The morphology of the femoral footprint of the anterior cruciate ligament changes with aging from a large semicircular shape to a small flat ribbon-like shape

Abstract

Purpose Compare the differences in the morphology of the ACL femoral footprint between the cadavers of the young and elderly in consideration of the degenerative physiological process that occurs with aging. Methods The femoral footprint of the ACL was dissected in 81 knees of known gender and age (45 male/36 female). They were divided into four groups by age and gender, establishing 50 years as the cut-off point to divide patients by age. Three observers analyzed the femoral footprint dissections, and the shapes were described and classified. The area and morphometric characteristics of the femoral insertion of the ACL were determined and these were compared between genders and age groups. Results The femoral footprint of the ACL from the cadavers of males younger than 50 years of age presented a semicircular morphology in 90% of the cases. In males aged more than 50 years, a ribbon-like morphology was found in 96% of the cases. In women less than 50 years old, the semicircular morphology was observed in 93.7% of the cases. In women aged over 50 years old, the ribbon-like morphology was found in 95% of the cases. A significant difference was observed between the prevalence rates of the morphologies, area size and measurements of the younger and older groups (p < 0.001 for both genders). Conclusions The femoral insertion of the ACL presents variations in its morphology, area and morphometric characteristics over time. It goes from a large semicircular shape that almost contacts the posterior articular cartilage to a smaller, flattened ribbon-like shape that moves away from the edge of the articular cartilage. It is bounded anteriorly by the lateral intercondylar ridge. These findings should be considered to avoid employing reconstruction techniques in which femoral tunnels with oval or rectangular shapes are used in patients under 50 years of age because they do not correspond to the morphology of the femoral insertion of the ACL in this age group.

Anterior cruciate ligament femoral footprint is oblong‐ovate, triangular, or two‐tears shaped in healthy young adults: three‐dimensional MRI analysis

“…These discrepancies might be attributed to the exact plane definition employed in this study, which focuses exclusively on the direct insertion portion, presenting a more accurate representation of the true footprint. In addition, it should be noted that the discrepancies could also be attributed to the 2D evaluation methods employed in earlier studies involving elderly cadavers, which might yield different results compared to the younger adults assessed in this 3D MRI study [17].…”

“…The morphology of the ACL femoral footprint has been diversely described in various studies [13,17,29]. Fu et al illustrated it as an elliptical shape with distinct separation into the anteromedial bundle (AMB) and the posterolateral bundle (PLB) [13].…”

“…The morphology of the ACL femoral footprint has been diversely described in various studies [13, 17, 29]. Fu et al .…”

Accuracy of Magnetic Resonance Imaging in the Diagnosis of Multiple Ligament Knee Injuries: A Multicenter Study of 178 Patients

“…This could be correlated with changes in the ACL in older patients, who generally show weaker and thinner ligaments with smaller footprints of the direct insertion of the ACL. 19,20 It is known that ACL morphology is influenced by sex, 2 but no influence of sex on the diagnostic accuracy of MRI for the ACL was found. In contrast, the correlation between sex and the diagnostic accuracy of MRI for the ITB and femoral cartilage has not been previously described and could be the focus of future studies.…”

ACL stump and ACL femoral landmarks are equally reliable in ACL reconstruction for assisting ACL femoral tunnel positioning

“…Therefore, any small deviation in the placement of the femoral insertion site can result in a mismatch between the tension and elongation changes of the graft [20]. Several landmarks have been used for anatomical femoral tunnel positioning, including the lateral intercondylar ridge, the lateral bifurcate ridge, and the cartilage margin [8, 17, 34], but it is often difficult to locate anatomical landmarks without sacrificing the remnant tissue both at the tibial and femoral sites. Remnant preservation (RP) has shown multiple advantages including preservation of the proprioceptive function [1, 6, 32], preservation of laxity [7], reduction of tunnel enlargement [7, 33], and promotion of graft healing [19].…”