Expandable intervertebral implant

A joint spacer for therapeutically maintaining a separation of bones of a joint, comprising:

• a frame having distal and proximal ends defining a longitudinal axis extending therebetween;
• a carriage slideably retained within said frame and having a first portion including a first ramped surface, a second portion including a second ramped surface, and an opening between the first and second portions, said carriage further including a threaded bore, and wherein the carriage is slideably supported in the frame by two support screws engaged with the carriage and passable through respective channels formed in the frame;
• an actuator screw threadably engaged with said carriage threaded bore, said actuator screw configured to bear against said frame to cause said carriage to slideably move within said frame when said actuator screw is rotated, wherein the actuator screw extends from the first portion, through the opening, and into the second portion of the carriage, and the actuator screw is supported in the frame by a second screw extending through the frame and into a distal end of the actuator screw;
• a first endplate configured to engage a first bone of the joint, and having at least one channel having a ramped surface engageable with said at least one of said first or second ramped surface of the carriage, whereby when said carriage is slideably moveable by rotation of said actuator screw in a first direction, said at least one endplate ramped surface slideable against said first or second ramped surface of the carriage to cause said first endplate to move along an axis transverse to said longitudinal axis to increase a height of the spacer;
• a second endplate configured to engage a second bone of the joint;
• and
• a fastener
• wherein said second endplate includes at least one aperture through which said fastener passes to secure said second endplate to a bone of the joint,
• wherein said carriage is slideably supported by said actuator screw and the channels are elongated in a direction parallel to the longitudinal axis such that the two support screws are slideable along the respective elongated channels.