Intervertebral cage which is expandable in steps and implantation instrument therefor
AssigneeFacet-Link Inc.
InventorKlaus DMUSHEWSKY
Life of this patent
Estimating the term…
Loading patent…
AssigneeFacet-Link Inc.
InventorKlaus DMUSHEWSKY
Estimating the term…
The invention relates to an intervertebral fusion implant for fusing two adjacent vertebrae (9, 9′), comprising a base piece (2) and a top piece (3) which in each case are designed to come to rest against a facing end plate (92) of one of the adjacent vertebrae (9, 9′), wherein the top piece (3) is vertically adjustable relative to the base piece (2), wherein a ratchet device (4), which effects a vertical adjustment in steps and secures a set height against reversion, is provided between the base piece (2) and the top piece (3). Thus a defined expansion can be achieved which is dependent upon the number of actuations. Precise control over the state of expansion is enabled in a purely haptic manner. Furthermore, implantation instruments are provided which are configured as parallel spreaders and have a stop as spreading path limiter or co-operating force and path measuring device. Thus it can be implanted more reliably, wherein the risk of overloading or injury to the vertebrae and the nerves and ligaments of the vertebrae is decreased.
An intervertebral fusion implant for fusion of two adjacent vertebrae (9, 9′), comprising a base piece (2) and a cover piece (3) which are each designed to bear on a facing end plate (92) of one of the adjacent vertebrae (9, 9′), the cover piece (3) being adjustable in height relative to the base piece (2), characterized in that a ratchet mechanism (4), provided between base piece (2) and cover piece (3), effects a stepped adjustment of height and secures an adopted height against reversal.
The intervertebral fusion implant as claimed in one of the preceding claims, characterized in that a catch mechanism (5) is provided, which limits adjustment movement of the cover piece (3), wherein preferably the catch mechanism (5) is formed by a pawl (52), which interacts with a shoulder projection (53), and/or by a transverse pin on the cover piece (3), which transverse pin engages in slot-like apertures on the base piece (2).
An implantation instrument for an expandable intervertebral fusion implant as claimed in one of the preceding claims, characterized in that the implantation instrument (7, 8) has a cross section which at most is as great as that of the intervertebral fusion implant (1).
Dependencies are inferred from the claim text.