Paragraph Number

59

The shank 212 may optionally have multiple screw threads. For example, a first screw thread 240 may extend from the head 210 to the tip 214. The first screw thread 240 may be designed to penetrate both cortical and cancellous bone. A second screw thread 242 may extend from the head 210 to the intermediate portion 202 of the screw 104, between the head 210 and the tip 214. In some embodiments, the second screw thread 242 may extend along a length of the shank 212 that generally corresponds to the expected thickness of cortical bone in the bone 102. Thus, the denser and stronger cortical portion of the bone 102 is penetrated by both the first screw thread 240 and the second screw thread 242, while the weaker and more porous cancellous portion of the bone 102 receives only the first screw thread. Such a design may maximize purchase in the cortical portion of the bone, while avoiding exertion of too much shear stress on the cancellous bone.

Added by DJM 5 2021