| 摘要 |
An intervertebral disc prosthesis comprises a first plate designed for attachment to an upper vertebra and a second plate designed for attachment to a lower vertebra. A prosthesis core is positioned between the first plate and the second plate. At least one spring is connected between the first plate and the second plate. The spring comprises a U-shaped torsion bar including a first leg and a second leg. The first leg of the U-shaped torsion spring is attached to the first plate and the second leg is attached to the second plate. The spring provides a selected amount of resistance to movement of the first plate relative to the second plate. In one embodiment, the selected resistance is provided by the attachment locations of the spring to the plates. In another embodiment, the selected resistance is provided by a predetermined spring rate of the springs of the prosthesis.
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