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War injuries drive orthopaedic advances

By Peter Pollack

New treatments, techniques helping to save lives

It has been said that war often drives medical advancement. More than 33,000 U.S. service members have been wounded in Iraq and Afghanistan. An estimated 60 percent to 70 percent of those wounded have musculoskeletal injuries. As a result, the war on terror has presented extreme challenges to orthopaedic surgeons.

Those challenges, and the orthopaedic response, were the subject of the symposium held Thursday, “Advances in the Care of Battlefield Orthopaedic Trauma,” moderated by CAPT Dana C. Covey, MC, USN, and featuring presentations by COL Mark W. Richardson, MC, USAF; CDR Michael T. Mazurek, MC, USN; Steven J. Morgan, MD; and MAJ Joseph R. Hsu, MC, USA.

COL Mark W. Richardson, MC, USAF

Negative pressure safe for air transport?

Dr. Richardson reviewed issues surrounding the use of portable vacuum-assisted wound closure devices (VACs) for negative pressure wound therapy (NPWT) during medical evacuation. Blast injuries, he said, often produce large exudative wounds that are difficult to manage with traditional dressings.

Although the use of NPWT has been increasing among surgeons in the civilian trauma community, controversy over the safety of using NPWT in an air evacuation situation exists among surgeons in the military community.

If a VAC device fails during flight, the closed environment could result in an anaerobic infection. These concerns seem to have been borne out when some patients evacuated from Iraq and Afghanistan were treated with NPWT and arrived in the United States with failed VACs and wound sepsis.

Proponents of NPWT respond that negative pressure maintains a closed environment, eliminating the need to change dressings during flight and thus decreasing the risk of secondary contamination. Furthermore, NPWT promotes granulation tissue, removes exudate, and resuscitates borderline tissue in the zone of stasis.

A retrospective review of 277 patients with VAC dressings who were transported to Landstuhl Regional Medical Center (LRMC) between October 2006 and September 2007 found 37 complications in 36 patients. All but one of the complications was considered minor. In the major complication, the VAC device had seven problems during the flight, four of which required prolonged clamping.

An issue of concern is that, if the VAC fails during the flight, the medical crew may not be able to hear the alarm in the noisy environment aboard the airplane.

In Dr. Richardson’s opinion, dry dressings can be problematic, particularly in situations that would require changing dressing during transport. His team has begun experimenting with using antibiotic beads and NPWT at the same time to combat the potential failure of VACs. Although he admitted that the VAC will suck out some of the “antibiotic soup,” the beads remain as a filler. If the VAC fails during transport, the patient is left with what is effectively a bead pouch.

Bone where it shouldn’t be

Dr. Mazurek discussed his experience treating heterotopic ossification (HO). HO, he explained, is the formation of mature lamellar bone in tissues that normally do not exhibit ossification, such as muscle, joint capsules, ligaments, and tendons. HO is commonly associated with head or spinal cord trauma, blunt injury trauma, peri­articular injury, arthroplasty, or genetic causes.

According to Dr. Mazurek, the amount of trauma a patient is exposed to seems to play a role in the development of heterotopic bone. This is particularly applicable to war injuries. In one study of 243 war wounded who underwent at least one operation, HO developed in 157 (64.6 percent). Variables that were found to be independent in the study were age (less than 30 years), amputation, multiple extremity injury, traumatic brain injury, and an injury severity score of less than 16.

HO can develop to varying degrees of pathology, from no functional limitation (Brooker I) to ankylosis (Brooker IV). Symptoms include pain, swelling, and stiffness; as the disease it progresses, joint range of motion may decrease. Dr. Mazurek stated that the pathophysiology of HO seems to be the stimulation of stem cells resulting in bone formation.

Radiation treatment (XRT) has been proposed as a possible prophylaxis for HO. A study that compared XRT, indomethacin prophylaxis, and no treatment found no statistically significant difference between XRT and indomethacin, but HO developed in 100 percent of the patients not treated.

However, in a randomized, double-blind, placebo-controlled study, the researchers found no significant difference between incidence of HO among patients given indomethacin and placebo.

Unfortunately, patients who are treated with HO prophylaxis are more likely to develop nonunions. When HO develops in patients, the extra bone material is excised.

Visiting scholars program

Dr. Morgan talked about the AAOS Distinguished Visiting Scholars Program, which was modeled after the Visiting Senior Trauma Surgeon Program conducted by the American College of Surgeons. The goal of the program is to transfer advances made in the military orthopaedic community to the civilian orthopaedic community more quickly than might otherwise occur. Additionally, military surgeons are able to gain continuing medical education (CME) credits by taking classes taught by the visiting civilian surgeons.

The program sends civilian surgeons to LRMC where they work alongside military surgeons as Red Cross volunteers.

Dr. Morgan explained that, given the potential for terrorist attacks in the continental United States, it is important to develop an institutional memory for how to deal with cases of extreme trauma resulting from high velocity injuries. With that in mind, 20 surgeons have been sent so far to LRMC, and more will be sent in 2009.

To participate in the program, surgeons must submit a formal application, pass review by a selection committee of civilian and military trauma surgeons, be fellowship-trained in orthopaedic trauma care, and have at least 10 years experience in the practice of extremity trauma.

While working at LRMC, visiting surgeons participate in a daily morning conference in which they discuss care plans, incoming injuries, and transport plans to return wounded warriors back to the United States. They also participate in surgical care, evaluate new patients, and take part in video conferences to discuss specific cases with other surgeons. Finally, they offer a weekly lecture that the military surgeons can attend for CME credit.

The price of war

Research conducted by Dr. Hsu looked at the costs of dealing with extremity injuries in the military. According to his study, extremity injuries require the greatest medical resources and are the greatest source of physical disability in combat casualties from the current conflicts in Iraq and Afghanistan. Thus far, extremity injuries have been responsible for an estimated $463 million in initial hospitalization costs and $1.2 billion in disability benefits.

To determine cost, Dr. Hsu’s team looked at 1,333 consecutive admissions to the Joint Theater Trauma Registry from October 2001 to January 2005. They found that disabilities due to extremity injury accounted for 64 percent of total disability compensation.

Furthermore, extremity injuries accounted for 65 percent of resource utilization, 63 percent of primary admission diagnoses, and longer than average inpatient stays.

Disclaimer: Opinions presented by military personnel are their own, and may not represent the official position of the U.S. Department of Defense.

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

2009 Annual Meeting News
Wednesday through Saturday, February 25 – 28, 2009.
http://www.aaos.org/news/acadnews/2009/AAOS17_2_28.asp

Annual Meeting News

AAOS Annual Meeting News