| 摘要 |
The assembly is used for the stabilisation of two adjacent vertebral bodies (10) of the spine. It comprises two pedicle screws (1), having a threaded shaft (2) with a tapering first end (3) for introduction into the vertebral bodies (10) and a head portion (4) with a second end (5). It further comprises a flexible longitudinal fulcrum (6) with two portions (8), which can be disposed transversely to said pedicle screws (1), and fixed with its end portions (8) to the head portions (4) of said two pedicle screws (1) at a distance x from said second end. The assembly further comprises an elastic ligament (7) which can be disposed transversely to said two pedicle screws (1) and fixed to the head portions (4) of said two pedicle screws (1) at a distance y<x from the end portion of the fulcrum (8). By introduction of a fulcrum, lying close to the axis of flexion and extension of the spinal motion segment, the posteriorly placed ligament distracts the whole disc, and the fulcrum istself becomes a load-bearing structure. This reduces the load over the disc, and makes it an even distribution of load across the end-plate throughout the range of movement of the motion segment, that is allowed by the implant. |
