis.

RESULTS: Finally, a total of 38 participants with ACL reconstruction were recruited for this study, including 21 with autograft tendons and 17 with allograft tendons. Generally, the signal/noise quotient values of the ACL grafts increased from 3 to 6 months and then decreased from 6 to 12 months. There was no significant association between graft signal/noise quotient value and IKDC, Lysholm, or Tegner scores at each time point. Graft signal/noise quotient value had a significant positive association with ATTD for the cohort (p = 0.002) and for the autograft group (p = 0.004) at 3 months. However, there was no significant association between graft signal/noise quotient value and ATTD at 6 or 12 months, respectively.

CONCLUSION: The MRI-based graft maturity does not have the ability to predict clinical and functional outcomes in patients at the first-year follow-up. Graft maturity should not be used as an objective test to determine the appropriate time to return to sports during the first year after ACL reconstruction. The results from this study will allow clinicians to determine graft-specific health to determine whether the graft is healed enough to return to sports during the first postoperative year.

LEVEL OF EVIDENCE: III.