Intervertebral disc prosthesis with transversally arched, curved cyclindrical articulation surfaces for the lumbar and cervical spine
First Claim
1. An intervertebral disc prosthesis for total replacement of an intervertebral disc within a lumbar or cervical spine, comprisingan upper sliding partner adapted to firmly assemble to an upper vertebral body and a lower sliding partner adapted to firmly assemble to a lower vertebral body and a middle sliding partner located between the upper and lower sliding partners, wherein said sliding partners articulate with respect to each other and whereina) the middle sliding partner has an upper and lower surface where the upper and lower surfaces each have a convexity, andb) the upper and lower sliding partner each has a concavity corresponding to the convexity of the upper and lower surfaces of the middle sliding partner, respectively, andthe convexities of the upper and lower surfaces of the middle sliding partner and the concavities of the upper and lower sliding partners correlate to a cylinder along its longitudinal axis laterally from right to left, wherein the cylinder has a transversal ventrally directed arched curvature and the concavities of the upper and lower sliding partners are surrounded dorsally, ventrally and laterally, at both sides, by edges,c) wherein the edges extend between an outer rim and each concavity of the upper and lower sliding partners define an outwardly opening aperture angle upon assembly, and whereina. no inclination of the upper and lower sliding partners towards each other in the lateral direction is possible, andb. a maximal possible motion of the sliding partners in dorsoventral direction is limited by a gap-closure of the outwardly opening aperture angle defined by the edges of the upper and lower sliding partners, andd) wherein rotation of the upper, middle and lower sliding partners towards each other is limited by a tolerance laterally right and left of the convexities and concavities.
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Abstract
An intervertebral disc prosthesis for the total replacement of a intervertebral disc within the lumbar and cervical spine is disclosed. The intervertebral disc prosthesis comprises articulating sliding partners, wherein the upper sliding partner has means for a firm assembly to an upper vertebral body and the lower sliding partner has means for a firm assembly to a lower vertebral body and at least one sliding surface that is between two sliding partners. Functional two- and three part designs are planned and both prostheses have in common, that only a dorsoventral- and rotation movement is possible as a result of laterolaterally aimed, transversally arched, ventrally curved cylindrical convexity(ies) and corresponding concavity(ies), however without an inclination of the sliding partners in a lateral direction. In a further design, the cylindrical articulation surfaces have no curvature, enabling a motion of the sliding partners in only a ventrodorsal direction. According to the invention, the intervertebral disc prostheses are suited for implantation from lateral and ventrolateral, particularly in revision surgeries.
28 Citations
40 Claims
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1. An intervertebral disc prosthesis for total replacement of an intervertebral disc within a lumbar or cervical spine, comprising
an upper sliding partner adapted to firmly assemble to an upper vertebral body and a lower sliding partner adapted to firmly assemble to a lower vertebral body and a middle sliding partner located between the upper and lower sliding partners, wherein said sliding partners articulate with respect to each other and wherein a) the middle sliding partner has an upper and lower surface where the upper and lower surfaces each have a convexity, and b) the upper and lower sliding partner each has a concavity corresponding to the convexity of the upper and lower surfaces of the middle sliding partner, respectively, and the convexities of the upper and lower surfaces of the middle sliding partner and the concavities of the upper and lower sliding partners correlate to a cylinder along its longitudinal axis laterally from right to left, wherein the cylinder has a transversal ventrally directed arched curvature and the concavities of the upper and lower sliding partners are surrounded dorsally, ventrally and laterally, at both sides, by edges, c) wherein the edges extend between an outer rim and each concavity of the upper and lower sliding partners define an outwardly opening aperture angle upon assembly, and wherein a. no inclination of the upper and lower sliding partners towards each other in the lateral direction is possible, and b. a maximal possible motion of the sliding partners in dorsoventral direction is limited by a gap-closure of the outwardly opening aperture angle defined by the edges of the upper and lower sliding partners, and d) wherein rotation of the upper, middle and lower sliding partners towards each other is limited by a tolerance laterally right and left of the convexities and concavities.
Specification