DEXA Scan Discrepancies: Spine improvement and hip worsened

Posted by anewyorker @anewyorker, Mar 3 8:47am

Good morning to all,

I just received my DEXA results from last week’s scan, and they were a classic good news, bad news story.

The good news is that my spine improved dramatically from a year ago, from a T score of -3.3 to -2.3. Distal radius was unchanged, femoral neck was marginally worse (-1.7 now vs. -1.3 last year).

The big change was in the hip—from -1.6 last year to -2.1.

I’ve had osteoporosis for 20 years. Recent treatment: I was on Prolia from 2020 through spring 2024, with little change in DEXA results. I stopped the Prolia and began taking Fosamax last April; the plan was to stay on that until January 2024, at which point I would switch insurance carriers to one that would cover Tymlos or Forteo.

Unfortunately, I developed very bad GERD problems and had to discontinue the Fosamax. So I was on nothing from October until January, when I began taking Tymlos. I’ve been lucky to be able to tolerate the full dosage from Day 1 with minimal side effects.

I’ve had one compression fracture, at L1, after a bad trip and fall last October. I’m doing PT to strengthen muscles ( I have a whole list of unrelated orthopedic problems that limit my mobility).

I’m 77, in quite good overall health.

So my question is whether anyone can help me understand why my spine improved so dramatically (did the Tymlos really make such a difference after only 7 weeks?) even as my hip worsened noticeably?

I should note that the two scans were done in the same place, so there shouldn’t be a huge discrepancy because no two machines give exactly the same result.

I’m sorry this is so long. All our situations are so complicated, aren’t they?

Thanks for your help.

Interested in more discussions like this? Go to the Osteoporosis & Bone Health Support Group.

Spinal fractures can be silent or, in my case, since it was 3 at once, very very painful and at least temporarily disabling. I live alone and was not able to function. It was hard to get out of bed and I would end up crawling on the floor in pain. I could not cook, wash dishes, do laundry. This was still during COVID so I talked to a PT online. (I can look it up but scores were mid -3's.

I had two or three traumatic fractures in 2006 that were thoracic. I slipped on icy steps and fell on my back on the corner of the concrete steps. That was painful too but nowhere near as bad as the osteoporotic ones that involved no trauma at all, just one unwise movement.

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I think the total hip score is the one most reliant on placement on the Dexa machine. If your hip is not aligned exactly as it was in your previous scan the results can be anomalous. They use a Ward’s Triangle to draw a box around the top of your tibia as it enters your pelvis to determine the score. So your next scan could be substantially different, depending on the skill and experience of the dexatometrist. IMHO.

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@anewyorker

I’ve checked the report and it says only “Spine.” I don’t believe I have access to the images. But I will absolutely ask my doctor this week.

Too bad! I was so happy to see the excellent results ! I should have known that an improvement from -3.3 to -2.3 was too good to be true.

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I was able to get all my data and images by going to the scan site and asking politely. Maybe you can too.

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Update:

Well, I saw my endocrinologist today, and she took one look at the T score for the spine and said what gently and windyshores said- that the technician should not have included my fractured L1 vertebra in the calculation. Without it, the T score for L2-L5 was -3.2–essentially unchanged from the 3.3 of a year ago. Darn.

She did say that Tymlos can take three months before it makes a noticeable difference in bone density, and, as I noted, I had been on it for only seven weeks when I had the scan, after a mishmash of stuff last year. So that phenomenal improvement was always suspect. But the illusion was nice while it lasted ! Anyway, for now I’ll stay on Tymlos and keep my fingers crossed.

Thanks again to everyone who responded. I always learn from you.

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As mlwh observed, my endocrinologist noted that positioning affects the reading for the hip more than for the spine. She suspects that accounts for the change in the T score for my hip.

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anewyorker, I had a similar experience with my DEXA exams. Actually Dr McCormick caught the possible discrepancy. The facility that did the DEXA changed machines. This was caught by the machine serial # on the DEXA report. My 2014 & 2016 DEXA reports had one serial # for the machine, my 2018 & 2022 DEXA reports had a different serial # for the machine. The discrepancy was noticed in the 2018 DEXA report. It's also possible that I was positioned differently on the machine. After the 2022 scan, I've had a spine x-ray and MRI. Neither showed a fracture. All my doctors (McCormick, Ortho Dr, Endo) have concluded it was the machine.

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The radiology technicians at different centers need to be made aware of how critical positioning on a table for DEXA and the maintenance records for machines.

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Well Good Morning to my Connect Buddies!
Today is 13 March, and the discussion regarding getting off of Prolia has happened this morning.
On 02 March, I again hit the ER with yet another chest infection; that's 3 in 4 months, so the impact of Prolia on my infection rate has been confirmed, beyond all doubt.
With this development my Respirologist and my Rheumatologist has been in the fray.
My G.P. is following my Rheumatologist's suggestion of discontinuing Prolia, and commencing Forteo.
Also, my bone density is booked.
I am feeling much relief at leaving Prolia.
I thank you all so much for your excellent suggestions and great support
As soon as this infection is done, I commence the Forteo.
So onward to better things!

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@thisoldewe

Well Good Morning to my Connect Buddies!
Today is 13 March, and the discussion regarding getting off of Prolia has happened this morning.
On 02 March, I again hit the ER with yet another chest infection; that's 3 in 4 months, so the impact of Prolia on my infection rate has been confirmed, beyond all doubt.
With this development my Respirologist and my Rheumatologist has been in the fray.
My G.P. is following my Rheumatologist's suggestion of discontinuing Prolia, and commencing Forteo.
Also, my bone density is booked.
I am feeling much relief at leaving Prolia.
I thank you all so much for your excellent suggestions and great support
As soon as this infection is done, I commence the Forteo.
So onward to better things!

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Christine, if you were on Prolia for only 4 months the info below would apparently not apply. But for anyone on Prolia past 1-2 years (I am only posting this because a friend of mine just went through the consequences described):

According to McCormick's book Great Bones (page 569), and Dr. Ben Leder's You Tube lecture Combining and Sequential Approaches to Osteoporosis (minute 35) , not only does Forteo (or Tymlos) after Prolia not work, but there is a decline in bone density and strength and increase in cortical porosity and fracture risk . The only medication that can stop the rebound loss of bone density and dramatic increase in fracture risk after stopping Prolia, is Reclast or, to a lesser extent, Fosamax.

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@windyshores

Christine, if you were on Prolia for only 4 months the info below would apparently not apply. But for anyone on Prolia past 1-2 years (I am only posting this because a friend of mine just went through the consequences described):

According to McCormick's book Great Bones (page 569), and Dr. Ben Leder's You Tube lecture Combining and Sequential Approaches to Osteoporosis (minute 35) , not only does Forteo (or Tymlos) after Prolia not work, but there is a decline in bone density and strength and increase in cortical porosity and fracture risk . The only medication that can stop the rebound loss of bone density and dramatic increase in fracture risk after stopping Prolia, is Reclast or, to a lesser extent, Fosamax.

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Hi windyshores!
Yes, all this quite correct for folks who do not have other autoimmune conditions.
My various lung problems cause some complications on the usual process.
I have gad a total of 3 Prolia shots. My infection rate increased one month after my first shot. To date, I have had 7 infections since commencing Prolua. Even with my severe asthma, bronchiatesis, and tracheobronchomalasia (sp), this rate of infection is too high, and is escalating.
Also, my osteoporosis seems due to high prednisone treatment, for the lungs and arthritis.
It is my Rheumatologist's recommendation to discontinue Prolia and go to Forteo.
The main concern is to get away from the bisphosphonates and their decrease in the immune system (mine has been in the basement most of my life) asthma starting at 2 years of age, and rheumatoid arthritis at 23.
So, in the midst of this pickle, the priority us protecting the lungs. (Pulmonary function drops with every infection)... and lungs are necessary for life! I have lost significant function since the Prolia, due to infections.
Bottom line, there is no perfect answer for this situation.
I do appreciate the soundness of your statements, for most people.
Thanks for replying.
I so appreciate all the support!

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