1. Joint malformation or deformity: Ellis was born with dysarthrosis in his left ankle in that it was turned outwards and made it difficult for him to walk, to wear regular shoes, etc.
2. A misperceived development of a bone closure where none is actually present: Jasper's thumbs were so flexible it appeared that he had dysarthrosis; however, he was double-jointed and his thumb joints could flex in either direction.