That portion of a horse's leg is sometimes called the "cannon". Have no idea why.
I have a problem with one of my carpals, due to Agent Orange. The AO sometimes attacks the cartilage in joints, such as with my spine. They've attached nifty Titanium plates in my spine, which really helps a lot.
But the #1 Carpal, right hand, connects the thumb to the wrist - and the wrist end of that carpal is really messed up - constant pain. The last orthopedic Doc at the VA merely gave me a nasty little plastic and Velcro brace - which hurts more than the dang bone end does! It went out with the trash.
I'm limited to typing with my right index finger and use the thumb on the space bar - sucks to be me sometimes.