Sorry I missed this Nom, but I am glad you're dad is doing well after surgery.
My family is an expert on Knee trubbles.
I had 2 surgeries when 14-15 on both knees.
My dad has had at least 3. My mom recently had knee surgery.
My Grandma has broken both knee caps.
Both uncles I think have had them too.
I will continue to send good thoughts and prayers your way!