Fatal head and neck injuries in military underbody blast casualties.

INTRODUCTION: Death as a consequence of underbody blast (UBB) can most commonly be attributed to central nervous system injury. UBB may be considered a form of tertiary blast injury but is at a higher rate and somewhat more predictable than injury caused by more classical forms of tertiary injury. Recent studies have focused on the transmission of axial load through the cervical spine with clinically relevant injury caused by resultant compression and flexion. This paper seeks to clarify the pattern of head and neck injuries in fatal UBB incidents using a pragmatic anatomical classification. METHODS: This retrospective study investigated fatal UBB incidents in UK triservice members during recent operations in Afghanistan and Iraq. Head and neck injuries were classified by anatomical site into: skull vault fractures, parenchymal brain injuries, base of skull fractures, brain stem injuries and cervical spine fractures. Incidence of all injuries and of each injury type in isolation was compared. RESULTS: 129 fatalities as a consequence of UBB were identified of whom 94 sustained head or neck injuries. 87 casualties had injuries amenable to analysis. Parenchymal brain injuries (75%) occurred most commonly followed by skull vault (55%) and base of skull fractures (32%). Cervical spine fractures occurred in only 18% of casualties. 62% of casualties had multiple sites of injury with only one casualty sustaining an isolated cervical spine fracture. CONCLUSION: Improvement of UBB survivability requires the understanding of fatal injury mechanisms. Although previous biomechanical studies have concentrated on the effect of axial load transmission and resultant injury to the cervical spine, our work demonstrates that cervical spine injuries are of limited clinical relevance for UBB survivability and that research should focus on severe brain injury secondary to direct head impact.

Defining the essential anatomical coverage provided by military body armour against high energy projectiles.

INTRODUCTION: Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles. METHODS: A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy. RESULTS AND CONCLUSIONS: Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage.

What Is the Magnitude and Long-term Economic Cost of Care of the British Military Afghanistan Amputee Cohort?

BACKGROUND: Personal protection equipment, improved early medical care, and rapid extraction of the casualty have resulted in more injured service members who served in Afghanistan surviving after severe military trauma. Many of those who survive the initial trauma are faced with complex wounds such as multiple amputations. Although costs of care can be high, they have not been well quantified before. This is required to budget for the needs of the injured beyond their service in the armed forces. QUESTION/PURPOSES: The purposes of this study were (1) to quantify and describe the extent and nature of traumatic amputations of British service personnel from Afghanistan; and (2) to calculate an estimate of the projected long-term cost of this cohort. METHODS: A four-stage methodology was used: (1) systematic literature search of previous studies of amputee care cost; (2) retrospective analysis of the UK Joint Theatre Trauma and prosthetic database; (3) Markov economic algorithm for healthcare cost and sensitivity analysis of results; and (4) statistical cost comparison between our cohort and the identified literature. RESULTS: From 2003 to 2014, 265 casualties sustained 416 amputations. The average number of limbs lost per casualty was 1.6. The most common type of amputation was a transfemoral amputation (153 patients); the next most common amputation type was unilateral transtibial (143 patients). Using a Markov model of healthcare economics, it is estimated that the total 40-year cost of the UK Afghanistan lower limb amputee cohort is £288 million (USD 444 million); this figure estimates cost of trauma care, rehabilitation, and prosthetic costs. A sensitivity analysis on our model demonstrated a potential ± 6.19% variation in costs. CONCLUSIONS: The conflict in Afghanistan resulted in high numbers of complex injuries. Our findings suggest that a long-term facility to budget for veterans' health care is necessary. CLINICAL RELEVANCE: Estimates here should be taken as the start of a challenge to develop sustained rehabilitation and recovery funding and provision.

Management of penetrating abdominal trauma in the conflict environment: the role of computed tomography scanning.

BACKGROUND: Computed tomography (CT) scanning is a vital imaging technique in selecting patients for nonoperative management of civilian penetrating abdominal trauma. This has reduced the rate of nontherapeutic laparotomies and associated complications. Battlefield abdominal injuries conventionally mandate laparotomy, and with the advent of field deployable CT scanners it is unclear whether some ballistic injuries can be managed conservatively. METHODS: A retrospective 12 month cohort of patients admitted to a forward surgical facility in Afghanistan who sustained penetrating abdominal injury severe enough to warrant laparotomy or CT scan were studied. Patient details were retrieved from a prospectively maintained operative log and CT logs. Case notes were then reviewed and data pertaining to injury pattern, operative intervention, and survival were collected. RESULTS: A total of 133 patients were studied: 73 underwent immediate laparotomy (Lap group) and 60 underwent CT scanning (CT group). Of those undergoing CT scanning 17 underwent laparotomy and 43 were selected for nonoperative management. There were 15 deaths in the Lap group and none in the CT group. The median New Injury Severity and Revised Trauma Score was 29 and 7.55 in the Lap group and 9 and 7.8408 in the CT group, which is statistically significantly different (p < 0.001). Five patients in the CT-Lap group had nontherapeutic laparotomies and 1 patient failed nonoperative management. CONCLUSIONS: Computed tomography scanning can be used in stable patients who have sustained penetrating battlefield abdominal injury to exclude peritoneal breach and identify solid abdominal organ injury that can be safely managed nonoperatively.

The modern "deck-slap" injury--calcaneal blast fractures from vehicle explosions.

BACKGROUND: Anti-vehicle mines and improvised explosive devices remain the most prevalent threat to coalition troops operating in Iraq and Afghanistan. Detonation of these devices causes rapid deflection of the vehicle floor resulting in severe injuries to calcaneus. Anecdotally referred to as a "deck-slap" injury, there have been no studies evaluating the pattern of injury or the effect of these potentially devastating injuries since World War II. Therefore, the aim of this study is to determine the pattern of injury, medical management, and functional outcome of UK Service Personnel sustaining calcaneal injuries from under-vehicle explosions. METHOD: From January 2006 to December 2008, using a prospectively collected trauma registry (Joint Theater Trauma Registry), the records of all UK Service Personnel sustaining a fractured calcaneus from a vehicle explosion were identified for in-depth review. For each patient, demographic data, New Injury Severity Score, and associated injuries were recorded. In addition, the pattern of calcaneal fracture, the method of stabilization, local complications, and the need for amputation were noted. Functional recovery was related to the ability of the casualty to return to military duties. RESULTS: Forty calcaneal fractures (30 patients) were identified in this study. Mean follow-up was 33.2 months. The median New Injury Severity Score was 17, with the lower extremity the most severely injured body region in 90% of cases. Nine (30%) had an associated spinal injury. The overall amputation rate was 45% (18/40); 11 limbs (28%) were amputated primarily, with a further 3 amputated on return to the United Kingdom. Four (10%) casualties required a delayed amputation for chronic pain (mean, 19.5 months). Of the 29 calcaneal fractures salvaged at the field hospital, wound infection developed in 11 (38%). At final follow-up, only 2 (6%) were able to return to full military duty with 23 (76%) only fit for sedentary work or unfit for any military duty. CONCLUSION: Calcaneal injuries following under-vehicle explosions are commonly associated with significant multiple injuries including severe lower limb injury. The frequency of associated spinal injuries mandates radiologic evaluation of the spine in all such patients. The severity of the hindfoot injury is reflected by the high infection rate and amputation rate. Only a small proportion of casualties were able to return to preinjury military duties.

Prevention of infections associated with combat-related extremity injuries.

During combat operations, extremities continue to be the most common sites of injury with associated high rates of infectious complications. Overall, ∼ 15% of patients with extremity injuries develop osteomyelitis, and ∼ 17% of those infections relapse or recur. The bacteria infecting these wounds have included multidrug-resistant bacteria such as Acinetobacter baumannii, Pseudomonas aeruginosa, extended-spectrum ß-lactamase-producing Klebsiella species and Escherichia coli, and methicillin-resistant Staphylococcus aureus. The goals of extremity injury care are to prevent infection, promote fracture healing, and restore function. In this review, we use a systematic assessment of military and civilian extremity trauma data to provide evidence-based recommendations for the varying management strategies to care for combat-related extremity injuries to decrease infection rates. We emphasize postinjury antimicrobial therapy, debridement and irrigation, and surgical wound management including addressing ongoing areas of controversy and needed research. In addition, we address adjuvants that are increasingly being examined, including local antimicrobial therapy, flap closure, oxygen therapy, negative pressure wound therapy, and wound effluent characterization. This evidence-based medicine review was produced to support the Guidelines for the Prevention of Infections Associated With Combat-Related Injuries: 2011 Update contained in this supplement of Journal of Trauma.

Executive summary: Guidelines for the prevention of infections associated with combat-related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society.

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

Guidelines for the prevention of infections associated with combat-related injuries: 2011 update: endorsed by the Infectious Diseases Society of America and the Surgical Infection Society.

Despite advances in resuscitation and surgical management of combat wounds, infection remains a concerning and potentially preventable complication of combat-related injuries. Interventions currently used to prevent these infections have not been either clearly defined or subjected to rigorous clinical trials. Current infection prevention measures and wound management practices are derived from retrospective review of wartime experiences, from civilian trauma data, and from in vitro and animal data. This update to the guidelines published in 2008 incorporates evidence that has become available since 2007. These guidelines focus on care provided within hours to days of injury, chiefly within the combat zone, to those combat-injured patients with open wounds or burns. New in this update are a consolidation of antimicrobial agent recommendations to a backbone of high-dose cefazolin with or without metronidazole for most postinjury indications, and recommendations for redosing of antimicrobial agents, for use of negative pressure wound therapy, and for oxygen supplementation in flight.

Infectious complications of combat-related mangled extremity injuries in the British military.

BACKGROUND: During the wars in Iraq and Afghanistan, extremity injuries have predominated; however, no systematic review of field and stabilization care with subsequent infectious complications exists. This study evaluates the infectious complications and possible risk factors of British military casualties with mangled extremities, highlighting initial care and infections. METHODS: This is a retrospective cohort study of British military casualties in Iraq and Afghanistan between August 2003 and May 2008. Casualties with mangled extremities undergoing limb salvage were evaluated for management strategies at the time of injury through evacuation back to the United Kingdom and subsequent infections. RESULTS: There were 84 casualties with 85 extremities (20 infected and 65 uninfected). Infected extremities had more Gustilo Classification IIIb. There were no differences by Injury Severity Score, age, durations from injury to evacuation, or surgery, or arrival in England, use of clotting materials, or method of extremity stabilization between infected and uninfected extremity injuries. Tourniquet use in the field and fasciotomy were associated with infections. Antimicrobial coverage was associated with infections. Staphylococcus aureus were recovered later in casualties' clinical course in contrast to early recovery of Acinetobacter. On multivariate analysis, tourniquet in the field, antibiotics during evacuation and in the operating room, and fasciotomy were associated with infection as were certain bacteria, notably, Pseudomonas aeruginosa. CONCLUSION: Infections occurred in 24% of those with mangled extremities including 6% with osteomyelitis. Certain procedures, likely reflective of injury severity, were associated with infections along with certain bacteria, P. aeruginosa and possibly S. aureus. Continued clarification is required for antimicrobial coverage (penicillin-based regimens vs. additional anaerobic coverage) and certain surgical procedures to improve casualty care.

Comparison of development of heterotopic ossification in injured US and UK Armed Services personnel with combat-related amputations: preliminary findings and hypotheses regarding causality.

BACKGROUND: Recent reports have documented the rate of heterotopic ossification (HO) formation in the residual limbs of combat-related amputees from the US Armed Forces injured in Operations Iraqi and Enduring Freedom. Final amputation level within the zone of injury and blast as the mechanism of injury were identified as possible risk factors for the occurrence and grade of HO. There has been no previous description of HO in combat-related amputees from the UK service personnel. The purpose of this study was to examine potential differences in the prevalence of HO between UK and US Allied Forces, with particular attention to these risk factors, patient exposures, and any treatment differences between these two groups. METHODS: We reviewed the medical records and radiographs of 35 combat-related amputations from the UK and contrasted them with 213 previously reported amputations in US military personnel. We evaluated prevalence and severity of residual limb HO, Injury Severity Score (ISS), the mechanism and zone of injury, type and level of amputation, number of debridements, method of wound irrigation, presence of severe head injury and/or burns injury, use of topical negative pressure therapy and pulse lavage, number of days until wound closure, type of closure, and subsequent infections. All patients had a minimum of 2-month posthospital discharge radiographic follow-up. Comparisons were made using Fisher's exact, one-way analysis of variance, and chi2 analyses. RESULTS: There was no significant difference in either the overall prevalence of HO or the prevalence of moderate to severe HO in the two populations. Twenty of 35 (57.1%) limbs in the UK amputations developed HO compared with 134 of 213 (63%) in the US amputations (p > 0.05). The UK amputations had 12 cases (34.3%) of moderate to severe HO compared with 72 cases (33.8%) in the US amputations (p > 0.05). However, there was a significant difference in the number of UK amputations 0 of 20 (0%) versus the number of US amputations 25 of 134 (12%; p = 0.04), which required excision of symptomatic lesions. There was a significant association in the development of HO in UK personnel with the use of topical negative pressure treatment (p = 0.05) and increasing ISS scores (p = 0.04) and in the development of moderate to severe HO with increasing ISS (p = 0.006) and severe HI (p = 0.04). Unlike in the previous report, no significant association was found in UK personnel between any of the remaining hypothesized risk factors and either the presence or grade of HO. CONCLUSIONS: Although no difference was identified in the overall prevalence of HO, there are inconsistencies in the possible underlying causes of HO between the two cohorts. Further research is required in an ongoing effort to determine a causal relationship between treatment and subsequent HO formation.

Complications of extremity vascular injuries in conflict.

INTRODUCTION: The extremities remain the most common sites of wounding in conflict, are associated with a significant incidence of vascular trauma, and have a high complication rate (infection, secondary amputation, and graft thrombosis). AIM: The purpose of this study was to study the complication rate after extremity vascular injury. In particular, the aim was to analyze whether this was influenced by the presence or absence of a bony injury. METHODS: A prospectively maintained trauma registry was retrospectively reviewed for all UK military casualties with extremity injuries (Abbreviated Injury Score >1) December 8, 2003 to May 12, 2008. Demographics and the details of their vascular injuries, management, and outcome were documented using the trauma audit and medical notes. RESULTS: Thirty-four patients (34%)--37 limbs (30%)--had sustained a total of 38 vascular injuries. Twenty-eight limbs (22.6%) had an associated fracture, 9 (7.3%) did not. Twenty-nine limbs (23.4%) required immediate revascularization to preserve their limb: 16 limbs (13%) underwent an initial Damage Control procedure, and 13 limbs (10.5%) underwent Definitive Surgery. Overall, there were 25 limbs (20.2%) with complications. Twenty-two were in the 28 limbs with open fractures, 3 were in the 9 limbs without a fracture (p < 0.05). There was no significant difference in the complication rate with respect to upper versus lower limb and damage control versus definitive surgery. CONCLUSION: We have demonstrated that prognosis is worse after military vascular trauma if there is an associated fracture, probably due to higher energy transfer and greater tissue damage.

Micromotion and Push-Out Evaluation of an Additive Manufactured Implant for Above-the-Knee Amputees.

In comparison to through-knee amputees the outcomes for above-the-knee amputees are relatively poor; based on this novel techniques have been developed. Most current percutaneous implant-based solutions for transfemoral amputees make use of high stiffness intramedullary rods for skeletal fixation, which can have risks including infection, femoral fractures, and bone resorption due to stress shielding. This work details the cadaveric testing of a short, cortical bone stiffness-matched subcutaneous implant, produced using additive manufacture, to determine bone implant micromotion and push-out load. The results for the micromotions were all <20 µm and the mean push-out load was 2,099 Newtons. In comparison to a solid control, the stiffness-matched implant exhibited significantly higher micromotion distributions and no significant difference in terms of push-out load. These results suggest that, for the stiffness-matched implant at time zero, osseointegration would be facilitated and that the implant would be securely anchored. For these metrics, this provides justification for the use of a short-stem implant for transfemoral amputees in this subcutaneous application. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2104-2111, 2019.

Injuries from roadside improvised explosive devices.

BACKGROUND: After the invasion of Iraq in April 2003, coalition forces have remained in the country in a bid to maintain stability and support the local security forces. The improvised explosive device (IED) has been widely used by the insurgents and is the leading cause of death and injury among Coalition troops in the region. METHOD: From January 2006, data were prospectively collected on 100 consecutive casualties who were either injured or killed in hostile action. Mechanism of injury, new Injury Severity Score (NISS), The International Classification of Disease-9th edition diagnosis, anatomic pattern of wounding, and operative management were recorded in a trauma registry. The weapon incident reports were analyzed to ascertain the type of IED employed. RESULTS: Of the 100 casualties injured in hostile action, 53 casualties were injured by IEDs in 23 incidents (mean 2.3 casualties per incident). Twenty-one of 23 (91.3%) of the IEDs employed were explosive formed projectile (EFP) type. Twelve casualties (22.6%) were either killed or died of wounds. Median NISS score of survivors was 3 (range, 1-50). All fatalities sustained unsurvivable injuries with a NISS score of 75. Primary blast injuries were seen in only 2 (3.8%) and thermal injuries in 8 casualties (15.1%). Twenty (48.7%) of survivors underwent surgery by British surgeons in the field hospital. At 18 months follow, all but one of the United Kingdom Service personnel had returned to military employment. CONCLUSIONS: The injury profile seen with EFP-IEDs does not follow the traditional pattern of injuries seen with conventional high explosives. Primary blast injuries were uncommon despite all casualties being in close proximity to the explosion. When the EFP-IED is detonated, the EFP produced results in catastrophic injuries to casualties caught in its path, but causes relatively minor injuries to personnel sited adjacent to its trajectory. Improvements in vehicle protection may prevent the EFP from entering the passenger compartments and thereby reduce fatalities.

Ergonomic assessment of future methods of ballistic neck protection.

INTRODUCTION: Neck injuries from explosively propelled fragments are present in 11% of injured U.K. soldiers and result in significant mortality and long-term morbidity. U.S. forces in contrast sustain only neck wounds in 3 to 4% of those injured, which is believed to be because of their greater acceptance in the wearing of issued neck protection. METHOD: A three-piece neck collar, two-piece neck collar, a nape pad, a ballistic scarf, and an enhanced protection under body armor shirt (EP-UBACS) reinforced at the collar were objectively compared during a treadmill test using physiological measurements. Designs were subjectively compared regarding their effect on soldier performance using representative military tasks. RESULTS: Both neck collars and the EP-UBACS prototype demonstrated 90% acceptability in terms of military task performance. No statistical difference in tympanic temperature and heart rate was found between prototypes. The statistically significant higher skin temperatures found for prototypes lying close to the skin (EP-UBACS and ballistic scarf) were unrelated to perceived comfort. DISCUSSION: Neck collars remain the most successful design in terms of military performance, comfort, and potential levels of ballistic protection. However the EP-UBACS concept should also be developed further, with future iterations potentially removing the zip and increasing skin standoff.

Use and complications of operative control of arterial inflow in combat casualties with traumatic lower-extremity amputations caused by improvised explosive devices.

BACKGROUND: Proximal traumatic lower-extremity amputation has become the signature injury of the war in Afghanistan. Casualties present in extremis and often require immediate operative control of arterial inflow to prevent exsanguination. This study evaluated the use of this strategy and its complications. METHODS: This is a retrospective analysis of case notes of UK service personnel, identified from the UK Joint Theatre Trauma Registry, who sustained traumatic lower-extremity amputation requiring suprainguinal vascular control, following improvised explosive device injury in Afghanistan, between July 2008 and December 2010. RESULTS: Fifty-one casualties were identified with a median Injury Severity Score (ISS) of 30. In 10 casualties, control was obtained via an extraperitoneal approach, and in 41, control was obtained via midline laparotomy and intraperitoneal (IP) approach. The most commonly controlled vessel in extraperitoneal control was the external iliac artery, and in IP control, the common iliac artery. Within the 41 patients who had IP control, 13 also required a therapeutic laparotomy, and 9 patients had bilateral injuries at the level of the proximal femur or higher. One patient, who had undergone IP control, experienced an injury to the common iliac vein, which was repaired. There were no other immediate complications recorded, and 39 casualties survived to discharge. CONCLUSION: This is the first study to characterize the methods of proximal control in high wartime lower-extremity amputees. Although some casualties will have abdominal injuries that necessitate laparotomy, the majority in our study did not; however, in the critically ill casualty, rapid proximal control is required. Novel methods of temporary hemorrhage control may reduce the need for, and burden of, cavity surgery. LEVEL OF EVIDENCE: Epidemiologic study, level III; prognostic study, level IV.

Outcomes of IED foot and ankle blast injuries.

BACKGROUND: Improvements in protection and medical treatments have resulted in increasing numbers of modern-warfare casualties surviving with complex lower-extremity injuries. To our knowledge, there has been no prior analysis of foot and ankle blast injuries as a result of improvised explosive devices (IEDs). The aims of this study were to report the pattern of injury and determine which factors are associated with a poor clinical outcome. METHODS: U.K. service personnel who had sustained lower leg injuries following an under-vehicle explosion from January 2006 to December 2008 were identified with the use of a prospective trauma registry. Patient demographics, injury severity, the nature of the lower leg injury, and the type of clinical management were recorded. Clinical end points were determined by (1) the need for amputation and (2) ongoing clinical symptoms. RESULTS: Sixty-three U.K. service personnel (eighty-nine injured limbs) with lower leg injuries from an explosion were identified. Fifty-one percent of the casualties sustained multisegmental injuries to the foot and ankle. Twenty-six legs (29%) required amputation, with six of them amputated because of chronic pain eighteen months following injury. Regression analysis revealed that hindfoot injuries, open fractures, and vascular injuries were independent predictors of amputation. At the time of final follow-up, sixty-six (74%) of the injured limbs had persisting symptoms related to the injury, and only nine (14%) of the service members were fit to return to their preinjury duties. CONCLUSIONS: This study demonstrates that foot and ankle injuries from IEDs are associated with a high amputation rate and frequently with a poor clinical outcome. Although not life-threatening, they remain a source of long-term morbidity in an active population.

Primary blast lung injury prevalence and fatal injuries from explosions: insights from postmortem computed tomographic analysis of 121 improvised explosive device fatalities.

BACKGROUND: Primary blast lung injury (PBLI) is an acknowledged cause of death in explosive blast casualties. In contrast to vehicle occupants following an in-vehicle explosion, the injury profile, including PBLI incidence, for mounted personnel following an external explosion has yet to be as well defined. METHODS: This retrospective study identified 146 cases of UK military personnel killed by improvised explosive devices (IEDs) between November 2007 and July 2010. With the permission of Her Majesty's Coroners, relevant postmortem computed tomography imaging was analyzed. PBLI was diagnosed by postmortem computed tomography. Injury, demographic, and relevant incident data were collected via the UK Joint Theatre Trauma Registry. RESULTS: Autopsy results were not available for 1 of 146 cases. Of the remaining 145 IED fatalities, 24 had catastrophic injuries (disruptions), making further study impossible, leaving 121 cases; 79 were dismounted (DM), and 42 were mounted (M). PBLI was noted in 58 cases, 33 (79%) of 42 M fatalities and 25 (32%) of 79 DM fatalities (p < 0.0001). Rates of associated thoracic trauma were also significantly greater in the M group (p < 0.006 for all). Fatal head (53% vs. 23%) and thoracic trauma (23% vs. 8%) were both more common in the M group, while fatal lower extremity trauma (7% vs. 48%) was more commonly seen in DM casualties (p < 0.0001 for all). CONCLUSION: Following IED strikes, mounted fatalities are primarily caused by head and chest injuries. Lower extremity trauma is the leading cause of death in dismounted fatalities. Mounted fatalities have a high incidence of PBLI, suggesting significant exposure to primary blast. This has not been reported previously. Further work is required to determine the incidence and clinical significance of this severe lung injury in explosive blast survivors. In addition, specific characteristics of the vehicles should be considered.

FASS is a better predictor of poor outcome in lower limb blast injury than AIS: implications for blast research.

OBJECTIVES: Due to the absence of clinical blast data, automotive injury data using the abbreviated injury score (AIS) has been extrapolated to define current North Atlantic Treaty Organisation (NATO) injury thresholds for anti-vehicle mine tests. We hypothesized that AIS, being a marker of fatality rather than disability, would be a worse predictor of poor clinical outcome compared with the lower limb-specific foot and ankle severity score (FASS). METHODS: Using a prospectively collected trauma database, we identified UK Service Personnel sustaining lower leg injuries from under-vehicle explosions from January 2006 to December 2008. A full review of all medical documentation was performed to determine patient demographics and the severity of lower leg injury, as assessed by AIS and FASS. Clinical endpoints were defined as (1) need for amputation or (2) poor clinical outcome (defined as amputation or ongoing clinical problems). Statistical models were developed to explore the relationship between the scoring systems and clinical endpoints. RESULTS: Sixty-three UK casualties (89 limbs) were identified with a lower limb injury after under-vehicle explosion. The mean age of the casualty was 26.0 years. At 33.6 months follow-up, 29.1% (26 of 89) required an amputation and 74.6% (67 of 89) having a poor clinical outcome. Only 9 (14%) casualties were deemed medically fit to return to full military duty. Receiver operating characteristic analysis revealed that both AIS = 2 and FASS = 4 could predict the risk of amputation, with FASS = 4 demonstrating greater specificity (43% vs. 20%) and greater positive predictive value (72% vs. 34%). In predicting poor clinical outcome, FASS was significantly superior to AIS. Probit analysis revealed that a relationship could not be developed between AIS and the probability of a poor clinical outcome. CONCLUSIONS: Our study clearly demonstrates that AIS is not a predictor of long-term clinical outcome and that FASS would be a better quantitative measure of lower limb injury severity.

Design of a traumatic injury simulator for assessing lower limb response to high loading rates.

Current military conflicts are characterized by the use of the improvised explosive device. Improvements in personal protection, medical care, and evacuation logistics have resulted in increasing numbers of casualties surviving with complex musculoskeletal injuries, often leading to life-long disability. Thus, there exists an urgent requirement to investigate the mechanism of extremity injury caused by these devices in order to develop mitigation strategies. In addition, the wounds of war are no longer restricted to the battlefield; similar injuries can be witnessed in civilian centers following a terrorist attack. Key to understanding such mechanisms of injury is the ability to deconstruct the complexities of an explosive event into a controlled, laboratory-based environment. In this article, a traumatic injury simulator, designed to recreate in the laboratory the impulse that is transferred to the lower extremity from an anti-vehicle explosion, is presented and characterized experimentally and numerically. Tests with instrumented cadaveric limbs were then conducted to assess the simulator's ability to interact with the human in two mounting conditions, simulating typical seated and standing vehicle passengers. This experimental device will now allow us to (a) gain comprehensive understanding of the load-transfer mechanisms through the lower limb, (b) characterize the dissipating capacity of mitigation technologies, and (c) assess the bio-fidelity of surrogates.

Limb wounding and antisepsis: iodine and chlorhexidine in the early management of extremity injury.

Extremity injury and contamination as consequence are features of high-energy wounding. A leading cause of disability and the commonest cause of late complications, prevention of wound infection determines the ultimate outcome in these populations. Multiple variables influence the development of infection, one of which is the dressing used on the wound. Antiseptic-soaked gauze dressings feature in the early management of limb trauma despite a lack of evidence to support this. Iodine and chlorhexidine are ubiquitous in other aspects of health care however, and a plethora of studies detail their role in skin antisepsis, the recommendations from which are often anecdotally applied to acute wounding. To contextualize the role for antiseptic dressing use in acute, significant limb injury this review explores the evidence for the use of chlorhexidine and iodine in skin antisepsis. The paucity of experimental data available for antiseptic use in early wound management and the need for further research to address this evidence void is highlighted.