Bone Density readings in already fused segments?

mmglobal · #1 (**permalink**) 12-04-2006, 04:48 PM

Greetings from Nijmegen, Holland! I'm about 1/2 way through an amazing trip with some quite incredible surgeries and happenings along the way. I'll try to post more later. I just want to throw some info out there because I found it quite interesting.

One of my clients has a long scoliosis fusion from high thoracic to mid lumbar regions. Prior to surgery, a bone density test was done and my heart sank whan I saw the readings and average t-score that indicated severe osteoporosis.

Further discussions with the surgeons revealed that while her t-score indicates severe osteoporosis, she may not be osteoporotic at all. She had harrington rods that spanned the fused segments for 15 years. In the 2 years since the rods were removed, she's been substantially disabled, so her activity levels have been extremely low and she's spent much of the time bedridden.

In the 15 years following the fusion, the spine was substantially off-loaded by the harrington rods. It is considered that she is not really osteoporotic, she has localized bone density issues where the harrington rods relieved the loading... this reduced bone density is a natural and expected side-effect of her configuration. Fortunately it did not represent a challenge for the surgery... I hope to post details of this major recontstruction later.

Mark

sahuaro · #2 (**permalink**) 12-05-2006, 05:52 AM

Mark:
You raise an important issue about interpreting spinal bone density readings and the need to put them in the context of spinal issues. Apparently, scoliosis can lead to falsely decreased readings while vertebral fractures, osteoarthritis (osteophytes?) and aortic calcification can lead to falsely increased readings.

Maria · #3 (**permalink**) 12-06-2006, 06:39 PM

Mark,
This is really interesting. I'm so glad to hear that this issue wasn't an obstacle for this person and the surgery~ my best to her with recovery!

I would like to say that I have confidence in the BMD testing in the U.S. tho I guess because I happen to have spine osteopenia and hip osteoporosis I worry about ADR w/o option of vertebroplasty.

Please do keep us updated ~ what incredible things you are able to learn and take part in!!!!

Michelle · #4 (**permalink**) 12-08-2006, 06:52 AM

Wow, great info Mark! My mom has the same fusion for scoliosis. I wonder if they considered this when they did her bone-density testing, though she wasn't considering surgery. If I may ask, what was the reasoning for taking out the Harrington rods? They offered this to Mom, but she couldn't see the benefit. Just curious. Have a great trip!