Multiple spindle adjustable interbody fusion devices and methods of use

An interbody fusion device, comprising:

• a base member including an outer bone contacting surface configured to interface with a bone;
• a top member detachably coupled to the base member and cooperatively forming a cavity with the base member, the top member defines a channel sized to receive the base member and including an outer bone contacting surface configured to interface with a bone;
• one or more tabs protruding inwardly into the channel from an inner surface of the top member;
• one or more notches formed in the outer bone contacting surface of the base member and sized to receive a corresponding tab;
• and
• an expansion mechanism disposed in the cavity, wherein the expansion mechanism includes a first assembly having a first gear ring, a first threaded rod defining a longitudinal axis and threadably coupled to the first gear ring such that the first threaded rod is axially translated along the longitudinal axis when the gear ring is rotatably driven, a first load head pivotally coupled to a top end of the first threaded rod and engaged with the top member, and a first support member that secures the first gear ring within a portion of the base member,
• wherein the first support member is further defined as a snap ring.