There’s a new article about osteoarthritis in XLH patients, “Biomechanical Impact of Phosphate Wasting on Articular Cartilage Using the Murine Hyp Model of XLH” in the Journal of Bone and Mineral Research.
While the science in the discussion is a bit advanced for me, the conclusion is simple and opens up possibilities for better understanding arthritis in general, not just XLH patients, as well as confirming the need for state-of-the-art treatment early in an XLH patient’s life, no matter how seeming mild the visible symptoms are:
Our findings also challenge the belief that abnormal alignment and distribution of load on weight-bearing joints as the sole cause of OA in these patients. Importantly, these data suggest that early and sustained treatment to maintain the biosynthetic capacity of articular chondrocytes throughout life is an important consideration to delay or prevent OA and associated osteophytes.
In other words, it’s long been assumed that our high rates of osteoarthritis are due to misalignment of our bones causing excessive wear and tear. And obviously that’s a contributing factor. But apparently, even if our joints are properly aligned (i.e., through surgery), we’d still be at heightened risk of arthritis due to mineralization issues.
The reason I find this interesting, in practical terms, is that it undermines the theory that only “severe” cases of XLH should be treated with burosumab. There are still too many clinicians who believe they can treat XLHers adequately with some combination of phosphorus, calcitriol, and surgery. They point at their patients and say, “look, the legs are straight, the bones are aligned properly, so our treatment worked just fine.” Except, as this arthritis article points out, there are a number of symptoms that canNOT be seen, and that are not adequately treated with phos/calcitriol.
We’re learning more and more about these invisible symptoms of XLH, the ones that phos/calcitriol and surgery can’t address. It seems likely that in another ten or twenty years, the evidence will be so overwhelming in favor of burosumab for all XLH patients of all ages, that med students will wonder why anyone even considered using the old treatment after the introduction of burosumab. Unfortunately, the damage done to existing XLH patients from inadequate treatment for ten years can be immense, the difference between a good quality of life and a poor one. We need to advocate for ourselves and for others, shouting to anyone who will listen, that the old treatment Does. Not. Work. and insisting that it does condemns patients to a future of pain and disability.
There may soon be an opportunity to share your experience with the inadequacies of old treatment, to help make the effective treatment more broadly available to adults, and I hope you’ll take the time to do it. Stay tuned for more information!
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Please note that the author is a well-read patient, not a doctor, and is not offering medical or legal advice.
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