An apparatus includes a support member and a retention member. The support
member has at least a portion configured to be disposed between a first
spinous process and a second spinous process. The retention member is
movably coupled to an end portion of the support member. The retention
member is configured to displace a bodily tissue. The retention member is
configured to move relative to the support member from a first position
to a second position. The retention member is configured to limit
movement of the support member along the longitudinal axis and relative
to the first spinous process and the second spinous process when in the
second position.