Tranexamic Acid in Hip Hemiarthroplasty Surgery: A Retrospective Analysis of Perioperative Outcome.

Introduction: Implantation of a dual-head hip prosthesis to treat medial femoral neck fractures is often associated with significant blood loss. In elective endoprosthetics procedures, it has already been demonstrated that administration of tranexamic acid (TXA) reduces blood loss and need for postoperative transfusions, as well as reducing the frequency of postoperative complications. The aim of this study is to show whether the administration of TXA also leads to a reduction in perioperative blood loss and haemorrhage-associated complications when applied as part of treatment of femoral neck fractures using a dual-head prosthesis. Methods: In a single-centre retrospective cohort study, 1 g TXA i.v. was administered preoperatively to 93 patients who had suffered from femoral neck fractures. This group was compared to a comparison group of 65 patients who did not receive TXA (nonTXA). Outcomes were evaluated on the basis of perioperative blood loss, frequency of transfusion, and frequency of specific complications occurring. Results: The transfusion rate in the TXA group was 6% lower, whereby the volume of blood transfused was 26.7% lower than in the nonTXA group. However, neither result was significant. The calculated perioperative blood loss remained the same. Similarly, the incidence of postoperative renal failure was not significantly lower in the TXA group, at 6.5%, as compared to the nonTXA group (7.7%). A higher rate of complications or deaths as a result of TXA administration was not observed. The tranexamic acid effect seems to be related to the dose. Conclusion: Preoperative administration of TXA during implantation of a dual-head prosthesis for treatment of a femoral neck fracture does not lead to an increased complication rate. The study revealed a trend towards fewer transfusions required, but a significant reduction in blood loss could not be demonstrated. There should be further investigation of other factors influencing blood loss, in particular the dosing regimen followed for perioperative administration of TXA. Level of Evidence: Level 4: retrospective case-control study.

Causes of Death in the Seriously Injured -Why do Severely Injured Patients Die Today? / Todesursachen von Schwerverletzten - Woran stirbt das Polytrauma heute?

HINTERGRUND: Trauma ist die häufigste Todesursache bei unter 45-Jährigen und trotzdem gibt es nur wenig Daten zu den genauen Todesursachen Schwerverletzter nach Klinikeinlieferung in Deutschland aus den letzten 10 Jahren. Ziel der Arbeit ist 1. eine Auswertung der Daten der verstorbenen Schwerverletzten eines überregionalen TraumaZentrums aus den letzten 10 Jahren. Erforscht werden sollen Verlässlichkeit der Daten, Häufigkeit der Todesursachen und Zusammenhänge mit dem Unfallmechanismus und 2. die Nachvollziehbarkeit der Daten im TraumaRegister DGU. PATIENTEN UND METHODEN: Es erfolgte die Auswertung der Daten von 203 verstorbenen schwerverletzten Patienten aus dem Universitätsklinikum Jena, die von 2007 bis 2017 verunfallt sind. ERGEBNISSE: Eine eindeutige Festlegung der Todesursache ist anhand von Klinikdaten in ca. 85% der Fälle möglich. Häufigste Todesursache von Schwerverletzten nach Klinikeinlieferung ist mit 59,6% das Schädel-Hirn-Trauma, gefolgt von 17% Organversagen, 14% Hämorrhagie und 9,4% sonstigen Todesursachen. Die Verifizierung anhand von Daten aus dem TraumaRegister DGU ist möglich. Es besteht ein klarer Zusammenhang zwischen Unfallmechanismus und Todesursache. SCHLUSSFOLGERUNGEN: Welche Todesursache angegeben wird, unterliegt immer auch einer subjektiven Einschätzung. Insbesondere bestehen Schwierigkeiten bei Patienten, die vor weiterer Diagnostik im Schockraum versterben. Häufigste Todesursache ist heute das Schädel-Hirn-Trauma. Es ist sinnvoll, die Todesursache im TraumaRegister DGU extra zu erfassen, da diese anhand von anderen Registerdaten nur teilweise abgeleitet werden kann. Die Zusammenhänge zwischen Unfallmechanismus und Todesursache könnten ggf. für Präventionsmaßnahmen genutzt werden. BACKGROUND: The leading cause of death among people under 45 years of age is trauma. However, there is little information from the last 10 years on the exact causes of death of seriously injured people after hospital admission in Germany. The aim of the study is to evaluate the data of a level I trauma centre from the last 10 years. The reliability of the data, frequency of the causes of death and correlations with the mechanism of injury as well as the confirmability of the data in the TraumaRegister DGU are to be investigated. MATERIALS AND METHODS: The University Hospital Jena data were analysed for 203 deceased trauma patients from accidental death between 2007 and 2017. RESULTS: A clear determination of the cause of death is possible in about 85% of cases on the basis of hospital data. The most frequent cause of death of severely injured patients after admission to the hospital is traumatic brain injury (59.6%), followed by organ failure (17%), haemorrhage (14%) and other causes of death (9.4%). Verification using data from the TraumaRegister DGU is possible. There is a clear correlation between mechanism of injury and cause of death. CONCLUSIONS: The cause of death is very often a subjective assessment of the recording doctor. In particular, there are difficulties with patients who die in the resuscitation room before further diagnosis. The most frequent cause of death today is traumatic brain injury. For future evaluations, the new information in the TraumaRegister DGU is helpful because the cause of death can only be partially derived from other registry data. The correlation between the type of accident and the cause of death could be used for preventive measures.

Tranexamic acid in pertrochanteric fractures: a retrospective analysis of perioperative outcomes after fixation with a proximal femoral nail.

BACKGROUND: Treatment of pertrochanteric femoral fractures is often associated with significant blood loss. It has already been demonstrated that the administration of tranexamic acid (TXA) for endoprosthetic procedures reduces blood losses and leads to a decreased frequency of postoperative complications. The aim of this study is to demonstrate whether the administration of TXA as part of osteosynthesis treatment for pertrochanteric fractures using a proximal femoral nail reduces perioperative blood losses and haemorrhage-related complications. METHODS: In a two-centre retrospective cohort study, 1 g TXA i.v. was administered preoperatively to 294 patients who had suffered from pertrochanteric femoral fractures. The subjects were compared clinically to a historical control group who did not receive TXA (nonTXA). Outcomes were evaluated on the basis of perioperative blood loss, transfusion requirement, and occurrence of complications. RESULTS: The TXA group showed evidence of a reduction in blood loss (TXA = 0.97 ± 0.47 l; nonTXA = 1.06 ± 0.47 l; p = 0.004) and a lower frequency of transfusion (TXA = 20%; nonTXA = 31%; p = 0.032) as compared to the nonTXA group. However, evidence of this therapeutic effect could only be demonstrated at one of the centres on subgroup comparison between the two centres. At the second centre, the data did not show a significant difference. A trend could be seen towards a reduction in postoperative renal failure. No complications occurred resulting from the administration of tranexamic acid. CONCLUSION: Preoperative administration of TXA does not lead to an increased rate of thromboembolic complications when applied for treatment of pertrochanteric femoral fractures. Evidence of a positive effect could be seen in principle in relation to the reduction in perioperative blood loss and the frequency of transfusion. The difference in effect between the two centres remains to be clarified: for this reason, it is possible to assume that further factors influencing the efficacy of TXA administration are at play which were not taken into account in this study.

Inhibition of Inducible Nitric Oxide Synthase Prevents IL-1ß-Induced Mitochondrial Dysfunction in Human Chondrocytes.

Interleukin (IL)-1ß is an important pro-inflammatory cytokine in the progression of osteoarthritis (OA), which impairs mitochondrial function and induces the production of nitric oxide (NO) in chondrocytes. The aim was to investigate if blockade of NO production prevents IL-1ß-induced mitochondrial dysfunction in chondrocytes and whether cAMP and AMP-activated protein kinase (AMPK) affects NO production and mitochondrial function. Isolated human OA chondrocytes were stimulated with IL-1ß in combination with/without forskolin, L-NIL, AMPK activator or inhibitor. The release of NO, IL-6, PGE2, MMP3, and the expression of iNOS were measured by ELISA or Western blot. Parameters of mitochondrial respiration were measured using a seahorse analyzer. IL-1ß significantly induced NO release and mitochondrial dysfunction. Inhibition of iNOS by L-NIL prevented IL-1ß-induced NO release and mitochondrial dysfunction but not IL-1ß-induced release of IL-6, PGE2, and MMP3. Enhancement of cAMP by forskolin reduced IL-1ß-induced NO release and prevented IL-1ß-induced mitochondrial impairment. Activation of AMPK increased IL-1ß-induced NO production and the negative impact of IL-1ß on mitochondrial respiration, whereas inhibition of AMPK had the opposite effects. NO is critically involved in the IL-1ß-induced impairment of mitochondrial respiration in human OA chondrocytes. Increased intracellular cAMP or inhibition of AMPK prevented both IL-1ß-induced NO release and mitochondrial dysfunction.

Tangential View and Intraoperative Three-Dimensional Fluoroscopy for the Detection of Screw-Misplacements in Volar Plating of Distal Radius Fractures.

BACKGROUND: Volar locking plate fixation has become the gold standard in the treatment of unstable distal radius fractures. Juxta-articular screws should be placed as close as possible to the subchondral zone, in an optimized length to buttress the articular surface and address the contralateral cortical bone. On the other hand, intra-articular screw misplacements will promote osteoarthritis, while the penetration of the contralateral bone surface may result in tendon irritations and ruptures. The intraoperative control of fracture reduction and implant positioning is limited in the common postero-anterior and true lateral two-dimensional (2D)-fluoroscopic views. Therefore, additional 2D-fluoroscopic views in different projections and intraoperative three-dimensional (3D) fluoroscopy were recently reported. Nevertheless, their utility has issued controversies. OBJECTIVES: The following questions should be answered in this study; 1) Are the additional tangential view and the intraoperative 3D fluoroscopy useful in the clinical routine to detect persistent fracture dislocations and screw misplacements, to prevent revision surgery? 2) Which is the most dangerous plate hole for screw misplacement? PATIENTS AND METHODS: A total of 48 patients (36 females and 13 males) with 49 unstable distal radius fractures (22 x 23 A; 2 x 23 B, and 25 x 23 C) were treated with a 2.4 mm variable angle LCP Two-Column volar distal radius plate (Synthes GmbH, Oberdorf, Switzerland) during a 10-month period. After final fixation, according to the manufactures' technique guide and control of implant placement in the two common perpendicular 2D-fluoroscopic images (postero-anterior and true lateral), an additional tangential view and intraoperative 3D fluoroscopic scan were performed to control the anatomic fracture reduction and screw placements. Intraoperative revision rates due to screw misplacements (intra-articular or overlength) were evaluated. Additionally, the number of surgeons, time and radiation-exposure, for each step of the operating procedure, were recorded. RESULTS: In the standard 2D-fluoroscopic views (postero-anterior and true lateral projection), 22 screw misplacements of 232 inserted screws were not detected. Based on the additional tangential view, 12 screws were exchanged, followed by further 10 screws after performing the 3D fluoroscopic scan. The most lateral screw position had the highest risk for screw misplacement (accounting for 45.5% of all exchanged screws). The mean number of images for the tangential view was 3 ± 2.5 images. The mean surgical time was extended by 10.02 ± 3.82 minutes for the 3D fluoroscopic scan. An additional radiation exposure of 4.4 ± 4.5seconds, with a dose area product of 39.2 ± 14.5 cGy/cm(2) were necessary for the tangential view and 54.4 ± 20.9 seconds with a dose area product of 2.1 ± 2.2 cGy/cm(2), for the 3D fluoroscopic scan. CONCLUSIONS: We recommend the additional 2D-fluoroscopic tangential view for detection of screw misplacements caused by overlength, with penetration on the dorsal cortical surface of the distal radius, predominantly observed for the most lateral screw position. The use of intraoperative 3D fluoroscopy did not become accepted in our clinical routine, due to the technical demanding and time consuming procedure, with a limited image quality so far.

Impact of plasma histones in human sepsis and their contribution to cellular injury and inflammation.

INTRODUCTION: Circulating histones have been identified as mediators of damage in animal models of sepsis and in patients with trauma-associated lung injury. Despite existing controversies on actual histone concentrations, clinical implications and mechanism of action in various disease conditions, histone levels in human sepsis, association with disease progression and mediated effects on endothelial and immune cells remain unreported. This study aimed to determine histone levels and its clinical implication in septic patients and to elucidate histone-mediated effects ex-vivo. METHODS: Histone levels, endogenous activated protein C (APC) levels and clinical data from two independent cohorts of septic patients were obtained. Histone levels were compared with various control groups including healthy individuals, intensive care unit (ICU) patients without sepsis, ICU patients with multiple organ failure and patients with minor or multiple trauma, all without infection. Endothelial and monocytic cells were stimulated with histones. Cellular integrity and sepsis prototypical cytokines were evaluated. The mechanism of action of histones via Toll-like receptor 4 (TLR4) was evaluated using a function blocking antibody. Histone degradation in plasma was studied by immunoblotting. RESULTS: Histone H4 levels were significantly elevated in patients with sepsis (cohort I; n = 15 and cohort II; n = 19) versus ICU controls (n = 12), patients with multiple organ failure (n = 12) or minor trauma (n = 7), associated with need for renal replacement therapy and decrease in platelet count during disease progression, and remarkably were significantly associated with increased mortality rates in septic patients (ICU-, 28 day- and 90 day mortality rates). There was an inverse correlation between plasma histones and endogenous APC levels. Histone stimulation induced the release of sepsis prototypic cytokines and decreased cell integrity indicated by a significant increase of lactate dehydrogenase (LDH) and propidium iodide (PI) staining. Blocking of TLR4 decreased cellular cytotoxicity on endothelial cells. The calculated half-life of histones in spiked plasma was 4.6 minutes. CONCLUSIONS: Histone levels in septic patients are significantly increased and might mediate disease aggravation by cellular injury and inflammation via TLR4 signaling, which potentially results in multiple organ failure and fatal outcome.

Arthroscopic controlled reduction of femoral condyle fractures using a retrograde navigated approach.

Isolated depression fractures of the femoral condyle are rare, but severe injuries due the destroyed congruency of the articular surface in the weight-bearing region of the joint. In most cases, an arthrotomy with fragment reduction and internal fixation by screws buttress or plates is performed. Disadvantages of this procedure are the approach-related complications. Furthermore, an implant removal is necessary, if a secondary osteoarthrosis develops. We present a female patient with a hyperflexion trauma of her right knee, resulting in an isolated depression fracture of the medial femoral condyle. To avoid arthrotomy-related morbidity, the impressed fragment was retrograde addressed using navigated guidance and reduced indirectly under arthroscopic control. Via the retrograde intraosseous tunnel a biodegradable screw was used as a buttress against the fragment to prevent a re-dislocation. The fracture healed without any complications and the patient re-administered her sports activities at 10 weeks follow-up. This procedure enables an accurate reduction and stable fixation of joint depression fragments via a minimal invasive approach.

2D-fluoroscopic navigated percutaneous screw fixation of pelvic ring injuries--a case series.

BACKGROUND: Screw fixation of pelvic ring fractures is a common, but demanding procedure and navigation techniques were introduced to increase the precision of screw placement. The purpose of this case series was the evaluation of screw misplacement rate and functional outcome of percutaneous screw fixation of pelvic ring disruptions using a 2D navigation system. METHODS: Between August 2004 and December 2007, 44 of 442 patients with pelvic injuries were included for closed reduction and percutaneous screw fixation of disrupted pelvic ring lesions using an optoelectronic 2D-fluoroscopic based navigation system. Operating and fluoroscopy time were measured, as well as peri- and postoperative complications documented. Screw position was assessed by postoperative CT scans. Quality of live was evaluated by SF 36-questionnaire in 40 of 44 patients at mean follow up 15.5 +/- 1.2 month. RESULTS: 56 iliosacral- and 29 ramus pubic-screws were inserted (mean operation time per screw 62 +/- 4 minutes, mean fluoroscopy time per screw 123 +/- 12 seconds). In post-operative CT-scans the screw position was assessed and graded as follows: I. secure positioning, completely in the cancellous bone (80%); II. secure positioning, but contacting cortical bone structures (14%); III. malplaced positioning, penetrating the cortical bone (6%). The malplacements predominantly occurred in bilateral overlapping screw fixation. No wound infection or iatrogenic neurovascular damage were observed. Four re-operations were performed, two of them due to implant-misplacement and two of them due to implant-failure. CONCLUSION: 2D-fluoroscopic navigation is a safe tool providing high accuracy of percutaneous screw placement for pelvic ring fractures, but in cases of a bilateral iliosacral screw fixation an increased risk for screw misplacement was observed. If additional ramus pubic screw fixations are performed, the retrograde inserted screws have to pass the iliopubic eminence to prevent an axial screw loosening.

Navigation of vertebro-pelvic fixations based on CT-fluoro matching.

Different navigation procedures (based on 2D-, 3D-fluoroscopy or CT modalities) with their respective limitations are established in orthopedic surgery. The hypothesis is that intraoperative matching of different modalities (fluoro and CT) increases the precision of navigated screw placement and reduces the fluoroscopy time. Vertical unstable pelvic ring fractures of 12 patients were treated with vertebro-pelvic fixations (6 in the standard technique and 6 using the fluoro-CT navigation). An optimal osseous corridor could be determined by the navigation procedure increasing the overall precision of screw placement (no misplacement in the second group as compared to one misplaced pedicle screw in the standard group). The achieved screw lengths were [(mean ± SE) 78 ± 5 vs. 53 ± 4 mm, p < 0.001). Less invasive open approaches and a reduction of fluoroscopy time (time per screw in seconds: 121 vs. 62 s) were observed. CT-fluoro-matched navigation improves the intraoperative visualization of osseous structures and increases the precision of screw placement with less radiation exposure.

Influence of an infrapatellar fat pad edema on patellofemoral biomechanics and knee kinematics: a possible relation to the anterior knee pain syndrome.

INTRODUCTION: An edema of the infrapatellar fat pad following knee arthroscopy or in case of chronic anterior knee pain syndrome is suspected to increase the patellofemoral pressure by a modification of the patellofemoral glide mechanism. The study was performed to evaluate this hypothesis. MATERIALS AND METHODS: Isokinetic knee extension from 120 degrees of flexion to full extension was simulated on 10 human knee cadaver specimens (six males, four females, average age at death 42 years) using a knee kinemator. Joint kinematics was evaluated by ultrasound sensors (CMS 100, Zebris, Isny, Germany), and retro-patellar contact pressure was measured using a thin-film resistive ink pressure system (K-Scan 4000, Tekscan, Boston). Infrapatellar tissue pressure was analyzed using a closed sensor cell which was implanted inside the fat pad (GISMA, Buggingen, Germany). An inflatable fluid cell was implanted by ultrasound control in the center of the infrapatellar fat pad and filled subsequently with water to simulate a fat pad edema. All parameters were recorded and analyzed from 0 to 5 ml volume of the fluid cell. RESULTS: Simulating a fat pad edema resulted in a significant (P < 0.01) increase of the infrapatellar fat pad pressure (247 mbar at 0 ml to 615 mbar at 5 ml volume). In knee extension and flexion the patella flexion (sagittal plane) was decreased while we did not find any other significant influence of the edema on knee kinematics. During the analysis of the patellofemoral biomechanics, a simulated fat pad edema resulted in a significant (P < 0.05) decrease of the patellofemoral force between 120 degrees of knee flexion and full extension. The contact area was reduced significantly near extension (0 degree-30 degrees) by an average of 10% while the contact pressure was reduced at the entire range of motion up to 20%. CONCLUSION: An edema of the infrapatellar fat pad does not cause an increase of the patellofemoral pressure or a significant alteration of the patellofemoral glide mechanism. Anterior knee pain in case of a fat pad edema may be related to a significant increase of the tissue pressure and possible histochemical reactions.

The influence of patellar bracing on patellar and knee load-distribution and kinematics: an experimental cadaver study.

The aim of this study was to analyze the biomechanical consequences of patella bracing in order to evaluate possible mechanisms supporting its clinical application. The hypothesis is that the patellar bracing reduces patellofemoral pressure by influencing patellar and knee kinematics, and load distribution. Physiologic isokinetic knee extension motions were simulated on ten human knee cadaver specimens using a knee kinematic simulator. Joint kinematics were evaluated using an ultrasound-based motion analysis system and patellofemoral contact pressure was measured using a thin-film piezoresistive pressure measuring system. Infrapatellar tissue pressure was analyzed using a closed sensor-cell. Three different patella braces were fitted to the knee cadavers and their influence on the kinematic and kinetic biomechanical parameters were evaluated and compared to the physiologic situation. Patellar bracing resulted in a significant (p = 0.05) proximalization of the patella up to 3 mm. Depending on the type of brace used, a decrease in the infrapatellar fat pad pressure was found and the patellofemoral contact area was decreased significantly (p = 0.05) between 60 degrees of knee flexion and full extension (maximum 22%). Patella bracing significantly (p = 0.05) reduced the patellofemoral contact pressure an average of 10%, as well as the peak contact pressure which occurred. Patellar bracing significantly influences patella biomechanics in a reduction of the patellofemoral contact area and contact pressure as well as a decrease in the infrapatellar tissue pressure. The application of infrapatellar straps is suggested for the treatment and prevention of anterior knee pain, especially in high level sports.

Biomechanical and kinematic influences of a total infrapatellar fat pad resection on the knee.

BACKGROUND: This biomechanical study was performed to evaluate the consequences of total infrapatellar fat pad resection on knee kinematics and patellar contact pressure. HYPOTHESIS: Resection of the infrapatellar fat pad produces significant changes in knee kinematics and patellar contact pressure. STUDY DESIGN: Biomechanical cadaveric study. METHODS: Isokinetic knee extension was simulated on 10 human knee cadaveric specimens (6 men, 4 women; mean age at death, 44 years). Joint kinematics were evaluated by an ultrasound-based 3D motion analysis system, and retro-patellar contact pressure was measured using an electronic pressure-sensitive film. All data were taken before and after resection of the infrapatellar fat pad and statistically analyzed. RESULTS: A total resection of the infrapatellar fat pad resulted in a significant decrease of the tibial external rotation relative to the femur between 63 degrees of flexion and full knee extension (maximum: 3 degrees rotation difference at 0 degrees knee flexion, P = .011), combined with a significant medial translation of the patella between 29 degrees and 69 degrees of knee flexion (range, 0.9-1.3 mm, P = .017-.028). Retro-patellar contact pressure was significantly reduced (from 20% to 25%, P = .008-.021) at all flexion angles. CONCLUSION: A resection of the infrapatellar fat influences patellar biomechanics and knee kinematics. CLINICAL RELEVANCE: The infrapatellar fat pad may have a biomechanical function and may play a role in anterior knee pain syndrome.