Clinical history “Kiwi" was a 13 month old female terrier hit by a car 5 days ago. At that time, she was non-weight-bearing on the right forelimb and palpation suggested a luxation of the right shoulder joint. Several days later she was presented by the owners to evaluate treatment for this suspected injury since she remained unable to bear weight on that limb. In addition, on physical examination, the antebrachium was swollen and this injury seemed unassociated with the shoulder injury. Also, she was breathing with some difficulty. Radiographs were made of the right antebrachium because of the persistent soft tissue swelling. (fig 1) Fig #1 - Radiographs of the right antebrachium - List the important radiographic findings Radiographic findings
- Soft tissue swelling
- Air pocket mid-portion antebrachium (arrow)
- Soft tissue radiopaque shadows adjacent to a malformed olecranon process
- Probably osteophyte formation proximal radius laterally
- Elbow joint appears unaffected
- Radiocarpal joint appears unaffected
What are possible explanations for the radiopaque soft tissue shadows (arrows)?? What are possible explanations for the radiopaque soft tissue shadows (arrows)??
- A. gravel or dirt within the soft tissues or on the surface of the skin creating artifacts
- B. fracture fragments indicative of recent injury
- C. nonunion fracture fragments that have modeled indicative of chronic injury
- D. calcified hematoma suggesting chronicity
- E. a form of congenital/developmental anomaly
Radiographic diagnosis The density and appearance of the soft tissue shadows is compatible with multiple comminuted fracture fragments from the olecranon process - the appearance of the fragments suggests chronicity - Comparison with a lateral radiograph of a normal elbow clearly shows the anatomical difference and the nature of the fractures - it is important to note that the anconeal process and the trochlear notch are intact. Fig #2 - Thoracic radiographs were made on day 5 because of the difficulty in breathing Radiographic diagnosis (thorax day 5) Pneumothorax as indicated by the separation of the elevated cardiac silhouette from the sternum and ability to identify the border of the collapsed lung lobes separated from the chest wall and the spine (arrows). Cranial mediastinal fluid adjacent to the sternum ventrally and cranially suggests hemomediastinum (arrows). Plate-like atelectasis mid-thorax caudally suggests pulmonary injury. Widening of the thoracic cavity as indicated by position of the ribs suggests dyspnea. Final radiographic diagnosis Communited avulsion fracture from the olecranon process with preservation of the elbow joint - fracture suggests an abrasive type of injury Soft tissue injury indicated by the soft tissue air pocket Thoracic injury including pneumothorax plus pulmonary hemorrhage and probable mediastinal hemorrhage. Comments Because of the lack of a single intact bone fragment, the use of a comparison radiographs of a normal limb is helpful in evaluation of the injury and in making a radiographic diagnosis. The comminuted fracture makes fragment reduction impossible. The appearance of the fracture fragments suggests an older injury and the possibility that the owner did not know the time of the original injury The soft tissue air pocket suggests a puncture wound making soft tissue infection a likely complication healing. A pneumothorax persistent for 5 days post trauma is secondary to an injury to the lung that is more severe than usual and close clinical observation is required. A radiographic examination of the thorax should be a part of a clinical workup in a trauma patient, especially if there is known injury to the thoracic limbs. The hemorrhage within the mediastinum also tell of more severe changes secondary to the trauma than are usual. It is possible that the dog sustained more than one injury since the pulmonary lesions appear more acute than the bone lesions.
