Clinical history A 6 year old male, intact cat was hit by car, the patient was dyspneic - he was in shock making identification of pain by physical examination difficult, radiographs were made of the entire patient. Catogram Pelvis - enlarged Radiographic findings
- Generalized increase in interstitial density in lungs typical for pulmonary contusion/ hemorrhage
- Malposition of pelvic bones suggest acute fracture/luxation
- Cranial displacement of ilia with approximately 50% sacroiliac luxation bilaterally
- Narrowing of the pelvic inlet caudally without clear identification of fracture line
Pelvis - day 2 - pre surgery - patient now without pain on palpation Radiographic findings on day 2 Lateral view - better pelvic positioning - – No evidence of sacral or pelvic fracture. Ventrodorsal view with limbs flexed (an attempted “frog leg” view)
- This positioning fails to cause any motion of the pelvis at the sacroiliac joints and permits identification of bony response around the right sacroiliac joint -(arrows)
- Persistent pelvic canal narrowing without change in positioning of the pubis or ischia and no identification of fracture lines
Final radiographic diagnosis Pulmonary contusion post trauma Healed pelvic injury, the result of old trauma without evidence of acute trauma
- with failure of motion of the pelvis at the sacroiliac joints even with different pelvic positioning - this indicates healing/stabilization of old sacroiliac luxations without acute instability today
- failure to identify fracture lines indicates healing of old pubic and ischial fractures - superimposition of bony fragments indicating healed ischial fractures - (arrow)
Comments Many patients live in a style in which owners are not knowledgeable about all past traumatic events - thus, when presented for diagnosis and treatment of known trauma, it is without a history of earlier trauma. In this cat, the pulmonary changes are classic for acute hemorrhage and contusion and support the clinical history of acute trauma - the radiographic changes originally seen in the pelvis present in a manner suggestive of those seen in acute trauma. On day 2, the cat was showing only minimal pelvic pain suggesting that the radiographs had been incorrectly interpreted - the use of multiple radiographic positionings of the pelvis demonstrated the absence of expected acute instability between bones leading to the new diagnosis of chronic healed fracture/ luxations.
