Histologic Three-dimensional Reconstructions Of The Anterior Cruciate Ligament Tibial Insertion In Human

Objective To divide the histologic-structural of anterior cruciate ligament(ACL) according to the tendency of difference of spatial structure and change rule of uncalcified fibrocartilage (UF) and calcified fibrocartilage(CF), tibial insertion footprint of ACL of knee was histologically reconstructed with three-dimensional method.Thereby,provided a novel method for empirical study and clinical operative reconstruction.Materials and Methods1.Materials: 4 fresh sample of nomal knee of adult cadavers safranin'o/fast green stain(Sheng gong company of shanghai) BX50F4 microscope of Olympus(Japanese) Alpha As-808P CCD camera lens(Japanese) Photoshop8.0.1 Amira4.1.12.Methods:(1)To measure the anatomical position of ACL tibial insertion on tibial plateau.(2)To transect ACL insertion footprint 4mm from the tibial plateau deep to 2mm underneath the subcondral bone. Prepare the specimens with Routine fixation, decalcification, dehydrolysis, and paraffin imbedding,the blocks were horizontally sectioned with continuously 8μm slices with an 100μm interval. Safranin` o/fast green stain was used. To observe and photograph under light microscope. After that the images were spliced by Photoshop8.01.(3)To describe circumscription of images and fill it with gray scale according to its structure. After that load the images and three-dimensional reconstruct with Amira4.1.1Results 1.The distance between anterior insertion edge and anterior tibial plateau border,between posterior insertion edge and posterior tibial plateau border,between medial insertion edge and medial tibial plateau,between lateral insertion edge and lateral tibial plateau was 7.36mm-9.67mm, 16.68mm-18.61mm,31.75mm-35.61mm,32.57mm-36.15mm respectively.2.The process of transition of four layers was not uniform.The transition deck of anteromedial and posteromedial part was relative high and the deck of anterolateral and posterolateral part was relative low.3.The results of three-dimensional reconstruction revealed the tendency of difference of UF layer thinkness and change rule.The calcified fibrocartilage(CF)appeared jagged and no obvious difference in all part.Conclusions1.We can divide ACL into two functional bundles: medial and lateral bundle according to the tendency of difference of spatial structure and change rule of UF and CF.Medial bundle was the mayor functional bundle and anteromedial fiber was the strength peak value fiber bundle.2.ACL should be double-bundle reconstructed in operation. Anteromedial strength peak value fiber bundle should be reconstructed in medial bundle renconstruction.The centre position of the tibial tunnel was medial deviation of 250-330 from the geometrical center of tibial insertion.Its distance was half of anteroposterior diameter dividing cosine value of angulation of medial deviation and multiplying 0.45. The centre position of the lateral bundle was the point of symmetry of centre of anteromedial strength peak value fiber bundle concerning centre of tibial insertion...