This work examines the Upper limb (UL) blast-mediated traumatic amputation (TA) significance from recent operations in Afghanistan. It is hypothesized that the presence of an UL amputation at any level is an independent predictor of torso injury. A joint theatre trauma registry search was performed to determine the number of British casualties with TA and their associated injuries. UL TA accounted for 15.7% of all amputations; distributed: shoulder disarticulation 2.5%, trans-humeral 30%, elbow disarticulation 10%, trans-radial 20% and hand 37.5%. The presence of an UL amputation was more likely in dismounted casualties (P=0.015) and is a predictor of an increased number of total body regions injured and thoracic injuries (P 0.001 and P 0.026 respectively). An increased Injury Severity Score (ISS) was seen in patients with multiple amputations involving the UL (UL TA present ISS=30, no UL TA ISS=21; P=0.000) and the ISS was not significantly different whether mounted or dismounted (P=0.806). The presence of an upper limb amputation at any level should insight in the receiving clinician a high index of suspicion of concomitant internal injury; especially thoracic injury. Therefore with regards to blast mediated TA the injury patterns observed reflect a primary and tertiary blast mechanism of injury.
Electron Microscopy and Synchrotron analysis of Heterotopic Ossification (HO) from blast-related amputees' has shown that HO is bone with a disorganised structure and altered remodelling. This research performs mechanical testing of HO to understand its biomechanical properties in an attempt to create an accurate model to predict its morphological appearance. The hypothesis of this work is that HO is mechanically mediated in its formation. Synchrotron mechanical analysis of HO samples was performed to measure Young's modulus, ultimate strength and density distribution. A novel algorithm based on Wolf's law was implemented in a Finite Element (FE) analysis model of HO to take into account the differing mechanical and biological properties measured and the presence of HO outside the skeletal system. An HO modeling factor, which considers boundary conditions, and regulates recruitment of the soft tissue into bone formation, results in a re-creatable formation of HO within the soft tissues, comparable to the appearance of HO seen in military amputees. The results and model demonstrates that certain types of HO are under the control of endogenous and exogenous mechanical stimulus. HO can thus be mechanically exploited in the casualty management and rehabilitation process to achieve better clinical outcomes.
The explosive device has successfully been used by terrorists globally, with their effects extending beyond the resulting injuries. Suicide bombings, in particular, are being increasingly deployed due to the devastating effect of a combination of, high lethality and target accuracy. This aim of this study was to analyse the demographics and casualty figures of terrorist bombings worldwide. Analysis of the Global Terrorism Database and a PubMed search (keywords “terrorist”, and/or “suicide”, and/or “bombing”) from 1970 to date was performed. Of 58,095 reported terrorist explosions worldwide, 5.08% were suicide bombings. Incidents per year is increasing (P<0.01). PubMed identified 41 publications reporting 167 incidents. Mean casualty statistics per incidents was 1.14 deaths and 3.45 wounded from non-suicide incidents, and 10.16 and 24.16 from suicide bombings (p<0.05). The Middle East witnessed the most incidents (26.9%), with Europe ranked 4th in the number of terrorist related explosion (13.2%). Differing injury patterns were seen in open, confined and building collapse incidents. Terrorist bombings continue to be a threat and are increasing in the Middle East and Europe. Suicide bombings are becoming an increased threat with greater casualty figures per incident seen. This data assists in the planning of security, logistics, casualty evacuation and care.
Heterotopic ossification (HO) is the formation of lamellar bone in extra-skeletal soft tissues. Its exact pathogenic mechanism remains elusive. Previous studies demonstrate observation only of HO at the microscopic scale. This study uses scanning electron microscopy (SEM), Back-scatter electron (BSE) imaging and mechanical testing to detail the organic and non-organic elements of HO, compared to normal bone, to guide stem cell and bio-modelling research into HO. Samples analysed were 5 military blast related HO patients, 5 control cadaveric samples (age and sex matched). Samples were imaged using SEM, BSE and the I13 beam Synchrotron x-ray diffraction scanner using validated quantitative and qualitative techniques of measurement. Appearances seen in HO compared to normal bone were characterised by the presence of a hyper-vascular network and high lacunae (osteocyte) counts, two distinct zones of bone mineral density distribution, with a tendency for hypermineralisation with kurtosis of the grey scale plots (mineral content as a weight percentage of Ca2+ was calibrated to atomic weight of C, Al and HA). Direction of dependence and collagen orientation in HO suggest isotropic properties. This research demonstrates that HO is bone, however its characteristics suggest a high metabolic turnover and disorganised ultra-structure consistent with an inflammatory origin.
Previous reports of the prevalence of Heterotopic Ossification (HO) in limbs from UK blast-related amputees from Afghanistan, is demonstrated to be 57.1%. With the end of UK military operations in Afghanistan in 2014 the aim of this study is establish the rate of HO, assess causality demographics and ascertain risk factors for the formation of HO during the entire period of operations in Afghanistan. Military databases, case notes and radiographs were scrutinised to quantify and qualify the prevalence and risk factors for the formation of HO. 256 servicemen sustained 398 military trauma related amputations. The overall prevalence of HO was 65.9%. Significant (p<0.05) risks identified for the formation of HO included a blast mechanism of injury, a zone of injury the same as the subsequent amputation, and an increased number of debridements prior to closure. Positive correlation existed between the number of amputations and the presence and grade of HO (p=0.04). HO presents clinical problems to military blast injury patient populations. This study demonstrates that both a blast mechanism of injury and an increased injury load are key factors in the increased prevalence of HO seen in military trauma.
With an increasing ageing population and a rise in the number of primary hip arthroplasty, peri-prosthetic fracture (PPF) reconstructive surgery is becoming more commonplace. The Swedish National Hip Registry reported that, in 2002, 5.1% of primary total hip replacements required revision due to PPF. Laboratory studies have indicated that age, bone quality and BMI all contribute to an increased risk of PPF. Osteolysis and aseptic loosening contribute to the formation of loosening zones as described by Gruen, with subsequent increased risk of fracture. The aim of the study was to identify significant risk factors for PPF in patients who have undergone primary total hip replacement (THR). Logbooks of three Consultant hip surgeons were filtered for patients who had THR-PPF fixation subsequent to trauma. Risk factors evaluated included sex, age, bone density (Singhs index), loosening zones, Vancouver classification, prosthesis stem angle relative to the axis of the femur, and length of time from THR to fracture. A control group of uncomplicated primary THR patients was also scrutinised. Forty-six PPF were identified representing 2.59% of THR workload. The male: female ratios in both groups were not significantly different (1:1.27 and 1:1.14 respectively). Average age of PPF was 72.1, which was significantly older than the control group (54.7, p>0.05). The commonest type of PPF was Vancouver type B. Whilst stem position in the AP plane was similar in both groups, in lateral views the PPF stem angle demonstrated significant antero-grade leg position compared to the non-PPF group (p.0.05). The PPF group demonstrated a greater number of loosening zones in pre-fracture radiographs compared to the control group (2.59 and 1.39 respectively, p>0.05) Our workload from PPF reflects that seen in Europe. Age, stem position and the degree of stem loosening appear to contribute to the risk of a peri-prosthetic fracture.
