System and method for securing tissue to bone
Disclosed herein are methods and devices for securing soft tissue to a rigid material such as bone. A tissue anchoring device is described that comprises an anchor body and a spreader such that tissue may be captured or compressed between outside surfaces on the anchor and inside surfaces of a bone tunnel to secure the tissue within the tunnel. Methods are described that enable use of the bone anchoring device to secure a tissue graft into the tibial and femoral bones during anterior cruciate ligament (“ACL”) reconstruction.
1 . An expandable bone anchor, comprising:
an anchor body comprising:
a plurality of first expandable side portions positioned at a proximal end of the anchor body, wherein the first expandable side portions expand by bending outward such that each of the first expandable side portions extends outward to a greater extent at its proximal portion than at its distal portion; and
a plurality of second expandable side portions positioned distally of the first expandable side portions, wherein the second expandable side portions expand by bending outward such that each of the second expandable side portion extends outward to a greater extent at its distal portion than at its proximal portion;
a distal tapered anchor tip comprising a fixed hole formed by and positioned through a distal portion thereof; and
a spreader configured to advance distally into the anchor body, thereby causing the first and second expandable side portions to expand outward.
2 . The anchor of claim 1 , wherein the spreader is coupled to the plurality of first expandable side portions.
3 . The anchor of claim 2 , wherein the spreader is slidably coupled to the first and second expandable side portions.
4 . The anchor of claim 2 , wherein the spreader comprises a plurality of longitudinal grooves and each of the first and second expandable side portion is coupled to one of the grooves such that the side portions can slide longitudinally along the grooves.
5 . The anchor of claim 1 , wherein the spreader comprises at least a portion that is tapered distally.
6 . The anchor of claim 1 , wherein the first and second expandable side portions comprise bone engaging features.
7 . The anchor of claim 6 , wherein the bone engaging features comprise teeth.
8 . The anchor of claim 6 , wherein the bone engaging features comprise ridges.
9 . The anchor of claim 1 , wherein at least one of the first side portions and the second side portions is formed by cuts in a side wall of the anchor body.
10 . The anchor of claim 1 , wherein the spreader has a constant diameter along its length.
11 . The anchor of claim 1 , wherein the spreader comprises a circumferential ridge positioned at or adjacent to its proximal end.
12 . The anchor of claim 1 , wherein the anchor tip has a hemispherical shape.
13 . The anchor of claim 1 , wherein the anchor tip has a conical shape.