Newton P O, Woo S L, MacKenna D A, Akeson W H
Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, USA.
J Orthop Res. 1995 Mar;13(2):191-200. doi: 10.1002/jor.1100130207.
The effects of immobilization of the knee joint on the mechanical and ultrastructural properties of the anterior cruciate ligament have not been well documented. Our goal was to determine these effects in a rabbit model and to assess the effect of knee flexion angle during immobilization. The knee joint was immobilized in either 170 degrees or 105 degrees of flexion, and new methodologies were utilized to determine the mechanical properties of the anterior cruciate ligament. In specimens from knees that had been immobilized, the cross-sectional area of the ligament was 74% of the control value. The stress-strain curve was altered slightly, and the strain at failure increased 32-40%. The modulus and stress at failure did not decrease significantly. There was no significant difference between the mechanical properties of the knees immobilized at 170 degrees and 105 degrees of flexion. Histological and ultrastructural evaluation demonstrated changes in the shape and intracellular make-up of the fibroblasts from the ligament after immobilization. This cellular response may account for the alterations in the mechanical properties of the anterior cruciate ligament.
膝关节固定对前交叉韧带力学及超微结构特性的影响尚未得到充分记录。我们的目标是在兔模型中确定这些影响，并评估固定期间膝关节屈曲角度的影响。膝关节分别固定在170度或105度屈曲位，并采用新方法来确定前交叉韧带的力学特性。在已固定膝关节的标本中，韧带的横截面积为对照值的74%。应力-应变曲线略有改变，破坏应变增加32%-40%。破坏模量和应力没有显著降低。在170度和105度屈曲位固定的膝关节力学特性之间没有显著差异。组织学和超微结构评估显示，固定后韧带中纤维母细胞的形状和细胞内组成发生了变化。这种细胞反应可能是前交叉韧带力学特性改变的原因。
