Posterior functionally dynamic stabilization system

摘要

A functionally dynamic stabilization unit and system for treatment of spinal instability are provided. Each unit, and collectively, the system, is configured to control flexion, extension and translation of the affected unstable vertebral area, thereby stabilizing the vertebral segments by restoring normal function. This is achieved by providing a unit and system that allow for lateral bending, axial compression, rotation, anterior segmental height adjustment, and posterior segmental height adjustment. The unit and system provide sufficient segmental stiffness, while also limiting, or controlling, the range of motion (i.e., sufficient stiffness in the neutral or active zone, while limiting or preventing motion outside of the active zone) to stabilize the vertebral segments. In use, the system mimics the natural movement of the normal spine. Furthermore, the system includes a rigid, fusion-promoting coupler configured for use in an adjacent level, or as a substitute for the functionally dynamic unit. The modularity of the system allows adjustment over time and easier revision surgery, and is configured for minimally-invasive, delivery or implantation.

主权项

1. A modular spinal stabilization system, comprising:
a flexible coupler including a flexible body, a pair of arms, the arms being located at opposed ends of the flexible coupler, and a range-of-motion limiting mechanism configured to control an amount of bending, an amount of compression, and an amount of extension of the flexible coupler, the range-of-motion limiting mechanism comprising an attachable sleeve with a narrowed distal opening residing within the flexible body and a pin comprising an elongated body with an enlarged head region and shoulder region, the pin being configured to be received within and cooperate with the attachable sleeve to form an extension and compression stop within the flexible body, the sleeve extending internally from a first end of the flexible coupler towards a second end of the flexible coupler, and the elongated body of the pin extending internally from the second end of the flexible coupler towards the first end of the flexible coupler, the enlarged head region of the pin being disposed within the sleeve and dimensioned such that the enlarged head region abuts the wall of the narrowed distal opening when the flexible coupler is elongated or bent, and the sleeve abuts the second end of the flexible coupler when the flexible coupler is compressed, wherein at least one of the arms has an adjustable connection to the flexible body that permits relative movement of the arm to the flexible body in order to adjust the overall length of the flexible coupler; a rigid coupler including a pair of arms, the arms being located at opposed ends of the rigid coupler; and a fixation system including a plurality of bone anchors configured to cooperate with the arms of the flexible and rigid couplers to attach the couplers to bone.