Rigid segmented flexible anchors
A prosthetic implant replaces hyaline cartilage in a synovial joint with a flexible polymer sliding surface, preferably of hydrogel, on a segmented support with an array of adjacent segments to which the hydrogel is molded. Adjacent segments are laterally and angularly displaceable permitting the implant to conform to rounded or irregular surfaces or to be rolled or folded for arthroscopic placement. Tension cables threaded through segments along a circuit can cinch segments together for stiffening the supporting layer and/or the cable can pull the implant against a bone surface. Adjacent segments can have inter-engaged structures. In some embodiments the segments are carried on a flexible foil or fibrous sheet.
1 . An implant for emulating hyaline cartilage in an articulating mammalian joint, comprising:
laterally adjacent segments encompassing an area of a surface corresponding to the hyaline cartilage,
wherein each segment is a polygonal segment configured to be mechanically attached to adjacent segments, and
wherein, when the segments are mechanically attached to one another, the segments are configured to diverge angularly from one another to conform to a topography to which the implant is to be attached.
2 . The implant of claim 1 , wherein the segments are displaceable in at least one of lateral inter-spacing and inclination relative to one another.
3 . The implant of claim 2 , wherein the segments define cannulae and further comprising at least one line passing through the cannulae of adjacent ones of at least a subset of the segments.
4 . The implant of claim 3 , wherein at least a mechanically attached subset of adjacent ones of the segments are configured to hinge relative to one another on at least one axis defined by cannulae through which the line passes.
5 . The implant of claim 3 , comprising a plurality of lines passing through the cannulae of adjacent ones of a tethered subset of the segments, wherein an outer one of the lines surrounds an inner one of the lines, and wherein the outer ones of the lines and the inner ones of the lines are tensioned separately.
6 . The implant of claim 2 , wherein the segments define aligned cannulae along a plurality of parallel lines and further comprising at least one line passing through the cannulae and defining hinge axes.
7 . The implant of claim 1 , wherein each polygonal segment is a hexagonal segment having three pairs of diametrically opposite sides, wherein:
each side in each pair of the three pairs of diametrically opposite sides is provided with a complementary hinging structure comprising a central hinge knuckle or two straddling hinge knuckles;
one side in each pair of the three pairs of diametrically opposite sides is provided with a first complementary hinging structure comprising the central hinge knuckle;
the other side in each pair of the three pairs of diametrically opposite sides is provided with the two straddling hinge knuckles; and
the central hinge knuckle of a first hexagonal segment is configured to fit between the two straddling hinge knuckles of a second hexagonal segment to mechanically attach the first hexagonal segment to the second hexagonal segment.
8 . The implant of claim 7 , wherein the central hinge knuckle is cannulated along at least one of a first axis of hingeable engagement that is parallel to the associated side of the associated hexagonal segment and a second axis extending through the associated hexagonal segment that is perpendicular to the associated side of the associated hexagonal segment.
9 . The implant of claim 1 , wherein the segments include a backer layer configured for tissue ingrowth.
10 . The implant of claim 1 , wherein the segments are structured to admit a fastener for affixing selected ones of the segments to underlying tissue.
11 . The implant of claim 10 , wherein the segments comprise vertical, horizontal and inclined frame members, and wherein at least one said fastener is configured to extend between spaced ones of the frame members.
12 . The implant of claim 11 , wherein the fastener comprises a staple and is configured for selective placement at one of at least two different angles relative to the frame members.
13 . The implant of claim 12 , wherein the staple is configured to extend through the frame members at a selected one of at least two angles relative to an underlying surface.
14 . The implant of claim 11 , wherein at least one of the frame members and the fastener is configured for attachment of a suture.
15 . The implant of claim 1 , wherein at least one of the laterally adjacent segments and subsets of the laterally adjacent segments are displaceable relative to one another at lines of abutment.
16 . The implant of claim 15 , wherein said at least one of the laterally adjacent segments and subsets of the laterally adjacent segments are configured to diverge angularly along the lines of abutment, whereby the implant can conform to a surface that has a changing gradient across the lines of abutment.
17 . The implant of claim 1 , further comprising a hydrogel layer affixed to at least one side of the implant and configured to provide an exposed sliding surface in the articulating joint.
18 . The implant of claim 1 , wherein, in an expanded position, at least some of the segments are entirely spaced apart from an adjacent one of the segments by a gap, and wherein a size of the gap is adjustable to enable the segments to converge toward one another or to diverge from one another to conform to the topography to which the implant is to be attached.
19 . An implant for emulating hyaline cartilage in an articulating mammalian joint, comprising:
an array of polygonal segments comprising complementary hinging structures provided on edges of the polygonal segments to mechanically attach laterally adjacent segments in the array to one another, wherein each polygonal segment in the array defines cannulae running
(i) through the associated complementary hinging structures parallel to the associated edges of the associated polygonal segment,
(ii) through a center region of the associated polygonal segment perpendicular to the associated edges of the associated polygonal segment, or
(iii) a combination thereof; and
a tensioning cable configured to pass through a subset of cannulae of an associated subset of polygonal segments,
wherein the polygonal segments in the array are configured to diverge angularly from one another to conform the array to a topography to which the implant is to be attached.
20 . An implant for emulating hyaline cartilage in an articulating mammalian joint, comprising:
polygonal segments encompassing an area of a surface corresponding to hyaline cartilage in an articulating mammalian joint,
wherein each polygonal segment comprises complementary hinging structures provided on edges of the associated polygonal segment and configured to mechanically attach the associated polygonal segment to adjacent polygonal segments, and
wherein lateral interspacings between adjacent polygonal segments are adjustable to enable the polygonal segments to conform to a topography to which the implant is to be attached.