“Leave the Subchondral Bone Alone: It Is the Cartilage Stupid!”
Dr. Yanke: Thank you. First of all, Peter, you and I have a similar amount of clinical experience. You have 35 years, while I have three to five years…but I have been very busy. This is a joint issue, Peter.
If this patient had significant varus-associated pain, then I certainly would take the high tibial osteotomy (HTO) approach. However, I’m going in a different direction here: bone marrow lesions can play a role but they’re just not the only thing that matters.
When you have large cartilage loss and a Kellgren-Lawrence grade 3 or greater, then I would not advocate for a cartilage procedure in this patient—nor would I recommend a subchondroplasty. I would try to mitigate her symptoms as much as possible in order to obtain a functionally asymptomatic X-ray or MRI.
While you can’t make a clinical decision based solely on X-rays, we must also take care not to make such judgements on an MRI alone. So, this could be an example of what this patient could look like where she has some joint space left. An HTO would work just fine—forget injecting something into the bone marrow edema.
Just remember, Peter, that the bone marrow lesions on a tibia will have a degenerative meniscus tear as well as early cartilage damage. It is imperative that both of these issues are addressed.
This young and active patient—a 43-year-old rock climber—is similar to the asymptomatic NBA players I treat in Chicago. We find that on their MRIs, 7% have a focal cartilage defect, 25% have a subchondral bone marrow lesion, and almost half of them have some cartilage abnormality. Overall, only 18% of people have asymptomatic normal MRIs.
There are two unseemly possibilities here. First, as physicians we don’t want BARF (Brainless Application of Radiologic Findings). And for patients, we don’t want a VOMIT situation (Victim of Modern Imaging Technology).
So, we have to definitively determine if this is clinically relevant for the patient or if it’s just something we see on the scan, but don’t have to worry about.
We know that there are many more contributors to pain than just the cartilage surface or the subchondral bone. And as we delve into these, we see that they actually play a much bigger role than some of the other structural aspects that we have focused on in the past.
