Patent ID: 8372148

Claim:
An intervertebral spacer comprising: a first contact surface; a second contact surface; a fluid chamber positioned between the first and second contact surfaces and configured to contain a fluid, the fluid chamber including an outer member with an open end, a sidewall, and a closed end, the outer member telescopingly receives an inner member; a slot in the sidewall of the outer member that extends inward from the open end; and a seal positioned in the slot to prevent the fluid from leaking from the fluid chamber; a retaining member attached to the outer member with a first section positioned on a first side of the slot and a second section positioned on an opposing second side of the slot; and wherein the retaining member is rotatably positioned within an opening in the outer member and movable between a first position with a width of the slot being a first distance and a second position with the width of the slot being a smaller second distance.