| 摘要 |
<p>A medullary-cavity drill head, preferably for removable attachment to a flexible drive shaft, has a distal-end cutting portion and a proximal-end shank portion for connection to the drive shaft; the drill head has a central bore for guidance along a guide wire within the medullary canal of a bone, such as a fractured femur or tibia. The cutting portion has plural equally spaced teeth with distally exposed cutting edges which generate a frustoconical surface of distal cutting action. The cutting edges determine a maximum diameter Dmax of cutting action, and all other surfaces of the teeth and remaining parts of the drill head are such as to generate profiles of revolution that are at least relieved from Dmax and therefore at offset within the geometric cylinder of cutting-edge action.</p> |
