If your doctor tells you that something is impacted, that's not a good thing. It means wedged together and unable to move.
Wisdom teeth are often impacted, which makes one question how wise they actually are. A fractured bone can be impacted as well, which means the two broken ends are wedged together. Perhaps you could say that your Christmas stocking is so jam packed and impacted with goodies that you can barely pull anything out — but that's about the only non-painful association with the word imaginable.