Postoperative Bone Marrow Lesions (BMLs) are Associated with Pain Severity in Patients Undergoing Open Wedge High Tibial Osteotomy (OWHTO)

Abstract

Background: The purpose of the study was to investigate the relationship between postoperative bone marrow lesions (BMLs) and pain severity in patients undergoing open wedge high tibial osteotomy (OWHTO). Methods: We retrospectively reviewed the patients undergoing OWHTO between April 2018 and April 2020. The demographic and clinical data of patients were collected. Clinically, VAS and Knee injury and Osteoarthritis Outcome Score (KOOS) were used to assess pain level and functional outcomes of patients. Histologically, The MRI Osteoarthritis Knee Score (MOAKS) was used to assess semi-quantitatively the total BMLs size in medial tibiofemoral (MTF), lateral tibiofemoral (LTF), and patellofemoral (PF) joints. Results: 98 patients were enrolled in the study, including 57 male and 41 female patients. The VAS scores improved significantly from 6.1 ± 0.8 to 1.5 ± 0.9 (p < 0.001), and all subscales of KOOS improved significantly after surgery (p < 0.001). There were no significant difference between the pre-and postoperative total BMLs size in PF and LTF joints (p > 0.05). We observed significant improvements in the total BMLs size of MTF joint (p < 0.001). All patients had preoperative MTF joint BMLs, in contrast, 13 patients had no postoperative MTF joint BMLs. The independent sample t-test showed that the VAS scores and KOOS pain scores improved better in patients without postoperative MTF joint BMLs (p < 0.001). Pearson correlations showed that postoperative MTF joint BMLs were correlated with postoperative VAS (p < 0.001) and KOOS pain (p < 0.001). Conclusion: Our study demonstrates that MTF joint BMLs improved significantly after OWTHO. We confirmed that the presence of postoperative MTF joint BMLs are strongly associated with pain severity, the greater the improvement in postoperative MTF joint BMLs, the less pain. Our findings provide valuable understandings of OWHTO in the treatment of Knee osteoarthritis (KOA), and potential future directions for KOA treatment approaches.