Patch for covering a defect in the annulus fibrosus of an intervertebral disc, and in particular also in the posterior longitudinal ligament, of a spine
The present invention refers to a patch for covering a defect in the annulus fibrosus of an intervertebral disc, and in particular also in the posterior longitudinal ligament, of a spine. A further aspect of the present invention refers to a surgical kit, including such a patch and at least one fastening element for fastening the patch body to the spine.
1 . A patch for covering a defect in an annulus fibrosus of an intervertebral disc of a spine, comprising:
a patch body that is formed as a sheet and has a tensile stiffness between 20×10 3 N/m and 40×10 3 N/m, parallel to a first axis, wherein the first axis lies on a main face of the patch body,
wherein the patch body also has a second axis, wherein the second axis lies on the main face of the patch body and is vertical to the first axis.
2 . The patch according to claim 1 , wherein the patch body has a total elongation equal to or higher than 160% parallel to the first axis and/or the second axis.
3 . The patch according to claim 1 , wherein the patch body is configured such that, for achieving a tensile elongation equal to or higher than 50% parallel to the first axis, a tensile load of equal to or less than 150N is required parallel to the first axis,
and/or
wherein the patch body is configured such that, for achieving a tensile elongation equal to or higher than 50% parallel to the second axis, a tensile load of equal to or less than 150N is required parallel to the second axis.
4 . The patch according to claim 1 , wherein the patch body is made of a material that has a yield strength between 5×10 6 Pa and 8×10 6 Pa.
5 . The patch according to claim 1 , wherein the patch body comprises at least one through opening for receiving a fastening element for fastening the patch to the spine.
6 . The patch according to claim 5 , wherein a reinforcing and/or stress distribution element is provided on the patch body around a boundary of the at least one through opening, wherein the reinforcing and/or stress distribution element is made of metal or plastic.
7 . The patch according to claim 6 , wherein the reinforcing and/or stress distribution element is formed as an insert that is inserted in the at least one through opening.
8 . The patch according to claim 6 , wherein the reinforcing and/or stress distribution element is fixedly connected to the patch body.
9 . The patch according to claim 5 , wherein a minimum distance between a boundary of the at least one through opening and a boundary of the patch body is at least 5% of a dimension of the patch body parallel to the first axis and/or the second axis.
10 . The patch according to claim 5 , wherein a minimum distance between a boundary of the at least one through opening and a boundary of the patch body is at least 10% of a dimension of the patch body parallel to the first axis and/or the second axis.
11 . The patch according to claim 1 , wherein the patch body has a rectangular shape and/or wherein the patch body extends parallel to the first axis more than it extends parallel to the second axis.
12 . The patch according to claim 1 , wherein the patch body is formed as a mesh made of non-woven fibers.
13 . The patch according to claim 12 , wherein the mesh comprises/is made of polytetrafluoroethylene fibers and/or expanded polytetrafluoroethylene fibers.
14 . A surgical kit, comprising the patch according to claim 1 and at least one fastening element for fastening the patch body to the spine.
15 . The patch according to claim 1 , wherein the patch is also configured for covering a defect in a posterior longitudinal ligament of the spine.
16 . The patch according to claim 1 , wherein:
the tensile stiffness is between 25×10 3 N/m and 35×10 3 N/m parallel to the first axis, and
wherein the tensile stiffness is between 25×10 3 N/m and 35×10 3 N/m parallel to the second axis.
17 . The patch according to claim 1 , wherein the patch body is configured such that, for achieving a tensile elongation equal to or higher than 50% parallel to the first axis, a tensile load of equal to or less than 100 N, is required parallel to the first axis,
and/or
wherein the patch body is configured such that, for achieving a tensile elongation equal to or higher than 50% parallel to the second axis, a tensile load of equal to or less than 100 N, is required parallel to the second axis.
18 . The patch according to claim 1 , wherein the patch body has a tensile stiffness between 20×10 3 N/m and 40×10 3 N/m, parallel to a second axis, wherein the second axis lies on the main face of the patch body and is vertical to the first axis.