US Patent 10137006 Geared cam expandable interbody implant and method of implanting same

A geared cam expandable spinal implant. Rotational motion of a rotating portion is translated into linear motion of a yoke, which moves geared cams at the distal end of the implant to mate with, and walk along, teeth of corresponding racks. The walking of the gear cam teeth along the rack teeth creates a regular rate of implant expansion, reduces initial excessive expansion force applied to the implant, and provides fine adjustment of the expansion rate and force.