Original Article
Osseous Landmarks of the Femoral Attachment of the Anterior Cruciate Ligament: An Anatomic Study

https://doi.org/10.1016/j.arthro.2007.09.008Get rights and content

Purpose: Anatomic tunnel placement is critical to the success of anterior cruciate ligament (ACL) reconstruction. The purpose of this study was to determine qualitatively and quantitatively the osseous landmarks of femoral attachment of the ACL. Methods: The femoral attachment of the ACL was studied histologically in seven human fetuses, arthroscopically in 60 patients who underwent ACL surgery, and grossly in 16 cadaveric knees. Three-dimensional laser digitizer pictures of the cadaveric specimens were taken to quantify length, area, and angulations of the femoral attachment of the ACL. Results: Two different osseous landmarks were detected. An osseous ridge that runs from proximal to distal ends was present in all the arthroscopic patients and cadaveric knees. It was named “lateral intercondylar ridge.” Another osseous landmark between the femoral attachment of the anteromedial (AM) and posterolateral (PL) bundles running from anterior to posterior was observed in 6 out of 7 fetuses, 49 out of 60 arthroscopic patients, and 13 out of 16 cadaveric knees. It was named “lateral bifurcate ridge.” A change of slope between the femoral attachment of the AM and PL bundles was observed in all specimens studied. The femoral attachment of the AM bundle formed an angle with the PL bundle of 27.6° ± 8.8° and a radius of curvature of 25.7 ± 12 mm. The area of the entire ACL footprint, AM, and PL bundle was 196.8 ± 23.1 mm2, 120 ± 19 mm2, and 76.8 ± 15 mm2, respectively. Conclusions: The ACL femoral attachment has a unique topography with a constant presence of the lateral intercondylar ridge and often an osseous ridge between AM and PL femoral attachment, the lateral bifurcate ridge. Clinical Relevance: These findings may assist surgeons to perform ACL surgery in a more anatomic fashion.

Section snippets

Histologic Study of the of the ACL in Human Fetuses

After approval of our institutional review board, seven aborted human fetuses (4 female and 3 male), ranging from 19 to 22 weeks’ gestation, were used in this study. The knees were dissected and the lateral femoral condyle was trimmed down to the ACL attachment. Standard histology preparation was performed, followed by 5-μm thick coronal sections to allow for standard hematoxylin–eosin staining. Observation was performed by a single observer (M.F.). The use of coronal sections allows the

Results

As shown below, in all sections of the study we found two distinct ridges that defined the femoral ACL origin, which we termed the “lateral intercondylar ridge” and the “lateral bifurcate ridge.”

Discussion

This study describes the osseous anatomy of the ACL femoral attachment both qualitatively and quantitatively. The data of this study contribute to the understanding of the ACL osseous anatomy and may assist surgeons in performing ACL surgery in a more anatomic fashion.

Several studies have focused on the anatomy of the ACL.11, 12, 13, 14, 15, 16, 17, 18, 19 In general, the majority of the authors agreed that the ACL contains two functional bundles, the AM and PL bundles.11, 12, 13, 15, 16, 17, 20

Conclusions

Our study revealed that the ACL femoral attachment has a unique osseous topography with two osseous ridges: the lateral intercondylar ridge and the lateral bifurcate ridge.

Acknowledgment

We thank Drs. William Clancy and Daniel Cooperman for their helpful discussion in preparation of the manuscript, and Mr. Mark Klingler for his artistic drawing of figure 7.

References (24)

  • D.C. Fithian et al.

    Prospective trial of a treatment algorithm for the management of the anterior cruciate ligament-injured knee

    Am J Sports Med

    (2005)
  • P.S. Cha et al.

    Arthroscopic double-bundle anterior cruciate ligament reconstruction: An anatomic approach

    Arthroscopy

    (2005)
  • Cited by (437)

    View all citing articles on Scopus

    The authors report no conflict of interest.

    View full text