Trial disk implant

A trial intervertebral disk implant, comprising:

• a) a first plate;
• b) a second plate, adjacent to the first plate;
• and
• c) a sensor at a surface of at least one of the first and the second plates proximal to an abutting vertebra.

A trial intervertebral disk implant, comprising:

• a) a first plate;
• b) a second plate, adjacent to the first plate;
• and
• c) indicating means, disposed within at least one of the first or the second plate, for indicating the position of the first and the second plates relative to each other.

A trial intervertebral disk implant, comprising:

• a) a first plate;
• b) a second plate, adjacent to the first plate;
• and
• c) locating means, disposed within at least one of the first or the second plate, for identifying the position of the trial implant relative to the vertebrae between which said trial implant has been placed.

A trial intervertebral disk implant, comprising:

• a) a first plate;
• b) a second plate, adjacent to the first plate;
• c) at least one retractable member, connected to at least one of the first and the second plates, wherein the retractable member can be extended or retracted through an aperture defined by a surface of the plate that is proximal to an abutting vertebra;
• and
• d) operating means, in at least one of the first or in the second plate, for extending and retracting the retractable member.

A method of selecting an artificial intervertebral disk to be inserted between two adjacent vertebral endplates, comprising the steps of:

• a) inserting between two adjacent vertebral endplates a trial intervertebral disk implant that includes
• (i) a first plate;
• (ii) a second plate, adjacent to the first plate;
• (iii) a conformable layer between the first and the second plates;
• and
• (iv) a sensor, within the conformable layer, selected from a pressure sensor, an angle sensor, a distance sensor or a combination thereof;
• b) measuring a distribution of compression force exerted by the endplates between which the trial implant has been inserted;
• and
• c) comparing the measured distribution of compression force to a distribution that minimizes variation of distribution of compression force while supporting abutting vertebrae in a substantially correct position relative to each other to thereby select an artificial disk.

A method of identifying a location between two adjacent vertebral endplates for placement of an artificial intervertebral disk, comprising the steps of:

• a) inserting between two adjacent vertebral endplates a trial intervertebral disk implant that includes
• (i) a first plate;
• (ii) a second plate, adjacent to the first plate;
• (iii) at least one retractable member, connected to at least one of the first and the second plate, wherein the retractable member can be extended or retracted through an aperture in a surface of at least one of the first and the second plate proximal to an abutting vertebra;
• and
• (iv) operating means, in at least one of the first and the second plate, for extending and retracting the retractable member;
• and
• b) extending the retractable member from the second plate, thereby indenting at least one of the vertebral endplates between which the trial implant has been placed to identify the location for placement of an artificial intervertebral disk.