Evaluation of the Angle Between the Long Axis of the Femoral Anterior Cruciate Ligament Footprint and Bony Morphology of the Knee: A Cadaveric Descriptive Study

Makoto Suruga; Takanori Iriuchishima; Yoshiyuki Yahagi; Genki Iwama; Takashi Horaguchi; Shin Aizawa; Shuichi Hirai; Kazuyoshi Nakanishi

doi:10.1007/s43465-024-01131-5

Evaluation of the Angle Between the Long Axis of the Femoral Anterior Cruciate Ligament Footprint and Bony Morphology of the Knee: A Cadaveric Descriptive Study

Indian J Orthop. 2024 Apr 7;58(5):510-516. doi: 10.1007/s43465-024-01131-5. eCollection 2024 May.

Authors

Makoto Suruga¹, Takanori Iriuchishima², Yoshiyuki Yahagi³, Genki Iwama³, Takashi Horaguchi⁴, Shin Aizawa⁵, Shuichi Hirai⁵, Kazuyoshi Nakanishi³

Affiliations

¹ Department of Orthopaedic Surgery, Nihon University Hospital, 1-6, Kanda-Surugadai, Chiyoda-Ku, Tokyo, Japan.
² Kamimoku Hot Springs Hospital, Ishikura, 198-2, Minakami, Gunma, Japan.
³ Department of Orthopaedic Surgery, Nihon University Itabashi Hospital, 30-1, Oyaguchi Kamicho, Itabashi-Ku, Tokyo, Japan.
⁴ B&J Clinic Ochanomizu, 2-1-47 Kanda Surugadai, Chiyoda-Ku, Tokyo, Japan.
⁵ Department of Functional Morphology, Nihon University School of Medicine, 30-1, Oyaguchi Kamicho, Itabashi-Ku, Tokyo, Japan.

PMID: 38694688
PMCID: PMC11058129 (available on 2025-04-07)
DOI: 10.1007/s43465-024-01131-5

Abstract

Purpose: There have been numerous studies of the anterior cruciate ligament (ACL) anatomy, but few have focused on the long axis angle of the femoral ACL footprint. This study investigated the angle between the long axis of the femoral ACL footprint and the bony morphology of the knee.

Methods: This study is a cadaveric descriptive study. Thirty non-paired formalin-fixed knees of Japanese cadavers were used. Anteromedial (AM) and posterolateral (PL) bundles were identified according to the tension pattern differences during the complete range of motion of the knee. In the ACL femoral footprint, there is a fold between the mid-substance insertion site and fan-like extension fibers. After identifying AM and PL bundles of mid-substance fibers, the mid-substance and fan-like extension fibers were divided into those bundles and stained. We defined the line passing through the center of the AM and PL bundles as the long axis of the ACL. The center points of each of the four areas and the angle between the long axis of the ACL and the bony morphology of the knee were calculated using Image J software.

Results: The mean angle between the axis of the femoral shaft and the long axis of the ACL mid-substance insertion was 28.8 ± 12.2 degrees. The mean angle between the Blumensaat line and the long axis of the mid-substance was 54.2 ± 13.5 degrees.

Conclusion: The mean angle between the axis of the femoral shaft and the long axis of the femoral ACL footprint was approximately 29 degrees. There is a wide variation in the long axis of the femoral ACL footprint. To achieve better clinical results through a more anatomically accurate reconstruction, it can be beneficial to replicate the ACL femoral footprint along its native long axis.

Keywords: Anterior cruciate ligament; Anteromedial bundle; Fan-like extension fibers; Posterolateral bundle.

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