Relationships Among Bone Marrow Lesions, Cartilage Improvement, and Short- to Midterm Patient-Reported Outcomes After Opening-Wedge High Tibial Osteotomy

Background: Bone marrow lesions (BMLs) are associated with knee pain and predict structural changes and joint replacement. Their significance in the context of opening-wedge high tibial osteotomy (OWHTO) is, however, unclear. Purpose: To investigate whether preoperative BMLs are associated with cartilage regeneration-like tissue and postoperative patient-reported outcomes after OWHTO and to evaluate how 1-year changes in BMLs (ΔBML) relate to these outcomes. Study Design: Cohort study: Level of evidence, 3. Methods: In this retrospective study, 138 knees underwent arthroscopy during OWHTO, and 85 knees underwent follow-up arthroscopy. Participants also completed questionnaires and underwent magnetic resonance imaging (MRI). Cartilage status at the medial femoral condyle (MFC) and medial tibial plateau (MTP) was evaluated using the International Cartilage Research Society (ICRS) grading system during initial and follow-up arthroscopies to assess improvement after OWHTO. Postoperative outcomes were assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS). BMLs were scored according to the MRI Osteoarthritis Knee Score, and ΔBML was calculated. Results: = .045). Conclusion: Smaller preoperative BMLs were associated with greater postoperative cartilage improvement in MTP after OWHTO. Furthermore, BML improvement was significantly related to better knee symptoms in short- to midterm patient-reported outcomes after OWHTO.