Melenevsky Yulia, Mackey Robert A, Abrahams R Brad, Thomson Norman B
From the Department of Radiology and Imaging, Georgia Regents University, 1120 15th St, Room BA-1414, Augusta, GA 30912.
Radiographics. 2015 May-Jun;35(3):765-79. doi: 10.1148/rg.2015140156.
The talus, the second largest tarsal bone, has distinctive imaging characteristics and injury patterns. The predominantly extraosseous vascular supply of the talus predisposes it to significant injury in the setting of trauma. In addition, the lack of muscular attachments and absence of a secondary blood supply can lead to subsequent osteonecrosis. Although talar fractures account for less than 1% of all fractures, they commonly result from high-energy trauma and may lead to complications and long-term morbidity if not recognized and managed appropriately. While initial evaluation is with foot and ankle radiographs, computed tomography (CT) is often performed to evaluate the extent of the fracture, displacement, comminution, intra-articular extension, and associated injuries. Talar fractures are divided by anatomic region: head, neck, and body. Talar head fractures can be treated conservatively if nondisplaced, warranting careful radiographic and CT evaluation to assess rotation, displacement, and extension into the neck. The modified Hawkins-Canale classification of talar neck fractures is most commonly used due to its simplicity, usefulness in guiding treatment, and prognostic value, as it correlates associated malalignment with risk of subsequent osteonecrosis. Isolated talar body fractures may be more common than previously thought. The Sneppen classification further divides talar body fractures into osteochondral talar dome, lateral and posterior process, and shear and crush comminuted central body fractures. Crush comminuted central body fractures carry a poor prognosis due to nonanatomic reduction, bone loss, and subsequent osteonecrosis. Lateral process fractures can be radiographically occult and require a higher index of suspicion for successful diagnosis. Subtalar dislocations are often accompanied by fractures, necessitating postreduction CT. Familiarity with the unique talar anatomy and injury patterns is essential for radiologists to facilitate appropriate and timely management.
距骨是第二大跗骨，具有独特的影像学特征和损伤模式。距骨主要由骨外血管供血，这使其在创伤情况下易遭受严重损伤。此外，缺乏肌肉附着以及没有 secondary blood supply（此处可能有误，推测是“次要血供”）会导致随后的骨坏死。尽管距骨骨折占所有骨折的比例不到1%，但它们通常由高能创伤引起，如果未得到正确识别和处理，可能会导致并发症和长期致残。虽然初始评估采用足踝部X线片，但通常会进行计算机断层扫描（CT）以评估骨折的范围、移位、粉碎程度、关节内延伸情况以及相关损伤。距骨骨折按解剖区域分为：头部、颈部和体部。如果距骨头骨折无移位，可采用保守治疗，但需要仔细的X线和CT评估，以评估旋转、移位以及向颈部的延伸情况。距骨颈骨折的改良Hawkins-Canale分类法因其简单、对治疗有指导作用且具有预后价值而最为常用，因为它将相关的排列不齐与随后骨坏死的风险相关联。孤立的距骨体骨折可能比以前认为的更常见。Sneppen分类法进一步将距骨体骨折分为距骨软骨下骨穹窿骨折、外侧和后突骨折以及剪切和粉碎性中央体骨折。由于无法进行解剖复位、骨质丢失以及随后的骨坏死，粉碎性中央体骨折的预后较差。外侧突骨折在X线片上可能隐匿，需要更高的怀疑指数才能成功诊断。距下关节脱位常伴有骨折，复位后需要进行CT检查。放射科医生熟悉距骨独特的解剖结构和损伤模式对于促进适当和及时的处理至关重要。
