Radiographic Studies

Plain films, including anteroposterior and lateral views, of the involved extremities should be obtained in all cases. Oblique views may also offer additional information. It is important that the joints above and below the suspected injury site are imaged. Five general types of fracture patterns are created from bullets ( Fig.;... . .255-2). A drill hole pattern from penetration of cancellous bone is often seen in sites such as the proximal humerus, pelvis, and distal femur. These fractures have less comminution than those in cortical bone, because cancellous bone is more porous and less dense. Unicortical fractures of the metaphysis on long bones are often seen with bullet impact on a tangential plane. The majority of gunshot fractures of the diaphysis are comminuted, and the degree of comminution depends on the amount of energy transfer from the penetrating missile. Spiral fractures distant from the site of impact on the bone can occur if the bone is under a degree of torsional stress. There have also been reports of simple fractures of long bones caused by indirect damage from the temporary cavity. It is also important to note whether a joint has been penetrated, because this complication changes patient management. In the case of shotgun or blast injury, it is important to image the extremity distal to the injury in order to detect any pellets that may have embolized (Fig 255-3 and Fig 255-4).

FIG. 255-2. Types of fracture patterns created with bullets: drill hole, unicortical, distant spiral, comminuted. The fifth type seen is a simple fracture.

* f I

FIG. 255-3. Gunshot wound to the shoulder and axilla.

FIG. 255-3. Gunshot wound to the shoulder and axilla.

Computed tomography, although rarely useful in the acute diagnosis and treatment of extremity trauma, is considered helpful in selected cases before definitive orthopedic care. It can help diagnose bony pathology and determine if intraarticular fractures, fragments, or foreign bodies are present. Magnetic resonance imaging, once thought to be a promising tool in the assessment of extremity trauma, is not readily available in many institutions, is time consuming, and often is of low yield.

Angiography can be used to delineate the extent, nature, and location of vascular injuries with special situations such as shotgun wounds, multiple or severe fractures, chronic vascular disease, thoracic outlet wounds, or extensive soft tissue injury. The widespread availability and accuracy of angiography led to it become the gold standard in the evaluation of patients with wounds in proximity to major neurovascular bundles. Arteriography for the evaluation of proximity injuries in patients without hard signs of injury reveals normal results in 80 to 90 percent, with a complication rate of 1 to 2 percent from the procedure. Recent studies have shown that occult vascular injuries can exist, without hard clinical findings, in up to 23 percent of patients. Among these, however, fewer than 2 percent have surgically important lesions. Still, with observation and a careful examination, positive findings will eventually be more evident and the wounds subsequently repaired without increased morbidity.78,9 and 1°. The algorithm presented in Fjgure.255-1 outlines the approach to vascular injuries. In the presence of hard signs of vascular injury on clinical examination, immediate surgery is indicated in some conditions, without a preoperative angiogram. However, certain injuries are still best evaluated by angiography prior to surgical intervention. The need for angiography in patients with soft signs of vascular injury is still a matter of some debate among surgeons and radiologists. However, current practice in most centers is to observe patients with soft signs and conduct serial examinations. Angiography and surgery are delayed until there is clinical evidence of arterial injury.

Digital subtraction angiography has also been used in evaluation of vascular trauma with accuracy similar to standard techniques but is less reliable in detecting intimal disruption. The test requires a cooperative patient, because it is extremely sensitive to motion artifact. 5

Was this article helpful?

0 0
Your Heart and Nutrition

Your Heart and Nutrition

Prevention is better than a cure. Learn how to cherish your heart by taking the necessary means to keep it pumping healthily and steadily through your life.

Get My Free Ebook

Post a comment