Like others have said, pork is not graded like beef. Since this is the pork category, and you mentioned "spare ribs," we can safely assume they were pork.
If they felt slick and greasy when you opened them, that's surface bacteria. Chicken can have the same issues. In the past it was common practice to rinse away the greasy feel under cold water. That's no longer recommended due to splashing and mistng contaminating surrounding surfaces with the bacteria. Frankly, when I feel slick ribs that don't stink, I still carefully rinse them, then sanitize nearby surfaces.