"My left knee and shoulder absorbed the brunt of the fall and my helmet also made solid contact with the road surface. "
The Bicycle Helmet Safety Institute says that any time your helmet hits the pavement, it should be retired and replaced. The foam is designed to give its all in a crash and doesn't retain enough integrity to provide protection for a 2nd fall. The BHSI goes so far as to say that if you drop a helmet on a hard surface it should be replaced.
JM2CW