PDF(Pubmed)
Abstract：
Cranial cruciate ligament deficiency (CCLD) results in internal rotational instability of the stifle (RLS). By contrast, tibial torsion (TT) is an anatomical feature of the tibia along its longitudinal axis. The objective of this study was to validate a dynamic radiographic technique to measure internal rotational laxity of the stifle and differentiate it from TT. Models included transection of the CCL for RLS and an osteotomy for TT. One limb within eight pairs of canine cadaveric hind limbs was randomly assigned to CCLD. The contralateral limb underwent TT, followed by CCLD. Neutral and stress radiographs were taken with the limb in a custom rotating 3-D printed positioning device before and after each modification. The position of the calcaneus on neutral views and the magnitude of its displacement under standardized torque were compared within limbs and between groups. Transection of the CCL increased the magnitude of displacement of the calcaneus by 1.6 mm (0.3-3.1 mm, p < 0.05) within limbs. The lateral calcaneal displacement (dS-dN) tended to be greater when CCLD limbs were compared to limbs with intact CCL. A magnitude of calcaneal displacement of 3.45 mm differentiated limbs with RLS from intact limbs with 87.5% sensitivity and 68.7% specificity. The calcaneus was displaced further laterally by about 3 mm on neutral radiographs (dN) when limbs with experimental TT were compared to those without TT (p < 0.05). A calcaneus located at least 3.25 mm from the sulcus differentiated limbs with TT from intact limbs with 87.5% sensitivity and 87.5% specificity. The technique reported here allowed detection of RLS, especially within limbs. A calcaneus located at least 3.25 mm on neutral radiographs of large dogs should prompt a presumptive diagnosis of TT.
摘要：
颅骨交叉韧带缺陷（CCLD）导致窒息（RLS）的内部旋转不稳定。相比之下,胫骨扭转（TT）是胫骨沿其纵轴的解剖特征。这项研究的目的是验证一种动态射线照相技术，以测量窒息的内部旋转松弛度并将其与TT区分开。模型包括用于RLS的CCL横切和用于TT的截骨术。八对犬尸体后肢中的一条肢体被随机分配到CCLD。对侧肢体接受了TT，其次是CCLD。在每次修改之前和之后，在定制的旋转3D打印定位设备中对肢体进行中性和应力射线照相。在四肢内和组间比较了跟骨在中性视图上的位置及其在标准扭矩下的位移大小。CCL的横切使跟骨的位移幅度增加了1.6mm（0.3-3.1mm，p<0.05）在四肢内。当CCLD肢体与完整CCL的肢体相比时，跟骨外侧位移（dS-dN）倾向于更大。与完整肢体相比，具有RLS的3.45mm分化肢体的跟骨移位幅度为87.5％，特异性为68.7％。当将具有实验性TT的肢体与没有TT的肢体进行比较时，在中性射线照片（dN）上，跟骨进一步横向移位了约3mm（p<0.05）。跟骨距离沟至少3.25mm，与完整肢体的TT区分，敏感性为87.5％，特异性为87.5％。这里报道的技术允许检测RLS，尤其是四肢内。在大型犬的中性X射线照片上至少位于3.25mm的跟骨应该提示TT的推定诊断。
