Lateral anatomic structures at risk during transepiphyseal anterior cruciate ligament reconstruction

Six fresh-frozen cadaveric knees were utilized to evaluate which lateral anatomic structures were at risk when using an outside-in, percutaneous technique for placing guide pins for transepiphyseal reconstruction of the anterior cruciate ligament. With knees in the standard arthroscopic position, guide pins were placed percutaneously into the centers of the anteromedial and posterolateral bundle footprints using a transepiphyseal approach. After guide pin placement, the lateral aspect of the knee was dissected, and the proximity of each guide pin to the important lateral anatomic structures was measured. The current study has shown that multiple anatomic structures are at risk when using a percutaneous approach for guide pin placement during transepiphyseal anterior cruciate ligament reconstruction. The anteromedial bundle guide pin put the gastrocnemius tendon and lateral collateral ligament at risk as it was, on average, 0.76 and 2.4 mm from these structures, respectively. The posterolateral bundle guide pin was on average 0.7 and 1.1 mm from the lateral collateral ligament and popliteus tendon, respectively. The transepiphyseal technique is a promising option for anatomic reconstruction of the ACL in skeletally immature patients. When using an outside-in technique, a mini-open technique should be used to reach the lateral femoral cortex. When using inside-out, retrograde drilling devices, violation of the lateral cortex should be avoided to preserve the lateral anatomic structures.