calcium form enlarged (knots and spikes) on top of leg bones

I have a 82 Y/o Father that has calcium forming large knots and/or spikes on top of leg bones on the shin area. Yes he has had broken bones in his left. His left leg he has had his leg broken and ankle fused. He has had both knees replaced.

This spikes are so long that they punch through his skin, breaking through. His pain managament Doctor and General Physician both don't know what these are or the cause of them. He his around 3 to 5 per lower leg. He can walk, but he is now in pain. Not from these spikes, just in general pain due to old age I feel. These only give him pain when they are breaking though the skin.

Looking for answers, but really looking for information of what they are. Any link or link papers would be nice.

Thank you again

[Dr Vinod]

You need an X-ray and some blood tests to know about these growths.
He would need a proper diagnosis of the enlarge knots and spikes.
Follow up near an orthpaedician or take him to a good speciality.
Give him intermittent anti inflammatory drugs.