System and method for replacing degenerated spinal disks

An artificial replacement disk that is positionable between vertebrae comprising:

• a first housing including a first cavity;
• a second housing including a second cavity;
• a first spacer and a second spacer, said first and second spacers mounted on a shaft with a resisting member located between the first and the second spacers and arranged concentrically on the shaft, which resisting member can urge said first and second spacers apart;
• and
• said first and second spacers partially located in said first cavity and partially located in said second cavity;
• and
• when the first housing is urged toward the second housing by one or both of an extension and flexion motion of the vertebrae, the first and the second spacers move relative to each other and against the resisting member.

An artificial replacement disk that is positionahle between vertebrae comprising:

• a first housing including a cavity;
• a second housing;
• a first spacer and a second spacer, said first and second spacers mounted on a shaft with a resisting member located between the first and the second spacers, which resisting member can urge said first and second spacers apart;
• said first and second spacers at least partially located in said cavity;
• wherein the cavity has a sloping portion, and a cylindrical portion;
• and
• when the first housing is urged toward the second housing, by one or both of an extension and flexion motion of the vertebrae the first and the second spacers move relative to each other and against the resisting member with one of the first and second spacers moving along the sloping portion of the cavity and toward the cylindrical portion.

An artificial spinal disk adapted to be positioned between adjacent vertebrae of a spine, comprising:

• an upper plate;
• a lower plate positioned opposite the upper plate such that a gap having a maximum width exists between the lower plate and the upper plate;
• a device arranged between the upper plate and the lower plate for urging the upper and lower plates apart, the device including:
• a shaft,
• a first spacer slidably associated with the shaft,
• a second spacer associated with the shaft, and
• a resisting mechanism disposed between the first spacer and the second spacer such that the first spacer and the second spacer are urged apart;
• and
• wherein when the upper plate and the lower plate are urged together and the resisting mechanism is overcome by one or both of an extension and flexion motion of the vertebrae, the first spacer and the second spacer are urged together such that at least a portion of the gap collapses.

A artificial spinal disk for substituting at least a portion of a spinal disk between adjacent vertebrae, comprising:

• an upper housing adapted to be positioned adjacent to a first vertebra;
• a lower housing positioned opposite the upper housing, the lower housing adapted to be positioned adjacent to a second vertebra;
• an first spacer positioned between the upper housing and the lower housing;
• a second spacer positioned between the upper housing and the lower housing;
• wherein the first spacer and the second spacer urge a gap between the upper housing and the lower housing;
• a shaft;
• the first spacer and the second spacer mounted on the shaft, one or both of the first spacer and the second spacer being movable along the shaft;
• a resisting mechanism adapted to urge the first and second spacer apart;
• and
• wherein when a force is applied to the upper housing and the lower housing such that the resisting mechanism is overcome, the gap is reduced.

An artificial spinal disk that is adapted to be placed between adjacent vertebral bodies of a spine, comprising:

• an upper elongated housing;
• a lower elongated housing;
• a first spacer and a second spacer positioned relative to an elongated shaft between the first and second housings with the elongated shaft being about parallel to the upper and lower elongated housings;
• a spring mechanism positioned along said shaft in order to urge said first and second spacers apart;
• and
• wherein when the upper and lower housings are urged together, by one or both of an extension and flexion motion of the vertebrae at least one of the first and second spacers can move relative to the other against the spring mechanism.