Patent ID: 8574300

Claim:
An expandable interbody spacer for implantation between vertebra having a collapsed condition and an expanded condition, the spacer comprising: a superior component having an external surface for contacting at least a portion of one vertebrae; an inferior component having an external surface for contacting at least a portion of another vertebrae, the superior and inferior components moveable relative to each other so that the spacer may move between the collapsed condition and the expanded condition; at least one boss member positioned between and moveable relative to at least one of the superior component and interior component, the boss member including a side surface and a distal end surface; and at least one expandable clip member, each clip member having a top surface, a relaxed position, a deflected position, and a space, wherein the boss member is arranged and configured to pass through the space when the clip member is in the deflected position and the clip member interferes with the movement of and does not permit the boss member to pass through the space when the clip member is in the relaxed position, each of the clip members being in the deflected position when the spacer is in the collapsed position, each of the clip members deflecting in a series to the relaxed position as the distal end surface of the boss member passes a top surface of each of the clips as the spacer expands thereby allowing the spacer to expand in predefined increments.