Cervitech, Inc.

Nuvasive, Inc.

Paul C McAfee

Arnold Keller

Helmut D Link

An intervertebral disc prosthesis having two cover plates and a prosthesis core that extends to the circumferential edge of the cover plates. The prosthesis core is mounted to the lower cover plate and forms a spherical sliding surface with the upper cover plate. The connection surface of the cover plates may be set back from the circumferential perimeter of the cover plates to provide an optimum size of the spherical sliding surface despite the set-back nature of the connection surface. The set-back is configured as an inclined transition surface that adjoins the connection surface to the circumferential edge. The set-back allows the intervertebral disc prosthesis to be fully inserted into the prepared disc space into the spared dorsolateral corners without protruding ventrally.

Cervical intervertebral prosthesis

A cervical intervertebral disk prosthesis has two cover plates, at least one of which is provided with a wedge-shaped connection surface for connection to a vertebral body and which is wider than it is deep. The dorsal edge of the connection surface may be set back from the dorsolateral edge of the cover plate having the connection surface and be connected to the dorsal edge protruding above it via a rounding or bevel.

Method for implanting an intervertebral disk prosthesis

An intervertebral prosthesis, in particular for the cervical spine, includes a first cover plate to be connected to a first vertebral body, second cover plate to be connected to the second vertebral body, and a prosthesis core which forms an articulation with the second cover plate. The prosthesis core is held by seat of the first cover plate which is designed as a guide device. The core can be pushed into the guide device from the ventral side in the anterior-posterior (AP) direction relative to the first cover plate. A limit-stop plate is provided on the ventral edge of the first cover plate. This limit-stop plate is displaceable in a slide guide between a locking position and a nonlocking position.

Intervertebral prosthesis with a limit stop plate

A cervical intervertebral disk prosthesis has two cover plates, at least one of which is provided with a wedge-shaped connection surface for connection to a vertebral body and which is wider than it is deep. The dorsal edge of the connection surface may be set back from the dorsolateral edge of the cover plate having the connection surface and be connected to the dorsal edge, protruding above it, via a rounding or bevel.

Cervical intervertebral disk prosthesis

An intervertebral prosthesis system, in particular for the cervical spine, includes at least two types of prostheses. The type of prosthesis includes a first cover plate that is configured to be connected to a first vertebral body, a second cover plate that is configured to be connected to a second vertebral body, and a prosthesis core which is held by a seat on the first cover plate and forms an articulation with the second cover plate. The core of the first type of prosthesis is movable in the anterior-posterior direction relative to the first cover plate. Mobility can also be provided in the lateral direction and rotational direction. The second type of prosthesis of the system may be the same as the first type of prosthesis or may be different, but in all examples of the second type of prosthesis the core is not movable relative to either cover plate.

Intervertebral prosthesis system, in particular for the cervical spine

Instrument set for fitting an intervertebral prosthesis, comprising a guide device () for an instrument or a prosthesis part, which guide device () is to be secured on at least one vertebral body (). To be able to attach the guide device () precisely on the vertebral bodies despite the difficult operating conditions, an adjustment instrument () is provided which positions the guide device when this is being arranged on the vertebral body (). This adjustment instrument () expediently comprises an intervertebral plate () which is fitted into the intervertebral space so as to be positioned exactly in relation to the vertebral bodies.

Instrument set for fitting an intervertebral joint prosthesis

A cervical intervertebral prosthesis includes two cover plates which are each configured to be connected to adjacent vertebral bodies. At least one of the two cover plates has a toothed portion which faces toward the vertebral body and whose teeth have a steep, ventrally directed flank and a less steep, dorsally directed flank. When the prosthesis is fitted with sufficient pressing between its adjacent vertebral bodies, the combination of the serrated toothed portion and the abutment surface is sufficient to hold the prosthesis securely in the desired position. In many cases this makes it possible to dispense with additional screw fixation. The flange carrying the abutment surface is in this case expediently shortened so that it can be accommodated in a recess of the bone so that the prosthesis does not protrude ventrally beyond the ventral alignment surface of the adjacent vertebral bodies.

A cervical intervertebral prosthesis includes at least one cover plate that is configured to be connected to one of its two adjacent vertebral bodies and a securing plate which secures this cover plate and is configured to be fastened to the ventral surface of the vertebral body. The securing plate may be a separate part that is unconnected to the cover plate and can be biodegradable.

An intervertebral prosthesis, in particular for the cervical spine, includes a first cover plate to be connected to a first vertebral body, a second cover plate to be connected to the second vertebral body, and a prosthesis core which forms an articulation with the second cover plate. The prosthesis core is held by a seat of the first cover plate which is designed as a guide device. The core can be pushed into the guide device from the ventral side in the anterior-posterior (AP) direction relative to the first cover plate. A limit-stop plate is provided on the ventral edge of the first cover plate. This limit-stop plate is displaceable in a slide guide between a locking position and a nonlocking position.

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Baltimore, MD, United States of America

Paul C McAfee