J arch: A contemporary soft-tissue landmark for anatomic placement of femoral tunnel in remnant-preserving anterior cruciate ligament (ACL) reconstruction

Abstract

Objectives: Femoral tunnel placement is a critical step in ACL reconstruction surgery. Surgeons usually end up clearing the soft tissue to access the bony landmarks. Biological ACL reconstruction with preservation of soft tissue can be done with reliable soft tissue landmarks. Our objective is to assess the reliability of a soft tissue landmark- femoral ACL remnant, for appropriate femoral tunnel placement in soft tissue preserving ACL reconstruction. Materials and Methods: This study was a retrospective analysis of prospectively collected data of 40 consecutive patients who underwent primary ACL reconstruction in January 2018 by a single surgeon. An inverse J shaped tissue arch was identified and used as soft tissue landmark for anatomic placement of femoral tunnel. This arch was a part of femoral ACL remnant. MRI films were examined post-operatively to determine the position of the femoral tunnel. Postoperatively, MRI of these patients were reviewed to evaluate the femoral tunnel position in terms of depth and height from the proximal condylar surface and notch roof, respectively. Results: The center of the femoral tunnel was found to be at a mean depth of 27.12 ± 2.2% from the proximal condylar surface (parallel to Blumensaat’s line) and a mean height of 30.96 ± 2.75% from the notch roof (perpendicular to Blumensaat’s line), which is at par with previously defined data given by various studies. Conclusion: J arch can be used as a dependable soft tissue landmark and a guide for the anatomic placement of femoral tunnel in biological ACL Reconstruction.