Distribution of soluble and microsomal epoxide hydrolase in the mouse brain and its contribution to cerebral epoxyeicosatrienoic acid metabolism.

Epoxide hydrolases comprise a family of enzymes important in detoxification and conversion of lipid signaling molecules, namely epoxyeicosatrienoic acids (EETs), to their supposedly less active form, dihydroxyeicosatrienoic acids (DHETs). EETs control cerebral blood flow, exert analgesic, anti-inflammatory and angiogenic effects and protect against ischemia. Although the role of soluble epoxide hydrolase (sEH) in EET metabolism is well established, knowledge on its detailed distribution in rodent brain is rather limited. Here, we analyzed the expression pattern of sEH and of another important member of the EH family, microsomal epoxide hydrolase (mEH), in mouse brain by immunohistochemistry. To investigate the functional relevance of these enzymes in brain, we explored their individual contribution to EET metabolism in acutely isolated brain cells from respective EH -/- mice and wild type littermates by mass spectrometry. We find sEH immunoreactivity almost exclusively in astrocytes throughout the brain, except in the central amygdala, where neurons are also positive for sEH. mEH immunoreactivity is abundant in brain vascular cells (endothelial and smooth muscle cells) and in choroid plexus epithelial cells. In addition, mEH immunoreactivity is present in specific neuronal populations of the hippocampus, striatum, amygdala, and cerebellum, as well as in a fraction of astrocytes. In freshly isolated cells from hippocampus, where both enzymes are expressed, sEH mediates the bulk of EET metabolism. Yet we observe a significant contribution of mEH, pointing to a novel role of this enzyme in the regulation of physiological processes. Furthermore, our findings indicate the presence of additional, hitherto unknown cerebral epoxide hydrolases. Taken together, cerebral EET metabolism is driven by several epoxide hydrolases, a fact important in view of the present targeting of sEH as a potential therapeutic target. Our findings suggest that these different enzymes have individual, possibly quite distinct roles in brain function and cerebral EET metabolism.

[Clinical accuracy of fluoroscopic navigation at the thoracic and lumbar spine]. / Klinische Präzision der C-Arm-Navigation an der Brust- und Lendenwirbelsäule.

The aim of the present study was the verification of the accuracy of 2D fluoroscopy-based navigated pedicle screw placements at the thoracic and lumbar spine in a case series of traumatised patients. Within 36 months 111 pedicle screws were instrumented using C-arm based navigation in 29 patients, 60 at the thoracic and 51 at the lumbar spine. All screw positions were evaluated postoperatively by a routine thin-slice CT scan using multiplanar reconstruction. The position of a screw in relation of its pedicle was classified as: a) screw completely intraosseous, b) screw perforated less than thread level and c) screw perforated over thread level. In 34 thoracic (56.7%) and 32 lumbar (62.7%) screws complete intraosseous placement was observed, 14 thoracic screws (23.3%) and 14 lumbar screws (27.5%) perforated less than thread level. Perforations over thread level were found in 12 thoracic (20%) and 5 lumbar (9.8%) screws. Only medial and lateral perforations of the pedicle were documented (without neurological signs), cranial or caudal perforations did not occur. Segmentation of the C-arm navigation into two comparable treatment periods showed a learning curve with a reduction of perforations in the second sequence (after 57 pedicle instrumentations) of about 15%, this was not found to be statistically significant. The fluoroscopic navigation of pedicle screws is a safe procedure at the lumbar spine with equal accuracy compared to the non-navigated conventional instrumentation. Application of C-arm navigation at the thoracic spine showed more inaccuracies, so that 3D-based navigation seems to be more advantageous in this region.

[Therapy indications and options for skeletal metastases]. / Therapieindikationen und -optionen bei ossären Metastasen.

Pathological fractures are dreaded complications due to skeletal metastasis. Modern oncological therapies and more sophisticated new radiological techniques such as MRI and positron emission tomography have improved multimodal treatment concepts. Surgical intervention is determined by the primary disease, general condition and life expectancy of the patient. The goals of surgical treatment are improvement of life quality, pain relief and maintenance of mobility.

Hip arthroplasty with proximal transmission of force: first clinical results with a new partially cemented femoral stem.

BACKGROUND: Proximal stem fixation by partial cementing is a new concept in hip arthroplasty. We conducted a prospective clinical and radiological analysis to evaluate the preliminary outcome of this new technique with the Option 3000 stem (Mathys Orthopaedics, Bettlach, Switzerland). METHODS AND FOCUS: One hundred and thirty-three hip replacements in 123 patients have been performed between 1996 and 2003: All of them were followed up regularly both clinically and radiological and 53 were analysed with the EBRA-FCA method. Eighty-six patients with 95 hips could be seen in August 2004. At this point of time, the mean follow-up time was 61 months (5.08 years) with a maximum of 100 months (8.33 years) RESULTS: The clinical data reported an average Harris Hip Score of 85.5. Nine stems had to be exchanged over the period of study. The EBRA-FCA analysis reported a mean subsidence less than 1.5 mm after 2 years, then an average stable subsidence of 2.4 mm. So the results are similar to the early results obtained with other fixation concepts and the long-term results appear promising.

[Computer-assisted arthrodesis of the sacroiliac joint]. / Navigationsgestützte Arthrodese des Iliosakralgelenks.

Arthrodesis of the sacroiliac joint (SI) usually requires a large surgical exposure using the lateral approach. Computer-assisted surgery based on intraoperative 3D fluoroscopy imaging can reduce the approach to stab incisions. The clinical example shows the insertion of two screws and a cylindrical bone graft to achieve an arthrodesis of the SI joint. The intraoperatively navigated placement of implants and bone graft was performed only by stab incisions.

Difference in metallic wear distribution released from commercially pure titanium compared with stainless steel plates.

INTRODUCTION: Stainless steel and commercially pure titanium are widely used materials in orthopedic implants. However, it is still being controversially discussed whether there are significant differences in tissue reaction and metallic release, which should result in a recommendation for preferred use in clinical practice. MATERIALS AND METHODS: A comparative study was performed using 14 stainless steel and 8 commercially pure titanium plates retrieved after a 12-month implantation period. To avoid contamination of the tissue with the elements under investigation, surgical instruments made of zirconium dioxide were used. The tissue samples were analyzed histologically and by inductively coupled plasma atomic emission spectrometry (ICP-AES) for accumulation of the metals Fe, Cr, Mo, Ni, and Ti in the local tissues. Implant corrosion was determined by the use of scanning electron microscopy (SEM). RESULTS: With grades 2 or higher in 9 implants, steel plates revealed a higher extent of corrosion in the SEM compared with titanium, where only one implant showed corrosion grade 2. Metal uptake of all measured ions (Fe, Cr, Mo, Ni) was significantly increased after stainless steel implantation, whereas titanium revealed only high concentrations for Ti. For the two implant materials, a different distribution of the accumulated metals was found by histological examination. Whereas specimens after steel implantation revealed a diffuse siderosis of connective tissue cells, those after titanium exhibited occasionally a focal siderosis due to implantation-associated bleeding. Neither titanium- nor stainless steel-loaded tissues revealed any signs of foreign-body reaction. CONCLUSION: We conclude from the increased release of toxic, allergic, and potentially carcinogenic ions adjacent to stainless steel that commercially pure Ti should be treated as the preferred material for osteosyntheses if a removal of the implant is not intended. However, neither material provoked a foreign-body reaction in the local tissues, thus cpTi cannot be recommend as the 'golden standard' for osteosynthesis material in general.

[Precision of navigation-assisted surgery of the thoracic and lumbar spine]. / Präzision der navigationsgestützten Chirurgie an der Brust- und Lendenwirbelsäule.

The goal of these studies was to evaluate the accuracy of in vivo and in vitro application of CT- and C-arm-based navigation at the thoracic and lumbar spine. With CT based navigation, 82 pedicle screws were consecutively inserted, 53 into the thoracic and 29 into the lumbar spine. Seven (13%) perforations were detected at the thoracic spine and two (7%) at the lumbar spine. Additionally, minor perforations below the thread depth were seen in six (11%) thoracic and in two (7%) lumbar instrumentation. With C-arm-based navigation, 74 screws were consecutively placed into 38 thoracic and 36 lumbar pedicles. Perforations were noted in ten (26%) thoracic and four (11%) lumbar implants. Minor perforations were observed in another nine (24%) thoracic and ten (28%) lumbar pedicles. The observer-independent and standardized in vitro study based on a transpedicular 3.2-mm drill hole aiming a 4-mm steel ball in a plastic bone model showed pedicle perforations of the drill canal only in thoracic vertebrae, 1 of 15 in CT-based and 3 of 15 in C-arm navigation. The quantitative calculation of the smallest distance between the central line through the drill canal and the center of the steel ball resulted in 1.4 mm (0.5-4.8 mm) for the CT-based navigation at the thoracic spine and in 1.8 mm (0.5-3 mm) at the lumbar spine. For the C-arm based navigation the distance was 2.6 mm (0.9-4.8 mm) for the thoracic spine and 2 mm (1.2-3 mm) for the lumbar spine. In our opinion, the clinical results of the comparative accuracy of CT- and C-arm-based navigation in the present study showed moderate advantages of the CT-based technique in the thoracic spine, whereas CT- and C-arm based navigation had comparable perforation rates at the lumbar pedicle. The results of the experimental study correlated with the clinical data.

[Navigation of tumors and metastases in the area of the thoraco-lumbar spine]. / Navigation von Tumoren und Metastasen im Bereich der thorakolumbalen Wirbelsäule.

In this clinical feasibility study, CT-based verification of the efficacy of navigated decompression and pedicle screw placement in patients who had tumor-related posterior surgery was demonstrated. Eighty-six percent of the pedicle screws were positioned centrally in the bone without perforation; in all patients accurate decompression was seen. The accuracy of transpedicle screw implantation postoperatively was investigated with CT. In contrast to other published studies, no postoperative neurologic deterioration was seen in the patients as a result of using computer-aided surgical procedures. At the same time we were able to achieve complete decompression of the neural structures for radiologic and neurologic findings. Because of inaccurate registration, it was not possible to use computer-aided implantation surgery for 15% of the pedicles and, therefore, a conventional fluoroscopic approach was used. Our initial results indicate that computer-aided frameless navigation of tumor surgery of the spine is a safe technique which improves surgical performance during posterior decompression and transpedicle stabilization. In addition, CAS surgery improved the intraoperative information about the tumor and the current surgical intervention during decompression. Nevertheless the technique should be used only by experienced surgeons who can, if required, continue the operation using conventional techniques. Furthermore, the surgeon should have a complete theoretical understanding of the navigation system to minimize possible misinterpretation of computer guidance information.

[Radiation dosage in orthopedics -- a comparison of computer-assisted procedures]. / Strahlendosis im OP--ein Vergleich computerassistierter Verfahren.

Since the 1990s, computer-assisted methods have been well-established in the field of orthopedics and traumatology. In addition to the proven improvement in the field of surgical precisioncompared with conventional techniques, the decrease in the amount of emitted ionizing radiation inside of the operating room was cited to constitute an additional major advantage of computer-based navigation. The goal of this study was to quantify X-ray dose values exposed during both conventional methods and computer-assisted procedures, the latter being performed using a C-arm device SIREMOBIL Iso-C3D (Siemens Medical Solutions). The clinical measurements were supplemented by laboratory experiments using a pinpoint ionization chamber placed inside a standard lucite phantom. The clinical part of the study investigated the application of new, i.e. computer assisted, techniques in comparison with conventional procedures on in total 42 patients experiencing surgery either on their lower extremities (n = 14) or on the spine (n = 28). The techniques applied were: (1) conventional surgical procedure, (2) CT-based navigation, (3) C-arm navigation, and (4) Iso-C3D-navigation. The main focus of the clinical evaluation was the determination of radiation dose values by means of thermoluminescence dose meters, accompanied by the registration of the operation times of the X-ray tube during a surgical intervention. The conclusions from the clinical studies are in agreement with the results from the laboratory measurements. Computer-assisted techniques led to a significant reduction in X-ray dose exposure and drastically shortened irradiation times. The most pronounced decrease in the emission of ionizing radiation was achieved in case of the Iso-C3D-navigation, which has only recently been introduced into clinical practice, i.e. during runtime of this study.

Monitoring and healing analysis of 100 tibial shaft fractures.

BACKGROUND: We assessed the value of measuring biomechanical stiffness by assessing the fixator's external deformation as an objective means for monitoring fracture healing and determining the postoperative treatment regime, as compared to clinical and radiographic means of evaluation. PATIENTS AND METHODS: One hundred patients with tibial shaft fractures managed by unilateral external fixation had their fracture stiffness monitored. Stiffness was measured and clinical and radiological examinations were performed every 3-4 weeks. RESULTS: The time required for healing as indicated by stiffness measurement was an average of 2.5 weeks earlier than by radiological assessment. Eighty-two patients healed within 19 weeks (12.1+/-3.3 weeks) and ten patients in the following 6 weeks (24+/-4.3 weeks). Eight patients did not show an increase in fracture stiffness and received intramedullary nailing at a second operation. The average healing time was 11.3+/-4 weeks for type A, 13.1+/-3.6 weeks for type B fractures, and 15.1+/-5.9 weeks for type C fractures. The healing time for closed fractures was 11.3+/-3.2 weeks and for open fractures 14+/-4.9 weeks. CONCLUSIONS: The measurement of fracture stiffness allows the detection of patients at risk for nonunions. The healing time increased with increasing fracture gap size and was less in patients with younger age, less complex fractures, and lesser degrees of soft tissue damage.

[Combined posterior and anterior endoscopic supported instrumentation of the thoracic and lumbar spine. Arguments, concepts and first clinical results]. / Die dorsoventrale endoskopisch unterstützte Instrumentation der BWS und LWS. Argumente, Versorgungskonzepte und erste klinische Ergebnisse.

The operative therapeutic principles of thoracic and lumbar spine injuries are based on reposition, decompression and stabilization of the unstable area. Secondary loss of correction and consecutive deformation have negative impact on the long-term results after defect fractures of vertebral bodies and will be minimized only by the reconstruction of all involved spinal columns. With dissemination of thoracoscopic techniques at the thoracic spine and minimal invasive retroperitoneal approaches at the lumbar spine a decrease of the morbidity was achieved with equal effectivity for recalibration and fusion. Our experiences with the first consecutive 42 patients, treated minimal invasive are presented. Indications for anterior thoracoscopic and minimal invasive instrumentations after posterior transfixation are remaining osseous defects of the end plates of more than a quarter of the volume of the involved vertebra in case of migration of the vertebral disc, wedging of the vertebral body after posterior reposition of more than 10 degrees and persisting anterior encroachment of the spinal canal of more than 30 %. The decision is based on radiographs and CT-scans, performed after posterior stabilization.

[Sources of error and risks in CT based navigation]. / Fehlerquellen und Gefahren der CT-basierten Navigation.

Based on the experience of 4 cervical, 102 thoracic/lumbar pedicle screw and 14 transiliosacral screw implantations all problems and complications were collected. Problems noted within the data collection in the preoperative CT were an incomplete acquisition of the surgical target (n = 3), an exceeding of the processable scan slices (n = 1) and a non focused field of view. Transmission of the CT datas often were documented as incomplete (n = 16). Segmentation of the CT dataset turned out to be the significant problem with incorrect differentiation of the bone-soft tissue transition (n = 2), where as the choice of the matching points and the trajectories did not provoke any mistakes in the planning modus. The intraoperative matching of both corresponding datasets was insufficient (n = 7), while the assignment of the CT dataset to the correct vertebral was not a major problem (n = 1). Navigation was not possible (n = 2) due to an instability of the spinal process. All fiducial based matching procedures (pelvis) were carried out without any problems. During intraoperative navigation potential complications resulted from deformation of instruments (n = 1) and interaction of instruments and the data reference base (n = 2). Further, the CT-based navigation of fractured vertebrae or unstable iliosacral joints is not safe, because dislocations between acquisition of the dataset and operation will lead to misguidance.

Spinal navigation in cervical fractures--a preliminary clinical study on Judet-osteosynthesis of the axis.

OBJECTIVE: To evaluate the accuracy of CT-based and computer-aided screw insertion into the pedicles of the axis using the method of Judet. Materials and Methods In two patients, four transpedicular implants of C2 were positioned using a computer-guided technique. One patient with iatrogenic destabilization of the posterior structures C3 and C4 and one patient with a hangman's fracture of the axis required pedicular fixation. In addition, intraoperative documentation of the additional time required for the navigation procedures was made. Finally, postoperative CTs of each patient provided further information about transpedicular implant localization. RESULTS: Image-guided implantation of screws was possible in all scheduled pedicles of the axis. In the postoperative CT scans, none of the inserted screws perforated the medial or lateral pedicle. All screws were accurately positioned within the pedicles, and no anterior perforation of the screws into the vertebral foramen was observed. CONCLUSIONS: Our initial results using computer-aided implantation of Judet screws showed that these screws were inserted correctly. However, it is important to realize that movements can occur in the vertebral arch and lateral mass during the time between preoperative CT and surgery. This possibility for movement should be taken into account when procedures such as CT-based insertion of image-guided screws into patients with fractures of the isthmus C2 are performed, because damage to neurovascular structures can result. Therefore, this navigation system should only be used by experienced surgeons who can, if necessary, continue the intervention with more conventional techniques. In addition, it is essential that the surgeon have a complete understanding of the principles of the tracking systems to prevent possible misinterpretation of computer-generated information.

Quantitative assessment of the expression of melanoma-associated antigens by non-competitive reverse transcription polymerase chain reaction.

The assessment of tumor-associated antigens (TAA) recognized by T lymphocytes is a prerequisite for diagnosis and immunotherapy of melanoma. Different reverse transcription-polymerase chain reaction (RT-PCR) protocols allowing the quantification of the TAA mRNA expression in the solid tumor or the detection of circulating melanoma cells have been described. We have recently shown a positive correlation between the amount of specific product formed by RT-PCR and the staining intensity in immunohistochemical analysis of the corresponding sample. Here we describe a quantification procedure based on the direct digitization of the PCR products after separation on ethidium bromide-stained agarose gels, followed by computer-assisted densitometry. To standardize our method, we examined the linear range of the densitometric quantification procedure as reflected by the correlation of signal intensity to the amount of the corresponding DNA. As an internal measure for the so-termed cDNA in the different samples after RNA isolation and reverse transcription, a beta-actin PCR was introduced. Subsequently, we chose four sets of primers for the melanoma-associated antigens MAGE1, tyrosinase, Melan A/MART-1 and gp100/Pmel17 and performed PCR analysis over a range of cycle numbers. In each case, the amplification rate remained constant up to at least 26 cycles under the respective conditions. Plotting the logarithm of the amount of product against the cycle number yields a slope that equals the logarithm of the amplification rate. The amount of starting material can be determined from the intercept with the ordinate. In summary, the method introduced in the present work allows the quantification of TAA in melanoma which might be important for the monitoring of disease. Technically the method is sound and sensitive, avoids post-PCR manipulations and can be performed with the standard equipment of a molecular biology laboratory. It can be applied also to other solid tumors and leukemias.

[Computer assisted surgery, 2001 development and prospects. Results of a congress at Reisensburg Castle, 23-24 November 2000]]. / Computer assistierte Chirurgie, Entwicklung und Perspektiven 2001. Ergebnisse einer Arbeitstagung auf Schloss Reisensburg, 23./24.11.2000.

The progress in computer assisted surgery (CAS) is influenced by new technologies in imaging as well as by the input of the users. At present, CAS procedures are established in dorsal spine instrumentation, prosthetics and long bone surgery. Present status and future of CAS was a topic of an expert meeting at the Reisensburg castle. Imaging will speed up in the future using multi-detector techniques. C-arm navigation will gain more information using the 3D technology intraoperatively. CT based navigation procedures are standard in spine and will be established in pelvic surgery. CAS in robotics at the moment means the use of robot-assistance. A new concept is the modality-based navigated surgery, which can be used at various skeletal locations. Visualization of patient data will improve using 3D semi-transparencies with real time update. In the future it will be mandatory to find algorithms to fuse the different possibilities and techniques. A new concept of surgical training is necessary to teach CAS procedures. Therefore discussion must go on to improve these systems.

[Computer-assisted surgery: developments and prospects in 2001. Results of a workshop at Schloss Reisenburg, 23-24 November 2000]. / Computer assistierte Chirurgie, Entwicklung und Perspektiven 2001. Ergebnisse einer Arbeitstagung auf Schloss Reisenburg, 23./24.11.2000.

The progress in computer assisted surgery (CAS) is influenced by new technologies in imaging as well as by the input of the users. At present, CAS procedures are established in dorsal spine instrumentation, prosthetics and long bone surgery. Present status and future of CAS was a topic of an expert meeting at the Reisensburg castle. Imaging will speed up in the future using multi-detector techniques. C-arm navigation will gain more information using the 3D technology intraoperatively. CT based navigation procedures are standard in spine and will be established in pelvic surgery. CAS in robotics at the moment means the use of robot-assistance. A new concept is the modality-based navigated surgery, which can be used at various skeletal locations. Visualization of patient data will improve using 3D semi-transparencies with real time update. In the future it will be mandatory to find algorithms to fuse the different possibilities and techniques. A new concept of surgical training is necessary to teach CAS procedures. Therefore discussion must go on to improve these systems.

[Surgical treatment of injuries of the thoracolumbar transition--3: Follow-up examination. Results of a prospective multi-center study by the "Spinal" Study Group of the German Society of Trauma Surgery]. / Operative Behandlung von Verletzungen des thorakolumbalen Ubergangs--Teil 3: Nachuntersuchung. Ergebnisse einer prospektiven multizentrischen Studie der Arbeitsgemeinschaft "Wirbelsäule" der Deutschen Gesellschaft für Unfallchirurgie.

OBJECTIVES: Prospective, multicenter study addressing late results after operative treatment of acute thoracolumbar spinal injuries. METHODS: 682 patients (T10-L2) were included and 372 (80%) were postoperatively followed for 2 1/4 years (4-61 months). RESULTS: Comparing the initially included patients (n = 682) with the study group (n = 372), no differences were observed and results were assumed to be representative. A C-type lesion or polytrauma significantly prolonged the hospital stay. The method of operative treatment did not affect the length of the rehabilitation period. Neurological improvement was observed in 3 out of 7 patients with complete, and in 44 out of 64 (69%) with incomplete lesion. The operative method did not affect the improvement rate. The physical capacity significantly decreased. After a mean of 1/2 year of disability only 71% returned to work. 48% returned to their preoperative physical level. The mean Hannover Spine Score was 68 points (preoperative 94, p < 0.001), indicating permanent impairment of function. The angle-stable internal fixator was superior in restoration of spinal alignment and best radiological results were noted after combined stabilization. Posterior stabilization lead to high re-kyphosing. No correlations between radiologic and clinical parameters were observed. CONCLUSIONS: All treatment methods under study were appropriate for achieving comparable clinical and functional outcome. The internal fixator is superior in restoration of the spinal alignment. Best radiological outcome is achieved by combined stabilization. Merely by direct reconstruction of the anterior column the postoperative re-kyphosing is prevented and a gain in segmental angle is achieved.

[Incidence of complications of the screw osteosynthesis of odontoid process fractures]. / Inzidenz von Komplikationen der Schraubenosteosynthese von Frakturen des Dens axis, Literaturübersicht, Germany.

In this retrospective clinical study the incidence of complications in 58 consecutive, with anterior screw fixation stabilized patients after fractures of the odontoid process is evaluated. In 51 patients the fracture has been defined as type II according to Anderson, in 6 patients an oblique type II fracture was present and one patient showed a cephalad type III fracture. Preoperatively, in only 19 % of the patients (n = 11) no dislocation of the dens occurred. 32 patients were treated with single screw osteosynthesis, in 26 patients two screws were implanted. Significant complications with clinical relevance were registered in 14 patients (24 %), in 10 cases (17 %) an operative reintervention was required. Intraoperatively, in one patient a rupture of the carotid artery while winding around the motor drill occurred and in another case a complete malplacement of the screw posteriorly to the odontoid process was observed. A clearly excentric positioning of the implant was evaluated in 5 patients with a consecutive high rate of implant migration (n = 3). Two patients died perioperatively not related to the cervical injury. Postoperatively, one patient with a wound infection due to an iatrogenic perforation of the esophagus required reoperation as well as 4 patients with instability because of implant migration. Patients beyond the age of 65 years (n = 3) were significantly overrepresented in that group. In one case, the secondary intervention was caused by a pseudarthrosis of the dens axis. Complications without any relevance to the clinical and functional long term result were fusions in malposition of the odontoid process in 14 patients (24 %) and 10 (17 %) marginal screw perforations laterally. Differences in the use of one or two screws have not been observed in this study, although the investigations showed a tendency between marginal lateral screw perforations and double screw osteosynthesis and an increasing number of complications in the geriatric cohort.

Early inflammatory mediator response following isolated traumatic brain injury and other major trauma in humans.

The inflammatory response following isolated traumatic brain injury (TBI) is characterised by the release of pro- and anti-inflammatory mediators. In order to determine the important mediators regarding survival and outcome of patients with severe traumatic isolated head injuries, we performed this prospective preclinical and clinical study starting upon arrival at the site of the accident. After approval by the local ethics board committee, 94 multiple-injury patients were enrolled. Of these, 72 patients suffered from major injuries; the other 22 patients had a severe isolated brain injury and were allotted to subsets of survival or nonsurvival. Of the pro- and anti-inflammatory mediators (cytokines, arachidonic acid metabolites and soluble adhesion molecules), interleukin-6 (IL-6), IL-12 and malone dialdehyde (MDA) appeared to be of specific importance; maximum IL-6 plasma levels were eightfold higher in cases of nonsurvival than in those of survival. Patients that did not survive TBI were the only ones to express an IL-12 increase, whereas survivors and patients with other major trauma did not show any increase within the first 24 h. An early distinct decrease of MDA showed in patients who did not survive TBI, in contrast to survivor patients who exposed almost constant levels during the first 24 h.

Combined anteroposterior spinal fixation provides superior stabilisation to a single anterior or posterior procedure.

Fusion is the main goal in the surgical management of the injured and unstable spine. A wide variety of implants is available to enhance this. Our study was performed to evaluate the stabilising characteristics of several anterior, posterior and combined systems of fixation. Six thoracolumbar (T11 to L2) spines from 13-week-old calves were first tested intact. Then the vertebral body of T13 was removed and the defect replaced and supported by a wooden block to simulate bone grafting. Dorsal implants consisting of a Universal Spine System (USS) fracture system and an AO Fixateur interne (AOFI), and ventral implants comprising of a Kaneda Classic, a Kaneda SR, a prototype of the VentroFix single clamp/single rod construct (SC/SR) and the VentroFix single clamp/double rod construct (SC/DR) were first implanted individually to stabilise the removal of the vertebral body. Simulating the combined anteroposterior stabilisations, all ventral implants were combined with the AOFI. The range of motion (ROM) was measured under loads of up to 7.5 Nm. The load was applied in a custom-made spine tester in the three primary directions while measuring the intervertebral movements using a goniometric linkage system. The dorsal systems limited ROM in flexion below 0.9 degrees and in extension between 3.3 degrees and 3.6 degrees (median values). The improved Kaneda System SR yielded a mean ROM of 1.8 degrees in flexion and in extension. The median rotation found with the VentroFix (SC/DR) was 3.2 degrees for flexion and 2.8 degrees for extension. Reinforcement of the ventral constructs with a dorsal system reduced the ROM in flexion and extension in all cases to 0.4 degrees and lower. In rotation, the median ROM of the anterior systems ranged from 2.7 degrees to 5.1 degrees and for the posterior systems from 3.9 degrees to 5.7 degrees, while the combinations provided a ROM of 1.2 degrees to 1.9 degrees. In lateral bending, the posterior implants restricted movement to 1.1 degrees, whereas the anterior implants allowed up to 5.2 degrees. The combined systems provided the highest stability at less than 0.6 degrees. Our study revealed distinct differences between posterior and anterior approaches in all primary directions. Also, different stabilisation characteristics were found within the anterior and posterior groups. Combinations of these two approaches provided the highest stability in all directions.