Departments of Mechanical Engineering & Materials Science (R.M.C., M.J.J., and S.P.L.) and Orthopaedic Surgery (S.P.L. and R.H.B.), Washington University in St. Louis, St. Louis, Missouri.
J Bone Joint Surg Am. 2020 Nov 18;102(22):1948-1955. doi: 10.2106/JBJS.19.01395.
Injuries to the anterior cruciate ligament and posterior cruciate ligament are common, and often are treated with reconstruction. Limited quantitative data are available describing material properties of grafts used for reconstructions such as the bone-patellar tendon-bone (BPTB), hamstring tendon (HS), and quadriceps tendon (QT). The purpose of this study was to quantify and compare microstructural and mechanical properties of BPTB, HS, and QT grafts.
Forty specimens (13 BPTB, 13 HS, and 14 QT grafts) from 24 donors were used. Specimens were subjected to preconditioning, stress relaxation, and ramp to failure. Mechanical parameters were calculated for each sample, and polarization imaging was used to evaluate the direction and strength of collagen fiber alignment during testing.
QT had the largest modulus values, and HS had the smallest. BPTB exhibited the least disperse collagen organization, while HS were the least strongly aligned. Microstructural properties showed more strongly aligned collagen with increasing load for all grafts. All tissues showed stress relaxation and subtle microstructural changes during the hold period.
The mechanical and microstructural properties differed significantly among BPTB, HS, and QT grafts. QT exhibited the largest moduli and greatest strength of collagen alignment, while HS had the smallest moduli and least strongly aligned collagen.
This study identified mechanical and microstructural differences among common grafts and between these grafts and the cruciate ligaments they replace. Further research is needed to properly interpret the clinical relevance of these differences.
前交叉韧带和后交叉韧带损伤很常见，通常采用重建治疗。目前，有关用于重建的移植物（如骨-髌腱-骨（BPTB）、腘绳肌腱（HS）和股四头肌肌腱（QT））的材料特性的定量数据有限。本研究旨在定量比较和比较 BPTB、HS 和 QT 移植物的微观结构和力学性能。
使用 24 名供体的 40 个标本（13 个 BPTB、13 个 HS 和 14 个 QT 移植物）。标本进行预适应、应力松弛和斜坡至失效。为每个样本计算力学参数，并使用偏光成像评估测试过程中胶原纤维取向的方向和强度。
QT 的模量值最大，而 HS 的模量值最小。BPTB 表现出最小的胶原组织分散性，而 HS 的胶原排列最不整齐。随着载荷的增加，所有移植物的微观结构特性都表现出更整齐的胶原。所有组织在保持期内都表现出应力松弛和细微的微观结构变化。
BPTB、HS 和 QT 移植物之间的力学和微观结构特性存在显著差异。QT 表现出最大的模量和最强的胶原排列强度，而 HS 具有最小的模量和最不整齐的胶原。
本研究确定了常见移植物之间以及这些移植物与它们所替代的交叉韧带之间的力学和微观结构差异。需要进一步研究才能正确解释这些差异的临床意义。
