Race and Gender Differences in Anterior Cruciate Ligament Femoral Footprint Location and Orientation: A 3D‐MRI Study

Abstract

ObjectiveThe femoral tunnel position is crucial to anatomic single‐bundle anterior cruciate ligament (ACL) reconstruction, but the ideal femoral footprint position are mostly based on small‐sized cadaveric studies and elderly patients with a single ethnic background. This study aimed to identify potential race‐ or gender‐specific differences in the ACL femoral footprint location and ACL orientation, determine the correlation between the ACL orientation and the femoral footprint location.MethodsMagnetic resonance images (MRIs) of 90 Caucasian participants and 90 matched Chinese subjects were used for reconstruction of three‐dimensional (3D) femur and tibial models. ACL footprints were sketched by several experienced orthopedic surgeons on the MRI photographs. The anatomical coordinate system was applied to reflect the ACL footprint location and orientation of scanned samples. The femoral ACL footprint locations were represented by their distance from the origin in the anteroposterior (A/P) and distal‐proximal (D/P) directions. The orientation of the ACL was described with the sagittal, coronal and transverse deviation angles. The ACL orientation and femoral footprint position were compared by the two‐sided t‐test. Multiple regression analysis was used to study the correlation between the orientation and femoral footprint position.ResultsThe average femur footprint A/P position was −6.6 ± 1.6 mm in the Chinese group and −5.1 ± 2.3 mm in the Caucasian group, (p < 0.001). The average femur footprint D/P position was −2.8 ± 2.4 mm in Chinese and − 3.9 ± 2.0 mm in Caucasians, (p = 0.001). The Chinese group had a mean difference of a 1.5 mm (6.1%) more posterior and 1.1 mm (5.3%) more proximal in the position from the flexion‐extension axis (FEA). And the males have a sagittal plane elevation about 4–5° higher than females in both racial groups. Furthermore, for every 1% (0.40 mm) increase in A/P and D/P values, the sagittal angle decreased by about 0.12° and 0.24°, respectively; the coronal angle decreased by about 0.10° and 0.30°, respectively. For every 1% (0.40 mm) increase in D/P value, the transverse angle increased by about 0.14°.ConclusionThe significant race‐ and gender‐specific differences in the femoral footprint and orientation of the ACL should be taken in consideration during anatomic single‐bundle ACL reconstruction. Furthermore, the quantitative relationship between the ACL orientation and the footprint location might provide some reference for surgeons to develop a surgical strategy in ACL single‐bundle reconstruction and revision.

No Difference in Bone Tunnel Enlargement and Clinical Outcome between Cortical Suspension and Hybrid Femoral Fixation in Hamstring Anterior Cruciate Ligament Reconstruction

“…The femoral socket was positioned at 10 o'clock for the right knees and 2 o'clock for the left knees. 22 For the tibial tunnel, the transtibial technique was used. The tibial tunnel was shifted to match the diameter of the graft by using reamers that were compatible with the size of the grafts.…”

Tibial spine volume is smaller in ACL‐injured athletes compared to healthy athletes

“…Risk factors for anterior cruciate ligament (ACL) injury include anatomic variations, neuromuscular deficits, biomechanical abnormalities, playing environment and hormonal status [1-3, 11, 31]. When it comes to anatomic variation on the femoral side, the femoral ACL footprint has been studied in detail [5,21,22,32] and the intercondylar notch width and shape of the condyles measured on radiograph, computed tomography (CT) and magnetic resonance imaging have been reported to correlate with the occurrence of ACL injury [5,19,20,28].…”