CPC A61B 17/863 (2013.01) [A61B 17/7032 (2013.01); A61B 17/7037 (2013.01); A61B 17/8635 (2013.01); A61B 17/864 (2013.01)] | 22 Claims |
1. A bone anchor comprising:
a proximal head; and
a cannulated distal shaft extending distally from the proximal head and configured to engage bone, the distal shaft having a first threaded section distal to the proximal head, a second threaded section distal to and adjacent the first threaded section, and a third threaded section distal to and adjacent the second threaded section,
the first threaded section having a first major diameter, a first minor diameter, and a first length, the first major diameter and the first minor diameter being constant over the first length of the first threaded section, the first threaded section having a proximal portion with a first number of thread starts and a distal portion with a second number of thread starts, the second number of thread starts being less than the first number of thread starts,
the second threaded section having a second major diameter and a second length, the second major diameter tapering in a proximal to distal direction over the second length of the second threaded section, the second threaded section having the second number of thread starts, and
the third threaded section having a third major diameter and a third length, the third major diameter tapering in a proximal to distal direction over the third length of the third threaded section, the third threaded section having the second number of thread starts;
wherein the second and third threaded sections have a wall thickness defined between a minor diameter and a cannula diameter, wherein the wall thickness is either constant or increasing in a distal to proximal direction from a distal-most end of the third threaded section to a proximal end of the second threaded section.
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