Definition of occult hypoperfusion in trauma: A systematic literature review

INTRODUCTION

Occult hypoperfusion (OH) entails inadequate tissue oxygenation in the presence of normal vital signs. Numerous studies have demonstrated that this phenomenon is associated with impaired outcome and increased mortality, however definitions of OH differ between studies. The aim of the current study was to identify and evaluate the published definitions of the term `occult hypoperfusion` in trauma (tOH).

MATERIAL & METHODS

A review of literature was performed using the Medline database. The following MeSH terms have been used: occult hypoperfusion, severe trauma, polytrauma, resuscitation. Clinical studies on OH were included and utilized definitions have been compared. A predefined data-interpretation process was applied to create an integrative definition for tOH.

RESULTS

A total of 43 publications used the term OH. A definition of OH was provided in 16 manuscripts. A pooled mean number of participants of 729 (SD: 1158) was found per study. The majority of manuscripts combine multiple parameters for inadequate tissue oxygenation and normal vital signs to define OH in trauma. In 12 manuscripts, specific cut-off values for hemodynamic parameters (SBP/PR/UP) and in 11/16 papers exact metabolic thresholds (lactate/B.E) were defined. The following definition best integrates definitions in current literature: Lactate > 2 mmol/l or BE <-3 mmol/l (to define inadequate oxygenation) plus SBP > 90 mmHg and PR < 120 bpm (to define normal macroperfusion).

CONCLUSIONS

The current systematic review demonstrates that definitions of occult hypoperfusion in trauma differ in the literature. The following comprehensive definition for (tOH) is proposed: Lactate > 2 mmol/l or BE <-3 mmol/l plus SBP > 90 mmHg and PR < 120 bpm. This recommendation appears to represent current literature on tOH and may improve the identification of trauma patients at risk for OH and related complicated courses. Further validation studies are required to demonstrate the clinical role of tOH and the proposed definition.

Stress-induced impairment of fear extinction recall is associated with changes in neuronal activity patterns in PVT

Treatment resistance of anxiety-related disorders often arises from an inappropriate fear expression, impairment in fear extinction, and spontaneous return of fear. Stress exposure is considered a high risk factor for neuropsychiatric disorders, but understanding of the long-term consequences of stress is limited, particularly when it comes to treatment outcome. Therefore, studying the consequences of acute stress would provide critical information on the role of stress in psychopathology. In the present study, we investigated the effect of acute immobilization stress on anxiety-like behavior and on conditioned fear memory. Our results demonstrate that prior stress exposure had no effect on anxiety-related behavior, fear acquisition, as well as fear extinction compared to non-stressed controls, but resulted in significantly higher rates of freezing during recall of extinction, indicating a consolidation failure. Further, immunohistochemical analysis of the expression of the immediate early gene c-Fos after recall of extinction revealed increased neuronal activity in the posterior paraventricular nucleus of the thalamus (PVT) in previously stressed animals compared to non-stressed controls. These results indicate, firstly, that acute stress affects long-term fear memory even after successful extinction training, and secondly, a strong involvement of the PVT in maladaptive fear responses induced by prior stress. Thus, stress-induced changes in PVT neuronal activity might be of importance for the pathophysiology of stress-sensitive anxiety-related psychiatric disorders, since exposure to an earlier acute stressor could counteract the success of therapy.

A retrospective cohort study of 27,049 polytraumatized patients age 60 and above: identifying changes over 16 years

Aim

In this study, we establish an overview of changes we observed in demographics of older severe trauma patients from 2002 to 2017.

Findings

Trauma mechanism, as well as injury pattern, changed over time. We found length of stay and mortality decreased despite an increase in patient age.

Message

We ascribe this observation mainly to increased use of diagnostic tools and improved treatment algorithms and underline the importance of the implementation of specialized geriatric trauma centers allowing interdisciplinary care.

Purpose

The number of severely injured patients exceeding the age of 60 has shown a steep increase within the last decades. These patients present with numerous co-morbidities, polypharmacy, and increased frailty requiring an adjusted treatment approach. In this study, we establish an overview of changes we observed in demographics of older severe trauma patients from 2002 to 2017.

Methods

A descriptive analysis of the data from the TraumaRegister DGU^® (TR-DGU) was performed. Patients admitted to a level one trauma center in Germany, Austria and Switzerland between 2002 and 2017, aged 60 years or older and with an injury severity score (ISS) over 15 were included. Patients were stratified into subgroups based on the admission: 2002–2005 (1), 2006–2009 (2), 2010–2013 (3) and 2014–2017 (4). Trauma and patient characteristics, diagnostics, treatment and outcome were compared.

Results

In total 27,049 patients with an average age of 73.9 years met the inclusion criteria. The majority were males (64%), and the mean ISS was 27.4. The proportion of patients 60 years or older [(23% (1) to 40% (4)] rose considerably over time. Trauma mechanisms changed over time and more specifically low falls (< 3 m) rose from 17.6% (1) to 40.1% (4). Altered injury patterns were also identified. Length-of-stay decreased from 28.9 (1) to 19.5 days (4) and the length-of-stay on ICU decreased from 17.1 (1) to 12.7 days (4). Mortality decreased from 40.5% (1) to 31.8% (4).

Conclusion

Length of stay and mortality decreased despite an increase in patient age. We ascribe this observation mainly to increased use of diagnostic tools, improved treatment algorithms, and the implementation of specialized trauma centers for older patients allowing interdisciplinary care.

Different treatment strategies for acromioclavicular dislocation injuries: a nationwide survey on open/minimally invasive and arthroscopic concepts

Background

Injuries to the acromioclavicular (AC) joint are one of the most common among sporting injuries of the upper extremity. Several studies investigated different treatment options comparing surgical and non-surgical treatment, and type of operative interventions. This study aims to evaluate treatment decisions regarding injuries of the AC joint and to compare different treatment strategies depending on the specific training of the treating physician.

Methods

We performed a nationwide survey by contacting different experienced physicians and sending them questionnaires. The questionnaire included 37 questions that assessed preferred treatment strategies in AC joint injuries. We addressed different surgical and nonsurgical options as well as level of experience and factors that might influence the decision on treatment strategy. The physicians were stratified according to their training into general surgeons (group trauma associated) and orthopedic surgeons (orthopedic associated). The AC joint lesions were categorized according to the widely used Rockwood classification.

Results

This study analyses 96 questionnaires. We included 46 (47.9%) colleagues in group trauma and 50 (52.1%) in group orthopedics. Most of the colleagues (98.9%) prefer non-operative treatment of type I and type II AC lesions. Similarly, 96.8% agree on surgical treatment of types IV, V, and VI lesions. The treatment of type III lesions is performed in 41.6% of cases non-operatively and in 58.4% of cases surgically. Trauma-associated colleagues are 3.4 times more likely to treat AC lesions with a hook plate compared to orthopedic-associated colleagues (p = 0.05). In decreasing order, the most commonly used non-surgical technique is sling immobilization (63.7%), and the most commonly performed surgical treatment is the hook plate (41.1%) in treating type III injuries.

Conclusion

This study shows a distinct difference in treatment of AC joint injuries depending on the training of the physician. Further, the need for high-quality studies arises to define the optimal treatment of type III lesions.

[Abdominal injuries in polytraumatized adults : Systematic review]

Abdominal injuries are potentially life-threatening and occur in 20-25% of all polytraumatized patients. Blunt trauma is the main mechanism. The liver and spleen are most commonly injured and much less often the intestines. The clinical evaluation proves equivocal in many cases; therefore, the gold standard is computed tomography (CT), which has been increasingly used even in hemodynamically weakly stable or sometimes even unstable patients because it promptly provides precise diagnostic findings, which present the basis for successful therapy. Hemodynamically unstable patients always need an exploratory laparotomy (EL). An EL should also be carried out with a positive focused assessment with sonography for trauma (FAST) or CT for severe parenchymal lesions, hollow organ lesions, intraperitoneal bladder lesions, peritonitis and organ evisceration, impalement injuries and lesions of the abdominal fascia. Hemodynamically stable patients without signs of peritonitis and a lack of such findings can often be treated conservatively irrespective of the extent of an injury. Angiography (and if needed embolization) can additionally be diagnostically and therapeutically utilized.

Cardiac Depression in Pigs after Multiple Trauma - Characterization of Posttraumatic Structural and Functional Alterations

The purpose of this study was to define the relationship between cardiac depression and morphological and immunological alterations in cardiac tissue after multiple trauma. However, the mechanistic basis of depressed cardiac function after trauma is still elusive. In a porcine polytrauma model including blunt chest trauma, liver laceration, femur fracture and haemorrhage serial trans-thoracic echocardiography was performed and correlated with cellular cardiac injury as well as with the occurrence of extracellular histones in serum. Postmortem analysis of heart tissue was performed 72 h after trauma. Ejection fraction and shortening fraction of the left ventricle were significantly impaired between 4 and 27 h after trauma. H-FABP, troponin I and extracellular histones were elevated early after trauma and returned to baseline after 24 and 48 h, respectively. Furthermore, increased nitrotyrosine and Il-1β generation and apoptosis were identified in cardiac tissue after trauma. Main structural findings revealed alteration of connexin 43 (Cx43) and co-translocation of Cx43 and zonula occludens 1 to the cytosol, reduction of α-actinin and increase of desmin in cardiomyocytes after trauma. The cellular and subcellular events demonstrated in this report may for the first time explain molecular mechanisms associated with cardiac dysfunction after multiple trauma.

Update on the role of endothelial cells in trauma

PURPOSE

This review gives an overview of physiological processes, mainly regarding vascular endothelial cells and their important role in hemostasis, information processing, and communication during trauma. An insight is given into molecules and cells involved in the first innate immune response through to the behavior of endothelial cells in developing trauma. The goal of this review is to show the overlap of crucial factors related to the endothelium and the development of trauma.

METHODS

A systemic literature search was performed using Google scholar and PubMed.

RESULTS

The results of the literature search showed that the endothelium, especially the vascular endothelium, is involved in various cellular and subcellular pathways of activation, suppression, and transfer of information. A variety of molecules and cells are orchestrated, subsequently the endothelium gets in contact with a traumatizing event.

CONCLUSION

The endothelium is one of the first barriers that comes into contact with exo- and endogenous trauma-related signals and is a pivotal point in activating subsequent pathways and cascades by transfer of information.

Characterization of blunt chest trauma in a long-term porcine model of severe multiple trauma

Chest trauma has a significant relevance on outcome after severe trauma. Clinically, impaired lung function typically occurs within 72 hours after trauma. However, the underlying pathophysiological mechanisms are still not fully elucidated. Therefore, we aimed to establish an experimental long-term model to investigate physiological, morphologic and inflammatory changes, after severe trauma. Male pigs (sus scrofa) sustained severe trauma (including unilateral chest trauma, femur fracture, liver laceration and hemorrhagic shock). Additionally, non-injured animals served as sham controls. Chest trauma resulted in severe lung damage on both CT and histological analyses. Furthermore, severe inflammation with a systemic increase of IL-6 (p = 0.0305) and a local increase of IL-8 in BAL (p = 0.0009) was observed. The pO₂/FiO₂ ratio in trauma animals decreased over the observation period (p < 0.0001) but not in the sham group (p = 0.2967). Electrical Impedance Tomography (EIT) revealed differences between the traumatized and healthy lung (p < 0.0001). In conclusion, a clinically relevant, long-term model of blunt chest trauma with concomitant injuries has been developed. This reproducible model allows to examine local and systemic consequences of trauma and is valid for investigation of potential diagnostic or therapeutic options. In this context, EIT might represent a radiation-free method for bedside diagnostics.

[Chronic instability of the pubic symphysis : Etiology, diagnostics and treatment management]

The most frequent causes of chronic instability of the pubic symphysis are sports-related continual overload and traumatic symphyseal injuries. Acute injury of the pubic symphysis may be the result of external forces acting on the anterior pelvic ring or the result of internal forces, such as those arising during parturition. The postpartum form of instability following a complication-free birth is reversible and usually returns to normal within a few months through strengthening of the pelvic floor muscles. Residual instability of the pubis symphysis is on the whole a rare complication. Although established therapy options for acute symphyseal separation can be found in the literature, there are only a few case reports on chronic symphyseal instability. There are no guidelines on standardized therapy options. This review article examines the etiology, clinical findings, diagnostic techniques and management options for patients suffering from chronic symphyseal instability.

Reconstruction of a quadriceps tendon tear using Polyvinylidene fluoride sutures and patellar screw fixation: A biomechanical study

BACKGROUND

Acute quadriceps tendon tears are infrequent injuries requiring surgical treatment. Improved stability after surgical repair may allow for earlier weight-bearing and range of motion. Therefore, a new implant was tested and compared with the "gold standard", using transosseous sutures.

METHODS

Quadriceps tendon tears were constructed using a cadaveric model of 12 fresh matched-pair specimens (aged 61-97; mean age: 82 years). The biomechanical testing compared non-absorbable suture anchors (Polyvinylidene fluoride) versus transosseous absorbable sutures (Polydioxanon). Following anatomic reconstruction, the repaired specimens were loaded until they failed (testing machine: Hounsfield H10KM, Redhill, United Kingdom; maximum force: 1000 N; load speed: 25 mm/min; maximum test length: 150 mm; pre-load: 5 N). Values for load until tear displacement, maximum load until complete failure of the construct (pullout or breakage of the sutures or anchors) and stiffness of the reconstruction were recorded.

RESULTS

The stiffness found in the Polyvinylidene fluoride reconstruction (mean 9.83 N/mm) (standard deviation (SD) 7.75) showed a significant increase compared to the Polydioxanon reconstruction (mean 6.66 N/mm (SD 3.32); P=0.045). Transosseous fixation showed comparable results to the suture anchor system. There was no significant difference found in the maximum load to tear displacement (PVDF: 290.88 N (SD 106.01) vs. PDS: 266.75 N (SD 82.61); P=0.358).

CONCLUSIONS

Using the Polyvinylidene fluoride thread showed comparable results to the established method in reconstruction of ruptured quadriceps tendon. Stiffness of the Polyvinylidene fluoride thread reconstruction was even greater than Polydioxanon thread.

CLINICAL RELEVANCE

Improved stiffness may facilitate healing and is suggested as clinical relevance in reconstruction.

A porcine polytrauma model with two different degrees of hemorrhagic shock: outcome related to trauma within the first 48 h

BACKGROUND

An animal polytrauma model was developed, including trunk and extremity injuries combined with hemorrhagic shock and a prolonged post-traumatic phase. This could be useful for the assessment of different therapeutic approaches during intensive care therapy.

METHODS

A standardized polytrauma including lung contusion, liver laceration and lower leg fracture was applied in 25 pigs. They underwent controlled haemorrhage either with a blood volume loss of 45 % and a median arterial pressure (MAP) <30 mmHg/90 min (group L, n = 15) or a 50 % blood loss of and an MAP <25 mmHg/120 min (group H, n = 10). Five non-traumatized pigs served as a control (group C). Subsequently, intensive care treatment was given for an observational period of 48 h.

RESULTS

Both trauma groups showed signs of shock and organ injury (heart rate, MAP and lactate). The frequency of cardiopulmonary resuscitation (CPR) and lung injury was directly related to the severity of the haemorrhagic shock (CPR-group L: 4 of 15 pigs, group H: 4 of 10 pigs; Respiratory failure-group L: 3 of 13, group H: 3 of 9. There was no difference in mortality between trauma groups.

CONCLUSION

The present data suggest that our model reflects the mortality and organ failure of polytrauma in humans during shock and the intensive care period. This suggests that the experimental protocol could be useful for the assessment of therapeutic approaches during the post-traumatic period.

Impact of haemorrhagic shock intensity on the dynamic of alarmins release in porcine poly-trauma animal model

PURPOSE

Traumatic insults result in an altered inflammatory response, in which alarmins release has a central role. The impact of haemorrhagic shock intensity on the long-term kinetics of alarmins is not yet fully elucidated. We investigated these aspects in a combined trauma (chest, abdominal, and extremities injury) porcine model with different severities and durations of haemorrhagic shock.

METHODS

After induction of combined trauma (tibia fracture, lung contusion, and liver laceration), haemorrhagic shock was induced at different intensities: moderate haemorrhage (MH; n = 15): mean arterial pressure (MAP) <30 ± 5 mmHg [maximum loss of total blood volume (TBVmax): 45 %] for 90 min, and severe haemorrhage (SH; n = 10): MAP <25 ± 5 mmHg (TBVmax 50 %) for 120 min. Resuscitation was performed using a standardized crystalloid infusion protocol. Animals were mechanically ventilated and underwent ICU-monitoring for 48 h (MH) and 48.5 h (SH). Blood samples were collected over the clinical time course, and systemic levels of serum alarmins [High-Mobility Group Protein B-1 (HMGB-1) and Heat Shock Protein 70 (HSP70)] were measured using an ELISA kit.

RESULTS

Heart rate, systemic blood pressure, lactate, and base excess were significantly altered as a function of haemorrhagic shock in both trauma groups (MH and SH). Systemic HMGB-1 levels were significantly elevated in both trauma groups when compared to the sham group. Haemorrhagic shock severity and duration were positively correlated with HMGB-1 levels and compared to baseline values, concentrations remained significantly increased in SH when compared to MH. On the other hand, we observed a significant decrease in the systemic HSP70 levels of trauma groups (MH, and SH) when compared to the sham group, which was significantly decreased compared to baseline values in SH over the entire time course.

CONCLUSION

Our data show that haemorrhagic shock duration and severity affect the systemic levels of HMGB-1 and HSP70. This early alarmins release after trauma can be used to guide the treatment strategies (e.g. surgical procedures) of polytrauma patients.

Chronic diaphyseal osteomyelitis of long bones refractory to conventional therapy - Benefits and risks of reaming of the femoral medullary cavity

Osteomyelitis of long bones represents a severe complication during fracture healing. If ongoing infection occurs despite reoperation and if antibiotic treatment is of no benefit, reaming of the medullary canal may be beneficial. We investigated the long term follow up (minimum 2 years) of patients submitted to reaming of the medullary canal to evaluate the efficacy of this method. Criteria for successful procedure: no further operative procedure/ antibiotic treatment. 32 patients out of 37 were followed over a 9 year period. Mean incidence of surgical treatment for osteomyelitis prior to reaming: 3.2 operations. Mean duration until reexamination after reaming: 3.7 years. 89% of patients had a full range of motion upon reexamination, in the others further articular injuries were present. 84.3% of patients were working in the same profession as prior to the fracture, 72% were active in sports again, 97% of patients were pain free. One otherwise healthy patient suffering from sclerosing osteitis (Garré) died during reaming of the femur due to bone marrow embolism to the lung. Reaming of the medullary canal has a high rate of curing osteomyelitis even after several previous attempts of surgical revisions and/or antibiotic treatment. The most likely mechanism is based on improvement of local perfusion. During surgery care must be taken not to provoke pulmonary embolization. Intraoperative monitoring by pulmonary artery catheter should performed; reaming should be immediately discontinued, if a rise in pulmonary artery pressure occurs.

Measurement of compartment elasticity using pressure related ultrasound: a method to identify patients with potential compartment syndrome

PURPOSE OF THE STUDY Decision-making in treatment of an acute compartment syndrome is based on clinical assessment, supported by invasive monitoring. Thus, evolving compartment syndrome may require repeated pressure measurements. In suspected cases of potential compartment syndromes clinical assessment alone seems to be unreliable. The objective of this study was to investigate the feasibility of a non-invasive application estimating whole compartmental elasticity by ultrasound, which may improve accuracy of diagnostics. MATERIAL AND METHODS In an in-vitro model, using an artificial container simulating dimensions of the human anterior tibial compartment, intracompartmental pressures (p) were raised subsequently up to 80 mm Hg by infusion of saline solution. The compartmental depth (mm) in the cross-section view was measured before and after manual probe compression (100 mm Hg) upon the surface resulting in a linear compartmental displacement (Δd). This was repeated at rising compartmental pressures. The resulting displacements were related to the corresponding intra-compartmental pressures simulated in our model. A hypothesized relationship between pressures related compartmental displacement and the elasticity at elevated compartment pressures was investigated. RESULTS With rising compartmental pressures, a non-linear, reciprocal proportional relation between the displacement (mm) and the intra-compartmental pressure (mm Hg) occurred. The Pearson's coefficient showed a high correlation (r2 = -0.960). The intraobserver reliability value kappa resulted in a statistically high reliability (κ = 0.840). The inter-observer value indicated a fair reliability (κ = 0.640). CONCLUSIONS Our model reveals that a strong correlation between compartmental strain displacements assessed by ultrasound and the intra-compartmental pressure changes occurs. Further studies are required to prove whether this assessment is transferable to human muscle tissue. Determining the complete compartmental elasticity by ultrasound enhancement, this application may improve detection of early signs of potential compartment syndrome. Key words: compartment syndrome, intra-compartmental pressure, non-invasive diagnostic, elasticity measurement, elastography.

[Cost-benefit analysis of cranial computed tomography in mild traumatic brain injury--appropriate depiction within the G-DRG system?]

BACKGROUND

The treatment of patients with mild head injury is related to a continuous lack of finances. The current investigation summarises radiological costs of patients from a level I trauma centre and discusses the indication for CT scanning within the G-DRG system.

MATERIAL AND METHODS

The study includes all patients who underwent a CCT scan in 2011. Diagnosis, length of stay and cost data were recorded for every patient. Finally, frequent diagnosis groups were summarised to clusters (Basis-DRG/MDC 21A).

RESULTS

A total of 380 patients was treated. Within the largest group (G-DRG B80Z) the costs for a CCT already took up one quarter of the total proceedings. In combination with the high cost for monitoring patients with mild head injuries this causes an ongoing lack of finances.

CONCLUSION

In spite of the often necessary CCT investigation in mild head injuries, the earnings do not cover the costs of the patients. To improve the situation clear guidelines for CCT scanning should be provided and the reimbursement in particular in the diagnosis group of the G-DRG B80Z has to be improved.

Assessment of coincidence and defect sizes in Bankart and Hill-Sachs lesions after anterior shoulder dislocation: a radiological study

OBJECTIVE

Bankart and Hill-Sachs lesions are often associated with anterior shoulder dislocation. The MRI technique is sensitive in diagnosing both injuries. The aim of this study was to investigate Bankart and Hill-Sachs lesions with MRI to determine the correlation in occurrence and defect sizes of these lesions.

METHODS

Between 2006 and 2013, 446 patients were diagnosed with an anterior shoulder dislocation and 105 of these patients were eligible for inclusion in the study. All patients were examined using MRI. Bankart lesions were classified as cartilaginous or bony lesions. Hill-Sachs lesions were graded I-III using a modified Calandra classification.

RESULTS

The co-occurrence of injuries was high [odds ratio (OR) = 11.47; 95% confidence interval (CI) = 3.60-36.52; p < 0.001]. Patients older than 29 years more often presented with a bilateral injury (OR = 16.29; 95% CI = 2.71-97.73; p = 0.002). A correlation between a Bankart lesion and the grade of a Hill-Sachs lesion was found (ρ = 0.34; 95% CI = 0.16-0.49; p < 0.001). Bankart lesions co-occurred more often with large Hill-Sachs lesions (O  = 1.24; 95% CI = 1.02-1.52; p = 0.033).

CONCLUSION

If either lesion is diagnosed, the patient is 11 times more likely to have suffered the associated injury. The size of a Hill-Sachs lesion determines the co-occurrence of cartilaginous or bony Bankart lesions. Age plays a role in determining the type of Bankart lesion as well as the co-occurrence of Bankart and Hill-Sachs lesions.

ADVANCES IN KNOWLEDGE

This study is the first to demonstrate the use of high-quality MRI in a reasonably large sample of patients, a positive correlation of Bankart and Hill-Sachs lesions in anterior shoulder dislocations and an association between the defect sizes.

Femoral shaft fractures in adults: treatment options and controversies

Antegrade reamed femoral nailing via the piriformis entry point is the technique of choice in treating femoral shaft fractures, with retrograde nailing as an alternative. The supine position is favored to reduce complications, especially rotational malalignment. With navigation and robotic assistance fracture reduction can be supported and the rate of rotational, axis and length malalignement can potentially further reduced. Careful reaming is the procedure of choice to optimize bony healing and reduce systemic and local complications. In multiply injured patients reamed nailing can be safely integrated in the DCO- or ETC-concept and can be performed in the majority of patients, even when additional severe chest and head injuries are present. Initial resuscitation should focus on general stabilization before definitive femur fixation. Plate osteosynthesis of the femur can be an option in selected patients.

Partial rupture of the hamstring muscle complex: a literature review on treatment options

Injuries of the hamstring muscle complex (HMC) often affect athletes participating in specific sporting activities. Mild injuries that constitute a mere strain of the muscle can be managed symptomatically, while severe injuries often require surgical intervention to precipitate a return to function. Neglected injuries usually result in a long-term functional impairment. Therefore, surgical reconstruction of the HMC is advised for both partial and complete lesions. Without acute repair, a chronic lesion referred to as hamstring syndrome can result due to dysfunction of the HMC. Surgical intervention is usually recommended. A case of a chronic severe partial injury to the HMC managed conservatively in a 49-year old female is presented to illustrate the level of function that can be achieved after non-operative management. The clinical and radiological findings are presented 18 months post-injury along with a review of the current literature. There are no previous reports in the literature describing this scenario. This case indicates the need for re-evaluation in treatment options in partial hamstring muscle ruptures. A surgical treatment of partial rupture should be considered more often as an adequate treatment option and cofactors that influence the prognosis must be revealed. The indication of surgical intervention should be re-evaluated within the first months in case of conservative treatment.

Heterosynaptic long-term potentiation at interneuron-principal neuron synapses in the amygdala requires nitric oxide signalling

Long-lasting changes of synaptic efficacy are thought to be a prerequisite for memory formation and maintenance. In the basolateral complex of the amygdala (BLA), one of the main regions for fear and extinction learning of the brain, various forms of long-term potentiation (LTP) have been described for excitatory glutamatergic synapses. In contrast, little is known about the mechanisms of LTP at inhibitory GABAergic synapses. Here we provide evidence that (1) LTP at inhibitory GABAergic synapses (LTP(i)) between inhibitory interneurons and principal neurons (PNs) can be induced by theta-burst stimulation (TBS), (2) this LTP(i) is prevented by AMPA- or NMDA-receptor antagonists, and (3) this LTP(i) is abolished by the NO synthase (NOS) inhibitor L-NAME or the NO scavenger PTIO, and thus is critically dependent on nitric oxide (NO) signalling. These findings are corroborated by immunocytochemical stainings for neuronal (n) NOS, which revealed the existence of nNOS-positive neurons and fibres in the BLA. We conclude that LTP of GABAergic synaptic transmission to PNs is induced by activation of AMPA and NMDA receptors at glutamatergic synapses and subsequent retrograde NO signalling to enhance GABAergic transmission. This form of LTP at GABAergic synapses comprises a novel form of heterosynaptic plasticity within the BLA, apt to shape conditioned fear responses.

[Long-term results after polytrauma]

Rehabilitation treatment, which is necessary in the majority of polytrauma patients, is long-lasting and even after several years the final result is frequently not reached yet. Our study is the first in which a population of 510 patients were followed up for 10 years and more and in which many clinical and social parameters were determined. Our study showed that even after a period of 10 years and more the quality of life in several patients is still obviously impaired, according to the parametes "financial losses", "decreased net income", "loss of social services", "credit loan" and "loss of friends". In our study, differences according to financial and professional perspectives between injuries of the lower and upper extremities or combination injuries of the extremities were statistically significant. For the everyday clinic it is important to reintegrate children and young patients into a strong social network because there is a higher percentage of young patients who are socially impaired, even many years after trauma. Adult patients should get strong support to return to their original profession and financial status.

Bone graft substitutes for articular support and metaphyseal comminution: what are the options?

Subchondral and metaphyseal bone defects pose a great challenge for the Orthopaedic surgeon not only because the support for the articular surface has been lost but also because the mechanism for the nourishment of articular cartilage through the subchondral plate is distorted. A number of options are available to the surgeons, none of them perfect. Autografting has an appreciable high rate of harvest site morbidity, allograft is associated with infection transmission and host immunologic response. These realities have stimulated interest in supplying bone replacement materials (demineralised bone matrix, synthetic bone substitutes, bone morphogenic proteins). This paper presents the indications and applications of bone substitutes for metaphyseal defects and subchondral support in orthopaedic trauma.

Second hit phenomenon: existing evidence of clinical implications

The last two decades extensive research evidence has been accumulated regarding the pathophysiology of trauma and the sequelae of interventions that follow. Aim of this analysis has been to collect and categorise the existing data on the so-called "second hit" phenomenon that includes the biochemical and physiologic alterations occurring in patients having surgery after major trauma. Articles were extracted from the PubMed database and the retrieved reports were included in the study only if pre-specified eligibility criteria were fulfilled. Moreover, a constructed questionnaire was utilised for quality assessment of the outcomes. Twenty-six articles were eligible for the final analysis, referring to a total of 8262 patients that underwent surgery after major trauma. Sixteen retrospective clinical studies including 7322 patients and 10 prospective ones, including 940 patients were evaluated. Several variables able to reproduce a post-operative second hit were identified; mostly related to pulmonary dysfunction, coagulopathy, fat or pulmonary embolism, and the inflammatory immune system. Indicative conclusions were extracted, as well as the need for further prospective randomised trials. Suggestions on the content and the rationale of future studies are provided.

Scaffolds for bone healing: concepts, materials and evidence

Critical sized bone defects have to be filled with material to allow bone healing. The golden standard for this treatment is autogenous bone grafting. Because of donor size morbidity, equivalent synthetic bone scaffolds should be developed. Different materials, especially ceramics and polymers are in the focus of research. Calcium phosphate ceramics show similar properties to bone and are degradable. Different modifications can improve the bioactive features. This article gives an overview about the current materials and their evidence of clinical use.

Histopathological features of the brain, liver, kidney and spleen following an innovative polytrauma model of the mouse

OBJECT

Among the various introduced experimental traumatic brain injury models, there is a clear paucity of proper experimental polytrauma models. To overcome this experimental gap we introduced such a polytrauma model in the mouse including traumatic brain injury. Here, we report on the histopathological features of the brain, lung, kidney, spleen and liver.

MATERIALS AND METHODS

20 male C57BL mice with a mean weight of 23 g were anesthetized with ketamine and xylazine. The anaesthetized animals were subjected to a controlled cortical impact (CCI) over the left parieto-temporal cortex using rounded-tip impounder for application of a standardized brain injury. Following fracture of the right femur using a guillotine, a volume-controlled hemorrhagic shock was induced. The control groups included animals with CCI only (n=20) and animals with femur fracture plus hemorrhagic shock without CCI (n=20). Subjects were sacrified at 96 h following trauma. Brain, lung, kidney, spleen and liver of the animals underwent histopathological examinations.

RESULTS

The mortality rate at 96 h was 25% in the polytrauma group versus 10% in the control groups. Within the histopathological investigations, polytraumatized animals differ from those with a single trauma (traumatic brain injury or femur fracture with hemorrhagic shock) with various severity.

CONCLUSION

The findings of this study show that such a polytrauma model can be standardized resulting in a reproducible damage. This model fulfills the requirements of a standardized animal model. It allows adequate analogies and inferences to the clinical situation of a polytrauma in humans.

[Tissue engineering of bone tissue. Principles and clinical applications]

Complex fractures are still a major clinical challenge. The treatment options of large bony defects either with autografts or allografts are limited in terms of material availability and tissue in-growth. Tissue engineering might offer a solution to this problem. In an interdisciplinary approach artificial bony tissue can be generated which mimics normal bone in terms of function and morphology. So far tissue engineering of bone is mainly confined to laboratory investigations whereas clinical applications are still in the beginning. This manuscript presents the most important scaffolds as well as growth factors and cell systems. Furthermore, it focuses on clinical studies for the treatment of large bony defects using tissue engineered cell-matrix constructs.

Severe and multiple trauma in older patients; incidence and mortality

OBJECTIVE

To examine the differences between severely injured older patients (aged over 65 years) compared with similarly injured younger adults in terms of incidence, inpatient mortality and factors predicting outcome.

METHODS

Data prospectively entered into the Trauma Audit and Research Network (TARN) database from our level I trauma unit over a 5-year period were retrospectively examined, with 3172 patients included in the final analysis.

RESULTS

Older patients accounted for 13.8% of those with severe injuries (Injury Severity Score 16 or more) and almost 2% of our trauma admissions overall. High energy injuries were responsible for the majority of these injuries though relatively minor trauma became increasingly important in older patients. Mortality rates in the older patients were more than twice those seen in the adult population (19% in the under 40's to almost 50% in the over 75's). Age, Injury Severity Score and Glasgow Coma Score continued to be predictive of mortality in older patients but other factors relevant in younger adults were not.

CONCLUSIONS

Patients in the older group without physiological derangement on admission were still at a relatively high risk of inpatient mortality. This was in contrast to the younger patients, suggesting that it might be more difficult to predict which older patients might benefit from more aggressive monitoring or treatment. Despite increased mortality in older patients, significant survival rates were achieved even in the oldest. Active treatment should not be withdrawn on the basis of age alone.

[Voluminous bone graft harvesting of the femoral marrow cavity for autologous transplantation. An indication for the"Reamer-Irrigator-Aspirator-" (RIA-)technique]

Due to their excellent osteoinductive, osteogenetic, and osteoconductive properties, autologous bone grafts possess biomechanical advantages over synthetic bone substitutes. Furthermore, unlike cadaveric allografts and xenografts, they carry no risk of immunogenic response or transmission of infectious diseases. However, the limited availability of autologous bone grafts requires the use of the above-mentioned bone substitutes for management of large bone defects. The"Reamer-Irrigator-Aspirator-" (RIA-)technique may present an alternative method for harvesting a larger volume of autologous bone graft as compared with conventional harvesting procedures. We report on intramedullary reaming by the RIA technique to obtain autologous bone graft for a nonunion of the proximal femur. The contralateral femur was reamed and the bone graft was applied to the nonunion. The patient showed clinical and radiological healing of the nonunion without donor site complications.

Spreading Depression Enhances Human Neocortical Excitability in vitro

Cortical spreading depression (CSD) plays a role in migraine with aura. However, studies of the neuronal effects of CSD in human cortex are scarce. Therefore, in the present study, the effects of CSD on the field excitatory postsynaptic potentials (fEPSP) and the induction of long-term potentiation (LTP) were investigated in human neocortical slices obtained during epilepsy surgery. CSD significantly enhanced the amplitude of fEPSP following a transient suppressive period and increased the induction of LTP in the third layer of neocortical tissues. These results indicate that CSD facilitates synaptic excitability and efficacy in human neocortical tissues, which can be assumed to contribute to hyperexcitability of neocortical tissues in patients suffering from migraine.

Stimulation of the local femoral inflammatory response to fracture and intramedullary reaming

We have undertaken a prospective study in patients with a fracture of the femoral shaft requiring intramedullary nailing to test the hypothesis that the femoral canal could be a potential source of the second hit phenomenon. We determined the local femoral intramedullary and peripheral release of interleukin-6 (IL-6) after fracture and subsequent intramedullary reaming.

In all patients, the fracture caused a significant increase in the local femoral concentrations of IL-6 compared to a femoral control group. The concentration of IL-6 in the local femoral environment was significantly higher than in the patients own matched blood samples from their peripheral circulation. The magnitude of the local femoral release of IL-6 after femoral fracture was independent of the injury severity score and whether the fracture was closed or open.

In patients who underwent intramedullary reaming of the femoral canal a further significant local release of IL-6 was demonstrated, providing evidence that intramedullary reaming can cause a significant local inflammatory reaction.

The genetic predisposition to adverse outcome after trauma

Technological advances and shorter rescue times have allowed early and effective resuscitation after trauma and brought attention to the host response to injury. Trauma patients are at risk of progressive organ dysfunction from what appears to be an uncontrolled immune response. The availability of improved techniques of molecular diagnosis has allowed investigation of the role of genetic variations in the inflammatory response to post-traumatic complications and particularly to sepsis.

This review examines the current evidence for the genetic predisposition to adverse outcome after trauma. While there is evidence supporting the involvement of different polymorphic variants of genes in determining the post-traumatic course and the development of complications, larger-scale studies are needed to improve the understanding of how genetic variability influences the responses to post-traumatic complications and pharmacotherapy.

[Hannover-Polytrauma-Longterm-Study HPLS]

From the period of September 2000 to March 2006 Hannover Reinsurance and the Department of Traumatology of the Hanover Medical School conducted a retrospective observational study of the long-term outcome of patients after polytrauma. The follow-up period was on average 17 +/- 5 years. The goal of the study was to determine the social, financial, medical and psychological long-term outcome after a severe accident. Of the 1560 enrolled patients 519 patients died in the observed period, 397 patients were followed up but could not be examined, 637 patients (female n = 158, male n = 479) were examined and answered detailed questionnaires concerning their social, financial medical and psychological situation. 6 patients did not fullfil the input criteria and one patient had two polytraumata. The average age at the time of accident was 26.5 years (+/- 12.3).

RESULTS

Financial losses were observed in 41.1% of all males and 44.4% of females. 21.7% of all male (female 18.4%) had no financial protection at all. Due to the accident 30.1% of all men were unemployed and 19.8% permanently disabled (women 27.4% and 27.6% respectively). Psychological treatment almost doubled after discharge from rehabilitation centres. Even 20 years after the accident extra-mortality was substantially increased by 79%.

CONCLUSION

Ten to twenty years after polytrauma significant financial, social and medical impairments are still present.

Komplexe Kniegelenkverletzung beim Polytrauma

In polytraumatized patients severe joint injuries represent a special entity because their management is complex and lengthy. The surgeon must decide if limb salvage is indicated and which further surgical steps have to be instituted. The decision for amputation is based on the patient's general condition and the soft-tissue and neurovascular injury. Scoring systems are useful for decision making. Limb salvage is associated with a multistage surgical approach. Priority is given to restoration of sufficient blood supply and soft tissue repair; the indication for fasciotomy covers a wide field. To avoid further compromise to soft tissue and perfusion, temporary joint and fracture stabilization is required. Definitive surgery has to be delayed until the 2 week period, starting between the fifth and tenth day after trauma.

Accelerated bone healing and excessive callus formation in patients with femoral fracture and head injury

The effect of head injury on systemic physiology, including bone healing is still a topic of vivid discussion. Whether the observed changes genuinely represent accelerated fracture healing or are a form of local heterotopic ossification remains unclear. We aimed to investigate whether in patients with long bone fractures the presence of head injury is associated with accelerated bone healing and excessive callus formation. In total 67 patients were studied 17 with head injury and 50 without head injury (25 treated with reamed and the other 25 with the unreamed nailing technique). Both groups were comparable in terms of age, sex, ISS. All underwent stabilisation of their femoral fracture with intramedullary nailing. The quantification of fracture healing response was estimated by taking the radiological ratio of the largest diameter of callus formed into two planes and the adjacent normal diameter of femoral canal. The minimum follow up of the patients was 12 months. In patients with head injury, the mean time to fracture union was significantly shorter than either the reamed or unreamed group (10.5 weeks compared with 20.5 and 26.9 weeks, p<0.001). The difference between the mean callus to diaphyseal ratio was statistically significant for both the AP and Lateral projections (AP: mean difference 0.462, 95% CI 0.312 to 0.602, p<0.0001, LAT: mean difference 0.289, 95% CI 0.142 to 0.436, p<0.001) with the head injured patients having more florid callus compared to the control group.

Cellular processes in the amygdala: gates to emotional memory?

The amygdala is considered a core structure of the so-called limbic system and has been implicated in a variety of functions, including emotional interpretation of sensory information, emotional arousal, emotional memory, fear and anxiety, and related clinical disorders. Despite the clinical and functional importance of the amygdala, it is only recently that some general principles of intra-amygdaloid mechanisms of signal processing that are relevant for fear behavior and memory have emerged from behavioral, anatomical, electrophysiological, and neurochemical studies performed in the amygdala of various mammalian species in vivo, in situ and in vitro.

[Decision making and and priorities for surgical treatment during and after shock trauma room treatment]

OBJECTIVE

Concepts for optimal surgical treatment of the patient with blunt multiple injuries are being evaluated on the basis of the current literature.

METHODS

Clinical trials were systematically collected (Medline, Cochrane and hand searches) and classified into evidence levels (1 to 5 according to the Oxford system).

RESULTS

The posttraumatic clinical course is divided into four different periods: acute-, primary-, secondary- und tertiary period. The first and second period are important for life saving surgery and the stabilization of major fractures. After the cardiorespiratory systems have been stabilized, the following priorities have been formulated: head, face, spine, abdomen, extremities. To restrict the degree of operative burden on the patient it appears to be necessary to limit the duration of initial surgery to less than 6 hours. In patients at high risk to develop posttraumatic complications-"borderline patients"-it appears safer to perform only temporary fixation of major fractures.

CONCLUSIONS

Three different factors determine the clinical course after polytrauma: Trauma represents the first hit, followed by the therapy-induced burden (second hit). In addition, the third hit is represented by the individual response. An evaluation of the clinical status by immunologic monitoring can be performed in order to assess the patient's status.

Open pelvic fractures: epidemiology, current concepts of management and outcome

Open pelvic fractures constitute one of the most devastating injuries in musculo-skeletal trauma and must be treated aggressively, incorporating a multidisciplinary approach. Early treatment, focusing on prevention of haemorrhage and sepsis, is essential. The management of associated soft tissue injuries must also be aggressive, including early administration of broad-spectrum antibiotics and repeated, meticulous wound debridement and irrigation. Selective faecal diversion, based on wound location, is compulsory and safe, minimising the risk of sepsis and reducing mortality rates.

The impact of injuries below the knee joint on the long-term functional outcome following polytrauma

Previous studies have suggested that the lower-extremities are among the most frequently injured body regions in polytrauma patients and have a major impact on the functional recovery following polytrauma. In particular, injuries to the distal part of the lower-extremity appear to be associated with a poor functional outcome. Therefore, the goal of this study was to evaluate the impact of injuries below the knee joint on the long-term functional outcome following polytrauma. Three hundred eighty-nine polytrauma patients with associated lower-extremity fractures and a minimum follow-up of 10 years were included in this study. All patients were examined by a doctor, using a patient questionnaire and a standardised physical examination. Significantly, inferior outcomes were seen in patients with fractures below the knee joint as measured by the modified Karlström-Olerud score, Lysholm score, range of motion, weight bearing status, Hannover score for polytrauma outcome (HASPOC), SF-12, Tegner activity score, and inability to work (P < 0.05). Fractures below the knee joint have a significant impact on the functional recovery following polytrauma. We suggest that delayed treatment, thin soft tissue envelope below the knee joint, high-energy trauma, unfavorable blood supply, and complex fracture patterns contribute to these unfavorable outcomes.

[Evaluation of costs incurred for patients with multiple trauma particularly from the perspective of the hospital]

The aim of this study was to evaluate the costs involved in treating severely injured patients at the clinic differentiated by several characteristics (injury, age), sectors (emergency room, surgery, intensive and normal care), and kinds of costs (fixed costs, variable costs) and to determine influencing factors regarding costs based on the register of the DGU (Deutsche Gesellschaft für Unfallchirurgie). All patients were taken into account who had an injury severity score (ISS) of at least 16. On this basis costs of 3702 patients were analyzed. They were compared by using analysis of variance for different groups of patients classified according to kind of injury, severity of injury, and age. Moreover, multiple regression was performed to control the common influence of demographic factors and the type of injury on costs. The average ISS of the analyzed patients was 30.6 (+/-11.6) points. The average costs of the clinic were 32,166 (+/-25,404) EUR per patient. More than half of the costs was incurred by intensive care and about one-fourth by surgery. On average 30.6% were variable costs and 69.4% were fixed costs. The analysis of variance revealed that costs increased with advancing age and severity of injury (ISS). Multiple regression confirmed these interrelations indicating that extremities are very cost intensive. Due to the high portion of fixed costs, the overall costs strongly depend on the capacity utilization and less on hospital stay. That is why it may be necessary in the future to create centers for trauma care to maintain economic efficiency for treatment of these patients. Besides large differences of costs within closely defined groups of patients, hospitals carry a high economic risk so that a more complex reimbursement system should be discussed than implemented by the German DRGs.

Traumatic brain injury and stabilisation of long bone fractures: an update

In the era of "damage control orthopaedics", the timing and type of stabilisation of long bone fractures in patients with associated severe traumatic brain injury has been a topic of lively debate. This review summarises the current evidence available regarding the management of these patients. There appear to be no clear treatment guidelines. Irrespective of the treatment protocol followed, if secondary brain damage is to be avoided at all times, ICP monitoring should be used, both in the intensive care unit and in the operating theatre during surgical procedures, since aggressive ICP management appears to be related to improved outcomes. Treatment protocols should be based on the individual clinical assessment, rather than mandatory time policies for fixation of long bone fractures.