Compression and tension instruments and methods of use to reinforce ligaments
The disclosure provides apparatus and methods of use pertaining to syndesmosis reinforcement. Embodiments include a clamp having two jaws that extend toward each other to clamp two bone portions therebetween. The clamp may include an angle gauge and an adjustment mechanism having a force gauge that combine to enable the compression of the two bone portions in an optimal direction or angle and at an optimal, measurable compression force. Embodiments also include a tension instrument configured to knotlessly lock a flexible strand construct between two anchors at the same optimal direction and tension applied by the clamp. Further embodiments include an exemplary syndesmosis reinforcement procedure that employs the clamp and the tension instrument to construct a ligament reinforcement construct that achieves optimal anatomic positioning in both directional alignment and the reduction force applied by the construct. Other embodiments are disclosed.
1. A tension instrument for tensioning and knotlessly locking a flexible strand having first and second opposing flexible strand ends, the first flexible strand end fixed adjacent to a first member and the second flexible strand end free proximal to the first member and adjacent to a second member, the tension instrument comprising:
a member engagement feature configured to engage with the second member through which the second flexible strand end passes; and
an adjustment mechanism operably coupled to a proximal end of the member engagement feature, the adjustment mechanism including:
a selectively adjustable flexible strand clamp configured to capture the second flexible strand end and translate the second flexible strand end proximally relative to the member engagement feature to place a tensile force on the flexible strand between the first and the second members;
a force gauge operably coupled with the selectively adjustable flexible strand clamp, the force gauge including force indicia to provide an indication of the tensile force placed on the flexible strand; and
a pathway extending through the adjustment mechanism from a proximal end to a distal end adjacent the member engagement feature to provide clearance for fixation hardware that knotlessly locks the second flexible strand end relative to the second member to maintain the tensile force between the first and the second flexible strand ends.
2. The tension instrument of claim 1 , wherein the adjustment mechanism includes a gross adjustment control and a fine adjustment control.
3. The tension instrument of claim 1 , wherein the clamp includes finger grips and a thumb grip configured to enable one-handed operation to apply compression force.
4. The tension instrument of claim 1 , wherein the clamp includes a release trigger configured to release compression force.
5. The tension instrument of claim 4 , wherein the release trigger is configured to enable one-handed operation for both application of compression force and release of compression force.
6. The tension instrument of claim 1 , wherein at least one of the first and the second members comprises a bone portion.
7. The tension instrument of claim 1 , wherein at least one of the first and the second members comprises a flexible strand fixation anchor.
8. The tension instrument of claim 7 , wherein the member engagement feature comprises a fastener engagement feature configured to engage with the flexible strand fixation anchor.
9. The tension instrument of claim 7 , wherein the fastener engagement feature comprises a pair of counter-torque prongs.
10. The tension instrument of claim 1 , wherein the pathway extending through the adjustment mechanism is a cannula.
11. The tension instrument of claim 1 , wherein the tensile force between the first and the second flexible strand ends is placed only upon the flexible strand.
12. The tension instrument of claim 1 , wherein the adjustment mechanism further comprises:
a handle disposed about the force gauge, the handle having a proximal end and a distal end;
an outer shaft extending proximally to distally between the force gauge and the member engagement feature;
an inner shaft disposed within the outer shaft, the inner shaft extending proximally to distally between the proximal end of the handle and the member engagement feature;
a force spring disposed about the inner shaft in a space between the inner shaft and the force gauge, the force spring extending proximally to distally between the proximal end of the handle and the outer shaft, wherein an amount of force required to compress the force spring is proportional to a distance the force spring is compressed;
a receiver mounted upon the selectively adjustable flexible strand clamp, the receiver slidably coupled with the inner shaft, wherein:
when the member engagement feature is engaged with the second member and the second flexible strand end is secured within the selectively adjustable flexible strand clamp, translating the receiver proximally relative to the inner shaft forces the outer shaft and the force gauge distally relative to the inner shaft, thereby causing the handle to move proximally over the force gauge against the force spring and compressing the force spring such that the distal end of the handle aligns with one of the force indicia indicating the tensile force placed on the flexible strand.