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MRI finding of osteonecrosis



I had surgery on my left knee due to a 3rd degree posterior meniscus tear due to a non-traumatic event. My doctor removed most of the meniscus. I went to rehab and have been working out every day. I am still in a great degree of discomfort and I am not able to do the same activities pre-surgery and pre-injury.

I just had a second MRI which said I had osteonecrosis with a subchondral collapse. It also said the adjacent medial meniscus was abnormal and partially resected.

Can you please tell me what all this means in lay terms? Can this be treated? Will I ever be able to play sports again?


I haven’t been able to find what is meant by a “3rd degree meniscus tear”, but based on the fact your surgeon removed a portion of your meniscus, your meniscus tear must not have been repairable (the majority of meniscus tears which remain symptomatic are treated by partial removal rather than repair).

The fact you continue to have pain despite partial meniscus removal indicates the torn meniscus may have accounted for only a portion of your pain. Now that another MRI scan has revealed osteonecrosis, this condition can certainly be a source of joint pain, and may or may not have been present to some degree prior to your meniscus surgery. Even if the report from the first (pre-surgical) MRI made no mention of osteonecrosis, comparing the actual MR images from the two studies – and not just the reports – would be necessary to determine whether there was any evidence for osteonecrosis on the first MRI.

“Osteo” means bone, and “necrosis” means “dying”. If the blood supply to a portion of a bone is disrupted – which can result from trauma, excessive alcohol or steroid use, among other causes, but at other times can occur for no identifiable reason – that portion of bone may have inadequate nutrition to remain viable/alive, and as a result, may “die.”
When this involves a weight-bearing bony surface, the compressive forces on this weakened portion of bone may cause it to collapse, meaning flatten or indent. “Subchondral” means “beneath cartilage”, and refers to bone underlying a layer of cartilage.

The MRI finding that the “medial meniscus was abnormal and partially resected” is what is expected following partial removal of the medial (inner, as opposed to lateral or outer) meniscus.

Treatment options for your particular situation should be discussed with your orthopedist. The “stage” of osteonecrosis, along with the exact location and extent of involvement, will determine whether nonsurgical or further surgical treatment options would be most appropriate for you, and depending on what’s decided, the degree to which your future sports participation should be restricted.

Low impact or nonimpact sports will most likely still be an option for you. If high impact sports involving jumping and cutting are what you prefer, returning to and then continuing to participate in such activities after the removal of the majority of your meniscus would not typically be recommended, but again, these considerations all need to be discussed with your orthopedist.

For more information:

Go to the Sports Medicine health topic.