Extra joint stabilization construct
The disclosure provides devices and methods of use pertaining to extra joint stabilization. Embodiments include a number of suture returning and locking anchors that feature both a suture return element and a suture locking feature that employs an interference fit between a flexible synthetic strand, a receiver of the anchor, and a set screw, where the receiver and the set screw each have a number of gradual, opposing tapers to facilitate gradual proximal-to-distal gripping and releasing of the flexible strand to achieve an optimal locking force while preventing severing of the flexible strand. Embodiments also include a counter-torque anchor driver configured to resist torsional forces generated during and translated to the anchor during set-screw insertion. Further embodiments include extra joint reinforcement, stabilization, and attachment constructs formed using the disclosed devices. Other embodiments are disclosed.
1. A counter-torque driver for rotationally driving an anchor into bone, the anchor having a proximal end, a distal end, and a driver feature, the driver feature comprising two opposing slots formed in the proximal end of the anchor, the counter-torque driver comprising:
a longitudinal body extending from a proximal end to a distal end and defining a longitudinal axis that extends along a longitudinal direction, the longitudinal body including an axial through hole extending from the proximal end to the distal end along the longitudinal axis;
two opposing tabs extending from the distal end of the longitudinal body, the two opposing tabs centered about the longitudinal axis and configured to engage with the two opposing slots formed in the proximal end of the anchor; and
two opposing legs disposed proximal to the two opposing tabs, the two opposing legs centered about the longitudinal axis and defining first and second opposed clearance slots configured to provide clearance between the distal end of the longitudinal body and the proximal end of the anchor for a path of a flexible synthetic strand into and out of the anchor, wherein the second clearance slot is shorter than the first clearance slot along the longitudinal direction,
wherein when the two opposing tabs of the counter-torque driver are engaged with the two opposing slots of the anchor and the counter-torque driver is rotated, the anchor is rotationally driven into the bone; and
wherein when the two opposing tabs of the counter-torque driver are engaged with the two opposing slots of the anchor and the counter-torque driver is held stationary, each of the two opposing tabs provides a respective distal facing bearing surface to resist torsional forces generated when tensioning the flexible synthetic strand via a rotational input to a set screw inserted through the axial through hole of the counter-torque driver into the anchor, such that the engagement of the two opposing tabs and the two opposing slots on its own counters the torsional forces to maintain an original insertion alignment of the anchor within the bone.
2. The counter-torque driver of claim 1 , wherein the proximal end of the longitudinal body of the counter-torque driver includes a handle.
3. The counter-torque driver of claim 1 , wherein the axial through hole comprises a cannula.
4. The counter-torque driver of claim 1 , wherein a set screw driver is advanced through the axial through hole of the longitudinal body of the counter-torque driver to apply the torsional forces via the rotational input to the set screw.
5. An external construct for stabilizing a joint, comprising:
the counter-torque driver of claim 1 ;
a flexible synthetic strand having first and second opposing ends;
a first fixation secured at the first end of the flexible synthetic strand;
a second fixation secured at the second end of the flexible synthetic strand, the second fixation comprising the anchor configured to be inserted into a bone portion, the anchor having a body with a proximal end, a distal end, and defining a longitudinal axis, the longitudinal body forming an axial passage having a threaded receiver located at the proximal end, wherein:
the second end of the flexible synthetic strand enters the anchor through the axial passage at the proximal end of the longitudinal body;
the flexible synthetic strand is tensioned between the first and the second fixations; and
the second end of the flexible synthetic strand is locked relative to the anchor resulting in a continuous, uninterrupted length of the flexible synthetic strand configured to extend externally across the joint between the first and the second fixations.
6. The external construct of claim 5 , wherein the anchor includes a return feature located distal to the threaded receiver and in communication with the axial passage, and wherein the flexible synthetic strand enters the return feature through the axial passage at the proximal end of the longitudinal body, routes around the return feature, and exits the return feature through the axial passage at the proximal end of the longitudinal body.
7. The external construct of claim 6 , wherein the flexible synthetic strand enters the anchor through the axial passage at the proximal end of the longitudinal body, routes around the return feature, and exits the return feature through a sidewall of the longitudinal body at a location distal to the proximal end of the longitudinal body.
8. The external construct of claim 5 , wherein the flexible synthetic strand enters the anchor through the axial passage at the proximal end of the longitudinal body, and exits through a distal end of the longitudinal body in opposition to the proximal end of the longitudinal body.
9. The external construct of claim 5 , wherein the second end of the flexible synthetic strand is locked via a threaded set screw that is rotationally inserted into the threaded receiver.
10. The external construct of claim 9 , wherein the threaded receiver comprises a proximal portion, a mid portion, and a distal portion and the set screw comprises a proximal portion, a mid portion, and a distal portion, the threaded set screw configured for rotational insertion into the threaded receiver to achieve a progressively increasing interference fit about the flexible synthetic strand passing between the proximal portions and the mid portions of the threaded receiver and the threaded set screw and a progressively decreasing interference fit about the flexible synthetic strand passing between the mid portions and the distal portions of the threaded receiver and the threaded set screw, wherein the progressively increasing interference fit and the progressively decreasing interference fit combine to lock the flexible synthetic strand relative to the anchor.
11. The external construct of claim 10 , wherein the second fixation is reversible in that the set screw is rotationally removable from the threaded receiver in a manner that maintains an integrity of the flexible synthetic strand for repeated tensioning and locking.
12. The external construct of claim 5 , wherein the second end of the flexible synthetic strand is trimmed flush with the proximal end of the longitudinal body of the anchor.
13. The external construct of claim 5 , wherein the first fixation comprises a second anchor inserted into another bone portion such that the construct provides bone fracture stabilization or ligament reinforcement.
14. The external construct of claim 5 , wherein the first fixation comprises the first end of the flexible synthetic strand passed through a soft tissue portion such that the construct provides soft tissue repair or tendon attachment.
15. A system comprising:
the counter-torque driver of claim 1 ; and
the anchor.
16. The system of claim 15 , wherein when the two opposing tabs are fully seated in the two opposing slots of the anchor, first and second clearances are defined between the counter-torque driver and the anchor, so that a suture extends through the first clearance and into the anchor, and exists the anchor and extends through the second clearance.
17. The system of claim 16 , wherein the anchor comprises a first transverse hole, a second transverse hole spaced from the first transverse hole, and an axial hole that extends through a proximal end of the anchor and intersects the second transverse hole.
18. The system of claim 17 , wherein the second transverse hole is disposed between the proximal end and of the anchor and the first transverse hole.
19. The system of claim 18 , further comprising the suture, wherein suture enters the axial hole, exists through a first opening of the second transverse hole, extends through the first transverse hole, enters through a second opening of the second transverse hole, and extends out the axial hole.
20. The counter-torque driver of claim 1 , wherein the two opposing tabs extend from the distal end of the longitudinal body in a distal direction, and the second clearance slot tapers toward the longitudinal axis of the longitudinal body as it extends in the distal direction.