Zhang J H, Ren S, Shao J Y, Niu X Y, Hu X Q, Ao Y F
Institute of Sports Medicine, Peking University Third Hospital; Beijing Key Laboratory of Sports Injuries, Beijing 100191, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2019 Jun 18;51(3):586-590. doi: 10.19723/j.issn.1671-167X.2019.03.031.
To provide new concepts of anterior cruciate ligament (ACL) reconstruction by anatomical gross observation of ACL tibial insertion and finite element analysis of distribution of ACL mechanical insertion.
In the anatomical study, ten fresh adult cadaveric knees were dissected, including 6 males and 4 females, all knees were generally observed through standard medial parapatellar approaches, paying attention to the close anatomical relationship of tibial insertion and anterior horn of lateral meniscus, and ACL was exposed and gradually removed from the inside. The shape of tibial insertion of ACL was observed and recorded, and anterior-posterior diameters and left-right diameters of tibial insertion were measured with vernier caliper. For the study of finite element analysis, three-dimensional thin-layer magnetic resonance imaging of normal knee joint was used to establish knee joint model. Three-dimensional reconstruction software MIMICS and finite element analysis software ANSYS were used to establish knee joint model, subsequently, clinical physical examination Lachman test and pivot-shift test were simulated to observe the force distribution of ACL tibial insertion and femoral insertion.
The ACL tibial mechanical insertion was rather flat and long similar as an arc shape without a clear separation between anterior medial bundle (AMB) and posterolateral bundle (PLB) in gross observation. The dense fibers lies belonged to the medial intercondylar ridge and ended up anterior with the osseous landmark of anterior ridge. Its average anterior-posterior diameter was (13.8±2.0) mm, the average left-right diameter of midsubstance was (5.3±0.6) mm, and the average left-right diameter of anterior margin was (11.5±1.2) mm. The finite element analysis showed that distribution on the femoral side was oval shape mainly below the residents' ridge, while the tibial side was rather flat mainly along the medial intercondylar ridge, which was consistent with the anatomical observation. The biomechanical characteristics of ACL attachments were verified theoretically.
Anatomical study and finite element analysis have confirmed the flat arc shape of ACL tibial insertion. The ideal reconstruction technique of ACL should be based on its biomechanical insertion. Based on anatomical study and biomechanical analysis, we have proposed the idea of ACL biomechanical insertion reconstruction (BIR) and established a surgical model with oval femoral tunnel and rounded-rectangle tibial tunnel.
通过对前交叉韧带（ACL）胫骨止点的解剖大体观察及ACL力学止点分布的有限元分析，为ACL重建提供新的概念。
在解剖学研究中，解剖10例新鲜成人尸体膝关节，其中男性6例，女性4例，均经标准髌旁内侧入路进行大体观察，注意胫骨止点与外侧半月板前角的紧密解剖关系，显露ACL并从内侧逐渐切除。观察并记录ACL胫骨止点的形态，用游标卡尺测量胫骨止点的前后径和左右径。在有限元分析研究中，采用正常膝关节的三维薄层磁共振成像建立膝关节模型。利用三维重建软件MIMICS和有限元分析软件ANSYS建立膝关节模型，随后模拟临床体格检查Lachman试验和轴移试验，观察ACL胫骨止点和股骨止点的受力分布。
大体观察显示，ACL胫骨力学止点较为扁平且长，呈弧形，前内侧束（AMB）和后外侧束（PLB）之间无明显分隔。致密纤维束属于髁间嵴内侧，向前止于前嵴的骨性标志处。其平均前后径为（13.8±2.0）mm，中点处平均左右径为（5.3±0.6）mm，前缘平均左右径为（11.5±1.2）mm。有限元分析表明，股骨侧的分布主要在髁间嵴下方呈椭圆形，而胫骨侧主要沿髁间嵴内侧较为扁平，这与解剖学观察结果一致。从理论上验证了ACL附着点的生物力学特性。
解剖学研究和有限元分析证实了ACL胫骨止点呈扁平弧形。理想的ACL重建技术应基于其生物力学止点。基于解剖学研究和生物力学分析，我们提出了ACL生物力学止点重建（BIR）的理念，并建立了股骨隧道为椭圆形、胫骨隧道为圆角矩形的手术模型。
