| abstract |
The invention provides a facet prosthesis assembly (500, 700, 56) comprising (a) a first artificial facet joint structure (510a, 710, 66) and a first fixation stem (520a, 720, 65) adapted to anchor the first artificial facet joint structure to a first pedicle (102a) of a cephalad vertebra; (b) a second artificial facet joint structure (510b, 710, 66) and a second fixation stem (520b, 720, 65) adapted to anchor the second artificial facet joint structure to an opposite second pedicle (102b) of the cephalad vertebra; (c) a third artificial facet joint structure (315) adapted to articulate with the first artificial facet joint structure and a third fixation stem (310) adapted to anchor the third artificial facet joint structure to a third pedicle of a caudal vertebra; (d) a fourth artificial facet joint structure (315) adapted to articulate with the second artificial facet joint structure and a fourth fixation stem (310) adapted to anchor the fourth artificial facet joint structure to an opposite fourth pedicle of the caudal vertebra; and (e) a cephalad connecting member (505, 750, 761, 762, 70) for directly connecting the first fixation stem and the first artificial facet joint structure to the second fixation stem and the second artificial facet joint structure. |