Interspinous process implants and methods of use

An apparatus comprising:

• an implant having a central portion, a distal end portion, and a proximal portion disposed generally opposite the distal end portion relative to the central portion;
• at least a portion of the central portion configured to be disposed between a pair of adjacent spinous processes of a human spine;
• the proximal portion having a flange extending outward beyond the central portion;
• a retention member rotatably coupled to the distal end portion of the implant and configured to rotate about a first axis between a first position and a second position;
• the retention member having a cross-sectional area projected on to a plane orthogonal to the first axis, the cross-sectional area of the retention member being within a cross-sectional area of the distal end portion of the implant projected on to a plane orthogonal to the first axis when the retention member is in the first position, the retention member configured to limit lateral movement of the implant relative to the pair of adjacent spinous processes when in the second position;
• wherein the implant, including the central, distal, and proximal portions, is configured to be surgically implanted in a human spine such that the central portion is disposed between adjacent spinous processes and extends through a sagittal plane defined by the spinous processes with the flange disposed on one lateral side of the spinous processes and the retention member in its second position is disposed on a second lateral side of the spinous processes
• a rotatable member having a threaded portion configured to move the retention member from the first position and the second position when the rotatable member is rotated about a second axis non-parallel to the first axis.

An apparatus, comprising:

• an implant having a central portion configured to be disposed between a pair of adjacent spinous processes;
• a retention member rotatably coupled to the implant and configured to rotate about an axis between a first position and a second position, the retention member configured to limit lateral movement of the implant relative to the pair of adjacent spinous processes when in the first position;
• and
• a rotatable member coupled to the implant, the retention member having a wall defining at least a portion of a cavity within which at least a portion of the rotatable member is disposed when the retention member is in the second position, the rotatable member configured to move the retention member between the first position and the second position;
• the rotatable member having a tool engagement feature adapted to receive a tool, for rotating the rotatable member, from a direction along an axis of rotation of the rotatable member.