Patent ID: 8747472

Claim:
An assembly for implantation across two spinal vertebrae comprising: an externally threaded distal anchor for engagement with a distal vertebra; an externally threaded proximal anchor for engagement with a proximal vertebra; a spanning component that is threadedly engaged with the proximal anchor and extends into an interior of the distal anchor, wherein the spanning component may be rotated to set a minimum distance between a distal end of the proximal anchor and a proximal end of the distal anchor; and a compression inducing element adapted to: extend into an open interior of the spanning component; engage a shoulder within an interior of the proximal anchor, the shoulder facing a proximal end of the proximal anchor; engage a threaded bore within an interior of the distal anchor; and receive rotational input at a driver engagement section at a proximal end of the compression inducing element accessible via a proximal end of the proximal anchor such that a driver engaged with the driver engagement section of the compression inducing element has a capacity to reduce a distance between the distal anchor and the proximal anchor by pulling the distal anchor towards the proximal anchor, and wherein the shoulder within the interior of the proximal anchor is part of a component threadedly engaged to the interior of the proximal anchor.