Michael Kreinest

Development of a new Emergency Medicine Spinal Immobilization Protocol for trauma patients and a test of applicability by German emergency care providers

BackgroundIn order to match the challenges of quickly recognizing and treating any life-threatening injuries, the ABCDE principles were established for the assessment and treatment of trauma patients. The high priority of spine protection is emphasized by the fact that immobilization of the cervical spine is performed at the very first step in the ABCDE principles. Immobilization is typically performed to prevent or minimize secondary damage to the spinal cord if instability of the spinal column is suspected. Due to increasing reports about disadvantages of spinal immobilization, the indications for performing spinal immobilization must be refined.The aim of this study was (i) to develop a protocol that supports decision-making for spinal immobilization in adult trauma patients and (ii) to carry out the first applicability test by emergency medical personnel.MethodsA structured literature search considering the literature from 1980 to 2014 was performed. Based on this literature and on the current guidelines, a new protocol that supports on scene decision-making for spinal immobilization has been developed. Parameters found in the literature concerning mechanisms and factors increasing the likelihood of spinal injury have been included in the new protocol. In order to test the applicability of the new protocol two surveys were performed on German emergency care providers by means of a questionnaire focused on correct decision-making if applying the protocol.ResultsBased on the current literature and guidelines, the Emergency Medicine Spinal Immobilization Protocol (E.M.S. IMMO Protocol) for adult trauma patients was developed. Following a fist applicability test involving 21 participants, the first version of the E.M.S. IMMO Protocol has to be graphically re-organized. A second applicability test comprised 50 participants with the current version of the protocol confirmed good applicability. Questions regarding immobilization of trauma patients could be answered properly using the E.M.S. IMMO Protocol.DiscussionCurrent literature increasingly reports of disadvantages that may be associated with immobilization. Based on the requirements of the current guidelines, a new protocol that supports decision-making for indications for out-of-hospital spinal immobilization has been developed in this study. In contrast to established protocols, the new protocol offers different options for immobilization as well as a decicion-support.ConclusionsThe E.M.S. IMMO protocol provides a decision-support tool for indications for spinal immobilization in adult trauma patients that permits variable decision-making depending on the current condition of the trauma patient and the pattern of injuries for immobilization in general and for immobilization method in particular.

Tribologische Messungen am Gelenkknorpel

Values for the friction coefficient of articular cartilage are given in ranges of percentage and lower and are calculated as a quotient of the friction force and the perpendicular loading force acting on it. Thus, a sophisticated system has to be provided for analysing the friction coefficient under different conditions in particular when cartilage should be coupled as friction partner. It is possible to deep-freeze articular cartilage before measuring the friction coefficient as the procedure has no influence on the results. The presented tribological system was able to distinguish between altered and native cartilage. Furthermore, tissue engineered constructs for cartilage repair were differentiated from native cartilage probes by their friction coefficient. In conclusion a tribological equipment is presented to analyze the friction coefficient of articular cartilage, in vivo generated cartilage regenerates and in vitro tissue engineered constructs regarding their biomechanical properties for quality assessment.ZusammenfassungMit geeigneten tribologischen Prüfsystemen kann die Reibungszahl von Knorpelgewebe ermittelt werden, für die eine Größenordnung im Prozent- bis Promillebereich anzusetzen ist. Die Reibungszahl wird aus der Reibkraft und der senkrecht darauf stehenden Belastungskraft errechnet. Ihr Betrag wird durch verschiedene Prüfparameter beeinflusst. Zur Ermittlung der Reibungszahl wurde ein geeignetes Prüfsystem entwickelt, mit dem Reibungszahlen für Knorpelgewebe unter verschiedenen Fragestellungen bestimmt wurden. Dabei wurde nachgewiesen, dass sich die Reibungszahl für den Knorpel aus dem medialen und dem lateralen Kompartiment von Kniegelenken von Schlachthofschweinen nicht unterscheidet. Gefroren gelagerter Knorpel unterscheidet sich in seiner Reibungszahl nicht von frischem Knorpelgewebe. In einem Ansatz mit geschädigtem Knorpel und in einem Pilotversuch mit In-vitro-Tissue-Engineering(TE)-Konstrukten wurden Unterschiede zu einer nativen Kontrollgruppe gesehen. Die Ergebnisse zeigen, dass mit dem tribologischen Prüfstand die biomechanische Kompetenz von Gelenkknorpel, Regeneraten aus In-vivo-Studien und von In-vitro-TE-Konstrukten zur Qualitätssicherung ermittelt werden kann.AbstractValues for the friction coefficient of articular cartilage are given in ranges of percentage and lower and are calculated as a quotient of the friction force and the perpendicular loading force acting on it. Thus, a sophisticated system has to be provided for analysing the friction coefficient under different conditions in particular when cartilage should be coupled as friction partner. It is possible to deep-freeze articular cartilage before measuring the friction coefficient as the procedure has no influence on the results. The presented tribological system was able to distinguish between altered and native cartilage. Furthermore, tissue engineered constructs for cartilage repair were differentiated from native cartilage probes by their friction coefficient. In conclusion a tribological equipment is presented to analyze the friction coefficient of articular cartilage, in vivo generated cartilage regenerates and in vitro tissue engineered constructs regarding their biomechanical properties for quality assessment.

Analysis of complications and perioperative data after open or percutaneous dorsal instrumentation following traumatic spinal fracture of the thoracic and lumbar spine: a retrospective cohort study including 491 patients

PurposeThe aim of the current study is to analyze perioperative data and complications of open vs. percutaneous dorsal instrumentation after dorsal stabilization in patients suffering from fractures of the thoracic or lumbar spine.MethodsIn the time period from 01/2007 to 06/2009, open surgical approach was used for dorsal stabilization. The percutaneous surgical approach was used from 05/2009 to 03/2014. In every time period, all types of fractures were treated only by open or by percutaneous approach, respectively, to avoid any selection bias. Retrospectively, epidemiological data, complications and perioperative data were documented and statistically analyzed.ResultsA total of 491 patients met the inclusion criteria. Open surgery procedure was carried out on 169 patients, and percutaneous surgery procedure was carried out on 322 patients. Fracture level ranged from T1 to L5, and fractures were classified types A, B, and C. In 91.4% of all patients, no complication occured following dorsal stabilization after traumatic spine fracture during their hospital stay. However, 42 complications related to dorsal stabilization have been documented during the hospital stay. The complication rate was 14.8% if open surgical approach has been used and was significantly reduced to 5.3% using percutaneous surgical approach. Post-operative hospital stay was also reduced significantly using the percutaneous surgical approach.ConclusionsAccording to the current study, percutaneous dorsal stabilization of the spine could also be safely used in trauma cases and is not restricted to degenerative spinal surgery.

[Tribological assessment of articular cartilage. A system for the analysis of the friction coefficient of cartilage, regenerates and tissue engineering constructs; initial results].

Values for the friction coefficient of articular cartilage are given in ranges of percentage and lower and are calculated as a quotient of the friction force and the perpendicular loading force acting on it. Thus, a sophisticated system has to be provided for analysing the friction coefficient under different conditions in particular when cartilage should be coupled as friction partner. It is possible to deep-freeze articular cartilage before measuring the friction coefficient as the procedure has no influence on the results. The presented tribological system was able to distinguish between altered and native cartilage. Furthermore, tissue engineered constructs for cartilage repair were differentiated from native cartilage probes by their friction coefficient. In conclusion a tribological equipment is presented to analyze the friction coefficient of articular cartilage, in vivo generated cartilage regenerates and in vitro tissue engineered constructs regarding their biomechanical properties for quality assessment.ZusammenfassungMit geeigneten tribologischen Prüfsystemen kann die Reibungszahl von Knorpelgewebe ermittelt werden, für die eine Größenordnung im Prozent- bis Promillebereich anzusetzen ist. Die Reibungszahl wird aus der Reibkraft und der senkrecht darauf stehenden Belastungskraft errechnet. Ihr Betrag wird durch verschiedene Prüfparameter beeinflusst. Zur Ermittlung der Reibungszahl wurde ein geeignetes Prüfsystem entwickelt, mit dem Reibungszahlen für Knorpelgewebe unter verschiedenen Fragestellungen bestimmt wurden. Dabei wurde nachgewiesen, dass sich die Reibungszahl für den Knorpel aus dem medialen und dem lateralen Kompartiment von Kniegelenken von Schlachthofschweinen nicht unterscheidet. Gefroren gelagerter Knorpel unterscheidet sich in seiner Reibungszahl nicht von frischem Knorpelgewebe. In einem Ansatz mit geschädigtem Knorpel und in einem Pilotversuch mit In-vitro-Tissue-Engineering(TE)-Konstrukten wurden Unterschiede zu einer nativen Kontrollgruppe gesehen. Die Ergebnisse zeigen, dass mit dem tribologischen Prüfstand die biomechanische Kompetenz von Gelenkknorpel, Regeneraten aus In-vivo-Studien und von In-vitro-TE-Konstrukten zur Qualitätssicherung ermittelt werden kann.AbstractValues for the friction coefficient of articular cartilage are given in ranges of percentage and lower and are calculated as a quotient of the friction force and the perpendicular loading force acting on it. Thus, a sophisticated system has to be provided for analysing the friction coefficient under different conditions in particular when cartilage should be coupled as friction partner. It is possible to deep-freeze articular cartilage before measuring the friction coefficient as the procedure has no influence on the results. The presented tribological system was able to distinguish between altered and native cartilage. Furthermore, tissue engineered constructs for cartilage repair were differentiated from native cartilage probes by their friction coefficient. In conclusion a tribological equipment is presented to analyze the friction coefficient of articular cartilage, in vivo generated cartilage regenerates and in vitro tissue engineered constructs regarding their biomechanical properties for quality assessment.

A Porcine Animal Model for Early Meniscal Degeneration - Analysis of Histology, Gene Expression and Magnetic Resonance Imaging Six Months after Resection of the Anterior Cruciate Ligament.

Background/Objective The menisci of the mammalian knee joint balance the incongruence between femoral condyle and tibial plateau and thus menisci absorb and distribute high loads. Degeneration processes of the menisci lead to pain syndromes in the knee joint. The origin of such degenerative processes on meniscal tissue is rarely understood and may be described best as an imbalance of anabolic and catabolic metabolism. A standardized animal model of meniscal degeneration is needed for further studies. The aim of the current study was to develop a porcine animal model with early meniscal degeneration. Material and Methods Resection of the anterior cruciate ligament (ACLR) was performed on the left knee joints of eight Göttingen minipigs. A sham operation was carried out on the right knee joint. The grade of degeneration was determined 26 weeks after the operation using histology and magnetic resonance imaging (MRI). Furthermore, the expression of 14 genes which code for extracellular matrix proteins, catabolic matrix metalloproteinases and inflammation mediators were analyzed. Results Degenerative changes were detected by a histological analysis of the medial meniscus after ACLR. These changes were not detected by MRI. In terms of their gene expression profile, these degenerated medial menisci showed a significantly increased expression of COL1A1. Conclusion This paper describes a new animal model for early secondary meniscal degeneration in the Göttingen minipig. Histopathological evidence of the degenerative changes could be described. This early degenerative changes could not be seen by NMR imaging.

Osteoarthritis in the Knee Joints of Göttingen Minipigs after Resection of the Anterior Cruciate Ligament? Missing Correlation of MRI, Gene and Protein Expression with Histological Scoring.

Introduction The Göttingen Minipig (GM) is used as large animal model in articular cartilage research. The aim of the study was to introduce osteoarthritis (OA) in the GM by resecting the anterior cruciate ligament (ACLR) according to Pond and Nuki, verified by histological and magnetic resonance imaging (MRI) scoring as well as analysis of gene and protein expression. Materials and Methods The eight included skeletally mature female GM were assessed after ACLR in the left and a sham operation in the right knee, which served as control. 26 weeks after surgery the knee joints were scanned using a 3-Tesla high-field MR tomography unit with a 3 T CP Large Flex Coil. Standard proton-density weighted fat saturated sequences in coronal and sagittal direction with a slice thickness of 3 mm were used. The MRI scans were assessed by two radiologists according to a modified WORMS-score, the X-rays of the knee joints by two evaluators. Osteochondral plugs with a diameter of 4mm were taken for histological examination from either the main loading zone or the macroscopic most degenerated parts of the tibia plateau or condyle respectively. The histological sections were blinded and scored by three experts according to Little et al. Gene expression analysis was performed from surrounding cartilage. Expression of adamts4, adamts5, acan, col1A1, col2, il-1ß, mmp1, mmp3, mmp13, vegf was determined by qRT-PCR. Immunohistochemical staining (IH) of Col I and II was performed. IH was scored using a 4 point grading (0—no staining; 3-intense staining). Results and Discussion Similar signs of OA were evident both in ACLR and sham operated knee joints with the histological scoring result of the ACLR joints with 6.48 ± 5.67 points and the sham joints with 6.86 ± 5.84 points (p = 0.7953) The MRI scoring yielded 0.34 ± 0.89 points for the ACLR and 0.03 ± 0.17 for the sham knee joints. There was no correlation between the histological and MRI scores (r = 0.10021). The gene expression profiles as well as the immunohistochemical findings showed no significant differences between ACLR and sham knee joints. In conclusion, both knee joints showed histological signs of OA after 26 weeks irrespective of whether the ACL was resected or not. As MRI results did not match the histological findings, MRI was obviously unsuitable to diagnose the OA in GM. The analysis of the expression patterns of the 10 genes could not shed light on the question, whether sham operation also induced cartilage erosion or if the degeneration was spontaneous. The modified Pond-Nuki model may be used with reservation in the adult minipig to induce an isolated osteoarthritis.

In vitro mapping of 1H ultrashort T2* and T2 of porcine menisci

In this study, mapping of ultrashort T2 and T2* of acutely isolated porcine menisci at B0 = 9.4 T was investigated. Maps of T2 were measured from a slice through the pars intermedia with a spin echo‐prepared two‐dimensional ultrashort‐TE T2 mapping technique published previously. T2* mapping was performed by two‐dimensional ultrashort‐TE MRI with variable acquisition delay. The measured signal decays were fitted by monoexponential, biexponential and Gaussian‐exponential fitting functions. The occurrence of Gaussian‐like signal decays is outlined theoretically. The quality of the curve fits was visualized by mapping the value δ = abs(1 – χ2red). For T2* mapping, the Gaussian‐exponential fit showed the best performance, whereas the monoexponential and biexponential fits showed regionally high values of δ (δ > 20). Interpretation of the Gaussian‐exponential parameter maps was found to be difficult, because a Gaussian signal component can be related to mesoscopic (collagen texture) or macroscopic (slice profile, shim, sample geometry) magnetic field inhomogeneities and/or residual 1H dipole–dipole couplings. It seems likely that an interplay of these effects yielded the observed signal decays. Modulation of the T2* signal decay caused by chemical shift was observed and addressed to fat protons by means of histology. In the T2 measurements, no modulation of the signal decay was observed and the biexponential and Gaussian‐exponential fits showed the best performance with comparable values of δ. Our results suggest that T2 mapping provides the more robust method for the characterization of meniscal tissue by means of MRI relaxometry. However, mapping of ultrashort T2, as performed in this study, is time consuming and provides less signal‐to‐noise ratio per time than the mapping of T2*. If T2* mapping is used, pixel‐wise monitoring of the fitting quality based on reduced χ2 should be employed and great care should be taken when interpreting the parameter maps of the fits. Copyright

Minimally invasive reduction and percutaneous posterior fixation of one-level traumatic thoraco-lumbar and lumbar spine fractures

IntroductionAlthough open procedures are the gold standard, the alternative approach of minimal invasive reduction using percutaneous screws for thoracic and lumbar spine fractures is under discussion. Aim of this study was to investigate the results of reduction and the accuracy of screw placement in minimally invasive percutaneous posterior instrumentation for these fractures.Materials and methodsOne hundred and twenty-seven patients with thoraco-lumbar and lumbar burst fractures and minimal invasive dorsal instrumentation were analyzed retrospectively in terms of the accuracy of pedicle screw placement and results of fracture reduction.ResultsIn total, 542 screws were placed. Thirty-four (6.3%) screws of 22 patients (17.3%) were misplaced, but misplacement was minimal, replacement of any screw position due to instability was not necessary, and no new neurological deficit occurred. In thoraco-lumbar fractures (82/64.5%), reduction succeeded from 2.5 ± 6° kyphosis to 5.6 ± 5.7° lordosis (p < 0.001) and in lumbar spine fractures from 6.9° ± 10.3° lordosis to 14.5° ± 8.8° lordosis (p < 0.001).ConclusionMinimal invasive percutaneous dorsal instrumentation of burst fractures of the thoraco-lumbar and lumbar spine provides adequate reduction and reliable regular screw placement.Level of evidenceLevel IV (retrospective series).

Motion and dural sac compression in the upper cervical spine during the application of a cervical collar in case of unstable craniocervical junction—A study in two new cadaveric trauma models

Background Unstable conditions of the craniocervical junction such as atlanto-occipital dislocation (AOD) or atlanto-axial instability (AAI) are severe injuries with a high risk of tetraplegia or death. Immobilization by a cervical collar to protect the patient from secondary damage is a standard procedure in trauma patients. If the application of a cervical collar to a patient with an unstable craniocervical condition may cause segmental motion and secondary injury to the spinal cord is unknown. The aim of the current study is (i) to analyze compression on the dural sac and (ii) to determine relative motion of the cervical spine during the procedure of applying a cervical collar in case of ligamentous unstable craniocervical junction. Methods and findings Ligamentous AOD as well as AOD combined with ligamentous AAI was simulated in two newly developed cadaveric trauma models. Compression of the dural sac and segmental angulation in the upper cervical spine were measured on video fluoroscopy after myelography during the application of a cervical collar. Furthermore, overall three-dimensional motion of the cervical spine was measured by a motion tracking system. In six cadavers each, the two new trauma models on AOD and AOD combined with AAI could be implemented. Mean dural sac compression was significantly increased to -1.1 mm (-1.3 to -0.7 mm) in case of AOD and -1.2 mm (-1.6 to -0.6 mm) in the combined model of AOD and AAI. Furthermore, there is a significant increased angulation at the C0/C1 level in the AOD model. Immense three-dimensional movement up to 22.9° of cervical spine flexion was documented during the procedure. Conclusion The current study pointed out that applying a cervical collar in general will cause immense three-dimensional movement. In case of unstable craniocervical junction, this leads to a dural sac compression and thus to possible damage to the spinal cord.

Influence of demographic factors and clinical status parameters on long-term neurological, psychological and vegetative outcome following traumatic brain injury

ABSTRACT Primary Objective: We evaluated the neurologic, psychological and vegetative outcome, the health status and changes of the personal and occupational status of patients after traumatic brain injuries (TBIs). Correlations between outcome parameters and basic demographic factors and initial clinical status parameters of the patients were assessed. Research Design: Monocentric, retrospective follow-up analysis. Methods and Procedures: We evaluated the neurologic, psychological and vegetative outcome and health status of patients, who survived TBI with a mean follow-up time of 54 months. Glasgow Outcome Scale (GOS), Disability Rating Scale (DRS) and a questionnaire on Quality of Life were used for outcome measurement. The personal and occupational status, trauma-derived changes to that status and medical and demographic factors that have an impact on the health condition of patients after TBI were assessed. Main Outcomes and Results: With a median GOS of 5.0 and median DRS of 3.0, our patients showed just moderate disabilities. Fifty-six per cent of the patients felt ‘very good’ or ‘good’. Age, gender, the preclinical Glasgow Coma Scale (GCS), state of pupil reaction and surgical treatment did not seem to affect the GOS or DRS. Correlations between body mass index, age and gender and distinct neurologic, psychological and vegetative symptoms were found. The personal status did not change significantly after TBI. Changes to occupational and socioeconomic status were evident. Conclusions: One-third of the patients are heavily affected by neurological, psychological and vegetative symptoms after surviving TBI. Some demographic factors affected this integrity.