| 摘要 |
<p>The basic plate (2) can be made of several segments, each provided with an upper (6) and a lower disc with an eccentrically positioned opening (10). The opening (10) in the lower, thicker disc is of a conical shape, the wider area located at the bottom. The shaft of the bone screw can be swiveled around a ball element positioned between head and shaft and also slightly laterally moved inside the conical hole after being inserted into the basic plate (2).</p> |
