Method of using a vertebral retainer-distracter
A method for distracting at least two adjacent vertebrae and/or retaining them in a spaced apart position. Anchor screws are secured to the adjacent vertebrae and tubes of a retainer-distracter instrument frame are slid down over the anchor screws, after which the anchor screws are positively secured to the tubes of the frame. The frame includes a structure for moving the arms and hence the anchor screws and vertebrae toward and away from each other. After the anchor screws and frame are attached, a separate distracter distracts the vertebrae away from each other, whereupon the instrument acts only as a retainer to hold the vertebrae apart.
1 . A method for separating adjacent vertebrae from each other and maintaining them in a spaced apart condition, comprising the steps of:
attaching anchor screws to at least two adjacent vertebrae, which anchor screws are operatively mounted to a frame to be freely moveable away from each other but not freely moveable towards each other,
separating the adjacent vertebrae from each other by a mechanism other than through the anchor screws, as the anchor screws are moved, under the force of the separation, away from each other, and then retaining the adjacent vertebrae in the spaced apart condition with the anchor screws after the adjacent vertebrae have been separated.
2 . A method according to claim 1 , wherein the step of separating the adjacent vertebrae from each other includes engaging the intervertebral space between the adjacent vertebrae with a distracter instrument after the anchor screws have been secured to the vertebrae and the frame.
3 . A method according to claim 1 , including securing two anchor screws into two adjacent vertebrae.
4 . A method according to claim 1 , including securing three anchor screws, one to each of three adjacent vertebrae.