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Dr. Rick, MD
Dr. Rick, MD, Board Certified MD
Category: Medical
Satisfied Customers: 11355
Experience:  20+ years as a doctor. Internal Medicine Internship in NYC
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Why did the knee MRI not show peroneal nerve injury, but the

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Why did the knee MRI not show peroneal nerve injury, but the EMG shows injury? I had the MRI done July 30,2013 and EMG done Oct. 16. The burning and pain has been going on since oats knee surgery Jan 2013.
Hi. My name is***** and I am online and available to help you today. Thank you for your patience.
Do you have any medical problems or take any medications?
This is not an answer, but an Information Request. I need this information to answer your question. Please reply, so I can answer your question. I look forward to helping you.
MRIs are not a magic lens into the morphology of your has limits and is not perfect.
The EMG actually tests physiologic function which -- as you can see -- may be reduced/damaged without any physical abnormalities visible to imaging studies like MRI.
This is why doctors do multiple tests, conduct physical exams and review your history to come up with a diagnosis and treatment plan.
Does this make sense to you?
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Thanks in advance,
Dr. Rick MD FACS
Customer: replied 3 years ago.
I take lyrica 200 mg a day, Xanax, percocetvas needed. I was a fitness fanatic prior to my injury last year at boot camp. I had a grade 4 lesion in my articulate cartilage and had OATS surgery jan. 28 2013 after PT did not allow me to go back to boot camp. After surgery I had dvt and pe which are both gone now. Since surgery and have had intense burning and muscle weakness.
After months of complaining my knee dr finally got me a mri on my knee, but did not show nerve damage. I finally went to neurologist and got EMG last week showing peroneal nerve injury. I want to understand how the mri would not show it.
It write up of emg results it states "decreased amplitude of the tibialis anterior and edb motor nerves".
I assume I got this during surgery since that is when issues started.
What type of nerve damage would do this? Compression? The dr said it is too late to do surgery and I am trying to get second opinion now too. I want to be active again.
The MRI only shows structural damage, it can not illuminate physiological damage that might occur, for example, by your peroneal being slightly compressed (perhaps only for a short time interval) or the nerve loosing some of its blood supply in a small area.
Could it have happened during your surgery? Maybe. But it may have happened before or even during the post op recovery....and, unlike what many lawyers would like to have you believe, there is no way to know.
I'm sorry, but what function you have after about 6 months when it comes to nerve damage is about what you can expect to have for the rest of your life.
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