| 摘要 |
An orthopaedic implant provides a simple yet effective retention system requiring no additional components beyond the implant and the associated fastener(s). A plurality of anti-rotation protrusions on the fastener or screw head that match recesses in the implant. The protrusions engage the recesses to prevent the fastener from reversing direction, thereby assuring that the associated fastener does not backout during normal motion of the spine and other anatomical structures. A land on the fastener screw thread assures the fastener will not disengage from the implant should it strip out of the bone. Preventing the fastener from backing out assures it will not detach from the implant or staple, assuring that the implant will remain in place until all fasteners in the system have catastrophically failed. The anti-backout features of the invention provide feedback as they engage, allowing the surgeon to move quickly when placing a fastener without the concern for inadvertent over-tightening. Although ideally suited to a spinal correction system such as a cervical plate, the invention is applicable to other orthopedic devices, including plates and staples for other applications. |
