| 摘要 |
Prosthesis comprising two plates (1, 2) secured to the corresponding vertebrae (L4, L5), and a ball joint linking the plates to one another, its centre of rotation (C), in an anterior-posterior plane (OX, OY) being offset rearwards in the posterior part of the plates. The ball joint with reference to a transversal plane (OX, OZ) is located substantially in the middle of the plates, and with reference to a vertical plane (OY, OZ) is located under the plate (1) of the lower vertebra (L5). The prosthesis also includes an elastic intercalary cushioning ring (10) having an opening (10a) for the passage of the joint (3) and being lodged in the space delimited between the plates and around the joint. This positioning of the centre of curvature (C) prevents straining of the articular apophyses during movements of the vertebrae, while the elastic ring (1) matches the prosthesis to the physiological lordosis of the vertebral column, cushioning the multiple stresses occurring during these movements. |
