Did he press charges?

He was going to leave their shared home, but turned back b/c he was in such pain.

He can't go anywhere for the time being.

History of dysfunction to say the least.

I don’t know how long it would take to heal, but I hope your friend made a police report. What kind of person, drunk or sober, pushes their 77-year-old father down the steps? That is just appalling.

WTF

He is lucky he was not killed.

He is going to be in a lot of pain and healing time depends upon his overall health
and medical care. And not being pushed down the stairs again.

Pneumonia is a possible problem.
Ball park is two months healing time.

Here's the tragedy:

Five years ago, he was in a head-on collision and was medically decapitated save for one bone fragment in his neck. Had surgery and struggled to return to a normal life. All that surgery and work could have been snuffed out had he landed on his neck or back of his head.

Further, he's a professional trumpet player. You KNOW he won't be able to play for a loooooong time as breathing will be quite painful.

He is going to be in a great deal of pain. So I don't think playing a trumpet will
be something he can do for a while.

I wonder if he can be admitted to a nursing home for some medical care.

Does his doctor know he was pushed?

Maybe someone will call adult protective services.

He just admitted privately to his sister that his son pushed him while drunk.

And there is an investigation.

He should be in a nursing home to help him stabilize and be safe.

It takes bones 6 weeks to heal for a healthy young person.
Definitely longer for a 77 yoa man. If he has health problems, it might take him even longer than a regular 77 yoa.
the son definitely needs to get off alcohol for the man to be safe around his home.

Do some research on supplements for healing bones. It's about more than just calcium. The type of calcium, added nutrients, boron, hypaxitite, some type of soy, are important. Query AI. There are many bone builder formulas for older folks.

although some pain can persist for a while. He will have to take it easy and have some help for the first couple of weeks, until the clot and callus start to form at the fracture site. Aftr that, he can do light activity like making his own sandwiches and coffee, although someone else will have to do his shopping.

I hope sonnt boy is in jail and nobody lets him out until he starts jailhouse AA meetings. Yeah, he needs to press charges. This is serious, and he won't be doing his son any favors by not pressing assault charges.