Objective: To observe the anatomical morphology of the tibial insertion of the anterior cruciate ligament (ACL) in Chinese adults so as to offer theoretical guidance for ACL reconstruction and meniscus transplantation.
Methods: Fifteen adult cadaveric knees (8 left knees and 7 right knees) were dissected, including 10 males and 5 females, with an age ranged from 25 to 47 years (mean, 32.4 years). All knees were generally observed through standard medial parapatellar approaches, then the ACL midsubstance and the tibial insertion (direct and indirect insertions) were anatomically measured.
Results: In all specimens, the ACL was flat with a lot of fine fibers. The anteromedial bundle and posterolateral bundle could be observed in 13 of 15 knees. However, no obvious bundles were found in 2 knees. The arc-shaped tibial direct insertion started at the medial tibial eminence and ended at the anterior horn of the lateral meniscus. The width of the arc was (11.2 ± 2.4) mm; the thickness was (3.0 ± 0.3) mm; and the cross-sectional area was (28.8 ± 7.8) mm2. And the left-right diameter of the whole insertion was (9.5 ± 1.8) mm; anteroposterior diameter was (11.9 ± 0.6) mm; and the cross-sectional area was (117.8 ± 12.5) mm2. The width of the anterior horn of lateral meniscus was (12.3 ± 2.0) mm. The anterior horn of lateral meniscus was surrounded by arc-shaped direct insertion in the middle, and its fibers were partly intertwined with indirect insertion of ACL.
Conclusion: Anatomical ACL reconstruction may therefore require a arc-shaped tibial footprint. There are overlap covering relationship between the attachment location of anterior horn of the lateral meniscus and tibial insertion of ACL. It should pay more attention to protecting tibial insertion of ACL in lateral meniscus transplantation.