How Did this Bone Spur Form?

First off, I’m not asking for advice on what to do about my bone spur. I am curious as to how I aquired it.

The spur is visible through the skin, on the inside of my left wrist. I believe it to have formed on the point of my Radius. It is large enough that I would not be able to wear a watch on my left wrist, if I were so inclined (I’ve always worn it on my right, although I’m right-handed)

Some facts:
About 15 years ago I had a fracture in this same general location.
I did not trip, fall, or otherwise impact my wrist.
It formed during a time when I was doing a fair amount – 2-4 hours daily) of physical labor including: shoveling, lifting (not more than 30#), scooping, and pouring. No hammering or other impact-type labor (due to tennis elbow, I avoid this type of work).
As mentioned I am right-handed.
I am prone to tendon injuries due to hyperflexibility in my arm joints, including my wrist (established by medical evaluation, not my own opinion)

Any thoughts on what caused this spur to form?

Are you sure it’s bone? Ganglion cysts can form hard lumps on the wrist.

That is an excellent question. Obviously I’m planning to have it xrayed and otherwise investigated. But from my uneducated observation, it seems like bone/calcification. It’s hard and unmoving. From what I’ve been reading a ganglion cyst is made of “jellylike material.”

That said, the pictures I’ve been able to find of a ganglion cyst do look very like what I have. And the causes are very consistent with my history of being susceptible to RSI.

Very interesting (and I enjoyed reading that once upon a time, the treatment was to smack it with a large book, also known as “bible therapy.”)