Can MRI predict return to sport after anterior cruciate ligament reconstruction? A systematic review of the literature

Purpose: To analyze whether magnetic resonance imaging (MRI) can predict return to sport after anterior cruciate ligament (ACL) reconstruction and whether a correlation exists between return to sports, level of activity and MRI signals. Methods: The search terms selected for inclusion in the title, abstract, and keyword fields were as follows: 'anterior cruciate ligament' OR 'ACL' AND 'graft maturation' OR 'MRI' AND 'return to sport' OR 'sports activity.' For each study, patient data and the MRI protocol used to assess graft maturation were extracted. An analysis of the correlations between MRI and ACL reconstruction was performed. Results: A total of 394 patients were included from 7 studies. The mean radiological follow-up was 19.06 ± 11.02 months. Three studies reported no correlations between graft bending angle, signal/noise ratio, signal intensity or Howell score and return to sport. One study revealed that T2* was correlated with return to sport. A further investigation demonstrated that those who were able to regain their preinjury athletic performance exhibited considerably lower ACL/PCL ratio and ACL/muscle ratio of the ACL mid-substance compared to those who were unable to attain the same level of athletic performance. Only one study reported correlations between 12-month SNRs and 60-month Cincinnati, Lysholm and Tegner activity scales, whereas Biercevicz revealed that the combination of volume and the SI predicted the KOOS score at the 5-year follow-up. Conclusions: There are no reliable radiological parameters available that correlate with return to sport after anterior cruciate ligament reconstruction, but MRI can potentially play a key role in closing this gap. Level of evidence: Systematic review of level IV. Study registration: PROSPERO-CRD42024574365.