>1.0 DIFFERENCE BETWEEN T-SCORES HIP & SPINE ON DEXA?

[MyCatsNameIsMouse]

Hi folks, this is my first post and I'm new to this site but I've been doing heaps of reading and research into T-scores thrown up by DEXA scans. I run a pilates studio and work with many people with OP and osteopænia so, as part of my work, I do a lot of reading!

I'm coming across a lot of people are told that their DEXAs shows (for example) osteoporosis in the spine but osteopenia in the hip and they're been told they need to take medication to treat the osteoporosis.

​OP is a systemic condition. Unless there is a good reason for it not to be, in normally mobile people bone density should be reasonably uniform through the spine and lower limbs. If a DEXA result shows a T-score difference of greater than 1.0 or if the diagnostic category of the two areas is different e.g., osteopænia in the hip and osteoporosis in the spine, this is a "discordance".

​Some discordances are minor because of the way bone density results are presented. For instance, a T-score of -2.4 at the hip is rated as osteopænia but a T-score in the spine of -2.5 is osteoporosis. This represents a minor discordance as the actual bone density of the two areas is very similar. These minor discordances occur equally frequently with both DEXA and REMS.

​However, DEXA seems to have a much higher rate of major discordances where a person might be told they have normal bone in one area and osteoporosis in the other, or the difference between T-scores is much greater than 1.0.

One in twenty DEXA scans are affected in this way. Read that again

The commonest reason for these discordant results is operator technique when the DEXA scans are performed.

For the first 1000 REMS scans performed by OsteoscanUK the rate of major discordances has been 0% because the REMS scan results are not operator-dependent. All REMS scan/scan appointments are carried out by bone health specialist and spinal consultant, Mr Nick Birch (GMC No 3086328 if anyone needs to know!), so operator/interpretational mistakes just don't happen! I personally this think this is the main USP for REMS.

​In almost every case of a major discordance thrown up by DEXA they (OsteoscanUK) have come across, their REMS scans are able to resolve the problem and frequently shows that a diagnosis of osteoporosis in one site and osteopænia at the other is incorrect and both sites are actually classed as osteopænia.

REMS is quickly becoming the go-to scan system to have for this, and many other, reasons. It originated from Italy and now has been included within the Guidelines published by the National Institute of Health in Italy for the management of Fragility Fractures. It's only a matter of time before the UK is the same. GPs are becoming more aware of the "failings" of the DEXA system and REMS is the ideal replacement.

Sorry for the long post!

[Met00]

Here's a link to Osteoscan UK: osteoscanuk.com/. I'm one of the many who have discovered their DEXA scan result was wrong, with osteoporosis diagnosed and medication given when it was almost certainly osteopenia in both areas, not just hip. I thoroughly recommend the REMS scan, not just for more reliable results, but because you get a consultation with an expert, rather than a maximum of 10 minutes with a GP, many of whom know little about osteoporosis.

[MyCatsNameIsMouse in reply to Met00]

Once I'd read up about it, I had a REMS scan about a year ago and took my 84yr old mother along for one as well. Like you, I was thoroughly impressed by the kit and set up and the fact that we could actually chat to Nick about our results and what it meant etc, was very reassuring. Sadly the NHS is so stretched and underfunded doctors and specialists just don't have the time to do this.

[Daisi124]

I have a vast difference in scores -2.7 hip and -4.8 spine...

[Met00 in reply to Daisi124]

Have they been able to explain the reason for this discordance? Do you use a wheelchair (that would make your spine score worse)? Do you have arthritis in your hips (that might make your hip score better)? Do you take a medication that worsens the score in your spine but not your hips? If you're able to afford a REMS scan and can get to one of their venues, that would give you more accurate scores (osteoscanuk.com/), plus it includes a half-hour consultation with an orthopaedic consultant who specialises in osteoporosis and spines.

[Daisi124 in reply to Met00]

I have had very little info on my diagnosis I was told over the phone and prescribed AA. I did book a private appointment with a specialist who was a complete waste of money. I had blood tests to rule out bone cancer and parathyroidism. No I do not use a wheelchair and was walking 4 miles a day before fracturing my spine lifting an oven bowl into the kitchen sink. I take lansoprazol for 20 years. Propranalol and a statin. I also have a kidney stone and told not to take calcium until they Sort it out. They picked that up on an x-ray when I had the fracture. Confirmed as 6mm on ultrasound. I am still waiting for an appointment. I tried to stop lansoprazol but it caused night coughing and made my spine a whole lot worse. I am getting most of my calcium through dairy as I cannot eat high oxolate veg. I am taking Vit D3 and k2. I ignored the calcium supplement advice and am taking 400mg a day otherwise I cannot get enough through dairy. A pint of milk and a portion of yoghurt is the most I can manage. I asked GP about magnesium and he said not to take it until I had had a blood test which is not until the middle of January. I know I do not get enough magnesium so thought about taking a half dose (185mg). Still pondering on that.

[Met00 in reply to Daisi124]

Sorry to hear you've had a fracture, which unfortunately does raise your risk for further fractures. It's likely that the lansoprazole has affected your bone health, but I don't know if it affects the spine more than the hips. However, that doesn't mean there aren't other underlying causes for your osteoporosis. Have they checked your Vitamin D, calcium and parathyroid levels? It's done via a blood test, and all should be tested at the same time as they interact with each other. Many doctors don't seem to do this as a matter of routine, though most are willing to do so when asked.

[Daisi124 in reply to Met00]

Yes all the tests you mentioned have been done Vit D3 was 71 too low so I am taking extra. To be honest my GP seems more bothered about the kidney stone than my bones. My kidney function test was very good. I am waiting for a hospital appointment about the kidney stone but have been told due to Covid it will be maybe January February. So on a restricted diet due to stones (low oxalate) which hampers my intake of calcium and magnesium. I have great anxiety ATM and convinced I am about to drop dead or that my spine is going to crumble. I also have leg pains in the night I never had before. I am in a bit of a sorry state. Thanks for your reply.

[Met00 in reply to Daisi124]

So sorry that you're struggling so much at the moment. I hope your fracture heals fast and your kidney stones are resolved soon.

[Daisi124 in reply to Met00]

Thanks x

[Yogi_Bear]

What a great explanation which totally equates to my experience of having both DXA and REMS. Thank you.

[1000Miler]

I too am very skeptical about the use of DEXA scans as a diagnostic tool.

I have had two DEXA scans. The first one, taken two years ago, recorded T scores of -1.7 for hip and -3.9 for spine. My GP prescribed alendronic acid, which I've been taking weekly for two years.

I had a 2nd DEXA scan a couple of weeks ago and have just seen the T scores: again they are discordant at -1.7 hip and -3.3 spine. The scan was on the same machine as previously but with a different operator.

Interestingly, I also had a REMS scan a few months ago. That scan returned almost equal T scores, bringing my hip into the osteoporosis range, at -2.7, and the spine to almost the same, at -2.8.

It does seem to me that the REMS results are more likely to be correct than the DEXA scores.

It's widely recognised that, in order to compare results, follow-up DEXA scans must be done on the same machine because of the size of the margin of error between different machines. If that error margin is so great as to render the T score results from different machines non-comparable, what does that actually say about the accuracy of the results from any particular DEXA scanner?

In theory, two people with identical REMS bone T scores of, say, -2.6, could have very different experiences with DEXA. One could go to hospital A and the DEXA results would be in the osteoporosis range and the patient would be put on (potentially damaging and life-changing) medication. The other could go to hospital B and have a scan that resulted in a diagnosis of osteopaenia, so they would then not be medicated at all.

If we're going to use machines to scan and assess the strength and quality of people's bones - and make clinical treatment decisions based on the results of those scans - then surely we should be using a system that returns repeatable and reliable results with a reasonable degree of accuracy?

[osteo2021]

Thank you so very much for your post!

Like Met00, I found my hip and spine t-scores to be WAY more aligned with REMS. I also appreciate REMS’s fragility scores which provide some sense of bone quality—and its 5 year fracture risk calculated through t and fragility scores.

I’ve had several conversations with my orthopedist and GP but they still don’t take my REMS scores seriously and want me to go on very serious daily injections based on my DEXA scores. I’m 69 with no fractures to date. My doctors won’t even consider the REMS fragility scores which indicate that my spine bone quality is in the normal range and my hip is osteopenic. My doctor didn’t know that REMS was approved for use in the US last year and claimed she had heard there were problems with REMS machines not being calibrated correctly, but I’ve had my REMS scores done multiple times on two different machines with very similar results. Best I can get is my doctor admitting that DEXA has it’s problems but it is the best tool available. Frustrating ... but as they say ... big ships turn slowly.

[BarbaraOsteo in reply to osteo2021]

Does anyone know where to go to get a REMS test in the Northeast (USA). I live in eastern Massachusetts (Cape Cod), and I also have a huge difference in DXA between my spine and hip. Total hip and femoral neck are normal; spine ranges between -2.7 and -3.5 (from different machines). (I also have somewhat high urinary calcium and recently discovered Celiac Disease, which may- or may not- account for the difference)

[osteo2021 in reply to BarbaraOsteo]

BarbaraOsteo I went to New Jersey for my scans but that’s far for you. For information on where REMS scans are available in the US contact Vicki Baldwin [e-mail].

[uncountable3]

Osteoporosis may be systemic but that doesn't mean all bones receive the same mechanical stresses. Less stress means lower density. What scientific studies show that hip and spine T-scores should always be within 1? Also, T-scores are not the same as density. The lumbar spine is normally denser than the femoral neck. In my first DXA, my spine showed slightly higher density than the femoral neck but the T-score was 1 *lower*. In my second DXA, the hips had improved so they are now 5% denser than the spine but now the T-score discrepancy is 1.5. Both scans were done at a highly regarded facility so it seems unlikely that they made the same mistake twice. Also, the studies that I have seen for establishing REMS accuracy have used DXA as the baseline.

[Met00 in reply to uncountable3]

As you say, REMS has been compared to DEXA as a baseline for determining accuracy, and found to be comparable. It is gaining recognition and has already been approved for diagnosis of osteoporosis in both Italy and the USA (and possibly other countries that I'm unaware of). REMS scans consistently show similar t-scores for hip and spine, so as studies have shown both REMS and DEXA to be equally accurate, how can this be explained? One explanation is that REMS, being more fully automated, is more reliable because it's less open to operator and interpretation error. Another point that really worries me about DEXA scans is that results from different machines cannot be compared. If two DEXA machines give different results (one showing osteopenia, the other osteoporosis for example), how can you possible know which is correct? There's also a much wider margin of error with DEXA than REMS (which is a major reason why it's recommended to have at least 2 years between DEXA scans), with DEXA scans this potentially being as high as 5-6% (medpagetoday.com/endocrinol.... In addition, DEXA scans only measure bone density, whereas REMS scans also provide a measure of bone strength, which isn't necessarily directly equated to density - hence why it isn't unusual to fracture with osteopenia, yet others with very low bone density may never fracture.

[uncountable3 in reply to Met00]

While the reduced discord with REMS is interesting, without a third reference, we can't determine which of REMS and DXA are correct. And it is possible they are both wrong. One item to consider is that the lumbar spine and femoral neck have different composition. It is possible that REMS measurement of the femoral neck is a little off and fails to detect differences that it should. The studies that I have seen compare DXA to REMS only concern spinal density.

[Met00 in reply to uncountable3]

I've seen references to spinal, total hip and neck of femur density. It's more common for REMS to agree with total hip and femur neck density as measured by DEXA, but to give a different spinal measurement. However, where, for example, there's arthritis in the hips, REMS gives a more reliable reading. There was an article in the British Medical Journal about this: "These preliminary data suggest that REMS technique, which has been shown to have high sensitivity, specificity and accuracy when compared with DXA in diagnosing and monitoring osteoporosis [3], is not affected by the presence of alterated soft tissues composition. it would therefore be particularly useful for the evaluation of bone fragility in subjects at risk of osteoarthritis." ard.bmj.com/content/78/Supp...

[osteo2021]

To Met00’s point, understanding the difference between bone density and bone strength is critical. In conversations with my orthopedist, she mentioned that she has many patients with normal DEXA t-scores that repeatedly fracture. What’s difficult to diagnose are patients with low T-scores and no fractures. I asked about the new DEXA software [TBS} that measures bone texture, but it isn’t available anywhere in my region. I can’t imagine why it is not used more on DEXA machines unless this is about money and/ or consumer demand. Has anyone had experience with this software?

[Mahler02]

Thanks so much for the post! I was -3.3 LS but -1.8 in hip so the conversation about site discordance is really interesting! My blood tests for secondary osteoporosis were fine. I walk 3-5 miles a day, which affects hips but not spine, so I am targeting my spine in strength training and daily yoga poses.