Posterior Proximal Cartilage of the Lateral Femoral Condyle as a Reference for Positioning the Femoral Tunnel in ACL Reconstruction

Abstract

Background: Due to the similarity among specimens in the height of the anterior cruciate ligament (ACL) on the distal proximal axis in relation to the proximal posterior cartilage of the lateral femoral condyle (point C), it is known this point can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel in ACL reconstruction. Indications: For ACL reconstruction, point C can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel on the distal proximal and anteroposterior axes. Technique Description: For access to the joint, standard arthroscopic ports, both anterolateral (AL) and anteromedial (AM), are used. By directing the camera toward the posterior region of the lateral femoral condyle through the AM port, it is possible to visualize the end of the posterior and proximal articular cartilage, the so-called C point. In this case, we sought to position the center of the femoral tunnel in the center of the AM band of the ACL. Holding the camera through the AM portal and visualizing point C, a millimeter-scale femoral guide is introduced through the AL portal toward the posterior femoral cartilage (point C) and positioned over it, creating a line between point C and the lateral distal femoral cartilage. The distance between point C and the distal femoral cartilage is measured. At this time, an accessory AM portal 1.5 cm from the AM port is constructed. Through it, with the aid of an ice pick or radiofrequency tip, a marking is made in the deep to shallow axis at 35% of this distance. Then, approximately 2 mm above the imaginary line formed by the union of point C and the lateral distal femoral cartilage, the center of the femoral tunnel is marked. Results: Point C is an anatomical landmark that is easy to view and is present in all knees; thus, it can be used as a reference during surgery for positioning the femoral tunnel. Discussion/Conclusion: Point C can be used as an arthroscopic intraoperative parameter to define the position of the femoral tunnel in ACL reconstruction. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.