Knee Bone Marrow Lesions: Do You Have BMLs on Your Knee MRI?

This morning I have some interesting MRIs from a patient who was treated down at Regenexx Cayman with the Regenexx-C procedure. They nicely show the concept of  Knee Bone Marrow Lesions or BML.

What is a Bone Marrow Lesion?

No single knee MRI finding over the past 5 years has been associated with pain more than a BML. We used to believe that meniscus tears were sure signs of knee pain, then research dispelled that myth. We also used to believe that the degree of arthritis was associated with pain (i.e. more arthritis equals more pain), then research dispelled that myth as well. One of the few MRI findings that has withstood the test of time and many different research studies as being related to pain is the BML. What is it? Knee Bone Marrow Lesions, are an area in the bone that’s swollen. Basically, its the bone’s reaction to bad cartilage, or a bad meniscus, or the excessive forces due to instability. For lack of a better term, it’s “pissed off bone”. Many researchers have also associated it with small fractures in the bone.

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What is Their Significance?

Basically, you can think of a BML as the Canary in the coalmine of the knee. Many patients will get these as their cartilage or meniscus first goes bad, but then the bone and the remaining tissues react and get thicker and stronger, so they go away (as does the pain). Chronic knee Bone Marrow Lesions are a bad sign, as it means the knee’s ability to compensate for the bad cartilage or a torn meniscus is sub-par. I bring this increasingly important lesion up, as it’s the single most consistent MRI finding that we have seen change with the Regenexx-C procedure. Basically, we’ve seen many of them go away after treatment  Case in point is this gentleman’s knee above. Look at the before pictures above, where the dark bone in the white dashed circle is lighting up like a Christmas tree (the Bone Marrow Lesion). Now look at the after treatment images below, where the BLM is dramatically less. In addition, the size of the cartilage lesion above that bone has also diminished.

The upshot? Bone marrow lesions are bad news and according to many research studies a much bigger deal in terms of knee pain and overall knee health than meniscus tears or the severity of the arthritis. This is because they show a knee that’s literally falling apart and unable to fix itself. A healthy knee reacts to forces by making itself stronger, so lacks knee Bone Marrow Lesions.

NOTE:  Not all patients should expect to experience the same results. Regenexx-C is only avaialbe in Grand Cayman.

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications. View Profile

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NOTE: This blog post provides general information to help the reader better understand regenerative medicine, musculoskeletal health, and related subjects. All content provided in this blog, website, or any linked materials, including text, graphics, images, patient profiles, outcomes, and information, are not intended and should not be considered or used as a substitute for medical advice, diagnosis, or treatment. Please always consult with a professional and certified healthcare provider to discuss if a treatment is right for you.