Comparison of radiography and computed tomography to evaluate fractures of the canine tarsus

Abstract

Detection and accurate classification of traumatic tarsal fractures are important for identifying cases requiring surgical intervention. The aim of this prospective, experimental, methods comparison study was to directly compare the accuracy, sensitivity, and specificity of tarsal computed tomography (CT), ten-view and two-view digital radiographs for detecting traumatic fractures of the canine tarsus. The working hypothesis was that tarsal fractures would be detected with higher accuracy, sensitivity, and specificity using CT imaging compared to radiography, and a tenview would be superior to a two-view radiographic study. Ten cadaver hind limbs of medium to large dogs received a CT scan and ten-view radiographic study before and after induction of fractures with a hydraulic press. All bones included in the radiographic images were assessed for fractures by two observers and gross dissection was used as the gold standard. The two-view radiographic study (dorsoplantar, lateromedial) was created from the ten-view study and reviewed 2 years later. All limbs sustained fractures, the most common locations were the talus and calcaneus (n = 7). The sensitivity of CT was greater than ten-view radiographic study (77% vs. 57%), while the specificity was similar (97% vs. 98%). The sensitivity and specificity of the ten-view and twoview radiograph studies were similar (57% vs. 55%; both 98%). Computed tomography images were reassessed postdissection to determine if failure to identify fractures resulted from observer error. Overall, CT was better than radiography for detecting fractures of the canine tarsus, however there was little improvement with ten-view compared to two-view radiographic studies.

Injuries involving the central tarsal bone in nonracing dogs: Short‐term outcomes and prognostic factors

“…2,10,12,14,20 Partial tarsal arthrodesis, which was used commonly in this case series, has been associated with complications, particularly those relating to the regional soft tissue structures (bandage sores, incision dehiscence, and infection). 5,31,32 These complications would be expected to be less commonly encountered after primary fixation; however, our results do not provide evidence to support a difference in complications or outcomes between these procedures. Findings described in previous literature comparing reconstruction and arthrodesis lead us to believe that it is possible that this finding is a type II error and that, with a larger cohort, we may find a more significant difference in complications between fixation groups.…”

“…With the high prevalence of soft tissue complications that were present in this study and have been described after similar tarsal fixations, our results provide evidence that postoperative antibiotic administration should be carefully considered after Tc fixation. 5,31,32 Fractures that are associated with major complications were over 5 times more likely to have a poorer outcome score (5.64, 95% CI 0.69-53.84, P = .11); however, the CI here does include 1, so this result must be interpreted carefully. The authors consider it likely that, even though this report represents by far the largest sample of Tc fractures to date, the relatively small sample contributed to the failure of our results to reach statistical significance.…”

“…Specifically, the presence of fractures associated with the Tc luxations that are reported here cannot be ruled out. The use of computed tomography (CT) to assess the canine tarsus has been shown to improve sensitivity, particularly when assessing the Tc and 4th tarsal bones, 30,31 and to improve intraobserver agreement in classifying Tc fractures and identifying concomitant tarsal injuries. 30 Because most cases were diagnosed as type V fractures and the prevalence of concomitant tarsal bone injury appears consistent with previous studies, it is not likely that the routine use of CT would have altered our conclusions substantially; however, the authors acknowledge the potential for incomplete descriptions of intra-articular pathology.…”

CT characterisation of the feline os penis

“…11 The fact that the feline os penis is seen more frequently on CT images can be explained by the superior contrast resolution of CT when compared with radiography. 14 In the present study, cats showed, on average, a shorter cylindrical bone than in anatomical reports. 2,4 The reason for this difference is unclear, but the lower sample size could have influenced this difference.…”

“…11 The fact that the feline os penis is seen more frequently on CT images can be explained by the superior contrast resolution of CT when compared with radiography. 14…”