My mother has been diagnosed with a hip problem called arthrokatadysis. I can’t find anything on this. What is it?

Arthrokatadysis means there is a subsidence of the joint. Subsidence is the medical term for sinking-in. Quite literally, the joint starts to sink down into the bone.

The cause of this problem is largely unknown and may vary from patient to patient. Something causes the bone supporting the joint to soften. This could be a lack of enough blood to the area from a blood clot or other vascular problem.

There may be some kind of systemic disorder of the organs or glands affecting the bones. Despite the fact that the condition was first described in the 1920s, not much is known about it. The number of cases reported is small, which contributes to a lack of understanding.