METALS study assessed functional outcomes, disability

Military personnel who sustain major lower limb trauma and are treated with amputation appear to have better functional outcomes than those who are treated with limb salvage, according to Military Extremity Trauma Amputation/Limb Salvage (METALS) study data presented at the Orthopaedic Trauma Association 2010 annual meeting.

“Little is known about the long-term consequences of severe lower limb trauma sustained in combat,” said COL (Ret) William C. Doukas, MD, who presented the study. “The Lower Extremity Assessment Project (LEAP) study showed that, among civilians, functional outcomes for amputation and limb salvage following lower extremity trauma were similar. We hypothesized the same would be true for military patients.”

The retrospective cross-sectional study included 317 U.S. service members who had sustained major lower limb trauma as a result of high-energy blast and ordnance-related mechanisms while serving in Afghanistan or Iraq. Both unilateral and bilateral lower limb traumatic injuries were included; 147 participants had received amputation only, 139 had received limb salvage only, and 31 had received both. Clinical data were obtained from participants’ medical records and through telephone interviews conducted at a mean of 38 months postinjury.

Nearly two-thirds of limb salvage patients had segmental defects requiring bone graft or bone transport, approximately one-third required free flap coverage or had compartment muscle loss, and a smaller percentage had complete deficit of a major nerve and/or required revascularization. Of the amputations, 37 percent were transfemoral and 52 percent were transtibial; in 20 percent of the amputees, surgery was delayed beyond 1 month from the date of injury.

Better scores for amputees
The Short Musculoskeletal Functional Assessment (SMFA) index was used to assess overall function in both treatment groups. Although all participants reported high levels of disability, the mean SMFA dysfunction score was significantly better for amputees compared to limb salvage patients in both the unilateral and bilateral groups (p < 0.05). Similar results were reported for SMFA mobility and emotional status subscores (Fig. 1). Other factors associated with better outcomes included younger age, higher military grade, less intense combat experiences, and being farther out from the date of injury.

Unilateral and bilateral amputees also reported engaging in more vigorous sports such as basketball, running, biking, and were less likely to screen positive for posttraumatic stress. No significant differences were found in depression, chronic pain, and return to work or active duty between the two groups. The researchers concluded that, as a group, military patients undergoing amputation appear to have better functional outcomes than those definitively treated with limb salvage.

In contrast to the civilian model (LEAP study), military injuries are typically blast injuries and include multiple limbs, noted Dr. Doukas. Military patients are also younger, have better pre-injury physical conditioning, are employed with guaranteed health care, and have higher levels of self efficacy and a strong support network. In addition, military patients, especially amputees, receive more focused rehabilitation early on in their recovery and have ready access to high-end prostheses and robust reintegration programs.

“Major limb trauma sustained in the military results in significant physical and psychosocial disability, and at a mean of 38 months postinjury, amputees appear to have better outcomes than limb salvage patients,” Dr. Doukas said. He stressed, however, that he and his fellow researchers do not recommend one treatment over the other. “We need to better understand the reasons for these differences and whether these results will hold up for the long term,” he explained. “In the meantime, greater attention should be paid to rehabilitating our limb-salvage patients.”

The METALS study is an ongoing outcomes study funded by the Department of Defense to describe the long-term consequences of major limb trauma.

Dr. Doukas’ coauthors of “The Military Extremity Trauma Amputation /Limb Salvage (METALS) Study: Comparing Outcomes for Amputation versus Limb Salvage following Major Lower Extremity Trauma,” included COL (Ret) Roman A. Hayda, MD; H. Michael Frisch, MD; LTC Romney C. Andersen, MD; COL James R. Ficke, MD; CDR John J. Keeling, MD; Anthony Carlini and Ellen J. MacKenzie, PhD.

Disclosure information: Dr. Hayda—AONA, BioIntraface. All other authors reported no conflicts.

Maureen Leahy is assistant managing editor of AAOS Now. She can be reached at leahy@aaos.org

Bottom Line

• Major lower limb trauma sustained in the military results in significant long-term disability.
• Amputees appear to have better outcomes than limb salvage patients in the military population.
• Additional study is needed to examine these differences and determine whether the results hold up longer term.
• Greater attention should be paid to rehabilitating military limb salvage patients.