The most accurate evaluation of knee osteoarthritis takes into account traditional x-rays and data from a bone scan (also referred to as scintigraphy). With a bone scan, the metabolic activity of bone (changes in the bone at the cellular level) can be assessed. Changes in the knee are detectable earlier than they are apparent on x-rays. According to a report in the September 2008 issue of Rheumatology News, early detection allows for early treatment -- and in some cases, possibly even a reversal of the disease process.
For many years, only traditional x-rays have been used to diagnose medial (middle) compartment knee osteoarthritis. If joint space narrowing, osteophytes, and bone-on-bone (severe cartilage deterioration) was found -- you were diagnosed with osteoarthritis. But researchers have found that as an "anterior-posterior technetium bone scan" provides a look at the metabolic activity of the living bone, your knee can be metabolically better or worse than what an x-ray shows. The bone scan looks for loss of osseous (tissue) homeostasis. If found when x-rays still appear normal, there may be time to treat you before irreversible structural changes occur in the knee. Even in patients with established knee osteoarthritis -- it may be possible to metabolically slow down the disease process.
Related Resources:
- Joint Space Narrowing - What's the Significance?
- What Are Osteophytes?
- X-ray Evidence of Osteoarthritis
- 10 Things You Should Know About Cartilage
Join the Discussion:
Photo by Susan Law Cain (iStockphoto)
I had two bone scans back in the early 1990s that showed something was going on with my knees and it showed the osteoarthritis. However, I didn’t know that’s what it showed til I got to a rheumatologist in Jan 1992. The reason is that up until then the only thing those scans showed was that I had a pool of blood around my kneecap and such and the orthopedic surgeon I went to thought that I had a tumor there. So he then sent me to the specialists at the University of FL and there I found out that my kneecaps were off their tracks, and then after doing that and going back to the orthopedic surgeon I was sent to a Rheumatologist who told me that I had osteoarthritis. What clinched the diagnosis though was the bloodwork that was done.
Fast forward to May 2008 when I told my rheumatologist that I had noticed some changes with my osteoarthritis although not for the better. He then sent me for another bone scan (it was the 3rd in 17 years). The results this time? It didn’t show anything abnormal with the joints and such although it did confirm a diagnosis of scoliosis in my lower back which initially got diagnosed thru MRI in Jan of this year.
I don’t know if the machine that my bone scan done in May could have been a problem as far as showing the problem but it was interesting what the results showed. I’m tempted to ask my rheumatologist to send me back for another but at the hospital where I had the other two done 17 years ago to compare to see if the machine as far as its strength matters like it can with the different types of MRI machine.
I’ve had total replacement of both knees knees and the pain has never gone away. I can walk, which I most like couldn’t without the surgery. But there is something wrong when there is still so much pain after all this time. I’m going to a different orthopod who is now sending me for a bone scan. Neither doctor that I had before even mentioned this test to me. Maybe I’ll find out what’s going on.