2015 ISAKOS Biennial Congress ePoster #1271

Arthroscopic Anatomy of the Posterior Side of the ACL

Matthieu Sanchez, MD, Boulogne FRANCE
Nicolas Pujol, MD, Le Chesnay FRANCE
Philippe Boisrenoult, MD, Le Chesnay FRANCE
Philippe Beaufils, MD, Versailles FRANCE

Centre Hospitalier De Versailles, West Paris University, Orthopedic department, Le Chesnay, FRANCE

FDA Status Not Applicable

Summary: Is there a concordance between arthroscopic measurements of the femoral insertion of the native ACL and called anatomic placement of the femoral tunnel after reconstruction? Arthroscopic assessment of the ACL using posterior portals

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Abstract:

Introduction

Modern anatomic single bundle anterior cruciate ligament (ACL) reconstruction is aimed to reproduce the native insertion of the ACL in order to restore normal anatomy and biomechanics of the knee. Numerous anatomical variations exist between individuals concerning the insertion sites of the ACL. Moreover, the arthroscopic anatomy varies to that obtained when the knee is dissected. The aim of this anatomical study was to arthroscopically identify by a posterior approach the femoral insertion of the native ACL and arthroscopically verify if the femoral placement of the reconstructed ACL using a hamstring tendon graft is accurate.

Methods

20 fresh cadaveric knees were utilized. The anatomical relationship of the native ACL and the cartilaginous edge of the condyle was measured using an arthroscopic millimeter graduated ruler introduced through the postero-medial portal after having performed an extensive posterior synovectomy. Two measurements were performed at 90 degrees of knee flexion: 1) the distance between the most posterior part of the ACL insertion and the posterior cartilage of the femoral condyle (named deep or posterior measurement) and 2) the distance between the inferior part of the ACL insertion and the inferior cartilage of the femoral condyle (named shallow or inferior measurement). The intercondylar notch was debrided using a shaver. A single bundle (four strands hamstring tendon graft) ACL reconstruction was then performed. An inside-out femoral aimer introduced through the antero-medial portal was used to perform the femoral tunnel. A femoral aimer with 6mm offset was chosen after calibrating the tendon graft to 8mm. After the reconstruction, the measurements were repeated with the knee at 90 degrees of knee flexion.

Results

The femoral insertion of the native ACL was situated on average 2.7mm (2.0-3.5) away from the posterior femoral condyle cartilage and 2.9mm (2.0-4.0) from the inferior cartilage.
The femoral insertion of the reconstructed ACL was located on average 3.1mm (2.0-4.0) away from the deep femoral condyle cartilage and 3.1mm (2.0-5.0) from the shallow cartilage.
These anatomical measurements were statistically similar in all studied knees. The variations between the posterior and inferior measurements were not found important.
The ACL reconstruction using a four fold hamstring tendon seems precise and reproducible with no significant variations in regard to the native ACL.

Conclusion

The anatomy of the femoral insertion of the ACL is reproduced when performing a hamstring graft ACL reconstruction using an inside-out femoral aimer introduced through the antero-medial portal and positioned in the modern horizontal manner in knee flexion.