Читать книгу Fractures in the Horse - Группа авторов - Страница 102

Open fractures are most commonly secondary to impact injuries. The presence of an open wound can be seen radiographically as disruption of and/or defects in the normal soft tissue opacity with varying degrees of gas opacity inclusions. Gas opacity extending to the fracture on two orthogonal projections suggests direct communication with the wound. A gas cap in the most proximal extent of a synovial cavity raises the suspicion of synovial penetration (see Figure 26.18). In the absence of a wound, gas in a joint can be explained by vacuum phenomena [40]. The authors have seen this occasionally following third metacarpal bone condylar fractures that have had concomitant joint capsule tearing identified during arthroscopy. Gas can also accumulate in the subarachnoid and cervical epidural spaces following some basilar skull fractures [41]. Frontal or sphenopalatine sinus fractures or a fractured petrous temporal bone in combination with a ruptured tympanic membrane can also lead to free gas within the calvarium [10, 41].