Stabilizing vertebrae with articulating implants

A spacer for separating bones of a joint, the spacer comprising:

• first and second driven modules, each including:
• first and second endplates, each having
• a first side forming a bone engaging surface,
• a second side opposite to the first side, and
• first and second angled sides extending from the first side in the direction of the second side,
• a single-piece shaft having
• a first end having threads, and
• a second end opposite to the first end and mateable with the second side of one of the first and second endplates;
• a collar slidably disposed upon the shaft proximate the shaft first end;
• and
• a nut threadably engaged with the shaft first end, the nut rotatable to push the collar in the direction of the shaft second end to move first and second endplates from a collapsed position to an expanded position, wherein in the expanded position the first and second endplates are spaced apart relative to each other;
• and
• a pair of link plates each having first and second spaced apart opposed ends pivotally joined to one of the first and second endplates of the first and second driven modules by a hinge connection, each link plate having a bone engaging surface such that when the first and second driven modules are vertically expanded, the link plates also expand vertically in the same direction such that the bone engaging surfaces of the link plates push against the bones to separate the bones of the joint,
• wherein in the collapsed position the first angled side of the first endplate engages the first angled side of the second endplate and in the expanded position the first angled side of the first endplate is separated from the first angled side of the second endplate, and
• wherein in the collapsed position the first angled side of the first endplate extends to the first side of the second endplate and the first angled side of the second endplate extends to the first side of the first endplate.

A spacer for separating bones of a joint, the spacer comprising:

• first and second endplates, each having
• a first side forming a bone engaging surface,
• a second side opposite to the first side, and
• first and second angled sides extending from the first side in the direction of the second side,
• a shaft having
• a first end, and
• a second end opposite to the first end and mateable with the second side of one of the first and second endplates;
• a collar slidably disposed upon the shaft proximate the shaft first end;
• and
• a nut threadably engaged with the shaft first end,
• a pair of link plates each having first and second spaced apart opposed ends pivotally joined to one of the first and second endplates of the first and second driven modules by a hinge connection, each link plate having a bone engaging surface such that as the first and second driven modules are vertically expanded, the link plates also expand vertically in the same direction such that the bone engaging surfaces of the link plates push against the bones to separate the bones of the joint,
• wherein in the collapsed position the first angled side of the first endplate engages the first angled side of the second endplate and in the expanded position the first angled side of the first endplate is separated from the first angled side of the second endplate,
• wherein the collar includes a threaded sleeve engageable by a surgical tool to couple the spacer and the tool, and
• wherein the threaded sleeve being an external threaded sleeve.