Patent ID: 8545499

Claim:
An expandable rod sized for insertion into a patient's bone, the expandable rod comprising: a shaft having a first end and a second end, wherein a portion of the shaft comprises a flat surface and a plurality of teeth comprising blocking faces oriented towards the first end of the shaft; an expansion member coupled to and adjustable along the shaft between a first, contracted state and a second, expanded state, the expansion member configured to expand radially outwardly from the contracted state to the expanded state, the expansion member including a first expansion segment and a second expansion segment, the first expansion segment having a higher slenderness ratio than the second expansion segment; and an actuator coupled to one end of the expansion member, wherein the actuator comprises: a central channel that receives the shaft such that the actuator is moveable along the shaft to adjust the expansion member between the contracted state and the expanded state; a cam biased toward the shaft and configured to slide over the plurality of teeth as the actuator moves along the shaft toward the first end and to catch on the blocking faces to prevent the actuator from moving toward the second end of the shaft; a release button configured to, when pressed, cause the cam to disengage from one of the blocking faces of the plurality of teeth to allow the actuator to move toward the second end of the shaft; and first and second circular surfaces connected by a cylindrical surface, wherein the central channel is aligned with and passes through a center of the first circular surface and a center of the second circular surface, wherein the release button is arranged in a slot in and protrudes radially outward from the cylindrical surface, and wherein the central channel comprises a flat wall that cooperates with the flat surface of the shaft to prevent the actuator and the shaft from rotating relative to one another.