Tendon harvesting assemblies and methods
A harvesting assembly for harvesting a tissue graft from surrounding tissue is disclosed including a guide. The guide includes a means for fixedly engaging with an anterior surface of the tendon. The guide also includes a means of guiding a cutting blade along a preferred trajectory into and along a length of the tendon. The guide also includes a means of guiding a truncating blade along a preferred trajectory across a width of tendon. The cutting blade may include two parallel blades for forming lateral sides of the tendon graft simultaneously. Each of the two parallel blades may define a leading edge that extends along at least a 90 degree arc that is equidistant from a stop on the cutting blade. The stop in combination with the guide may limit a cut depth into the tendon for a range of cutting blade handle elevation angles.
1. A tendon harvesting system for forming a target length of a graft from a native tendon comprising:
a guide having a first end, a second end and an elongate body therebetween; the elongate body configured to be placed along the native tendon and anteriorly spaced therefrom;
the first end being configured to engage the native tendon adjacent a patella of the native tendon;
the second end being configured to engage the native tendon at a proximal end of the target length;
a harvester including a first blade and a second blade, both of which are disposed at a leading end of the harvester with a handle extending therefrom; wherein the first blade and the second blade are configured to extend through the guide first end, and cut into and along an anterior surface of the native tendon disposed posterior to the first end, to form two lateral sides of the graft, the harvester being guided by the guide; and
an amputating tool configured to transect the native tendon at the guide second end, to form a proximal end surface of the graft.
2. The tendon harvesting system of claim 1 wherein the first blade and the second blade each define curved leading edges that are parallel to each other and separated laterally from each other to form the two lateral sides of the tendon graft simultaneously.
3. The tendon harvesting system of claim 2 wherein both of the curved leading edges are equidistant from a depth stop surface on the harvester, the depth stop surface configured to maintain a constant depth of cut into the native tendon for a range of harvester elevation angles relative to a guide longitudinal axis.
4. The tendon harvesting system of claim 3 wherein both of the curved leading edges extend along at least a 90 degree arc.
5. The tendon harvesting system of claim 3 wherein the range of elevation angles ranges between 0-80 degrees relative to the guide longitudinal axis.
6. The tendon harvesting system of claim 1 wherein the guide first end defines an entrance aperture, configured to receive the first and second blades therethrough.
7. The tendon harvesting system of claim 1 wherein the harvester includes a translation stop surface configured to engage a surface of the guide and limit translation of the harvester along the native tendon and towards the guide second end and thereby limit a length of the two lateral sides of the graft.
8. The tendon harvesting system of claim 7 wherein the harvester translation stop surface is axially spaced from the first and second blade and the handle, disposed between the first and second blade and the handle.
9. The tendon harvesting system of claim 7 wherein the harvester translation stop surface is configured to engage two legs of the guide to limit translation of the harvester towards the guide second end.
10. The tendon harvesting system of claim 1 wherein the guide includes a pair of legs configured to extend in a direction generally away from the native tendon anterior surface, the pair of legs configured to engage a stop surface of the harvester and define a translation limit of the first and second blades along the native tendon.
11. The tendon harvesting system of claim 1 wherein the guide elongate body is anteriorly spaced to allow for observation of the native tendon anterior surface.
12. The tendon harvesting system of claim 1 wherein the harvester is configured to operatively engage the guide to direct a trajectory of the harvester along the native tendon.