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 distal tapered anchor tip; and
a plurality of rigid side portions extending proximally from the anchor tip, each side portion coupled to the anchor tip through a double hinge; and
a spreader configured to advance distally into the anchor body, thereby causing the rigid side portions to expand outward.
2 . The anchor of claim 1 wherein the spreader is coupled to the side portions.
3 . The anchor of claim 1 , wherein the spreader is slidably coupled to the side portions.
4 . The anchor of claim 3 , wherein the spreader comprises a plurality of longitudinal tracks and each side portion is coupled to one of the tracks such that the side portions can slide longitudinally along the tracks.
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 anchor tip comprises a proximal locking member and the spreader comprises a distal locking member, wherein the two locking members are configured to lock together upon maximal distal advancement of the spreader.
7 . The anchor of claim 6 , wherein the proximal locking member on the tip comprises a post having an outwardly protruding ridge and the distal locking member on the spreader comprises a hollow cylinder configured to receive the post.
8 . The anchor of claim 7 , wherein the hollow cylinder comprises a groove on an inside surface configured to receive the protruding ridge.
9 . The anchor of claim 7 , wherein the hollow cylinder comprises expandable tabs.
10 . The anchor of claim 1 , wherein upon maximal expansion, the rigid side portions are expanded to a substantially uniform extent along their length.