Experimental Trauma Models: An Update

Treatment of polytrauma patients remains a medical as well as socioeconomic challenge. Although diagnostics and therapy improved during the last decades, multiple injuries are still the major cause of fatalities in patients below 45 years of age. Organ dysfunction and organ failure are major complications in patients with major injuries and contribute to mortality during the clinical course. Profound understanding of the systemic pathophysiological response is crucial for innovative therapeutic approaches. Therefore, experimental studies in various animal models are necessary. This review is aimed at providing detailed information of common trauma models in small as well as in large animals

Traumatic extremity arterial injury in children: Epidemiology, diagnostics, treatment and prognostic value of Mangled Extremity Severity Score

<p>Abstract</p> <p>Background</p> <p>Traumatic paediatric arterial injuries are a great challenge due to low incidence and specific characteristics of paediatric anatomy and physiology. The aim of the present study was to investigate their epidemiology, diagnostic and therapeutic options and complications. Furthermore, the prognostic value of the Mangled Extremity Severity Score (MESS) was evaluated.</p> <p>Methods</p> <p>In a retrospective clinical study 44 children aged 9.0 ± 3.2 years treated for traumatic extremity arterial lesions in our Level I trauma center between 1971 and 2006 were enrolled. Exclusion criteria were age > 14, venous and iatrogenic vascular injury. Demographic data, mechanism of injury, severity of arterial lesions (by Vollmar and MESS), diagnostic and therapeutic management, complications and outcome were evaluated.</p> <p>Results</p> <p>The most commonly injured vessel was the femoral artery (25%) followed by the brachial artery (22.7%). The mechanism of injury was penetrating (31.8%), isolated severe blunt extremity trauma (29.6%), multiple trauma (25%) and humeral supracondylar fractures (13.6%). In 63.6% no specific vascular diagnostic procedure was performed in favour of emergency surgery. Surgical reconstructive strategies were preferred (68.2%). A MESS < 7 was associated with initial (p < 0.05) and definite limb salvage (p < 0.001) of the lower extremity.</p> <p>Conclusions</p> <p>Traumatic paediatric vascular injuries are very rare. The most common situations of vascular lesions in childhood were penetrating injuries and fractures of the extremities either as isolated injuries or in multiply injured patients. In paediatric patients, the MESS could serve as a basis for decision making for limb salvage or amputation.</p

Risk of symptomatic heterotopic ossification following plate osteosynthesis in multiple trauma patients: an analysis in a level-1 trauma centre

<p>Abstract</p> <p>Background</p> <p>Symptomatic heterotopic ossification (HO) in multiple trauma patients may lead to follow up surgery, furthermore the long-term outcome can be restricted. Knowledge of the effect of surgical treatment on formation of symptomatic heterotopic ossification in polytrauma is sparse. Therefore, we test the effects of surgical treatment (plate osteosynthesis or intramedullary nailing) on the formation of heterotopic ossification in the multiple trauma patient.</p> <p>Methods</p> <p>We retrospectively analysed prospectively documented data of blunt multiple trauma patients with long bone fractures which were treated at our level-1 trauma centre between 1997 and 2005. Patients were distributed to 2 groups: Patients treated by intramedullary nails (group IMN) or plate osteosynthesis (group PLATE) were compared. The expression and extension of symptomatic heterotopic ossifications on 3-6 months follow-up x-rays in antero-posterior (ap) and lateral views were classified radiologically and the maximum expansion was measured in millimeter (mm). Additionally, ventilation time, prophylactic medication like indomethacine and incidence and correlation of head injuries were analysed.</p> <p>Results</p> <p>101 patients were included in our study, 79 men and 22 women. The fractures were treated by intramedullary nails (group IMN n = 50) or plate osteosynthesis (group PLATE n = 51). Significantly higher radiologic ossification classes were detected in group PLATE (2.9 ± 1.3) as compared to IMN (2.2 ± 1.1; p = 0.013). HO size in mm ap and lateral showed a tendency towards larger HOs in the PLATE group. Additionally PLATE group showed a higher rate of articular fractures (63% vs. 28% in IMN) while IMN demonstrated a higher rate of diaphyseal fractures (72% vs. 37% in PLATE; p = 0.003). Ventilation time, indomethacine and incidence of head injuries showed no significant difference between groups.</p> <p>Conclusion</p> <p>Fracture care with plate osteosynthesis in polytrauma patients is associated with larger formations of symptomatic heterotopic ossifications (HO) while intramedullary nailing was associated with a higher rate of remote HO. For future fracture care of multiply injured patients these facts may be considered by the responsible surgeon.</p

IL-6 predicts organ dysfunction and mortality in patients with multiple injuries

<p>Abstract</p> <p>Background</p> <p>Although therapeutic concepts of patients with major trauma have improved during recent years, organ dysfunction still remains a frequent complication during clinical course in intensive care units. It has previously been shown that cytokines are upregulated under stress conditions such as trauma or sepsis. However, it is still debatable if cytokines are adequate parameters to describe the current state of trauma patients. To elucidate the relevance of cytokines, we investigated if cytokines predict development of multiple organ dysfunction syndrome (MODS) or outcome.</p> <p>Methods</p> <p>A total of 143 patients with an injury severity score ≥ 16, between 16 and 65 years, admitted to the Hannover Medical School Level 1 Trauma Center between January 1997 and December 2001 were prospectively included in this study. Marshall Score for MODS was calculated for at least 14 days and plasma levels of TNF-α, IL-1β, IL-6, IL-8 and IL-10 were measured. To determine the association between cytokine levels and development of MODS the Spearman rank correlation coefficient was calculated and logistic regression and analysis were performed.</p> <p>Results and Discussion</p> <p>Patients with MODS had increased plasma levels of IL-6, IL-8 and IL-10. IL-6 predicted development of MODS with an overall accuracy of 84.7% (specificity: 98.3%, sensitivity: 16.7%). The threshold value for development of MODS was 761.7 pg/ml and 2176.0 pg/ml for mortality during the in patient time.</p> <p>Conclusion</p> <p>We conclude that plasma IL-6 levels predict mortality and that they are a useful tool to identify patients who are at risk for development of MODS.</p

Multidisciplinary inpatient rehabilitation improves the long-term functional status of geriatric hip-fracture patients

Background As the world population ages, the number of hip-related fractures in the elderly is steadily increasing. These fractures generate a major worldwide healthcare problem and frequently lead to deterioration of life quality, mobility and independence in activity of daily life of geriatric patients. At present, many studies have investigated and proved benefits of multidisciplinary orthogeriatric care for elderly hip-fracture patients. Only few studies however, have analyzed treatment concepts for those patients directly following discharge from hospital in specialized rehabilitation centers. The aim of this study was to evaluate effects of a multidisciplinary inpatient rehabilitation on the short- and long-term functional status of geriatric patients who suffered from hip fracture. Methods A total of 161 hip-fracture patients aged 80 years and above, or additionally 70 years and above suffering from age-typical multimorbidity were included in this study. Patients who had an initial Barthel Index lower than 30 points were excluded from this study, as most of these patients were not able to attend a therapy at the rehabilitation center due to a poor functional status. The patients were separated into two subgroups dependent on the availability of treatment spots at the rehabilitation center. No other item was used to discriminate between the groups. Group A (n = 95) stayed an average of 21 days at an inpatient rehabilitation center that specialized in geriatric patients. Group B (n = 66) underwent the standard postoperative treatment and were sent home with further treatment by their general practitioner, nursing staff and physiotherapists. To evaluate the patients’ functional status over the course of time we used the Barthel Index, which was evaluated for every patient on the day of discharge, as well as during checkups after 3, 6 and 12 months. Results The average Barthel Index at the day of discharge was 57.79 ± 14.92 points for Group A and 56.82 ± 18.76 points for Group B (p = 0.431). After 3 months, the average Barthel Index was 82.43 points for Group A and 73.11 points for group B (p = 0.005). In the 6-month checkup Group A’s average Barthel Index was 83.95 points and Group B’s was 74.02 points (p = 0.002). After 12 months, patients from Group A had an average Barthel Index of 81.21 while patients from Group B had an average Barthel Index of 69.85 (p = 0.005). Conclusion The results of this study reveal a significantly better outcome concerning both, short-term and long-term functional status after 3, 6 and 12 months for geriatric hip-fracture patients, who underwent an inpatient treatment in a rehabilitation center following the initial therapy

The T-pod is as stable as supraacetabular fixation using 1 or 2 Schanz screws in partially unstable pelvic fractures: a biomechanical study

Introduction: Unstable fractures of the pelvis remain the predominant cause of severe hemorrhage, shock and early death in severely injured patients. The use of pelvic binders has become increasingly popular, particularly in the preclinical setting. There is currently insufficient evidence available about the stability of the pelvic binder versus supraacetabular fixation using 1 or 2 Schanz screws. We aimed to analyze the stability of the pelvic binder and supraacetabular fixateurs using either 1 or 2 Schanz screws in a cadaver model of an induced pelvic B-type fracture. Materials and methods: The study was undertaken in 7 human fresh-frozen cadaveric pelvises with induced AO-type B fractures. Three stabilization techniques were compared: T-POD (pelvic bandage), supraacetabular external fixator with 1 pin on each side and external fixator with 2 pins on each side. Stability and stiffness were analyzed in a biomechanical testing machine using a 5-step protocol with static and dynamic loading, dislocation data were retrieved by ultrasound sensors at the fracture sites. Results: No significant differences in fracture fragment displacement were detected when using either the T-POD, a 1-pin external fixator or a 2-pin external fixator (P > 0.05). The average difference in displacement between the three methods was < 1 mm. Conclusions: Pelvic binders are suitable for reduction of pelvic B-type fractures. They provide stability comparable to that of supraacetabular fixators, independently of whether 1 or 2 Schanz screws per side are used. Pelvic binders provide sufficient biomechanical stability for transferring patients without the need to first replace them with surgically applied external fixators. However, soft tissue irritation has to be taken into consideration and prolonged wear should be avoided. Level of evidence: Level III

Radiographic cortical thickness parameters as predictors of rotational alignment in proximal tibial shaft fractures: a cadaveric study

AIM The treatment of tibial fractures with an intramedullary nail is an established procedure. However, torsional control remains challenging using intraoperatively diagnostic tools. Radiographic tools such as the Cortical Step Sign (CSS) and the Diameter Difference Sign (DDS) may serve as tools for diagnosing a relevant malrotation. The aim of this study was to investigate the effect of torsional malalignment on CSS and DDS parameters and to construct a prognostic model to detect malalignment. METHODS A proximal tibial shaft fracture was set in human tibiae. Torsion was set stepwise from 0° to 30° in external and internal torsion. Images were obtained with a C-arm and transferred to a PC for measuring the medical cortical thickness (MCT), lateral cortical thickness (LCT), tibial diameter (TD) in AP and the anterior cortical thickness (ACT) as well as the posterior cortical thickness (PCT) and the transverse diameter (TD) of the proximal and the distal main fragment. RESULTS There were significant differences between the various degrees of torsion for each of the absolute values of the examined variables. The parameters with the highest correlation were TD, LCT and ACT. A model combining ACT, LCT, PCT and TD lateral was most suitable model in identifying torsional malalignment. The best prediction of clinically relevant torsional malalignment, namely 15°, was obtained with the TD and the ACT. CONCLUSION This study shows that the CSS and DDS are useful tools for the intraoperative detection of torsional malalignment in proximal tibial shaft fractures and should be used to prevent maltorsion

Improved success rates using videolaryngoscopy in unexperienced users: a randomized crossover study in airway manikins

Background: Videolaryngoscopy has been proven to be a safe procedure managing difficult airways in the hands of airway specialists. Information about the success rates in unexperienced users of videolaryngoscopy compared to conventional laryngoscopy is sparse. Therefore, we aimed to evaluate if there might be more success in securing an airway if the unexperienced provider is using a videolaryngoscope in simulated airways in a randomized manikin study. Differences between commonly used videolaryngoscopes were elucidated. Methods: A standardized hands-on workshop prior to the study was performed. For direct laryngoscopy (DL) we used a Macintosh laryngoscope, whereas for videolaryngoscopy (VL) we used the cMac, the dBlade, and a King Vision videolaryngoscope. Endotracheal intubations in three simulated normal and difficult airways were performed. Main outcome parameters were time to view and time to intubation. Cormack and Lehane (C + L) classification and the percentage of glottic opening (POGO) score were evaluated. After every intubation, the participants were asked to review the airway and the device used. Results: 22 participants (14.8 +/- 4.0 intubations per year, mostly trauma surgeons) with limited experience in videolaryngoscopy (mean total number of videolaryngoscopy.4 +/- .2) were enrolled. We found improved C + L grades with VL in contrast to DL. We saw similar data with respect to the POGO score, where the participants achieved better visibility of the glottis with VL. The hyperangulated blade geometries of videolaryngoscopes provided a better visibility in difficult airways than the standard geometry of the Macintosh-type blade. The subjective performance of the VL devices was better in more difficult airway scenarios. Conclusions: After a short introduction and hands-on training, a videolaryngoscope seems to be safe and usable by unexperienced providers. We assume a standard geometry laryngoscope is optimal for a patient with normal anatomy, whereas VL device with a hyperangulated blade is ideal for difficult airway situations with limited mouth opening or restricted neck movement

Eradication of Acinetobacter baumannii/Enterobacter cloacae complex in an open proximal tibial fracture and closed drop foot correction with a multidisciplinary approach using the Taylor Spatial Frame®

Background Multi-drug-resistant bacteria (e.g. Carbapenem-resistant Acinetobacter baumannii, extended-spectrum betalactamase or carbapenemase-producing enterobacteriaceae) are emerging in early-onset infections. So far, there is no report describing the eradication of these bacteria in a osseous infection of an open proximal tibial fracture in combination with the hexapod technology to address both osseous consolidation and closed drop foot correction. Case presentation After sustaining a proximal tibial fracture (Gustilo 3B), a 41-year-old man was primarily treated with open reduction and internal fixation by a locking plate and split-thickness skin graft in the home country. At the time of admission to our hospital there was a significant anterolateral soft tissue defect covered with an already-necrotic split-thickness graft and suspicious secretion. CAT and MRI scans revealed no signs of osseous healing, intramedullary distinctive osteomyelitis, as well as a large abscess zone in the dorsal compartment. Multiple wound smears showed multi-drug-resistant bacteria: Acinetobacter baumannii (Carbapenem resistant) as well as Enterobacter cloacae complex (AmpC overexpression). After implant removal, excessive osseous and intramedullary debridements using the Reamer Irrigator Aspirator (RIA®) as well as initial negative pressure wound therapy were performed. Colistin hand-modelled chains and sticks were applied topically as well as an adjusted systemic antibiotic scheme was applied. After repetitive surgical interventions, the smears showed bacterial eradication and the patient underwent soft tissue reconstruction with a free vascularized latissimus dorsi muscle flap. External fixation was converted to a hexapod fixator (TSF®) to correct primary varus displacement, axial assignment and secure osseous healing. A second ring was mounted to address the fixed drop foot in a closed fashion without further intervention. At final follow-up, 12 months after trauma, the patient showed good functional recovery with osseous healing, intact soft tissue with satisfactory cosmetics and no signs of reinfection. Conclusions A multidisciplinary approach with orthopaedic surgeons for debridement, planning and establishing osseous and joint correction and consolidation, plastic surgeons for microvascular muscle flaps for soft tissue defect coverage as well as clinical microbiologists for the optimized anti-infective treatment is essential in these challenging rare cases