Dealing with open fractures and compartment syndrome

Increasingly, the issue of emergency department call has become a hot topic for both orthopaedic surgeons and hospitals. One of the most pressing concerns is whether to treat or to transfer, particularly if the surgeon on call is confronted with a patient whose injuries are on the fringes of the surgeon’s range of experience.

“Damage Control for the General Orthopaedic Surgeon: Getting Your Patient Safely to the Traumatologist”—a symposium held at the 2010 AAOS Annual Meeting—was designed to provide guidelines to help the general orthopaedist make quality decisions during that critical time. The presenters—all of whom are military orthopaedists—discussed four situations that are often found in an acute trauma environment and may raise concerns among orthopaedists unaccustomed to dealing with trauma.

“Our purpose is to look at lessons we’ve learned not only from treating combat-related injuries,” said moderator MAJ Joseph R. Hsu, MD, “but also from reviewing civilian literature. We want to provide some general principles for the nontraumatologist to get the patient out to the appropriate subspecialist.”

This article covers two of the four topics covered during the symposium—open fractures and compartment syndrome (Fig. 1). Next month, unstable pelvic fractures and mangled extremities will be addressed.

Reducing infection in open fractures
In dealing with open fractures, one of the most important and immediate areas of concern is reducing the risk of infection, according to LTC Romney C. Andersen, MD.

Relying on the results of a culture is not advised, said Dr. Andersen, in part because several studies have found poor sensitivity and specificity in cultures taken from open wounds. Even when the culture was taken postdébridement, the results often failed to correlate to infection.

“A 1997 study published in the journal Clinical Orthopaedics and Related Research, for example, found that 27 percent of patients had positive cultures, and the infecting organism grew out in only 28 percent of infected patients,” he said. “And 12 percent of the patients who had negative cultures became infected as well. Although there is strong evidence not to rely on cultures, no randomized, controlled studies have been conducted.”

Dr. Andersen said the evidence supports the use of cephalosporin within 3 hours of injury. He recommends against using gentamicin unless there is a specific reason to do so, such as with farm injuries. Although little clear evidence exists to support treatment duration for antibiotics, he pointed out that long-term use may lead to antibiotic resistance. Broad spectrum antibiotics have been found to encourage the development of resistance as well.

Dr. Andersen explained that, although studies show rapid débridement—within 6 hours—may reduce infection rates in military conditions, evidence in civilian settings finds that timing may be less critical. In addition, some experts suggest that waiting longer may help the surgeon to better determine which tissues to remove.

Irrigation, Dr. Andersen said, is not an alternative to proper débridement. At least one study found no difference between using normal saline or tap water for débridement, although Dr. Andersen pointed out that evidence suggests that pulsed lavage pushes bacteria deeper into wounds and can cause microscopic damage to the soft tissue. Adding soap seems to have no effect on infection rates, and there is evidence that bacitracin increases wound complications.

Dr. Andersen stated that evidence moderately supports the use of antibiotic beads and negative pressure wound therapy (NPWT) as adjuncts to irrigation and débridement.

“NPWT doesn’t reduce infections in closed wounds;” he said, “however, it decreases infection rates with open wounds. It does somewhat select out for gram-positive bacteria. It’s very helpful with pseudomonas infections.

“Some orthopaedists like to use antibiotic beads. You have to have a heat-stable antibiotic. You pack it into the wound, close the wound over, and make it a contained system. The wound gets very high levels of local antibiotics for a short time, but using antibiotic beads helps reduce systemic toxicity because the antibiotics don’t get picked up and sent through the whole body.”

Does the patient have compartment syndrome?
“What’s the gold standard?” asked CDR David M. Dromsky, MD, MC, USN, who discussed the diagnosis of compartment syndrome. “This is a stressful problem for surgeons, but clinical evaluation remains the cornerstone. When the injury story and the exam are suspicious, no one will fault you for heading straight to the operating room. When there is any question about the diagnosis, a properly chosen, properly placed, properly executed direct pressure measurement will answer the question.”

Dr. Dromsky explained that compartment syndrome is a dynamic condition that requires repeated evaluations, because it may develop hours after the injury. Many of the alternative methods of determining whether a patient has compartment syndrome are either experimental, impractical, or remain largely unvalidated. For that reason, he recommends a straightforward physical examination.

“If two or more factors point toward compartment syndrome and the patient describes symptoms commensurate with compartment syndrome, it’s probably reasonable to go straight to the operating room without a second thought.”

If a patient proves uncooperative or communication is difficult, Dr. Dromsky outlined the following examination process:

“Lower the leg to the level of the heart,” he said. “You do not want to raise the leg too high. Elevation above 30 degrees may actually decrease perfusion pressure and worsen the condition.”

According to Dr. Dromsky, it’s important to split all of the dressings down to the skin, so there’s nothing circumferential about the patient’s limb.

“You need to find your compartments,” he said. “Zero the meter and insert the needle clearly into the compartment. Inject a small amount of fluid—only 0.5 mL to 1 mL. The pressure measurement will spike, plateau, and then fade away. It’s the plateau that is the best indicator of the actual hydrostatic pressure.”

Absolute compartment pressure is not as important, he explained, as the difference between diastolic blood pressure and intracompartmental pressure (delta-P). A delta-P of 30 mm Hg, said Dr. Dromsky, is the threshold for decompression.

Dr. Dromsky prefers to insert the needle about 6 cm away from the joints (below the knee and above the ankle), to avoid the retinaculae and most of the nerves. Working on the lateral side, he would insert the needle a centimeter or more in front of the midline between the tibia and fibula; working on the medial side, he would use a line drawn 2 cm posterior to the tibia.

Choosing the proper tool is also important. A study that compared sideport needles, slit catheters, and straight needles found that sideport needles are the most accurate instrument for measuring compartment pressure, although slit catheters are the best choice if continuous measurement is desired.

Dr. Dromsky said that physicians must make an accurate determination on the presence of compartment syndrome. Although he was taught that a 10 percent false positive rate is reasonable, he disagrees.

“Fasciotomy is not just a hole in the skin. It’s not a completely benign operation, particularly if you stray too high or too low and damage a nerve, or if you damage the extensor retinaculum and lose the mechanical advantage of the anterior and lateral compartments.”

Disclosure information: Dr. Hsu—Society of Military Orthopaedic Surgeons, The Geneva Foundation; Dr. Andersen—Orthopaedic Trauma Association; Dr. Dromsky—Information not available.

Peter Pollack is a staff writer for AAOS Now. He can be reached at ppollack@aaos.org

References:

Efficacy of Cultures in the Management of Open Fractures