Abstract: An artificial disc includes an intermediate section which is disposed between upper and lower retainers. The intermediate section includes a first portion which resists rotation of one of the retainers, for example, the upper retainer, from a first position to a second position. A second portion of the intermediate section of the artificial disc resists rotation of the upper retainer from the second position to a third position. The second portion of the intermediate section of the artificial disc is ineffective to provide significant resistance to relative rotation between the retainers during rotation of the upper retainer relative to the lower retainer from the first position to the second position. The artificial disc may be provided with projections which engage protrusions on the intermediate section to resist rotation of the upper retainer relative to the lower retainer from the second position to the third position.

Abstract: An apparatus for replacing a spinal disc which has a rail extending from the outer surface to connect the apparatus to the first vertebra. The rail extends a first distance from the outer surface adjacent a first end. The rail extends a second distance from the outer surface adjacent a second end. The second distance is greater than the first distance. In another aspect of the apparatus, the first rail extends generally transverse to the first and second ends. The second rail extends generally transverse to the first rail.

Abstract: An apparatus for replacing a damaged spinal disc in a spinal column includes an artificial disc. The artificial disc includes a resilient core having a first surface and a second surface, a first retaining member connected to the first surface of the resilient core, and a second retaining member connected to the second surface of the resilient core. The first retaining member has an outer surface engageable with a first vertebra of the spinal column and an inner surface facing the first surface of the resilient core. The second retaining device has an outer surface engageable with a second vertebra of the spinal column and an inner surface facing the second surface of the resilient core. A first mounting member is connectable with the first vertebra and the artificial disc to position the artificial disc between the first and second vertebrae.

Abstract: A method for replacing a damaged spinal disc between first and second vertebrae of a spinal column includes connecting a first mounting member with the first vertebra of the spinal column. An artificial disc is moved between the first and second vertebrae and into engagement with the first mounting member to guide the artificial disc into position between the first and second vertebrae. The artificial disc includes a resilient core having a first surface and a second surface, a first retaining member connected to the first surface of the resilient core, and a second retaining member connected to the second surface of the resilient core. The first retaining member has an outer surface engageable with a first vertebra of the spinal column and an inner surface facing the first surface of the resilient core. The second retaining member has an outer surface engageable with the second vertebra of the spinal column and an inner surface facing the second surface of the resilient core.

Abstract: An artificial disc includes an intermediate section which is disposed between upper and lower retainers. The intermediate section includes a first portion which resists rotation of one of the retainers, for example, the upper retainer, from a first position to a second position. A second portion of the intermediate section of the artificial disc resists rotation of the upper retainer from the second position to a third position. The second portion of the intermediate section of the artificial disc is ineffective to provide significant resistance to relative rotation between the retainers during rotation of the upper retainer relative to the lower retainer from the first position to the second position. The artificial disc may be provided with projections which engage protrusions on the intermediate section to resist rotation of the upper retainer relative to the lower retainer from the second position to the third position.

Abstract: An apparatus for replacing a damaged spinal disc in a spinal column includes a resilient core having a first surface and a second surface. A first retaining device is connected to the first surface of the resilient core. The first retaining device includes an outer surface engageable with a first vertebra of the spinal column and an inner surface facing the first surface of the resilient core. A second retaining device is connected to the second surface of the resilient core. The second retaining device has an outer surface engageable with a second vertebra of the spinal column and an inner surface facing the second surface of the resilient core. The inner surface of the first retaining device is spaced from the core. The core deflects into engagement with the inner surface of the first retaining device upon relative movement between the first and second retaining devices.

Abstract: A spinal disc prosthesis to replace a damaged spinal disc in a spinal column (16) of a human, includes a body (10) having an upper surface (52) engageable with the upper vertebra (12) and a lower surface (152) engageable with the lower vertebra (14). The body (10) includes a crescent-shaped projection (62, 162) extending from one of the upper and lower surfaces (52, 152) of the body for receipt in a cavity in the adjacent vertebra (12, 14).