| 摘要 |
<p>The present invention discloses a screw (10) adapted for insertion into a bone and in particular a vertebra. The screw (10) is divided into two distinct regions (16 and 18) with the depth of the screw thread (20, 22) in each region being different to that in each other region whilst the overall diameter of the screw (10) is substantially constant over the length of the screw (10).</p> |
