| 摘要 |
An expandable cage for intercorporal fusion of lumbar vertebrae comprises a main body with two expandable parallel arms. Each arm has a supporting surface pointing outside and configured to contact an adjacent vertebral body, a groove pointing inside and extending along a transverse direction, and a channel pointing inside and extending along a longitudinal direction. An expansion element is instrument actuated and presses the arms apart expanding the cage. The expansion element is between the arms and comprises a cylindrical base body, two opposing radially aligned ribs on the base body, and a rectangular plate. Both the base body and ribs have curved, pair-wise opposed bearing surfaces. Depending on the cage's expansion state, either the base body bearing surfaces or the rib bearing surfaces contact channels provided in the arms, while the plate engages in the grooves of the arms. |
| 主权项 |
1. An expandable cage for the intercorporal fusion of lumbar vertebrae, comprising
an elongated main body that comprises
two expandable arms that extend in an at least substantially parallel fashion to each other, wherein each arm has
a supporting surface pointing outside and configured to contact an adjacent vertebral body,a groove pointing inside and extending along a transverse direction of the main body, anda channel pointing inside and extending along a longitudinal direction of the main body,a bridge-like connection section connecting the arms so that, in a medial longitudinal section, the main body has at least substantially a U-shaped profile and the arms have two free ends, wherein the bridge-like connection section has an opening that is configured to receive an instrument for expanding the cage; an expansion element that is configured to press, if the expansion element is actuated by the instrument, the arms apart thereby expanding the cage, wherein the expansion element
is located at the free ends of the arms and is rotatably mounted between the arms,comprises an elongated base body, two opposing radially aligned ribs attached to the base body and extending along the longitudinal direction of the main body, and a rectangular plate that
is connected to the base body,has rounded edges andhas short sides that engage in the grooves provided in the arms both in the unexpanded and expanded state of the cage, wherein the expansion element further comprises a driving device that is located at a rear side of the expansion element, points towards the bridge-like connection and is configured to establish a releasable connection to the instrument, wherein both the base body and the ribs have curved, pair-wise opposed bearing surfaces, and wherein, depending on the expansion state of the cage, either the bearing surfaces of the base body or the bearing surfaces of the ribs contact the channels provided in the arms. |
