Anterior cruciate ligament injury: post-traumatic bone marrow oedema correlates with long-term prognosis

Giuseppe Filardo1, Elizaveta Kon2, Francesco Tentoni1

  • 1II Orthopaedic and Traumatologic Clinic-Biomechanics and Technology Innovation Laboratory, Rizzoli Orthopaedic Institute, Via Di Barbiano, 1/10, 40136, Bologna, Italy.

Abstract

Insights

Bone marrow oedema (BME) in the knee is common after anterior cruciate ligament (ACL) injury and decreases over time. Persistent BME, however, negatively impacts clinical outcomes and return to sport, even after ACL reconstruction.

Area of Science:

  • Orthopedic surgery
  • Sports medicine
  • Radiology

Background:

  • Bone marrow oedema (BME) is frequently observed in acute anterior cruciate ligament (ACL) injuries.
  • BME's impact on clinical outcomes and return to sport following ACL injury requires further elucidation.

Purpose of the Study:

  • To evaluate the significance of BME, detected via MRI, in relation to clinical outcomes and return to sport in patients with ACL injury.
  • To assess the correlation between BME characteristics (extension, hyperintensity, area) and patient recovery.

Main Methods:

  • Analysis of 134 patients with ACL tear and MRI scans within six months of trauma.
  • Evaluation of BME presence, extension, hyperintensity, WORMS score, and area on MRI.
  • Clinical outcomes assessed using IKDC subjective score and Tegner score at a minimum five-year follow-up.

Main Results:

  • BME was present in 55.2% of knees, with a mean area of 523 mm².
  • BME decreased over time, detectable in only 25% of MRIs >3 months post-trauma.
  • No patients with BME after three months returned to their previous sport level, compared to 54% without BME.
  • BME area correlated negatively with return to sport after ACL reconstruction (p=0.038).

Conclusions:

  • BME is a common finding post-ACL injury that diminishes over time.
  • Persistent BME correlates with poorer clinical prognosis and reduced return to sport.
  • Increased BME area is a negative predictor for successful outcomes in sport-active patients undergoing ACL reconstruction.