Volume 18 · Issue 04 · 2015

Explosive blast injury has become the most prevalent injury in recent military conflicts and terrorist attacks. The magnitude of this kind of polytrauma is complex due to the basic physics of blast and the surrounding environments. Therefore, development of stable, reproducible and controllable animal model using an ideal blast simulation device is the key of blast injury research. The present review addresses the modeling of blast injury and applications of shock tubes.

With the increasing incidence of blast injury, the research on its mechanisms and protective measures draws more and more attention. Blast injury has many characteristics different from general war injuries or trauma. For example, soldiers often have various degrees of visceral injury without significant surface damage, combined injuries and arterial air embolism. Researchers in China began to investigate blast injury later than the United States and Sweden, but the development is so fast that lots of achievements have been gained, including the development of biological shock tube, the mechanisms and characteristics of blast injury in various organs, as well as protective measures under special environments. This article reviews the past and current situation of blast injury research in China.

Blast injury has become the major life- and function-threatening injuries in recent warfares. There is increased research interest in the mental disorders caused by blast-induced traumatic brain injury (bTBI), which has been proved as one of the "signature wounds" in modern battlefield. We reviewed the recent progresses in bTBI-related researches and concluded that the new era of blast injury research has shifted from the traditional physical impairments to cognitive dysfunctional/mental disorders that are proved to be more related to the outcome of combat casualty care.

Objective: To investigate the effects of three different ways of chronic caffeine administration on blast-induced memory dysfunction and to explore the underlying mechanisms. Methods: Adult male C57BL/6 mice were used and randomly divided into five groups: control: without blast exposure, con-water: administrated with water continuously before and after blast-induced traumatic brain injury (bTBI), con-caffeine: administrated with caffeine continuously for 1 month before and after bTBI, pre-caffeine: chronically administrated with caffeine for 1 month before bTBI and withdrawal after bTBI, post-caffeine: chronically administrated with caffeine after bTBI. After being subjected to moderate intensity of blast injury, mice were recorded for learning and memory performance using Morris water maze (MWM) paradigms at 1, 4, and 8 weeks post-blast injury. Neurological deficit scoring, glutamate concentration, proinflammatory cytokines production, and neuropathological changes at 24 h, 1, 4, and 8 weeks post-bTBI were examined to evaluate the brain injury in early and prolonged stages. Adenosine A1 receptor expression was detected using qPCR. Results: All of the three ways of chronic caffeine exposure ameliorated blast-induced memory deficit, which is correlated with the neuroprotective effects against excitotoxicity, inflammation, astrogliosis and neuronal loss at different stages of injury. Continuous caffeine treatment played positive roles in both early and prolonged stages of bTBI; pre-bTBI and post-bTBI treatment of caffeine tended to exert neuroprotective effects at early and prolonged stages of bTBI respectively. Up-regulation of adenosine A1 receptor expression might contribute to the favorable effects of chronic caffeine consumption. Conclusion: Since caffeinated beverages are widely consumed in both civilian and military personnel and are convenient to get, the results may provide a promising prophylactic strategy for blast-induced neurotrauma and the consequent cognitive impairment.

Purpose: To study the effects of transplantation of characterized uncultured stromal vascular fraction (SVF) on sciatic nerve regeneration. Methods: A 10-mm sciatic nerve defect was bridged using a silicone conduit filled with SVF. In control group, silicone conduit was filled with phosphate-buffered saline alone. In sham-operated group, the sciatic nerve was only exposed and manipulated. The regenerated nerve fibers were studied 8 and 12 weeks after surgery. Results: Behavioral and functional studies confirmed faster recovery of regenerated axons in SVF transplanted animals than in control group (p < 0.05). Gastrocnemius muscle mass in SVF transplanted animal was found to be significantly more than that in control group. Morphometric indices of the regenerated fibers showed the number and diameter of the myelinated fibers to be significantly higher in SVF transplanted animals than in control group. In immunohistochemistry, the location of reactions to S-100 in SVF transplanted animals was clearly more positive than that in control group. Conclusion: SVF transplantation combined with silicone conduit could be considered as a readily accessible source of stromal cells that improves functional recovery of sciatic nerve. It may have clinical implications for the surgical management of acute diabetic patients after facial nerve transection.

Purpose: To compare the outcomes of closed reduction and expert tibial nailing (ETN) versus open reduction and plate and screw fixation in treating two segmental tibial fractures. Methods: This study included 53 cases of two segmental fractures of the tibial shaft. They were admitted to our department between March 2010 and June 2013 and treated respectively by closed reduction and ETN (ETN group, n = 31) or open reduction fixation with plate and screws (PS group, n = 22). The general data of two groups including gender, age, injury cause, fracture type, etc showed no significant difference (p > 0.05). To compare the therapeutic effects between two groups, the intraoperative condition, postoperative function and related complications were investigated. Results: All the patients were successfully followed up. The period was 19.2 months for ETN group and 20.5 months for PS group. All the fractures in ETN group had union without complications such as malunion, infection, or osteofascial compartment syndrome; whereas there were 3 cases of superficial infection cured by repeated dressing change and 2 cases of delayed union in PS group. The total incidence of complication in PS group was 22.7% (5/22), much higher than that in ETN group (p < 0.05). Moreover, ETN group showed a better result in terms of intraoperative blood loss, operation time, postoperative weight bearing time and fracture union time. In ETN group, at one-year follow-up, Johner-Wruhs' criteria was adopted to assess the postoperative function, which was reported as excellent in 18 cases, good in 10 cases and fair in 3 cases in ETN group (100% excellent-good rate). While in PS group, the result was excellent in 10 cases, good in 7 cases, fair in 3 cases and poor in 2 cases (77.3% excellent-good rate). The comparison was insignificant (p > 0.05). Conclusion: Compared with plate and screw fixation, ETN fixation has the advantages of fewer complications, shorter operation time, being less invasive, earlier postoperative rehabilitation and weight bearing, quicker fracture union and better functional recovery, thus being an effective way to treat two segmental tibial fractures.

Purpose: To evaluate the usefulness and information collecting ability of speckle tracking imaging techniques in the assessment of myocardial regional ventricular contractility in a rabbit model with blunt cardiac injury. Methods: Fifteen healthy New Zealand rabbits weighing (2.70 ± 0.28) kg were anesthetized (3% pentobarbital sodium/i.v) and impacted using the BIM-II biological impact machine to induce myocardial contusion (MC). Hemodynamic parameters, such as heart rate, systolic pressure, mean arterial pressure, diastolic pressure and central venous pressure, were determined before and after MC. Further, parameters reflecting left ventricular functions, such as left ventricular end systolic pressure, left ventricular end diastolic pressure, isovolumic pressure (IP) and the maximal increasing/decreasing rate of left intraventricular pressure (±dp/dtmax), were also determined before and after MC. Left ventricular functions were determined either by two dimensional transthoracic echocardiography or by speckle tracking imaging for segmental abnormal ventricular wall motions. Results: Heart rate, systolic pressure, diastolic pressure and mean arterial pressure decreased significantly but transiently, while central venous pressure markedly increased after MC. In contrast to significant changes in diastolic functions, there was no significant change in cardiac systolic functions after MC. The speckle tracking imaging demonstrated that strain values of different myocardial segment significantly decreased post impact, and that of the ventricular segment decreased from segment to segment. Conclusion: Speckle tracking imaging is useful and informative to assess myocardial regional dysfunctions post MC.

Purpose: Pelvic ring fractures constitute 3%-8% of all fractures of the skeletal system and are generally related with high energy trauma. Sexual dysfunction following pelvic fracture has a high incidence, and affects the male patients both physically and psychologically. In this study, we aimed to investigate the impact and frequencies of comorbidities such as erectile dysfunction (ED) with adverse sociocultural and psychological consequences for the patient who had a pelvic ring fracture. Methods: This study included 26 men who corresponded to the inclusion criteria and agreed to participate our study. Results: According to fracture types, most of our cases were Tile type A1 and type A2. Severe and moderate ED were detected in 46.1% (12/26) of these patients via the International Index of Erectile Function-5 questionnaire. Conclusion: ED develops following pelvic fractures, especially in Tile type B and C pelvic fractures.

Double fracture-dislocations of the thumb are rare. Only a single case report of a simultaneous extraarticular fracture of the base of the first metacarpal and dislocation of the metacarpophalangeal joint has been previously reported. We report the second case report of this injury in a 20-year-old man. The patient had an excellent outcome after treatment.

Intrauterine contraceptive device (IUCD) is relatively safe but still with some serious risks. Uterus perforation is rare and would be fatal. A case of Cu-7 IUCD invading into the sigmoid colon through uterine perforation caused by a pelvic blunt trauma was presented. Our case showed that uterus perforation by an IUCD could induce utero-sigmoid fistula which is likely to be missed. Imaging is required when the patients with IUCD present abdominal pain, particularly with a history of trauma.

Either proximal tibial or tibial physeal injuries are rare. The combination of both is even rarer, let alone causes a vascular injury. Early intervention is the key for management. We hereby present an interesting case of simultaneous proximal tibiofibular physeal injury with popliteal arterial occlusion and common peroneal nerve injury. The present case is important in two aspects: firstly it reports a very rare occurrence of simultaneous proximal tibiofibular physeal injury associated with vascular insult and common peroneal nerve injury; secondly it highlights that with timely intervention excellent results can be achieved in paediatric patients.

Constrained total knee prostheses are used in knees with severe deformities and insufficiency of collaterals to provide stable and mobile knees. Dislocation after constrained knee prosthesis is an extremely rare and dreaded complication. When dislocation is associated with patellar tendon rupture, the management includes restoration of the extensor apparatus along with a stable knee. Repair of the patellar tendon is challenging due to poor soft tissue coverage in the area and a bulky repair can put tension on the wound closure. Ideal method of restoration of the extensor apparatus is a matter of debate. There are various modalities used ranging from primary end-to-end repair, augmentation by medial gastrocnemius flap, semitendinosus and synthetic implants and allograft tendoachilles. We report a rare case of a posterior dislocation of a constrained total knee arthroplasty in association with patellar tendon rupture due to a minor fall after a few weeks of surgery. The first episode was managed by reposition of the dislocation and V-Y plasty of the quadriceps and primary repair. The second episode of dislocation with re-rupture needed augmentation by semitendinosus along with the insertion of the thicker insert. The management of this complex problem along with the review of literature is discussed in this case report.

Type 2 manubriosternal dislocations with concomitant spinal fracture are rare and may be associated with thoracic visceral injuries. The complication of delayed haemothorax has not been reported yet. We report a case of a young male who suffered manubriosternal dislocation with chance type thoracic spine fracture due to fall of a tree branch over his back. The haemothorax presented late on day three. The possible injury mechanism is discussed along with review of literature. We conclude that a lateral chest radiograph is indicated in spinal fracture patients complaining of midsternal pain. Computerized axial tomography scan of chest with contrast is indicated to rule out visceral injuries and a chest radiograph should be repeated before the patient is discharged to look for delayed haemothorax.