Postoperative Decrease in Bone Marrow Lesion Associated With Better Clinical Outcomes Following Medial Open-Wedge High Tibial Osteotomy

Abstract

PurposeThe aim of the current study was to assess serial changes of preoperative bone marrow lesion(BML) following medial open-wedge high tibial osteotomy(MOWHTO) up to 2 years and evaluate whether postoperative change of BML affected patient-reported outcome measures(PROMs) till the 2 years follow-up. Factors related to the postoperative changes in BML were also evaluated. MethodsCurrent study retrospectively assessed prospectively collected data of consecutive patients between December 2016 and March 2018 who underwent MOWHTO for symptomatic knee osteoarthritis with varus malalignment(≥5°) and minimum 2-year follow-up. Serial MRIs at preoperative and postoperative 3, 6, 18, and 24 months were performed and the extent of BML was evaluated consecutively using two validated methods. Clinically, preoperative and postoperative PROMs and their achievement of minimal clinically important difference(MCID) values were evaluated. The associations of the extent of BMLs with PROMs at each follow-up period over time were analyzed using a linear mixed model. Furthermore, factors related to the postoperative changes of BML were assessed. ResultsOf 26 patients, 21(80.8%) had preoperative BML at medial femoral and tibial condyles. The postoperative decrease in BML was noted in 17(81.0%) and 18(85.7%) at medial femoral and tibial condyles. The BML decreased at postoperative 3 months and thereafter, the extent of BML gradually reduced until postoperative 24 months. The proportion of patients achieved MCID was 84.6% for total WOMAC scores and 80.8%, 76.9%, and 84.6% for KOOS symptom, pain, and activity of daily living subscales. Postoperative decrease in BML was significantly associated with better PROMs over postoperative 24 months. Furthermore, normo-correction(2°–5° valgus) was a significant factor for decreased BML following MOWHTO. ConclusionPreoperative BML gradually decreased with time following MOWHTO, and the postoperative decrease in BML related with better PROMs over postoperative 24 months. Moreover, postoperative valgus alignment was a significant factor relating the postoperative decrease of BML.