Hi D.,
I too was adopted. I knew the date, city and state, and the hospital I was born in. I wrote and received a copy of my original birth certificate (from vital satistics) which had my mother's name and age when she had me. I got hold of a phone book from the city where I was born and found initials matching my birth mothers from my certificate.
I understood she might not have wanted anything to do with me but I too had medical questions. I also knew this was a long shot because so many years had gone by. But then the letter I had sent to the address in the phone book was answered. My questions have been answered and I have met siblings I never had and always wanted. Knowing my biological parents now makes me more grateful for the parents that raised me.
Good luck. Your other option is to go to a lawyer and try to have your ceiled records reopened through the court system.
Joanie