A method of decorticating vertebral endplate material from vertebrae of a spine comprising the steps of:
- creating an incision in a body of a patient proximate to desired vertebrae whose endplates are to be decorticated;
- providing a vertebral endplate decorticating instrument comprising:
- a handle;
- a controller operably connected to the handle and including a rotatable control knob with an internally threaded bore, wherein rotation of the handle rotates the rotatable control knob;
- a shaft assembly having a longitudinal tube defining a longitudinal tube proximal end and a longitudinal tube distal end with a control rod disposed therein, the control rod defining a distal control rod end and a proximal control rod, the proximal control rod end having external threading that is received in the internally threaded bore of the rotatable control knob for controlled axial movement of the control rod by the handle;
- a decorticating head disposed at the distal end of the longitudinal tube distal end and defining a decorticating head proximal end and a decorticating head distal end, the decorticating head distal end having a first front angled dovetail slot slanted at a first angle, and a second front angled dovetail slot slanted at a second angle opposite the first angle, the decorticating head proximal end having a first rear angled dovetail slot slanted at a third angle complementary to the first angle of the first front angled dovetail, and a second rear angled dovetail slot slanted at a fourth angle complementary to the second angle of the second front angled dovetail;
- a first blade having a first blade front angled dovetail slanted at a fifth angle being the same as the first angle of the first front angled dovetail slot and a first blade rear angled dovetail slanted at a sixth angle being the same as the third angle of the first rear angled dovetail slot, the first blade front angled dovetail situated in the first front angled dovetail slot of the decorticating head, and the first blade rear angled dovetail situated in the first rear angled dovetail slot of the decorticating head, whereby the first blade is radially moveable relative to the decorticating head;
- and
- a second blade having a second blade front angled dovetail slanted at a seventh angle being the same as the second angle of the second front angled dovetail slot and a second blade rear angled dovetail slanted at an eighth angle being the same as the fourth angle of the second rear angled dovetail slot, the second blade front angled dovetail situated in the second front angled dovetail slot of the decorticating head, and the second blade rear angled dovetail situated in the second rear angled dovetail slot of the decorticating head, wherein the second blade is radially moveable relative to the decorticating head;
- wherein axial force against the first blade via the control rod in a first axial direction effects radially outward movement of the first blade relative to the decorticating head via interaction of the first blade front angled dovetail and the first front angled dovetail slot of the decorticating head, and the first blade rear angled dovetail situated in the first rear angled dovetail slot of the decorticating head, while axial force against the first blade via the control rod in a second axial direction opposite the first axial direction effects radially inward movement of the first blade relative to the decorticating head via interaction of the first blade front angled dovetail and the first front angled dovetail slot of the decorticating head, and the first blade rear dovetail situated in the first rear angled dovetail slot of the decorticating head;
- and
- wherein axial force against the second blade via the control rod in the first axial direction effects radially outward movement of the second blade relative to the decorticating head via interaction of the second blade front angled dovetail and the second front angled dovetail slot of the decorticating head, and the second blade rear angled dovetail situated in the second rear angled dovetail slot of the decorticating head, while axial force against the second blade via the control rod in the second axial direction opposite the first axial direction effects radially inward movement of the second blade relative to the decorticating head via interaction of the second blade front angled dovetail and the second front angled dovetail slot of the decorticating head, and the second blade rear angled dovetail situated in the second rear angled dovetail slot of the decorticating head;
- inserting the vertebral endplate decorticating instrument into the incision;
- positioning the inserted vertebral endplate decorticating instrument accordingly;
- and
- using the vertebral endplate decorticating instrument to decorticate the endplates of the desired vertebrae.