According to the 39 Health Network query, the difference between pig trotters and pig knuckles is as follows:

1. Part: Pig trotters refer to the front part of the pig's feet, including Half a toe and part of a hoof, in a semicircular shape. The pork knuckle is the lower end of the pig's leg, including the part above the pig's hind hoof, which is round in shape.

2. Appearance: The meat of the hoof is relatively tender and often contains a certain amount of collagen. It is easy to taste when cooked and has a soft texture. The meat of the elbow is firmer, especially the fat on the pork elbow is more than that of the hoof.

3. Usage: Trotters are often used to make dishes such as pork trotters, pork trotters cake, and braised pig trotters. The elbow is often used to cook soup, stew meat, braise the elbow, etc.