Knotless suture anchor
A suture anchor is disclosed having an outer body with an axial bore which receives and inner body for rotation. Suture passes between the inner body and outer body and rotation of the inner body wraps the suture thereabout locking the suture thereto. Rotation of the inner body also effects radial expansion of at least a portion of the outer body to engage to anchor into a bone hole.
1. A suture anchor comprising:
an outer body having a distal end a proximal end and an axial bore therethrough;
an inner body receivable within the outer body;
a suture limb captured between the inner body and the outer body by being wrapped around the inner body, a first portion of the suture limb passing out of the outer body whereby it may be connected to a tissue and a second portion of the suture limb passing out of the outer body whereby to allow a tension to be applied to the suture limb by a user;
the inner body having a distal end and a proximal end and wherein the inner body proximal end has outer threads which mate with inner threads on the proximal end of the outer body;
the outer body having a first configuration in which at least a portion thereof is radially contracted inwardly and a second configuration in which the portion is radially expanded outwardly, and wherein when the outer threads on the inner body are engaged into the outer body inner threads it holds the portion in the second configuration; and
wherein the inner body moves proximally into position to hold the outer body in its second configuration.
2. A suture anchor according to claim 1 wherein the inner body and the outer body are formed of a bioabsorbable material.
3. A suture anchor according to claim 2 wherein the inner body and outer body are formed of PLGA.
4. A suture anchor according to claim 1 configured such that as the inner body is moved toward the proximal end of the outer body the proximal end of the outer body expands outwardly radially.
5. A suture anchor according to claim 1 wherein the suture limb is wrapped around the inner body at least two times.
6. A suture anchor according to claim 5 wherein the suture limb is wrapped around the inner body at least five times.
7. A suture anchor according to claim 5 wherein the inner body comprises at least one tab extending outwardly radially whereby to effect wrapping of the suture about the inner body upon rotation of the inner body.
8. A suture anchor according to claim 1 and further comprising an inserter having a distal end which mates with the proximal end of the inner body and which has outer inserter threads engageable with the inner threads on the outer body.
9. A suture anchor according to claim 8 wherein the outer body has a first configuration in which at least a portion thereof is radially contracted inwardly and a second configuration in which the portion is radially expanded outwardly, and wherein when the outer inserter threads are engaged into the outer body inner threads it holds the portion in the second configuration.
10. A suture anchor according to claim 1 wherein a naturally relaxed position of the portion is in the second configuration.
11. A suture anchor according to claim 1 wherein the suture limb passes into a space formed between the inner body and the outer body at their proximal ends, passes out of the space at their distal ends and then passes proximally along an outer surface of the outer body.
12. A suture anchor according to claim 1 wherein the outer body has at its proximal end at least one axially extending slit therein whereby to relieve stresses upon radially outward expansion of the outer body proximal end.
13. A suture anchor according to claim 1 and further comprising at least one more suture limb captured between the inner body and the outer body.
14. A suture anchor according to claim 1 and further comprising at least three more suture limbs captured between the inner body and the outer body.
15. A suture anchor according to claim 1 wherein rotation of the inner body simultaneously winds the suture limb around the inner body and expands the outer body into its second configuration.