I'm not going to compare your grandson to our bulldog Hershey, but that is exactly what Hershey was born with.What is hypospadias?
"Hypospadias is a malformation that affects the urethral tube and the foreskin on a male's penis. The urethra is the tube that carries urine from the bladder to the outside of the body. Hypospadias is a disorder in which the male urethral opening is not located at the tip of the penis. The urethral opening can be located anywhere along the urethra. Most commonly with hypospadias, the opening is located along the underside of the penis, near the tip."
from reading that site, it's actually not an uncommon 'defect' effecting 1 out of 150-300 males.
Wishing the little guy the best of luck with the surgery! I'm sure he'll be just fine