Patent ID: 8128660

Claim:
A facet joint implant adapted that address ailments of the spine, the implant including: a facet joint spacer that is adapted to be inserted in a facet joint; an anchoring plate adapted to be secured to a vertebra, the anchoring plate having a first recess sized and shaped to receive a portion of the facet joint spacer, wherein when the portion of the facet joint spacer is received in the first recess an articulation joint is formed between the facet joint spacer and the anchoring plate such that the facet joint spacer is pivotally connected with the anchoring plate; a bone screw that is disposed through the anchoring plate and is adapted to secure the anchoring plate to the vertebra; a locking screw having an asymmetric head and a shaft, the asymmetric head being fixedly attached to the shaft such that the asymmetric head rotates with rotation of the shaft, the asymmetric head defining an engagement portion that holds the bone screw in place in the anchoring plate and a disengagement portion substantially opposing the engagement portion that allows the bone screw to be removed from the anchoring plate; wherein said locking screw has a first position that causes the engagement portion to be positioned closer to the bone screw than the disengagement portion in order to hold the bone screw in the anchoring plate and a second position that causes the disengagement portion to be positioned closer to the bone screw than the engagement portion to allow the bone screw to be removed from the anchoring plate, the locking screw being coupled to the anchoring plate while in the first and second positions.