i can understand your concern but I want to assure you that knee arthritis
is age related problem and it is not occur so early, so till 40 you are safe.Unfortunately there are not much you can do to prevent it because all running,jumping,sports and dance causes knee changes, and you can not stop all this. I would recommend you to at least do not do squatting and cross leg sitting. Also no running on hard surfaces. I would also advice to your dad to avoid steroid
injection as they are very harmful and in future can complicate knee replacement
also.So avoid these steroid injection in the knee.