Medial opening-wedge high tibial osteotomy (MOHTO) is a tried-and-true joint preservation technique for medial compartment knee osteoarthritis with varus alignment. Multiple studies have shown good short- and medium-term Kaplan-Meier survival with MOHTO, but questions remain regarding potential factors that lead to deteriorating outcomes over time. One such question is whether the presence of medial tibial bone marrow edema (BME) in a varus-aligned knee prior to MOHTO might lead to worse outcomes or survival afterward.
In the December 2, 2020 issue of The Journal, Yang et al. investigated this question with a retrospective case series of 105 patients with preoperative BME on MRI who underwent MOHTO. The BME was reviewed and graded by 2 independent observers based on both the diameter of the lesion and the volume of the medial tibia affected. The researchers radiographically evaluated postoperative alignment correction and compared preoperative and postoperative patient-reported outcomes using the Hospital for Special Surgery (HSS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS), and Short Form-12 (SF-12).
At an average follow-up of 6.2 years, Yang et al. found significant improvements in all patient-reported outcomes—with no correlation between outcomes and the presence or extent of BME. Overall survival was 95.2% at 6.2 years, showing that the improvements were durable throughout the study period, despite the preoperative presence of BME.
Although it would have been helpful to have a comparison group to see whether there were any functional-outcome differences between patients with and without BME, this study shows that MOHTO is a reliable and effective treatment for patients with BME, at least up until 6 years. And certainly, as the authors assert in the final sentence, “Preoperative BME should not be considered a contraindication for MOHTO.”
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media