Marzo John M, Kluczynski Melissa A, Clyde Corey, Anders Mark J, Mutty Christopher E, Ritter Christopher A
Jacobs School of Medicine and Biomedical Sciences, The State University of New York, University at Buffalo, Buffalo, NY, USA.
Quant Imaging Med Surg. 2017 Dec;7(6):678-684. doi: 10.21037/qims.2017.12.02.
For AO 44-B2 ankle fractures of uncertain stability, the current diagnostic standard is to obtain a gravity stress radiograph, but some have advocated for the use of weight-bearing radiographs. The primary aim was to compare measures of medial clear space (MCS) on weight-bearing cone beam computed tomography (CBCT) scans versus gravity stress radiographs for determining the state of stability of ankle fractures classified as AO SER 44-B2 or Weber B. The secondary aim was to evaluate the details offered by CBCT scans with respect to other findings that may be relevant to patient care. Nine patients were enrolled in this cross-sectional study between April 2016 and February 2017 if they had an AO SER 44-B2 fracture of uncertain stability, had a gravity stress radiograph, and were able to undergo CT scan within seven days. The width of the MCS was measured at the level of the talar dome on all radiographs and at the mid coronal slice on CT. Wilcoxon signed-ranks tests were used to compare MCS between initial radiographs, gravity stress radiographs and weight-bearing CBCT scans. MCS on weight-bearing CBCT scan (1.41±0.41 mm) was significantly less than standard radiographs (3.28±1.63 mm, P=0.004) and gravity stress radiographs (5.82±1.93 mm, P=0.02). There was no statistically significant difference in MCS measured on standard radiographs versus gravity stress radiographs (P=0.11). Detailed review of the multiplanar CT images revealed less than perfect anatomical reduction of the fractures, with residual fibular shortening, posterior displacement, and fracture fragments in the incisura as typical findings. Similar to weight-bearing radiographs, weight-bearing CBCT scan can predict stability of AO 44-B2 ankle fractures by showing restoration of the MCS, and might be used to indicate patients for non-operative treatment. None of the fractures imaged in this study were perfectly reduced however, and further clinical research is necessary to determine if any of the detailed weight-bearing CBCT findings are related to patient outcomes.
对于稳定性不确定的AO 44-B2型踝关节骨折，目前的诊断标准是拍摄重力应力位X线片，但也有人主张使用负重X线片。主要目的是比较负重锥形束计算机断层扫描（CBCT）与重力应力位X线片上内侧间隙（MCS）的测量值，以确定分类为AO SER 44-B2或Weber B型的踝关节骨折的稳定状态。次要目的是评估CBCT扫描提供的有关可能与患者护理相关的其他发现的细节。2016年4月至2017年2月期间，9例稳定性不确定的AO SER 44-B2骨折患者纳入了这项横断面研究，这些患者均拍摄了重力应力位X线片，且能够在7天内接受CT扫描。在所有X线片的距骨穹窿水平以及CT的冠状位中层面测量MCS的宽度。采用Wilcoxon符号秩检验比较初始X线片、重力应力位X线片和负重CBCT扫描之间的MCS。负重CBCT扫描时的MCS（1.41±0.41mm）显著小于标准X线片（3.28±1.63mm，P = 0.004）和重力应力位X线片（5.82±1.93mm，P = 0.02）。标准X线片与重力应力位X线片测量的MCS之间无统计学显著差异（P = 0.11）。对多平面CT图像的详细检查显示骨折的解剖复位并不完美，典型表现为腓骨残留缩短、向后移位以及切迹内的骨折碎片。与负重X线片类似，负重CBCT扫描可通过显示MCS的恢复来预测AO 44-B2型踝关节骨折的稳定性，并可用于指示非手术治疗的患者。然而，本研究中成像的骨折均未实现完美复位，需要进一步的临床研究来确定负重CBCT的任何详细发现是否与患者预后相关。
