Bertocci Gina E, Brown Nathan P, Mich Patrice M
Am J Vet Res. 2017 Jan;78(1):27-35. doi: 10.2460/ajvr.78.1.27.
OBJECTIVE To evaluate effects of an orthosis on biomechanics of a cranial cruciate ligament (CrCL)-deficient canine stifle joint by use of a 3-D quasistatic rigid-body pelvic limb computer model simulating the stance phase of gait and to investigate influences of orthosis hinge stiffness (durometer). SAMPLE A previously developed computer simulation model for a healthy 33-kg 5-year-old neutered Golden Retriever. PROCEDURES A custom stifle joint orthosis was implemented in the CrCL-deficient pelvic limb computer simulation model. Ligament loads, relative tibial translation, and relative tibial rotation in the orthosis-stabilized stifle joint (baseline scenario; high-durometer hinge]) were determined and compared with values for CrCL-intact and CrCL-deficient stifle joints. Sensitivity analysis was conducted to evaluate the influence of orthosis hinge stiffness on model outcome measures. RESULTS The orthosis decreased loads placed on the caudal cruciate and lateral collateral ligaments and increased load placed on the medial collateral ligament, compared with loads for the CrCL-intact stifle joint. Ligament loads were decreased in the orthosis-managed CrCL-deficient stifle joint, compared with loads for the CrCL-deficient stifle joint. Relative tibial translation and rotation decreased but were not eliminated after orthosis management. Increased orthosis hinge stiffness reduced tibial translation and rotation, whereas decreased hinge stiffness increased internal tibial rotation, compared with values for the baseline scenario. CONCLUSIONS AND CLINICAL RELEVANCE Stifle joint biomechanics were improved following orthosis implementation, compared with biomechanics of the CrCL-deficient stifle joint. Orthosis hinge stiffness influenced stifle joint biomechanics. An orthosis may be a viable option to stabilize a CrCL-deficient canine stifle joint.
目的 使用三维准静态刚体骨盆肢体计算机模型模拟步态站立期，评估一种矫形器对颅交叉韧带（CrCL）缺失犬 stifle 关节生物力学的影响，并研究矫形器铰链刚度（硬度计）的影响。样本 一个先前开发的用于健康的 33 千克 5 岁绝育金毛猎犬的计算机模拟模型。程序 在 CrCL 缺失的骨盆肢体计算机模拟模型中实施定制的 stifle 关节矫形器。确定矫形器稳定的 stifle 关节（基线情况；高硬度计铰链）中的韧带负荷、胫骨相对平移和胫骨相对旋转，并与 CrCL 完整和 CrCL 缺失的 stifle 关节的值进行比较。进行敏感性分析以评估矫形器铰链刚度对模型结果测量的影响。结果 与 CrCL 完整的 stifle 关节的负荷相比，矫形器减少了施加在尾交叉韧带和外侧副韧带上的负荷，并增加了施加在内侧副韧带上的负荷。与 CrCL 缺失的 stifle 关节的负荷相比，矫形器管理的 CrCL 缺失的 stifle 关节中的韧带负荷降低。矫形器管理后胫骨相对平移和旋转减少但未消除。与基线情况的值相比，增加矫形器铰链刚度可减少胫骨平移和旋转，而降低铰链刚度会增加胫骨内旋。结论和临床意义 与 CrCL 缺失的 stifle 关节的生物力学相比，实施矫形器后 stifle 关节生物力学得到改善。矫形器铰链刚度影响 stifle 关节生物力学。矫形器可能是稳定 CrCL 缺失犬 stifle 关节的可行选择。
