Retrodrill system

1. A method of creating a bone tunnel during ligament reconstruction surgery comprising:

placing a guide wire through a femur, the guide wire having:

at a first end of the guide wire a pointed tip end portion including a pointed tip, and

at a second end of the guide wire a drill bit assembly coupling end portion;

placing a drill mechanism over the pointed tip end portion of the guide wire, the drill mechanism having a first end portion including a drill bit and a second end portion including an attachment portion;

coupling an adaptor assembly to the attachment portion, the adaptor assembly including a shaft;

coupling a drill to the shaft and operating the drill to create a tunnel in the femur;

coupling a drill bit assembly to the drill bit assembly coupling end portion of the guide wire and locating the drill bit assembly against the drill bit of the drill mechanism; and

operating the drill to create a counter bore within the tunnel,

wherein coupling a drill bit assembly to the drill bit assembly coupling end portion of the guide wire further comprises fixating the drill bit assembly to the guide wire using a locking mechanism.

2. The method of claim 1 , wherein placing a guide wire through a femur comprises:

inserting a cannulated shaft of a drill guide into the femur joint;

positioning a cannulated shaft against the femur; and

inserting the cannulated guide wire through the shaft.

3. The method of claim 1 , wherein the locking mechanism comprises a spring and detent ball.

4. The method of claim 1 , further comprising inserting the guide wire through a patient's skin.

5. The method of claim 1 , further comprising:

inserting the guide wire back into the drill mechanism until the drill bit assembly abuts the drill bit of the drill mechanism.

6. The method of claim 1 further comprising:

locking the adaptor assembly to the guide wire by rotating a nut until a ring engages the guide wire.