microCT重建距骨骨内微小动脉三维结构的临床解剖学研究

Three-dimensional reconstruction of intraosseous vascular anatomy of the talus: a micro-computed tomography study

摘要:

目的获得距骨内微小动脉三维结构模型，对临床上不同分型的距骨骨折的预后做出更精确的解释和预测。方法对 12 例新鲜尸体下肢行股动脉插管并灌注铅造影剂。距骨取材，进行 microCT 扫描并且重建高精度模型，图像最终分辨率为 52.30 μm。最终获得距骨周围与距骨内血管在各个切面的图像，观察距骨表面动脉与骨内分支的走行和分布，并计数动脉的骨内分支数。结果距骨骨外血管集中分布于表面的韧带和关节囊内。距骨表面主要有 4 大血管分布区域，分别为跗骨管-跗骨窦区、距骨颈上表面、距骨体内侧面和后结节区。距骨颈周围血管环由跗骨管-跗骨窦区和距骨颈上表面的骨外血管连接而成(骨内分支数分别为 5.1±1.3 和 5.6±1.9)，是距骨的主要血供来源，分支分布于距骨头、距骨颈和大部分距骨体，并有丰富的吻合。此外，距骨体还接受距骨体内侧面(骨内分支 3.2±1.4)和后结节区(骨内分支 0.7±0.5)的骨内分支的血供。结论血管环是距骨的主要血供来源，骨内分支有丰富吻合。 距骨颈骨折的坏死风险取决于该分型对血管环骨内分支和吻合的破坏程度。 距骨体矢状面骨折和粉碎骨折对血管环的骨内分支的破坏较大，缺血坏死风险相对高。距骨头血供丰富，骨折时缺血坏死的可能小。

Abstract:

Objective To acquire three-dimensional intraosseous artery of the talus in order to interpret the prognosis of talus fractures. Methods Lower extremities of twelve fresh corpses were acquired. The femoral arteries in the femoral triangle were cannulated and manually perfused with lead-based contrast agent. Every harvested talus was scanned using a microCT scanner (Inveon, Siemens Ltd., USA). The 3D high-accuracy models of the talus were generated at 52.30 μm. The distribution and pattern of arteries in each section were obtained and the intraosseous branches were counted. Results The numerous extraosseous arteries were mainly running in the articular capsules and ligaments around the talus. We identified four vascular zones on the talus surface including tarsal canal-tarsal sinus, superior talus neck, medial talus body and posterior tubercle. A vessel ring around the talus neck was formed by the anastomosing of the extraosseous vessels in the tarsal canal-tarsal sinus and on the superior talus neck (the number of intraosseous branches are 5.1±1.3 and 5.6±1.9), which was the primary blood supply of the talus. The intraosseous branches of the ring were distributed in the talus head, talus neck and most of the talus body with abundant anastomoses. Besides from the ring, the talus body also received intraosseous blood supply from medial talus body (3.2±1.4 intraosseous branches) and posterior tubercle (0.7±0.5 intraosseous branches). Conclusion A severer destruction of the intraosseous branches of vascular ring resulting from talus neck fracture would pose a higher risk of talus avascular necrosis. As for talus body, the sagittal fracture and comminuted fracture caused relatively more damage to the intraosseous branches of vascular ring, thus leading to an increased potential of avascular necrosis. The osteonecrosis due to talar head fractures is rare because of the rich blood supply of talar head.