Fractured ribs most commonly are observed in neonates in conjunction with birth trauma. Rib fractures in older individuals most often result from collisions or kicks or falls. Birth trauma is the most common cause of rib fracture, and most neonates with fractures do not require medical or surgical intervention. However, rib fracture can cause life-threatening compromise to the integrity of the cardiopulmonary system and diaphragmatic hernia. Death can be due to hemorrhage into the thorax, pericardium, or abdomen, or shock, or a traumatic contact of the rib with the epicardium or myocardium that causes cardiac arrest.
Clinical Signs of Fractured Ribs
The clinical signs of fractured ribs are variable. Crepitus cannot be palpated consistently over the damaged area of the thoracic wall. In foals, simultaneous observation and palpation of the thoracic cage may reveal asymmetry of the thorax, especially at or near the costochondral junctions. Crepitation or “clicking” over a rib, heard with or without a stethoscope, is pathognomonic for the injury. Some patients reveal moderate thoracic edema ventral to the fracture sites. A stilted gait can indicate thoracic pain or the patient may “grunt” when manipulated or maneuvered. In severe cases, involving fractures in multiple consecutive ribs, the patient is in respiratory distress and presents with a flail thorax. The latter can be recognized when inspiratory effort results in collapse of the thoracic wall inward rather than the expected normal outward movement. If the patient has simultaneous pallor of the mucous membranes, internal hemorrhage should be suspected and promptly pursued in the diagnostic evaluation. Internal hemorrhage, including hemothorax, hemopericardium, and abdominal hemorrhage, may indicate that the diaphragm has been lacerated. Pneumothorax is an uncommon finding with fractured ribs in neonates but may be more likely in older individuals with fractures secondary to blunt trauma.
The location of the rib fractures is an important determinant of prognosis. Fractures in the cranioventral portion of the thorax, in proximity to the heart, can cause cardiac laceration and sudden death. Midthoracic rib fractures more frequently cause pulmonary laceration and hemothorax, occasionally with pneumothorax. Fractures in the mid-to-caudal thorax are capable of lacerating the diaphragm and causing secondary lung or abdominal visceral lesions.
Diagnosis of Fractured Ribs
The diagnosis of fractured ribs may be obvious when palpable crepitus is associated with an underlying rib. Ancillary diagnostic procedures include ultrasound evaluation and thoracic radiography. In most cases, use of ultrasound can reveal both rib fracture and displacement. Ultrasound is better than radiography for detecting the site of injury and also detects hemothorax, hemopericardium, pneumothorax, or diaphragmatic hernia. A single radiographic view provides an overall assessment of the thorax but ultrasound provides a detailed map.
Treatment of Fractured Ribs
The treatment of choice for fractured ribs is rest and confinement for 1 to 3 weeks. This conservative treatment is successful in nearly all cases of uncomplicated rib fracture. Supportive care is indicated for foals in pain, and manual assistance in helping foals to rise and nurse should be provided in a manner that avoids direct compression of either the fracture sites or the sternum. Affected foals may be assisted safely by lifting them from sternal recumbency by the elbows. Sedation may be required to prevent flailing or harmful struggling of some patients, and oxygen supplementation via nasal insufflation is indicated for obvious hypoxemia. If severe hypoxemia is present concurrently with a flail thorax, longer-term phenobarbital sedation may be required to maintain the foal in lateral recumbency. In these cases, the intact thoracic wall should be uppermost and occasionally the foal should be allowed to rest on its sternum. Foals that turn over can compress the underlying damaged lung. If the patient is allowed to be ambulatory, the primary concern is cardiac laceration and arrest if cranioventral fractures are further displaced by overactivity.
Surgical treatment of rib fractures is uncommon, but in these authors’ practice stabilization has been provided by use of dynamic compression plates. The long-term outcome of this procedure currently is being investigated. In cases where rib fractures are responsible for diaphragmatic hernia, surgical repair is essential to a favorable prognosis.