Method and apparatus for bone fixation with secondary compression
View Patent ↗Disclosed is a fracture fixation device, for reducing and compressing fractures in a bone. The fixation device includes an elongate body. An axially moveable proximal anchor is carried by the proximal end of the fixation device and comprises a tubular sleeve that includes a plurality of graduations positioned on an outer surface of the tubular sleeve. The device is rotated into position across the femoral neck and into the femoral head, and the proximal anchor is distally advanced to lock the device into place. In certain embodiments, the elongated body includes a distal anchor with a distal cutting tip.
1. A method of fixing an anchor to a bone, comprising the steps of:
providing a fixation device having central lumen extending from a proximal end to a distal end of the fixation device along a longitudinal axis and a double helix having a first radially outwardly extending element and a second radially outwardly extending element thereon, each radially outwardly extending element including a first cutting face extending longitudinally, and a second cutting face which extends along the central lumen from the first cutting face of the first radially outwardly extending element to the first cutting face of the second radially outwardly extending element, the first and second cutting faces forming the distal end of the fixation device by extending from an outer surface of the fixation device to the central lumen;
cutting a helical path into a bone with the distal end; and
rotating each radially outwardly extending element along the helical path.
2. The method of claim 1 , further comprising engaging a plurality of cutting edges of the first cutting faces with bone.
3. The method of claim 1 , wherein the first cutting faces have a neutral cutting angle.
4. The method of claim 1 , wherein the first cutting faces have a positive rake.
5. The method of claim 1 , wherein the first cutting faces have a negative rake.
6. The method of claim 1 , wherein at least one cutting edge of the first cutting faces extends generally parallel to the longitudinal axis of the fixation device.
7. The method of claim 1 , wherein at least one cutting edge of the first cutting faces extends generally perpendicularly to the longitudinal axis of the fixation device.