The Acorn Beath Couple: Articular Salvation for Double-Bundle Femoral Tunnels in Cruciate Ligament Reconstruction

With the recent increase in interest in arthroscopic double-bundle cruciate reconstructions, efficient, safe, and reproducible techniques are needed.

This technical trick is applicable to both arthroscopic anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) reconstruction when double-bundle femoral tunnels are performed through an accessory far lateral or far medial incision as with the all-inside femoral tunnel drilling approach.

A standard double-bundle cruciate reconstruction technique is applied until placement of the femoral footprint Beath pins in anticipation of tunnel drilling. Femoral footprint targeting with a Beath pin requires use of a far accessory portal. Before the long Beath pin is introduced into the joint, an acorn reamer is placed over the Beath pin to within 5 mm of the pin tip, thus creating an acorn Beath couple. The eyelet pin end is loaded onto a quick-release pin collet driver, leaving the acorn reamer free to turn. The acorn Beath couple is then introduced into the appropriate accessory portal and positioned in the center of the desired femoral footprint. An assistant holds the acorn reamer shaft while the Beath pin is advanced. The collet driver is then disengaged from the pin and replaced with an adjustable chuck and secured to the acorn reamer shaft of the acorn Beath couple.

The femoral tunnel is drilled to the appropriate depth, and the Beath pin is pulled out the anterior thigh. Doing so disengages the acorn reamer and allows for safe removal of the reamer from the notch. The technique is then repeated with the coupling of a 4.5 Endobutton reamer and the Beath pin.