Incidence and epidemiology of combat injuries sustained during "the surge" portion of operation Iraqi Freedom by a U.S. Army brigade combat team

Musculoskeletal Injuries in Iraq and Afghanistan: Epidemiology and Outcomes Following a Decade of War

The combined wars in Afghanistan and Iraq represent the longest ongoing conflicts in American military history, with a combined casualty estimate of >59,000 service members. The nature of combat over the last decade has led to precipitous increases in severe orthopaedic injuries, including traumatic amputations and injuries to the spine. Nearly 75% of all injuries sustained in combat now are caused by explosive mechanisms, and fractures comprise 40% of all musculoskeletal injuries. Injuries to the axial skeleton are more frequent among personnel exposed to combat, and spinal trauma is identified in nearly 40% of those killed. Musculoskeletal injuries are expensive and generate some of the highest rates of long-term disability. Noncombat musculoskeletal injuries are endemic within deployed military service members and occur at a greater than threefold rate compared with combat musculoskeletal injuries. Service members with musculoskeletal injuries or behavioral health conditions, such as posttraumatic stress disorder, depression, and psychosis, and those occupying a low socioeconomic status, have an increased risk of inferior outcomes.

Foot-Ankle Fractures and Injury Probability Curves from Post-mortem Human Surrogate Tests

This purpose of this study was to replicate foot-ankle injuries seen in the military and derive human injury probability curves using the human cadaver model. Lower legs were isolated below knee from seventeen unembalmed human cadavers and they were aligned in a 90-90 posture (plantar surface orthogonal to leg). The specimens were loaded along the tibia axis by applying short-time duration pulses, using a repeated testing protocol. Injuries were documented using pre- and post-test X-rays, computed tomography scans, and dissection. Peak force-based risk curves were derived using survival analysis and accounted for data censoring. Fractures were grouped into all foot-ankle (A), any calcaneus (B), and any tibia injuries (C), respectively. Calcaneus and/or distal tibia/pilon fractures occurred in fourteen tests. Axial forces were the greatest and least for groups C and B, respectively. Times attainments of forces for all groups were within ten milliseconds. The Weibull function was the optimal probability distribution for all groups. Age was significant (p < 0.05) for groups A and C. Survival analysis-based probability curves were derived for all groups. Data are given in the body of paper. Age-based, risk-specific, and continuous distribution probability curves/responses guide in the creation of an injury assessment capability for military blast environments.

US service member tourniquet use on the battlefield: Iraq and Afghanistan 2003–2011

Introduction

Tourniquet use has not been studied regarding specifically combat-intense military occupational specificities. This analysis examined the survivability, frequency of use, and nature of injuries in which tourniquets were employed among personnel in a single combat-specific military occupational specialty during combat operations.

Methods

Injuries sustained by the combat-specific soldier, the cavalry scout, from 2003 to 2011 were identified using the Joint Theater Trauma Registry. Basic demographic information, mechanism of injury, injury characteristics, and mortality were recorded.

Results

Of the 453 cavalry scouts wounded in action, 313 had adequate documentation upon arrival to a field hospital. Tourniquets were applied to 24 (7.7%) extremity wounds, 23 (96%) of these soldiers survived and one died of wounds (4.2%). Among those is in which tourniquets were used, there were seven (30%) senior enlisted and 16 (70%) junior enlisted soldiers with an average age of 24.8 years. Injuries were caused by gunshot wounds in 4 (17%), explosions in 18 (74%) and other mechanisms in two (8.3%). The primary reason for tourniquet application was open fracture ( n = 14, 61%), followed by vascular injury ( n = 5, 22%), and amputation ( n = 3, 13%). Other penetrating injuries were present in 19 (83%) of scouts.

Conclusion

The high survivability of patients transported with tourniquet in place underscores the importance of battlefield tourniquet application. Continued focus on education and equipping combat personnel with tourniquets is critical to survivability of the injured solider.

Combat related vascular injuries: Dutch experiences from a role 2 MTF in Afghanistan

BACKGROUND

In a combat environment, major vascular trauma endures as the leading cause of death. The Dutch role 2 Medical Treatment Facility (MTF), provided supportive care during the mission in Uruzgan, Afghanistan. Aim of this study was to conduct detailed analysis of the admitted major haemorrhages (vascular injuries) and to compare our findings with NATO coalition partners.

METHODS

Retrospective, descriptive study. Participants eligible for this study came from the role 2 MTF admission database, where they fitted the criteria 'Major haemorrhage (class 2 haemorrhage or more according to the ATLS(®) classification) between 2006 and 2010'. Results were contrasted with studies from coalition partners.

RESULTS

The query revealed 194 casualties sustaining 208 central (60% abdominal, 40% thoracic/neck), and 99 extremity major haemorrhages leading to 1.6 major haemorrhages per casualty. Survival was significantly better (p<0.05) in the peripheral vascular injuries cohort (96% versus 72%). Primary amputation was needed in 73/84 of lower, and in 8/15 of upper extremity major haemorrhages. Vascular repair or vascular Damage Control Surgery techniques (e.g. shunting) were used in 19/84 cases in the lower, and 7/15 in the upper extremity cohort, with a success rate of 69.2 percent. Amputation rates of coalition partners, using different inclusion and exclusion criteria, ranged from 5 to 60 percent.

CONCLUSIONS

Only in a few cases genuine peripheral vascular surgery was needed (<1%). This limited number of reconstructions does not demonstrate the need for extensive skills in all areas of vascular surgery. Achieved success rate until discharge was almost 70%. Vascular damage control surgery seems effective as initial limb saving skill in a role 2 MTF. The difference in usage of definitions concerning vascular injuries in current literature warrants further assessment. For optimal analysis there is need for detailed (NATO wide) registration with uniform definitions for vascular injuries.

LEVEL OF EVIDENCE

Level IV--Epidemiologic study.

Outcomes After Post-Traumatic AKI Requiring RRT in United States Military Service Members

BACKGROUND AND OBJECTIVES

Mortality and CKD risk have not been described in military casualties with post-traumatic AKI requiring RRT suffered in the Iraq and Afghanistan wars.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This is a retrospective case series of post-traumatic AKI requiring RRT in 51 military health care beneficiaries (October 7, 2001-December 1, 2013), evacuated to the National Capital Region, documenting in-hospital mortality and subsequent CKD. Participants were identified using electronic medical and procedure records.

RESULTS

Age at injury was 26±6 years; of the participants, 50 were men, 16% were black, 67% were white, and 88% of injuries were caused by blast or projectiles. Presumed AKI cause was acute tubular necrosis in 98%, with rhabdomyolysis in 72%. Sixty-day all-cause mortality was 22% (95% confidence interval [95% CI], 12% to 35%), significantly less than the 50% predicted historical mortality (P<0.001). The VA/NIH Acute Renal Failure Trial Network AKI integer score predicted 60-day mortality risk was 33% (range, 6%-96%) (n=49). Of these, nine died (mortality, 18%; 95% CI, 10% to 32%), with predicted risks significantly miscalibrated (P<0.001). The area under the receiver operator characteristic curve for the AKI integer score was 0.72 (95% CI, 0.56 to 0.88), not significantly different than the AKI integer score model cohort (P=0.27). Of the 40 survivors, one had ESRD caused by cortical necrosis. Of the remaining 39, median time to last follow-up serum creatinine was 1158 days (range, 99-3316 days), serum creatinine was 0.85±0.24 mg/dl, and eGFR was 118±23 ml/min per 1.73 m(2). No eGFR was <60 ml/min per 1.73 m(2), but it may be overestimated because of large/medium amputations in 54%. Twenty-five percent (n=36) had proteinuria; one was diagnosed with CKD stage 2.

CONCLUSIONS

Despite severe injuries, participants had better in-hospital survival than predicted historically and by AKI integer score. No patient who recovered renal function had an eGFR<60 ml/min per 1.73 m(2) at last follow-up, but 23% had proteinuria, suggesting CKD burden.

Analysis of Orthopaedic Research Produced During the Wars in Iraq and Afghanistan

BACKGROUND

Military orthopaedic surgeons have published a substantial amount of original research based on our care of combat-wounded service members and related studies during the wars in Iraq and Afghanistan. However, to our knowledge, the influence of this body of work has not been evaluated bibliometrically, and doing so is important to determine the modern impact of combat casualty research in the wider medical community.

QUESTIONS/PURPOSES

We sought to identify the 20 most commonly cited works from military surgeons published during the Iraq and Afghanistan conflicts and analyze them to answer the following questions: (1) What were the subject areas of these 20 articles and what was the 2013 Impact Factor of each journal that published them? (2) How many citations did they receive and what were the characteristics of the journals that cited them? (3) Do the citation analysis results obtained from Google Scholar mirror the results obtained from Thompson-Reuters' Web of Science?

METHODS

We searched the Web of Science Citation Index Expanded for relevant original research performed by US military orthopaedic surgeons related to Operation Iraqi Freedom and Operation Enduring Freedom between 2001 and 2014. Articles citing these studies were reviewed using both Web of Science and Google Scholar data. The 20 most cited articles meeting inclusion criteria were identified and analyzed by content domain, frequency of citation, and sources in which they were cited.

RESULTS

Nine of these studies examined the epidemiology and outcome of combat injury. Six studies dealt with wound management, wound dehiscence, and formation of heterotopic ossification. Five studies examined infectious complications of combat trauma. The median number of citations garnered by these 20 articles was 41 (range, 28-264) in Web of Science. Other research citing these studies has appeared in 279 different journals, covering 26 different medical and surgical subspecialties, from authors in 31 different countries. Google Scholar contained 97% of the Web of Science citations, but also had 31 duplicate entries and 29 citations with defective links.

CONCLUSIONS

Modern combat casualty research by military orthopaedic surgeons is widely cited by researchers in a diverse range of subspecialties and geographic locales. This suggests that the military continues to be a source of innovation that is broadly applicable to civilian medical and surgical practice and should encourage expansion of military-civilian collaboration to maximize the utility of the knowledge gained in the treatment of war trauma.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

[Treatment of gunshot fractures of the lower extremity: Part 1: Incidence, importance, case numbers, pathophysiology, contamination, principles of emergency and first responder treatment]

Gunshot wounds are rare in Germany and are mostly the result of suicide attempts or improper handling of weapons. The resulting injuries involve extensive tissue damage and complications which are thus unique and require a differentiated approach. As trauma centers may be confronted with gunshot wounds at any time, treatment principles must be understood and regularly reevaluated. Due to Bundeswehr operations abroad and the treatment of patients from other crisis regions a total of 85 gunshot wounds in 64 patients were treated between 2005 and 2011. In the majority of cases the lower extremities were affected and we were able to carry out treatment to preserve the extremities. In this article we report on our experiences and the results of treatment of gunshot wounds to the lower extremities. This part of the article deals with the epidemiology and pathophysiology of gunshot wounds to the lower extremities. By means of an evaluation of microbiological findings in a subgroup of patients involved in a civil war (n=10), the problem of multidrug resistant pathogen contamination, colonization and infection is discussed. In addition to a description of initial and emergency treatment of gunshot wounds, measures required for further treatment and decontamination are presented. Finally, the results are discussed with reference to the literature in this field.

Late amputation may not reduce complications or improve mental health in combat-related, lower extremity limb salvage patients

INTRODUCTION

Following severe lower extremity trauma, patients who undergo limb reconstruction and amputations both endure frequent complications and mental health sequelae. The purpose of this study is to assess the extent to which late amputation following a period of limb salvage impacts the evolution of the clinical variables that can affect the patient's perception of his or her limb: ongoing limb associated complications and mental health conditions.

PATIENTS AND METHODS

A case series of US service members who sustained a late major extremity amputation from September 2001 through July 2011 were analysed. Pre- and post-amputation complications, mental health conditions, and reason(s) for desiring amputation were recorded.

RESULTS

Forty-four amputees with detailed demographic, injury and treatment data were identified. The most common reasons for desiring a late amputation were pain and being dissatisfied with the function of the salvage limb. An average of 3.2 (range 1-10) complications were reported per amputee prior to undergoing late amputation and an average of 1.8 (range 0-5) complications reported afterwards. The most common complication prior to and after late amputation was soft tissue infection (24 (17%) and 9 (22%), respectively). Twenty-nine (64%) late amputees were diagnosed with a mental health condition prior to undergoing their amputation and 27 (61%) late amputees were diagnosed with mental conditions after late amputation. Only three of the 15 patients who did not have a mental health condition documented prior to their late amputation remained free of a documented mental health condition after the amputation.

DISCUSSION

Ongoing complications and mental health conditions can affect how a patient perceives and copes with his or her limb following severe trauma. Patient dissatisfaction following limb reconstruction can influence the decision to undergo a late amputation. Patients with a severe, combat related lower extremity injury that are undergoing limb salvage may not have a reduction in their overall complication rate, a resolution of specific complications or an improvement of their mental health after undergoing late amputation.

CONCLUSION

Surgeons caring for limb salvage patients should counsel appropriately when managing expectations for a patient who desires a late amputation.

Blurred front lines: triage and initial management of blast injuries

Recent armed conflicts and the expanded reach of international terror groups has resulted in an increased incidence of blast-related injuries in both military and civilian populations. Mass-casualty incidents may require both on-scene and in-hospital triage to maximize survival rates and conserve limited resources. Initial evaluation should focus on the identification and control of potentially life-threatening conditions, especially life-threatening hemorrhage. Early operative priorities for musculoskeletal injuries focus on the principles of damage-control orthopaedics, with early and aggressive debridement of soft-tissue wounds, vascular shunting or grafting to restore limb perfusion, and long-bone fracture stabilization via external fixation. Special considerations such as patient transport, infection control and prevention, and amputation management are also discussed. All orthopedic surgeons, regardless of practice setting, should be familiar with the basic principles of evaluation, resuscitation, and initial management of explosive blast injuries.

Risk factors for decreased range of motion and poor outcomes in open periarticular elbow fractures

INTRODUCTION

The purpose of this study was to identify risk factors present at the time of injury that predict poor functional outcomes and heterotopic ossification (HO) in open periarticular elbow fractures.

MATERIALS AND METHODS

We performed a retrospective review of 136 combat-related open elbow fractures from 2003 to 2010. Patient demographics, injury characteristics, treatment variables, and complications were recorded. Functional outcomes were analyzed to determine range of motion (ROM) and Mayo Elbow Performance Score (MEPS). Secondary outcome measures included the development of HO, return to duty, and revision operation.

RESULTS

At a median 2.7 years from injury the median MEPS was 67.8 (range 30-100) with an average ulnohumeral arc motion of 89°. Bipolar fractures, with periarticular fractures on both sides of the elbow and at least one side containing intra-articular extension, were independently associated with decreased ulnohumeral motion (p=0.02) and decreased MEPS (p<0.004). Additional independent risk factors for decreased ROM included more severe osseous comminution (p=0.001), and increased time to definitive fixation (p=0.03) and HO (p=0.02). More severe soft tissue injury (Gustilo and Anderson fracture type, p=0.02), peripheral nerve injury (p=0.04), and HO (p=0.03) were independently associated with decreased MEPS. HO developed in 65% (89/136) of extremities and was associated with more severe Orthopaedic Trauma Association (OTA) fracture type (p=0.01) and escalating Gustilo and Anderson fracture classification (p=0.049).

CONCLUSIONS

In the largest series of open elbow fractures, we identified risk factors that portend a poor clinical outcome and decreased ROM. Bipolar elbow fractures, which have not previously been associated with worse results, are particularly prone to decreased ROM and worse outcomes.

LEVEL OF EVIDENCE

Prognostic level IV.

Erosion of the healthy soldier effect in veterans of US military service in Iraq and Afghanistan

Background

This research explores the healthy soldier effect (HSE) – a lower mortality risk among veterans relative to the general population—in United States (US) veterans deployed in support of operations in Iraq and Afghanistan (OEF/OIF/OND). While a HSE has been affirmed in other OEF/OIF/OND populations, US veterans of OEF/OIF/OND have not been systematically studied.

Methods

Using US Department of Veterans Affairs (VA) administrative data, we identified veterans who (1) had been deployed in support of OEF/OIF/OND between 2002 and 2011 and (2) were enrolled in the VA health care system. We divided the VA population into VA health care utilizers and non-utilizers. We obtained Department of Defense (DOD) administrative data on the OEF/OIF/OND population and obtained VA and DOD mortality data excluding combat deaths from the analyses. Indirect standardization was used to compare VA and DOD cohorts to the US population using total population at risk to compute the Standardized Mortality Ratio (SMR). A directly standardized relative risk (DSRR) was calculated to enable comparisons between cohorts. To compare VA enrollee mortality on military specific characteristics, we used a DOD population standard.

Results

The overall VA SMR of 2.8 (95% Confidence Interval [CI] 2.8-2.9), VA utilizer SMR of 3.2 (95% CI 3.1-3.3), VA non-utilizer SMR of 0.9 (95% CI 0.8-1.1), and DOD SMR of 1.5 (95% CI 1.4-1.5) provide no evidence of a HSE in any cohort relative to the US standard population. Relative to DOD, both the total VA population SMR of 2.1 (95% CI 2.0-2.2) and the SMR for VA utilizers of 2.3 (95% CI 2.3-2.4) indicate mortality twice what would be expected given DOD mortality rates. In contrast, the VA enrollees who had not used clinical services had 40% lower than expected mortality relative to DOD.

Conclusions

No support was found for the HSE among US veterans of OEF/OIF/OND. These findings may be attributable to a number of factors including post-deployment risk-taking behavior, an abbreviated follow up period, and the nature of the OEF/OIF/OND conflict.

A model to predict limb salvage in severe combat-related open calcaneus fractures

BACKGROUND

Open calcaneus fractures can be limb threatening and almost universally result in some measure of long-term disability. A major goal of initial management in patients with these injuries is setting appropriate expectations and discussing the likelihood of limb salvage, yet there are few tools that assist in predicting the outcome of this difficult fracture pattern.

QUESTIONS/PURPOSES

We developed two decision support tools, an artificial neural network and a logistic regression model, based on presenting data from severe combat-related open calcaneus fractures. We then determined which model more accurately estimated the likelihood of amputation and which was better suited for clinical use.

METHODS

Injury-specific data were collected from wounded active-duty service members who sustained combat-related open calcaneus fractures between 2003 and 2012. One-hundred fifty-five open calcaneus fractures met inclusion criteria. Median followup was 3.5 years (interquartile range: 1.5, 5.1 years), and amputation rate was 44%. We developed an artificial neural network designed to estimate the likelihood of amputation, using information available on presentation. For comparison, a conventional logistic regression model was developed with variables identified on univariate analysis. We determined which model more accurately estimated the likelihood of amputation using receiver operating characteristic analysis. Decision curve analysis was then performed to determine each model's clinical utility.

RESULTS

An artificial neural network that contained eight presenting features resulted in smaller error. The eight features that contributed to the most predictive model were American Society of Anesthesiologist grade, plantar sensation, fracture treatment before arrival, Gustilo-Anderson fracture type, Sanders fracture classification, vascular injury, male sex, and dismounted blast mechanism. The artificial neural network was 30% more accurate, with an area under the curve of 0.8 (compared to 0.65 for logistic regression). Decision curve analysis indicated the artificial neural network resulted in higher benefit across the broadest range of threshold probabilities compared to the logistic regression model and is perhaps better suited for clinical use.

CONCLUSIONS

This report demonstrates an artificial neural network was capable of accurately estimating the likelihood of amputation. Furthermore, decision curve analysis suggested the artificial neural network is better suited for clinical use than logistic regression. Once properly validated, this may provide a tool for surgeons and patients faced with combat-related open calcaneus fractures in which decisions between limb salvage and amputation remain difficult.

Morbidity of early spine surgery in the multiply injured patient

INTRODUCTION

The optimal timing of surgery for multiply injured patients with operative spinal injuries remains unknown. The purported benefits of early intervention must be weighed against the morbidity of surgery in the early post-injury period. The performance of spine surgery in the Afghanistan theater permits analysis of the morbidity of early surgery on military casualties. The objective is to compare surgical morbidity of early spinal surgery in multiply injured patients versus stable patients.

MATERIALS AND METHODS

Patients were retrospectively categorized as stable or borderline unstable depending on the presence of at least one of the following: ISS >40, ISS >20 and chest injury, exploratory laparotomy or thoracotomy, lactate >2.5 mEq/L, platelet <110,000/mm(3), or >10 U PRBCs transfused pre-operatively. Surgical morbidity, complications, and neurologic improvement between the two groups were compared retrospectively.

RESULTS

30 casualties underwent 31 spine surgeries during a 12-month period. 16 of 30 patients met criteria indicating a borderline unstable patient. Although there were no significant differences in the procedures performed for stable and borderline unstable patients as measured by the Surgical Invasiveness Index (7.5 vs. 6.9, p = 0.8), borderline unstable patients had significantly higher operative time (4.3 vs. 3.0 h, p = 0.01), blood loss (1,372 vs. 366 mL, p = 0.001), PRBCs transfused intra-op (3.88 vs. 0.14 U, p < 0.001), and total PRBCs transfused in theater (10.18 vs. 0.31 U, p < 0.001).

CONCLUSIONS

The results indicate that published criteria defining a borderline unstable patient may have a role in predicting increased morbidity of early spine surgery. The perceived benefits of early intervention should be weighed against the greater risks of performing extensive spinal surgeries on multiply injured patients in the early post-injury period, especially in the setting of combat trauma.

Systematic review of the prevalence and characteristics of battle casualties from NATO coalition forces in Iraq and Afghanistan

BACKGROUND

The North Atlantic Treaty Organization (NATO) coalition forces remain heavily committed on combat operations overseas. Understanding the prevalence and characteristics of battlefield injury of coalition partners is vital to combat casualty care performance improvement. The aim of this systematic review was to evaluate the prevalence and characteristics of battle casualties from NATO coalition partners in Iraq and Afghanistan. The primary outcome was mechanism of injury and the secondary outcome anatomical distribution of wounds.

METHODS

This systematic review was performed based on all cohort studies concerning prevalence and characteristics of battlefield injury of coalition forces from Iraq and Afghanistan up to December 20th 2013. Studies were rated on the level of evidence provided according to criteria by the Centre for Evidence Based Medicine in Oxford. The methodological quality of observational comparative studies was assessed by the modified Newcastle-Ottawa Scale.

RESULTS

Eight published articles, encompassing a total of n=19,750 battle casualties, were systematically analyzed to achieve a summated outcome. There was heterogeneity among the included studies and there were major differences in inclusion and exclusion criteria regarding the target population among the included trials, introducing bias. The overall distribution in mechanism of injury was 18% gunshot wounds, 72% explosions and other 10%. The overall anatomical distribution of wounds was head and neck 31%, truncal 27%, extremity 39% and other 3%.

CONCLUSIONS

The mechanism of injury and anatomical distribution of wounds observed in the published articles by NATO coalition partners regarding Iraq and Afghanistan differ from previous campaigns. There was a significant increase in the use of explosive mechanisms and a significant increase in the head and neck region compared with previous wars.

Acute respiratory distress syndrome in wartime military burns: application of the Berlin criteria

BACKGROUND

Acute respiratory distress syndrome (ARDS) prevalence and related outcomes in burned military casualties from Iraq and Afghanistan have not been described previously. The objective of this article was to report ARDS prevalence and its associated in-hospital mortality in military burn patients.

METHODS

Demographic and physiologic data were collected retrospectively on mechanically ventilated military casualties admitted to our burn intensive care unit from January 2003 to December 2011. Patients with ARDS were identified in accordance with the new Berlin definition of ARDS. Subjects were categorized as having mild, moderate, or severe ARDS. Multivariate logistic regression identified independent risk factors for developing moderate-to-severe ARDS. The main outcome measure was the prevalence of ARDS in a cohort of patients burned as a result of recent combat operations.

RESULTS

A total of 876 burned military casualties presented during the study period, of whom 291 (33.2%) required mechanical ventilation. Prevalence of ARDS in this cohort was 32.6%, with a crude overall mortality of 16.5%. Mortality increased significantly with ARDS severity: mild (11.1%), moderate (36.1%), and severe (43.8%) compared with no ARDS (8.7%) (p < 0.001). Predictors for the development of moderate or severe ARDS were inhalation injury (odds ratio [OR], 1.90; 95% confidence interval [CI], 1.01-3.54; p = 0.046), Injury Severity Score (ISS) (OR, 1.04; 95% CI, 1.01-1.07; p = 0.0021), pneumonia (OR, 198; 95% CI, 1.07-3.66; p = 0.03), and transfusion of fresh frozen plasma (OR, 1.32; 95% CI, 1.01-1.72; p = 0.04). Size of burn was associated with moderate or severe ARDS by univariate analysis but was not an independent predictor of ARDS by multivariate logistic regression (p > 0.05). Age, size of burn, and moderate or severe ARDS were independent predictors of mortality.

CONCLUSION

In this cohort of military casualties with thermal injuries, nearly a third required mechanical ventilation; of those, nearly one third developed ARDS, and nearly one third of patients with ARDS did not survive. Moderate and severe ARDS increased the odds of death by more than fourfold and ninefold, respectively.

LEVEL OF EVIDENCE

Epidemiologic/prognostic study, level III.

Incidence and morbidity of concomitant spine fractures in combat-related amputees

BACKGROUND CONTEXT

High-energy blasts are the most frequent cause of combat-related amputations in Operations Iraqi and Enduring Freedom (OIF/OEF). The nondiscriminating effects of this mechanism often result in both appendicular and axial skeletal injuries. Despite this recognized coincident injury pattern, the incidence and consequence of spine fractures in trauma-related combat amputees are unknown.

PURPOSE

This study sought to determine the incidence and morbidity of the associated spine fractures on patients with traumatic lower extremity amputation sustained during OIF/OEF.

STUDY DESIGN/SETTING

Retrospective case control.

PATIENT SAMPLE

Two hundred twenty-six combat-related lower extremity amputees presenting to a single institution and injured between 2003 and 2008 were included for analysis.

OUTCOME MEASURES

Physiologic and functional outcome measures were used to determine the influence of spine fractures on combat amputees. Physiologic measures included intensive care unit (ICU) admission rates, injury severity score (ISS), rate of narcotic/neuropathic pain use, and heterotopic ossification (HO) rates. Functional outcome measures included return-to-duty rates and ambulatory status at final follow-up.

METHODS

Data from 300 consecutive combat-related lower extremity amputations were retrospectively reviewed and grouped. Group 1 consisted of amputees with associated spine fractures, and Group 2 consisted of amputees without spine fractures. The results of the two groups were compared with regard to initial presentation and final functional outcomes.

RESULTS

A total of 226 patients sustained 300 lower extremity amputations secondary to combat-related injuries, the most common mechanism being an improvised explosive device. Twenty-nine of these patients had a spine fracture (13%). Group 1 had a higher ISS than Group 2 (30 vs. 19, p<.001). Group 1 patients were also more likely to be admitted to the ICU (86% vs. 46%, p<.001). Furthermore, Group 1 patients had a significantly higher rate of HO in their residual limbs (82% vs. 55%, p<.005).

CONCLUSIONS

The incidence of spine fractures in combat-related amputees is 13%. The results suggest that combat-related amputees with spine fractures are more likely to sustain severe injuries to other body systems, as indicated by the significantly higher ISS and rates of ICU admission. This group also had a significantly higher rate of HO formation, which may be attributable to the greater local and/or systemic injuries sustained by these patients.

Internal fixation in a combat theater hospital

Limited data are available on the use of internal fixation in combat zone hospitals. The authors performed a retrospective review of 713 surgical cases during 2 Operation Enduring Freedom deployments to a Level III theater hospital in 2007 and 2009 to 2010. The epidemiology and short- to intermediate-term outcomes of patients treated with internal fixation devices were studied. The authors found that, with judicious use, internal fixation under a damage control protocol in a combat theater hospital can be performed with acceptable complication rates.

Cervical spine injury biomechanics: Applications for under body blast loadings in military environments

BACKGROUND

While cervical spine injury biomechanics reviews in motor vehicle and sports environments are available, there is a paucity of studies in military loadings. This article presents an analysis on the biomechanics and applications of cervical spine injury research with an emphasis on human tolerance for underbody blast loadings in the military.

METHODS

Following a brief review of published military studies on the occurrence and identification of field trauma, postmortem human subject investigations are described using whole body, intact head-neck complex, osteo-ligamentous cervical spine with head, subaxial cervical column, and isolated segments subjected to differing types of dynamic loadings (electrohydraulic and pendulum impact devices, free-fall drops).

FINDINGS

Spine injuries have shown an increasing trend over the years, explosive devices are one of the primary causal agents and trauma is attributed to vertical loads. Injuries, mechanisms and tolerances are discussed under these loads. Probability-based injury risk curves are included based on loading rate, direction and age.

INTERPRETATION

A unique advantage of human cadaver tests is the ability to obtain fundamental data to delineate injury biomechanics and establish human tolerance and injury criteria. Definitions of tolerances of the spine under vertical loads based on injuries have implications in clinical and biomechanical applications. Primary outputs such as forces and moments can be used to derive secondary variables such as the neck injury criterion. Implications are discussed for designing anthropomorphic test devices that may be used to predict injuries in underbody blast environments and improve the safety of military personnel.

Remote ballistic fractures in a gelatine model--aetiology and surgical implications

Background

Remote ballistic femoral fractures are rare fractures reported in the literature but still debated as to their existence and, indeed, their treatment. This study aimed to prove their existence, understand how they occur and determine which ammunition provides the greatest threat. In addition, fracture patterns, soft tissue disruption and contamination were assessed to aid in treatment planning.

Method

We filmed 42 deer femora embedded in ballistic gelatine and shot with four different military (5.56 × 45 mm, 7.62 × 39 mm) and civilian (9 × 19 mm, .44 in.) bullets, at varying distances off the bone (0–10 cm).

Results

Two remote ballistic fractures occurred, both with .44 in. hollow-point bullets shot 3 cm off the bone. These fractures occurred when the leading edge of the expanding temporary cavity impacted the femur's supracondylar region, producing a wedge-shaped fracture with an undisplaced limb, deceivingly giving the appearance of a spiral fracture. No communication was seen between the fracture and permanent cavity, despite the temporary cavity encasing the fracture and stripping periosteum from its base.

Conclusion

These fractures occur with civilian ammunition, but cannot prove their existence with military rounds. They result from the expanding temporary cavity affecting the weakest part of the bone, creating a potentially contaminated wedge-shaped fracture, important for surgeons considering operative intervention.

Risk factors for infection and amputation following open, combat-related calcaneal fractures

BACKGROUND

High-energy open calcaneal fractures are severe injuries complicated by high rates of infection, uncertain functional outcomes, and frequent need for later amputation.

METHODS

We conducted a retrospective review of 102 consecutive combat-related open calcaneal fractures. Patient demographics, injury mechanisms, fracture and wound characteristics, associated fractures, and methods of fracture fixation were reviewed to determine risk factors for eventual amputation or infection.

RESULTS

Eighty-nine patients, with a mean age of twenty-six years, sustained 102 open calcaneal fractures (thirteen bilateral). After a mean follow-up of four years (range, five to ninety-two months), 42% (forty-three limbs) underwent amputation. A delayed amputation (more than twelve weeks from the time of injury) was performed in 15% (fifteen) of 102 open calcaneal fractures. In a multivariate Cox proportional-hazards survival model with time to amputation as the end point, the blast mechanism of injury, plantar wound location, larger size of open wound (in square centimeters), and escalating Gustilo and Anderson classification types (p < 0.05 for all) were predictive of eventual amputation. At the time of the final follow-up, patients who had undergone amputation had lower visual analogue scale scores for pain (2.1 compared with 4.0; p < 0.0001) and higher Tegner activity levels (5.4 compared with 3.5; p < 0.0001) than limb salvage patients.

CONCLUSIONS

Lower-extremity amputation following open calcaneal fractures is predicted by the injury mechanism, wound location and size, and open fracture type and severity. After short-term follow-up, patients with open calcaneal fractures eventually requiring amputation exhibit improved pain and activity levels compared with patients with continued, ostensibly successful limb salvage.

Characterization of combat-related spinal injuries sustained by a US Army Brigade Combat Team during Operation Iraqi Freedom

BACKGROUND CONTEXT

The United States is presently engaged in the largest scale armed conflict since Vietnam. Despite recent investigations into the scope of injuries sustained by soldiers in Iraq and Afghanistan, little information is available regarding the incidence and epidemiology of spine trauma in this population.

PURPOSE

Characterize the incidence and epidemiology of spinal injuries sustained during combat by soldiers of a US Army Brigade Combat Team (BCT) that participated in Operation Iraqi Freedom.

STUDY DESIGN

Descriptive epidemiologic study.

PATIENT SAMPLE

A total of 4,122 soldiers who served in Iraq with an Army BCT during "The Surge" operation.

OUTCOME MEASURES

Spine injury epidemiology was calculated for the BCT, including the spine combat casualty rate, and percent medically evacuated (MEDEVAC).

METHODS

Unit rosters were obtained, and a comprehensive database identifying all combat-related spine injuries was created by querying each soldiers' electronic medical record and the unit's casualty rosters. Demographic information was recorded including age, sex, rank, injury mechanism, presence of polytrauma, and injury outcome. Injury outcomes were classified as killed in action, died of wounds, MEDEVAC, or returned to duty. The incidence of spine injuries was determined, and epidemiology was characterized using calculations of the spine combat casualty rate and percent MEDEVAC. Comparisons were made to published reports from previous conflicts.

RESULTS

A total of 29 soldiers sustained 31 combat-related spine injuries. These accounted for 7.4% (29 out of 390) of all casualties sustained during combat. Blunt trauma to the spine, often resulting from an explosive mechanism, was encountered in 65% of cases. Closed fractures of the spine occurred in 21% of casualties and open injuries occurred in 7%. The spine combat casualty rate was 5.6 out of 1,000 soldier combat-years, and the percent MEDEVAC was 19%.

CONCLUSIONS

This investigation is the first of its kind, documenting the nature of spine trauma in a major American conflict. The incidence of spine injuries in this study is the highest ever documented and is indicative of the tactics used by the enemy in the current war. Given this fact, it is likely that the prevalence of combat-related spine trauma will increase in the future. Larger, more extensive, studies of this kind must be conducted in the future.

Non-emergent orthopaedic injuries sustained by soldiers in Operation Iraqi Freedom

BACKGROUND

The majority of soldiers deployed to the theater of combat operations return safely after completion of the deployment. Many of these soldiers sustain non-emergent musculoskeletal injuries that initially are treated nonoperatively and ultimately require surgery following their combat tour.

METHODS

A prospective evaluation of the orthopaedic surgery consultations and surgical procedures required by soldiers returning from a full combat deployment was performed. Demographic information (including age and sex) as well as information on the mechanism of injury, the reason for orthopaedic consultation, and the procedures performed was collected for each soldier. The overall incidence of non-emergent orthopaedic injuries was calculated, and multivariate Poisson regression analysis was utilized to determine the effect of age and sex on the type of orthopaedic injury sustained.

RESULTS

There were 3787 soldiers who returned from combat operations at the end of a fifteen-month deployment without having been medically evacuated. There were 731 orthopaedic surgical consultations for the evaluation of a non-emergent musculoskeletal complaint, and 140 orthopaedic operations were performed as a result. An age of thirty years or more was an important risk factor for requiring an orthopaedic consultation (p < 0.0001). The most common surgical procedures were performed for shoulder stabilization, for superior labrum anterior to posterior lesion repair, for the treatment of internal derangement of the knee, and for the treatment of foot deformity.

CONCLUSIONS

Nineteen percent of all soldiers who completed a combat deployment required an orthopaedic surgical consultation on return, and 4% of soldiers required orthopaedic surgery. More than half of the surgical procedures involved the knee or shoulder. This represents a large burden of care for returning soldiers on orthopaedic surgical services and has important implications for future resource utilization.

Axioms altered with research

The medical community is actively engaged in research to provide the highest level of evidence to support clinical practice. The care of wounded warriors creates unique challenges, and conducting research that provides evidence for clinical practice is important to outcomes in this patient population. When the current wars began, much debate centered on the best way to care for wounded warriors. To address these concerns, we use a MythBusters format, based on the popular television show, to describe how recent research has dispelled some earlier misconceptions and clarify how clinical practice has been changed. In addition, we assess the progress that has been made on addressing the original prioritized research objectives of the first Extremity War Injuries symposium.

Estimating radiation effective doses from whole body computed tomography scans based on U.S. soldier patient height and weight

BACKGROUND

The purpose of this study is to explore how a patient's height and weight can be used to predict the effective dose to a reference phantom with similar height and weight from a chest abdomen pelvis computed tomography scan when machine-based parameters are unknown. Since machine-based scanning parameters can be misplaced or lost, a predictive model will enable the medical professional to quantify a patient's cumulative radiation dose.

METHODS

One hundred mathematical phantoms of varying heights and weights were defined within an x-ray Monte Carlo based software code in order to calculate organ absorbed doses and effective doses from a chest abdomen pelvis scan. Regression analysis was used to develop an effective dose predictive model. The regression model was experimentally verified using anthropomorphic phantoms and validated against a real patient population.

RESULTS

Estimates of the effective doses as calculated by the predictive model were within 10% of the estimates of the effective doses using experimentally measured absorbed doses within the anthropomorphic phantoms. Comparisons of the patient population effective doses show that the predictive model is within 33% of current methods of estimating effective dose using machine-based parameters.

CONCLUSIONS

A patient's height and weight can be used to estimate the effective dose from a chest abdomen pelvis computed tomography scan. The presented predictive model can be used interchangeably with current effective dose estimating techniques that rely on computed tomography machine-based techniques.

Mortality in female war veterans of operations enduring freedom and Iraqi freedom

BACKGROUND

Combat-wounded service members are surviving battle injuries more than ever. Given different combat roles held by men and women, female service members should survive wounds at an unprecedented rate.

QUESTIONS/PURPOSES

We determined whether the casualty rates for females differ from their male counterparts and characterized wounds sustained by female casualties.

METHODS

We calculated the percentage of the 5141 deaths among the 40,531 casualties by gender for those serving in Operations Enduring Freedom (OEF) and Iraqi Freedom (OIF) from Defense Manpower Statistics between 2001 and 2009. We searched the Joint Theatre Trauma Registry for female casualties and described their injury characteristics. No matched cohort of male casualties was searched.

RESULTS

Female veterans comprised 1.9% of all casualties and 2.4% of all deaths. In OIF, the percent death for women was 14.5% (103 deaths) versus 12.0% (4226 deaths) for men. In OEF, the percent death for women was 35.9% (19 deaths) versus 17.0% (793 deaths) for men. Battle-injured females had a greater proportion of facial and external injuries and more severe extremity injuries compared with those nonbattle-injured.

CONCLUSIONS

The casualty death rate appears higher for women than men although the mechanisms of fatal injuries are not known and may not be comparable. Although facial, external, and extremity injuries were common among battle-injured females, no conclusion can be made as to whether male casualties sustain similar wounding patterns.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Advancing critical care: joint combat casualty research team and joint theater trauma system

Despite the severity and complexity of injuries, survival rates among combat casualties are equal to or better than those from civilian trauma. This article summarizes the evidence regarding innovations from the battlefield that contribute to these extraordinary survival rates, including preventing hemorrhage with the use of tourniquets and hemostatic dressings, damage control resuscitation, and the rapid evacuation of casualties via MEDEVAC and the US Air Force Critical Care Air Transport Teams. Care in the air for critically injured casualties with pulmonary injuries and traumatic brain injury is discussed to demonstrate the unique considerations required to ensure safe en route care. Innovations being studied to decrease sequelae associated with complex orthopedic and extremity trauma are also presented. The role and contributions of the Joint Combat Casualty Research Team and the Joint Theater Trauma System are also discussed.

Epidemiology of psychiatric disorders sustained by a U.S. Army brigade combat team during the Iraq War

OBJECTIVE

This study was designed to describe the epidemiology of psychiatric illnesses experienced by soldiers in a combat environment, which has been previously underreported.

METHODS

A U.S. Army brigade combat team deployed to Iraq during the Iraq War "Troop Surge" was followed by reviewing unit casualty rosters and electronic medical records for psychiatric diagnoses made by treating providers. The main outcome was the incidence rates of psychiatric disease and nonbattle injury (DNBI).

RESULTS

Of the 4122 soldiers deployed, there were 308 psychiatric DNBI casualties (59.8 per 1000 soldier combat-years), which represented 23% of all DNBIs and was second only to musculoskeletal injuries (50% of all DNBI). Most psychiatric DNBI (88%) were treated in theater and returned to duty, 11% were medically evacuated and 1% died. Junior enlisted soldiers, compared with junior officers, and women, compared with men, were at a significantly increased risk for becoming a psychiatric DNBI casualty (77.3 vs. 32.2 per 1000 combat-years, P<.002 and 110.8 vs. 55.4 per 1000 combat-years P<.05, respectively).

CONCLUSIONS

Psychiatric diagnoses are second only to musculoskeletal injuries as a cause for DNBIs sustained in the current combat environment. Most can be treated in theater and permit soldiers to return to duty.

[Role of chest physician in the management of patient with thoracic trauma]

Thoracic traumas are frequent and potentially fatal, because of the associated neurological and abdominal lesions. They are observed in car crashes, combat environments and urban terrorist bombings. The mechanisms of the traumatic injury are complex and account for the diversity of the lesions. The management of a chest trauma patient is a model of multidisciplinary collaboration where the chest physician can make a significant contribution.