When we interviewed Dr. John Grant, he noted that it would be ideal to drill the ACL and ALLR tunnels with direct reference to each other to ensure they do not converge. This inspired our decision to pursue a 2-in-1 drill guide design.
The Dune prototype design was inspired by the Arthrex FlipCutter® III system comprised of the Flipcutter® drill as well as the drill guide, which only drills the ACL tunnel:
Photo: Arthrex Flipcutter® III system model on a human knee
The inside out drill guide allows for anatomic drill placement of ACL (and PCL) sockets and tunnels. It is ideal for hard-to-reach areas such as anatomic femoral socket placement for ACL tunnels. The FlipCutter® III drill itself also enables adjustability in drill hole diameter (from 6-12 mm), with its adjustable hook feature at the end of the drill. The FlipCutter® III has proven efficacy for ACLR, though it only has the capability of drilling the ACL tunnel.
Our goal in this Dune alpha prototype was to create a feature that can be added to a FlipCutter® III or similar guide to allow for the drilling of the ALL tunnel in relation to the ACL tunnel to avoid tunnel conflict. Having an add-on to the FlipCutter® III or similar guide enables user modularity, since the ALLR technique is not needed for all ACLR procedures. The Dune prototype used this FlipCutter® design as a template, and added an additional component to serve as a guide for drilling the ALL tunnel.
Dune alpha prototype CAD model
The arch component in our design resembles the FlipCutter® design (we printed our own approximation of a FlipCutter® guide, since we were not able to obtain an actual FlipCutter® for timing and budgetary reasons) with the ACL tunnel intended to be drilled through the large rectangular block and in line with the “hook” feature in the other end of the arch. This prototype is positioned on the knee the same way the FlipCutter® would be, with the T-tube (in yellow) being able to rotate freely about the thin bar to be able to drill at an appropriate anterior (towards the front of the body) angle to avoid the ACL tunnel. The reamer which drills the ALL tunnel is inserted through the pink L-tube attached to the T-tube.