Customized intervertebral prosthetic disc with shock absorption
A prosthesis system comprises plates that can be positioned against vertebrae and a selected resilient core that can be positioned between the plates to allow the plates to articulate. The selected resilient core can be chosen from a plurality of cores in response to patient characteristics, such as age and/or intervertebral mobility, such that the prosthesis implanted in the patient is tailored to the needs of the patient. The plurality of cores may comprise cores with different resiliencies, and one of the cores can be selected such that the upper and lower plates articulate with the desired shock absorbing resiliency and/or maximum angle of inclination when the one selected core is positioned between the plates.
1. An intervertebral disc prosthesis system comprising:
a disc prosthesis comprising:
upper and lower supports each support comprising, an outer surface which engages a vertebra and an inner surface; and
a core configured to be received between the inner surfaces of the upper and lower supports and to slide over the inner surfaces of the upper and lower supports to provide articulation of the intervertebral disc; and
a retaining formation which holds the core captive between the upper and lower supports; and
wherein the upper and lower supports are adapted to articulate with respect to one another and the core when the core is positioned between the upper and lower supports;
wherein the disc prosthesis is loaded on a cartridge comprising:
a central member configured to be positioned between the inner surfaces of the upper and lower supports; and
upper and lower flanges configured to engage the outer surfaces of the upper and lower supports, wherein the central member, upper and lower flanges together clamp the upper and lower supports while the disc prosthesis is advanced.
2. The system of claim 1 , wherein the retaining formation includes two or more groove-like recesses spaced apart about a periphery of the core and two or more inwardly directed pegs or pins on one of the upper and lower plates, wherein each peg or pin opposes a spaced recess.
3. The system of claim 2 , wherein the spaced recesses are formed in the lateral surfaces of the core.
4. The system of claim 3 , wherein the spaced recesses extend radially inward from the lateral surfaces of the core.
5. The system of claim 2 , wherein the retaining formation allows anterior, posterior and lateral motion of the core with respect to the first and second plates.
6. The system of claim 2 , wherein the pegs or pins are configured to extend into the recesses during sliding motion of the plates over the core.
7. The system of claim 1 , wherein the cartridge comprises inwardly facing projections provided on ends of the upper flange and lower flange.