Bf got kicked

So my bf got kicked in the balls at around 16 years old. He went to the doctor and they told him he was now 96% sterile. He had a kid around 18/19 years old and it’s now almost 10 years later is it possible he is now 100% sterile? If so is there any way a doctor can fix the situation since he managed to have one kid or is that going to be his only child? At first I said okay that’s fine because their is no harm in trying since he managed to be able to have two but one was a miscarriage. I just don’t understand. I wanna get pregnant by him and not anyone else meaning sperm donor. I am honestly thinking he is now 100% sterile and it hurts me so bad