US Ankle US is not routinely used as the first imaging study for the evaluation of acute trauma to the ankle in the setting of peripheral neuropathy or other exclusionary criteria. US may be useful as a secondary step in evaluation of foreign bodies or focal fluid collections. Variant 4: Adult or child 5 years of age or older. Acute trauma to the ankle with persistent pain for more than 1 week but less than 3 weeks. No exclusionary criteria present. Initial radiographs negative. Next study. Acute trauma includes immediate time of injury to <3 weeks, whereas subacute trauma includes 3 weeks to <6 months. The timeframe of this clinical scenario is at the intersection of the late acute and subacute phases, and the OAR criteria can still apply for acute ankle trauma in this setting. Persistent pain may be associated with a radiographically occult fracture, bone contusion, subtle cartilage injury, soft-tissue injury, or foreign body not visible on radiographic examination. Diagnosis is critical in determining appropriate and timely orthopedic fixation/treatment planning [1,5]. Bone Scan Ankle Bone scan is typically not used as the next step in this clinical scenario. CT Ankle CT of the ankle without intravenous (IV) contrast is useful in the trauma setting as the next study to evaluate for radiographically occult fractures and soft-tissue abnormalities. It is rare (<1%) for patients with a large joint effusion but no discernible fracture on radiographic examination, however, CT proved useful in demonstrating a fracture in one-third of cases in one large study [43,44]. Talar fractures (lateral process or comminuted talar body/dome fractures) and fractures associated with the subtalar joint can be difficult to detect on radiographs but are well identified on CT [45,46]. In patients with spiral fractures of the tibia, there is a higher incidence of nondisplaced posterior malleolar fractures that may be missed on radiographic examination [47].
Acute Trauma to the Ankle. US Ankle US is not routinely used as the first imaging study for the evaluation of acute trauma to the ankle in the setting of peripheral neuropathy or other exclusionary criteria. US may be useful as a secondary step in evaluation of foreign bodies or focal fluid collections. Variant 4: Adult or child 5 years of age or older. Acute trauma to the ankle with persistent pain for more than 1 week but less than 3 weeks. No exclusionary criteria present. Initial radiographs negative. Next study. Acute trauma includes immediate time of injury to <3 weeks, whereas subacute trauma includes 3 weeks to <6 months. The timeframe of this clinical scenario is at the intersection of the late acute and subacute phases, and the OAR criteria can still apply for acute ankle trauma in this setting. Persistent pain may be associated with a radiographically occult fracture, bone contusion, subtle cartilage injury, soft-tissue injury, or foreign body not visible on radiographic examination. Diagnosis is critical in determining appropriate and timely orthopedic fixation/treatment planning [1,5]. Bone Scan Ankle Bone scan is typically not used as the next step in this clinical scenario. CT Ankle CT of the ankle without intravenous (IV) contrast is useful in the trauma setting as the next study to evaluate for radiographically occult fractures and soft-tissue abnormalities. It is rare (<1%) for patients with a large joint effusion but no discernible fracture on radiographic examination, however, CT proved useful in demonstrating a fracture in one-third of cases in one large study [43,44]. Talar fractures (lateral process or comminuted talar body/dome fractures) and fractures associated with the subtalar joint can be difficult to detect on radiographs but are well identified on CT [45,46]. In patients with spiral fractures of the tibia, there is a higher incidence of nondisplaced posterior malleolar fractures that may be missed on radiographic examination [47].