US Patent 10117754 Expandable intervertebral implant

A joint spacer for therapeutically maintains separation of bones of a joint. A frame defines a longitudinal axis extending between distal and proximal ends. A carriage is slideably retained within the frame and has at least one ramped surface and a threaded portion. An actuator screw is threadably engaged with the threaded portion, and bears against said frame to cause the carriage to slideably move within the frame when the actuator screw is rotated. A first endplate engages a bone of the joint, and has at least one ramped surface that is mateable with the ramped surface of the carriage.