Medical Definition of ARTHRODESIS. : the surgical immobilization of a joint so that the bones grow solidly together: artificial ankylosis. the surgical immobilization of a joint so that the bones grow solidly together. ADVERTISEMENT.
Trapdoor spiders are not particularly harmful to man however, like Tarantulas, the tiny hairs on the legs of some species leave tiny red marks where the toothed hairs on the spiders' feet have clung to the skin. Mouse spiders are also a type of Trapdoor spider with huge chelicerae and may measure up to 35mm in body length.
Really, the thing we're concerned about is whether or not the spider is venomous enough to present a danger. While pretty much all spiders are venomous to some extent, very few are harmful to humans. Believe it or not, the spider is in fact more afraid of you that you are of it. Usually a spider bite results from the spider being trapped and threatened, e.g. inside a shoe, in clothing, or when someone places a hand or body part over the spider, as when moving a woodpile, for example.