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.
What makes this spider so dangerous though is its venom which according to Guinness World Records is the most powerful of any spider. This deadly neurotoxin is around 20 times more powerful as that of the notorious Black Widow spider and equal in strength to the venom of some deadly snakes.