Conflict in Afghanistan demonstrated predominantly lower extremity and pelvi-perineal trauma secondary to Improvised Explosive Devices (IEDs). Mortality due to pelvic fracture (PF) is usually due to exsanguination. This study group comprised 169 military patients who sustained a PF and lower limb injury. There were 102 survivors and 67 fatalities (39% mortality). Frequent fracture patterns were a widened symphysis (61%) and widening of the sacroiliac joints (SIJ) (60%). Fatality was 20.7% for undisplaced SIJs, 24% for unilateral SIJ widening and 64% fatality where both SIJs were disrupted, demonstrating an increase in fatality rate with pelvic trauma severity. A closed pubic symphysis was associated with a 19.7% mortality rate versus 46% when widened. Vascular injury was present in 67% of fatalities, versus 45% of survivors. Of PFs, 84% were associated with traumatic amputation (TA) of the lower limb. Pelvic fracture with traumatic lower limb amputation presents a high mortality. It is likely that the mechanism of TA and PF are related, and flail of the lower limb(s) is the current hypothesis. This study prompts further work on the biomechanics of the pelvic-lower limb complex, to ascertain the mechanism of fracture. This could lead to evidence-based preventative techniques to decrease fatalities.

Recent evidence suggests that both the accepted mechanism of blast-mediated traumatic amputation (TA) (shockwave then blast wind exposure) and the link with fatal shockwave exposure merit review. Searching UK military prospectively gathered trauma registry data and post mortem CT (PM-CT) records identified casualties from August 2008 to August 2010 with blast-mediated TAs. TA level and associated injuries were recorded. Data on pre-debridement osseous and soft tissue injuries were only consistently available for fatalities through PM-CT imaging. 146 Cases (75 survivors and 71 fatalities) with 271 TAs (130 in survivors and 141 in fatalities) were identified. Through-joint TA rate in fatalities was 34/141 (24.1%). PM-CT analysis demonstrated only 9/34 through joint TAs with contiguous fractures in the immediately proximal long bone/limb girdle. 18/34 had no fracture, and 7/34 had a non-contiguous fracture. The previously reported link between TA and blast lung injury was not present, calling into question the significance of shockwaves in generating blast-mediated TAs. Furthermore, contemporary blast injury theory cannot account for the high prevalence of through joint TAs (previously published rate 1.3%). The proportion of through joint TAs with no associated fracture or a non-contiguous fracture (74%) is supportive of pure flail as a mechanism for blast-mediated TA.

Traumatic amputations (TAs) are amongst the most significant orthopaedic sequelae following IED strikes. Biomechanically, longer residual limb length confers better function. However, post-trauma definitive through knee amputation (TKA) remains controversial.

UK military casualties sustaining ≥1 major TA, 01/08/2008–01/08/2010 were identified using the UK JTTR and post mortem CT databases. All through- and below-knee TAs were termed ‘potential TKAs’ (p-TKAs); hypothetical candidates for definitive TKA. We hypothesised that traumatic TKAs were more common than previously reported (4.5% of lower limb TAs) and a significant cohort of blast injuries exist suitable for definitive TKA.

146 cases (75 survivors, 71 fatalities) sustained 271 TAs (235 lower limb). TKA rate was 34/235 (14.2%). 63/130 survivor TAs and 66/140 fatality TAs merited analysis as p-TKAs. Detailed pathoanatomy was only available for fatality p-TKAs, for whom definitive TKA would have been proximal to the zone of injury (ZOI) in only 3/66 cases.

Blast-mediated traumatic TKAs are significantly more common than previously reported (p=0.0118). Most lower limb TAs are skeletally amenable to definitive TKA. Maximising stump length for function incurs the risks of definitive amputation within the original ZOI (including infection and heterotopic ossification) but proximal extent of blast soft tissue injury commonly makes this unavoidable.

The accepted mechanism of traumatic limb amputation following blast is initial bone disruption due to the shock wave, with amputation completed by the blast wind; survival is considered unlikely. The high survival rate of traumatic amputees following explosion, from the current conflict in Afghanistan, is at odds with previous work.

We reviewed extremity injuries, sustained in Afghanistan by UK military personnel, over a 2 year period. 774 British servicemen and women sustained AIS >1 injuries, 72.6% of whom survived. No significant difference was found in the survival rates following explosive blast or gunshot (p>0.05).

169 casualties (21.8%) sustained 263 lower limb and 74 upper limb traumatic amputations. Amputations were more common in the lower than the upper limbs and more common in the extremity proximal bone. Bilateral lower limb amputations were more common than a unilateral lower limb amputation. The majority (99%) of major amputations were sustained as a result of explosion. 46.3% (74) of those who sustained a major amputation following explosion survived.

Rates of fatalities caused by explosion, or by small arms are not statistically different. Blast-mediated amputations are not universally fatal, and a significant number were through joint, calling into question previously proposed mechanisms.

Background

The conflict in Afghanistan has been epitomised by the emergence of the Improvised Explosive Device (IEDs). Improvements in protection and medical treatments have resulted in increasing numbers of casualties surviving with complex lower extremity injuries. To date, there has been no analysis of foot and ankle blast injuries as a result of IEDs. Therefore the aims of this study are to report the pattern of injury and determine which factors were associated with a poor clinical outcome.

The defining weapon of the conflicts in Iraq and Afghanistan has been the Improvised Explosive Device (IEDs). When detonated under a vehicle, they result in significant axial loading to the lower limbs, resulting in devastating injuries. Due to the absence of clinical blast data, automotive injury data using the Abbreviated Injury Score (AIS) has been extrapolated to define current NATO injury thresholds for Anti-vehicle (AV) mine tests. We hypothesized that AIS, being a marker of fatality rather than disability would be a worse predictor of poor clinical outcome compared to the lower limb specific Foot and Ankle Severity Score (FASS).

Using a prospectively collected trauma database, we identified UK Service Personnel sustaining lower leg injuries from under-vehicle explosions from Jan 2006–Dec 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 (i) need for amputation or (ii) poor clinical outcome. Statistical models were developed in order to explore the relationship between the scoring systems and clinical endpoints.

63 UK casualties (89 limbs) were identified with a lower limb injury following under-vehicle explosion. The mean age of the casualty was 26.0 yrs. At 33.6 months follow-up, 29.1% (26/89) required an amputation and a further 74.6% (41/89) having a poor clinical outcome (amputation or ongoing clinical problems). Only 9(14%) casualties were deemed medically fit to return to full military duty. ROC 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 32%). In predicting poor clinical outcome, FASS was significantly superior to AIS (p<0.01). Probit analysis revealed that a relationship could not be developed between AIS and the probability of a poor clinical outcome (p=0.25).

Foot and ankle injuries following AV mine blast are associated with significant morbidity. 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. There is a requirement to reassess the current injury criteria used to evaluate the potential of mitigation technologies to help reduce long-term disability in military personnel. Our study highlights the critical importance of utilising contemporary battlefield injury data in order to ensure that the evaluation of mitigation measures is appropriate to the injury profile and their long-term effects.

Recent advances in combat casualty care have enabled survival following battlefield injuries that would have been lethal in past conflicts. While some injuries remain beyond our current capability to treat, they have the potential to be future ‘unexpected’ survivors. The greatest threat to deployed coalition troops currently and for the foreseeable future is the improvised explosive device (IED) Therefore, the aim of this study was to conduct an analysis of causes of death and injury patterns in recent explosive blast fatalities in order to focus research and mitigation strategies, to further improve survival rates.

Since November 2007, UK Armed Forces personnel killed whilst deployed on combat operations undergo both a post mortem computed tomography (PMCT) scan and an autopsy. With the permission of the coroners, we analysed casualties with PMCTs between November 2007 and July 2010. Injury data were analysed by a pathology-forensic radiology-orthopaedic multidisciplinary team. Cause of death was attributed to the injuries with the highest AIS scores contributing to the NISS score. Injuries with an AIS < 4 were excluded. During the study period 227 PMCT scans were performed; 211 were suitable for inclusion, containing 145 fatalities due to explosive blast from IEDs. These formed the study group. 24 cases had such severe injuries (disruptions) that further study was inappropriate. Of the remaining 121, 79 were dismounted, and 42 were mounted (in vehicles).

Leading causes of death were head CNS injury (47.6%), followed by intra-cavity haemorrhage (21.7%) in the mounted group, and extremity haemorrhage (42.6%), junctional haemorrhage (22.2%) and head CNS injury (18.7%) in the dismounted group.

The severity of head trauma in both mounted and dismounted IED fatalites would indicate that prevention and mitigation of these injuries is likely to be the most effective strategy to decrease their resultant mortality. Two thirds of dismounted fatalities have haemorrhage implicated as a cause of death that may have been amenable to prehospital treatment strategies. One fifth of mounted fatalites have haemorrhagic trauma which currently could only be addressed surgically. Maintaining the drive to improve all haemostatic techniques for combat casualties from point of wounding to definitive surgical proximal control alongside development and application of novel haemostatics could yield a significant survival benefit.

The mechanism of traumatic amputation (TA) from explosive blast has traditionally been considered to be a combination of blast wave induced bone injury – primary blast - followed by limb avulsion from the blast wind – tertiary blast. This results in a transosseous TA, with through joint amputations considered to be extremely rare. Data from previous conflicts has also suggested that this injury is frequently associated with a non-survivable primary blast lung injury (PBLI), further linking the extremity injury to the primary blast wave. However, our current experience in the Middle East would suggest that both the mechanism of TA and the link with fatal primary blast exposure need to be reconsidered. The aim of this study was to analyse the injury profile of the current cohort of TA fatalities to further investigate the underlying blast injury mechanism and to allow hypotheses on injury mechanisms to be developed for further analysis.

With the permission of the coroners, 121 post-mortem CT (PMCT) scans of UK Armed Forces personnel who died following an IED blast were analysed. All orthopaedic injuries were identified, classified and the anatomical level of any associated soft tissue injury noted. PMCT evidence of PBLI was used as a marker of significant primary blast exposure.

75/121 (62%) sustained at least 1 TA, with 138 TAs seen in total. 31/138 (22%) were through joints, with through knee amputations most common (23/31, 74%). Only 7/31(23%) through joint amputations had an associated fracture proximal to and contiguous with the amputation site. The soft tissue injury profile of through joint and transosseous TAs were not significantly different (p=0.569). When fatality location was considered (i.e. mounted or dismounted), no overall relationship between PBLI and TA was evident. The two pathologies were not seen to consistently occur concurrently, as has been previously reported.

The accepted mechanism for traumatic amputation following explosive blast does not adequately explain the significant number of through joint TAs presented here. The previously reported link between TA and PBLI in fatalities was not supported by this analysis of modern combat blast fatalities. Lack of an associated fracture with the majority of through joint TAs in conjunction with a lesser contribution of primary blast may implicate flail and periarticular soft tissue failure as a potential injury mechanism. Analysis of through joint TA incidence and associated injuries in survivors is now indicated. Case studies within the fatality dataset may facilitate generation of injury mechanism hypotheses. To further investigate the injury mechanism, work is required to understand osseous, ligamentous and other soft tissue behaviour and failure at high strain rates. This should allow characterisation and modeling of these injuries and inform mitigation strategies.

Counter-insurgency warfare in recent military operations has been epitomised by the use of Improvised Explosive Devices (IED) against coalition troops. Emerging patterns of skeletal fractures, limb amputations and organ injuries, which are caused by these weapons have been described over recent years. This paper describes a retrospective case series of knee dislocations caused by IEDs in recent conflict.

Data was obtained about military personnel from 2006 to 2011, who had sustained a knee dislocation while serving in Afghanistan from a prospectively gathered database, the Joint Theatre Trauma Registry (JTTR), maintained by the Academic Department of Military Emergency Medicine, Royal Centre for Defence Medicine. The diagnosis of knee dislocation and its associated skeletal injuries was assessed by review of all relevant plain radiographs, computed tomography scans and magnetic resonance images. The mechanism of injury, incidence of vascular injuries and other skeletal injuries was recorded.

During the study period, 23 casualties sustained a knee dislocation caused by an IED. Four casualties had an associated popliteal vascular injury. Eleven injuries were caused in enclosed spaces, and 10 injuries caused by IEDs out in the open. Anterior dislocations were common in the group caused in enclosed spaces. 19/20 patients had at least one other skeletal fracture.

Knee dislocations represent an uncommon but important diagnosis in modern warfare. Urgent and careful assessment for any associated vascular injuries or other skeletal injuries may help ensure timely treatment and promote future recovery. Mitigation against knee dislocation may be possible in the enclosed environment because of the predictable pattern of injury.

The conflict in Afghanistan has been epitomised by the emergence of the Improvised Explosive Device(IEDs). Improvements in medical treatments have resulted in increasing numbers of casualties surviving with complex lower extremity injuries. To date, there has been no analysis of foot and ankle blast injuries as a result of IEDs. Therefore the aims of this study are to firstly report the pattern of injury and secondly determine which factors were associated with a poor clinical outcome in order to focus future research.

Using a prospective trauma registry, UK Service Personnel who sustained lower leg injuries following an under-vehicle explosion between Jan 2006 and Dec 2008 were identified. Patient demographics, injury severity, the nature of lower limb injury and clinical management was recorded. Clinical endpoints were determined by (i)need for amputation and (ii)need for ongoing clinical output at mean 33.0 months follow-up.

63 UK Service Personnel (89 injured limbs) were identified with lower leg injuries from explosion. 50% of casualties sustained multi-segmental injuries to the foot and ankle complex. 26(29%) limbs required amputation, with six amputated for chronic pain 18 months following injury. Regression analysis revealed that hindfoot injuries, open fractures and vascular injuries were independent predictors of amputation.

Of the 69 limbs initially salvaged, the overall infection rate was 42%, osteomyelitis 11.6% and non-union rates was 21.7%. Symptomatic traumatic osteoarthritis was noted in 33.3% salvaged limbs. At final follow-up, 66(74%) of injured limbs had persisting symptoms related to their injury, with only 9(14%) fit to return to their pre-injury duties.

This study demonstrates that foot and ankle injuries from IEDs are frequently associated with a high amputation rate and poor clinical outcome. Although, not life-threatening, they remain a source of long-term morbidity in an active population. Primary prevention of these injuries remain key in reducing the injury burden.

Circumferential pelvic binders have been developed to allow rapid closure of the pelvic ring in unstable fracture patterns. Despite evidence to support the use of pelvic binders, there is a paucity of clinical data regarding the effect of binder position on symphyseal diastasis reduction.

All patients presenting to the UK's military hospital in Afghanistan who survived and underwent pelvic radiography were reviewed. Cases were identified by retrospective assessment of all digital plain pelvic radiographs performed between January 2008 and July 2010. All radiographs and CT images were assessed to identify the presence of any pelvic fracture. Patients were grouped into three categories according to the vertical level of the buckle: superior to the trochanters (high), inferior to the trochanters (low) and at the level of the trochanters (troch). Diastasis reduction was measured in patients with Anterior-Posterior Compression (APC) grades II and III, or Combined Mechanical Injuries(CMI). Comparison of diastasis reduction between the high and troch groups was assessed by an independent samples Student's t-test.

We identified 172 radiographs where the metallic springs in the buckle of a SAM Pelvic Sling^™ were clearly visible. The binders were positioned at the trochanteric level in 50% of radiographs. A high position was the commonest site of inaccurate placement (37%). In the patients with fractures and an open diastasis, the mean pelvic diastasis gap was 2.75 times greater in the high group compared to the trochanteric level (mean difference 22 mm) (p < 0.01).

Application of pelvic binders superior to the greater trochanters is commonplace and associated with inadequate fracture reduction, which is likely to delay cardiovascular recovery in these significantly injured casualties.

Introduction

Civilian fractures have been extensively studied with in an attempt to develop classification systems, which guide optimal fracture management, predict outcome or facilitate communication. More recently, biomechanical analyses have been applied in order to suggest mechanism of injury after the traumatic insult, and predict injuries as a result of a mechanism of injury, with particular application to the field so forensics. However, little work has been carried out on military fractures, and the application of civilian fracture classification systems are fraught with error. Explosive injuries have been sub-divided into primary, secondary and tertiary effects. The aim of this study was to 1. determine which effects of the explosion are responsible for combat casualty extremity bone injury in 2 distinct environments; a) in the open and b) enclosed space (either in vehicle or in cover) 2. determine whether patterns of combat casualty bone injury differed between environments Invariably, this has implications for injury classification and the development of appropriate mitigation strategies.

Introduction. This is the first study to illustrate spinal fracture distribution and the impact of different injury mechanisms on the spinal column during contemporary warfare. Methods Retrospective analysis of Computed Tomography (CT) spinal images entered onto the Centre for Defence Imaging (CDI) database, 2005-2009. Isolated spinous and transverse process fractures were excluded to allow focus on cases with implications for immediate management and prospective disability burden. Fractures were classified by anatomical level and stability with validated systems.

Clinical data regarding mechanism of injury and associated non-spinal injuries for each patient was recorded. Statistical analysis was performed by Fisher's Exact test. Results 57 cases (128 fractures) were analysed. Ballistic (79%) and non-ballistic (21%) mechanisms contribute to vertebral fracture and spinal instability at all regions of the spinal column. There is a low incidence of cervical spine fracture, with these injuries predominantly occurring due to gunshot wounding. There is a high incidence of lumbar spine fractures which are significantly more likely to be caused by explosive devices than gunshot wounds (p<0.05). 66% of thoracolumbar spine fractures caused by explosive devices were unstable, the majority being of a burst configuration. Associated non-spinal injuries occurred in 60% of patients.

There is a strong relationship between spinal injuries caused by explosive devices and lower limb fractures Conclusion Explosive devices account for significant injury to both combatants and civilians in current conflict. Injuries to the spine by explosions account for greater numbers, associated morbidity and increasing complexity than other means of injury.

The biomechanics of civilian fractures have been extensively studied with a view to defining the forces responsible e.g. bending, torsion, compression and crushing. Little equivalent work has been carried out on military fractures, although fractures from gunshot can be divided into direct and indirect. Given that the effects of blast can be sub-divided into primary, secondary, tertiary and quaternary, the aim of this study was to try to determine which effects of the blast are responsible for the bony injury. This may have implications for management and prognosis as well as prevention.

We reviewed emergency department records, case notes, and all radiographs of patients admitted to the British military hospital in Afghanistan over a 6 month period (Apr 08–Sept 08) to identify any fracture caused by an explosive mechanism. In addition we reviewed all relevant radiographs from the same period at the Royal Hospital Haslar, who report all radiographs taken, and keep a copy of the images. Early in the study it became clear that due to the complexity of some of the injuries it was inappropriate to consider bones separately and we used the term ‘fracture zone’ to identify separate areas of injury, which could involve from 1 – 28 bones. It also became clear that the pattern of injury differed considerably between patients in open ground, and those in houses or vehicles. These 2 groups were considered separately and compared.

We identified 86 patients with fractures. The 86 patients had 153 separate fracture zones (range 1–6). 56 casualties in the open sustained 87 fracture zones (mean 1.55 fracture zones per casualty). 30 casualties in a vehicle or other cover sustained 66 fracture zones (2.2 per casualty). Of the casualties in the open, 17 fracture zones were due the primary effects of blast, 10 a combination of primary and secondary effects, 30 due to secondary effects and 30 from the tertiary effects of blast. Of the casualties in vehicles we could not identify anyone with a fracture due to either the primary or secondary effects of blast, all 66 fracture zones appeared to be due to the tertiary effects.

In both groups there appeared to be a significant number of fractures, often with no break in the skin, caused by severe axial loading of the limb. This was possibly due to the casualty impacting against the ground, building or the inside of a vehicle, and this is a group of injuries we are now studying in greater detail.