| 主权项 |
1. An interspinous spacer device for the stabilization of a degraded spinal segment, the device comprising:
a base comprising:
a body containing a curved internal track, wherein the track opens upward into an aperture contained within an upper surface of the body, wherein the aperture has an aperture cross-sectional area that is smaller than a corresponding track cross-sectional area of the curved internal track; anda caudal attachment fitting comprising a first caudal attachment plate and a second caudal attachment plate projecting perpendicularly downward from opposite edges of the body of the base; and a sliding rod comprising:
a retaining plate situated within the curved internal track, wherein the retaining plate has a non-circular cross-sectional shape and a plate cross-sectional area that is larger than the aperture cross-sectional area and smaller than the track cross-sectional area;a column comprising an upper column end and a lower column end opposite to the upper column end, wherein the lower column end is attached to the retaining plate and the upper column end protrudes upward through the aperture and out of the upper surface of the body; anda cranial attachment fitting comprising a lower plate attached to the upper column end of the sliding rod, and a first cranial attachment plate and a second cranial attachment plate attached to opposite edges of the lower plate, wherein the first and second cranial attachment plates extend perpendicularly upwards from the lower plate; wherein the non-circular cross-sectional shape of the retaining plate is essentially matched with a cross-sectional shape of the curved internal track such that the retaining plate of the sliding rod freely slides within the curved internal track without significant resistance force to actuate an arcuate movement of the sliding rod along a range of movement limited by a length of the curved internal track, and with a center of rotation of the arcuate movement situated at a perpendicular distance from the track that is equal to a radius of curvature along the length of the curved internal track; and wherein the base is attachable to a caudal spinous process of a vertebra situated caudal to the degraded spinal segment and the sliding rod is attachable to a cranial spinous process of a vertebra situated cranial to the degraded spinal segment. |
