Polarisation compensation in non-planar image-rotating OPO ring resonators.

Non-planar image-rotating OPO ring resonators necessitate polarisation compensation in contrast to their planar counterparts. This is essential for maintaining phase matching conditions for non-linear optical conversion in the resonator during each cavity round trip. In this study, we examine the polarisation compensation and its impact on the performance of two types of non-planar resonators: RISTRA with a π2 image rotation and FIRE with a fractional image rotation (π2 fraction). The RISTRA is insensitive to mirror phase shifts, while the FIRE has a more complex dependence of polarisation rotation on mirror phase shifts. There has been debate over whether a single birefringent element can provide adequate polarisation compensation for non-planar resonators beyond RISTRA-type. Our results show that under certain experimentally feasible conditions, even FIRE resonators can achieve adequate polarisation compensation with a single half-wave plate. We validate our theoretical analysis through numerical simulations and experimental studies of OPO output beam polarisation using ZnGeP2 non-linear crystals.

OF-Pelvis classification of osteoporotic sacral and pelvic ring fractures.

OBJECTIVES: Osteoporotic fractures of the pelvis (OFP) are an increasing issue in orthopedics. Current classification systems (CS) are mostly CT-based and complex and offer only moderate to substantial inter-rater reliability (interRR) and intra-rater reliability (intraRR). MRI is thus gaining importance as a complement. This study aimed to develop a simple and reliable CT- and MRI-based CS for OFP. METHODS: A structured iterative procedure was conducted to reach a consensus among German-speaking spinal and pelvic trauma experts over 5 years. As a result, the proposed OF-Pelvis CS was developed. To assess its reliability, 28 experienced trauma and orthopedic surgeons categorized 25 anonymized cases using X-ray, CT, and MRI scans twice via online surveys. A period of 4 weeks separated the completion of the first from the second survey, and the cases were presented in an altered order. While 13 of the raters were also involved in developing the CS (developing raters (DR)), 15 user raters (UR) were not deeply involved in the development process. To assess the interRR of the OF-Pelvis categories, Fleiss' kappa (κF) was calculated for each survey. The intraRR for both surveys was calculated for each rater using Kendall's tau (τK). The presence of a modifier was calculated with κF for interRR and Cohen's kappa (κC) for intraRR. RESULTS: The OF-Pelvis consists of five subgroups and three modifiers. Instability increases from subgroups 1 (OF1) to 5 (OF5) and by a given modifier. The three modifiers can be assigned alone or in combination. In both surveys, the interRR for subgroups was substantial: κF = 0.764 (Survey 1) and κF = 0.790 (Survey 2). The interRR of the DR and UR was nearly on par (κF Survey 1/Survey 2: DR 0.776/0.813; UR 0.748/0.766). The agreement for each of the five subgroups was also strong (κF min.-max. Survey 1/Survey 2: 0.708-0.827/0.747-0.852). The existence of at least one modifier was rated with substantial agreement (κF Survey 1/Survey 2: 0.646/0.629). The intraRR for subgroups showed almost perfect agreement (τK = 0.894, DR: τK = 0.901, UR: τK = 0.889). The modifier had an intraRR of κC = 0.684 (DR: κC = 0.723, UR: κC = 0.651), which is also considered substantial. CONCLUSION: The OF-Pelvis is a reliable tool to categorize OFP with substantial interRR and almost perfect intraRR. The similar reliabilities between experienced DRs and URs demonstrate that the training status of the user is not important. However, it may be a reliable basis for an indication of the treatment score.

Cement augmentation as revision strategy for loosened thick-diameter non-fenestrated iliac screws - A biomechanical analysis.

BACKGROUND: Loosened/pulled-out iliac screws can be a challenging complication, as revision opportunities are limited because more distal anchorage is impossible. Insertion of thick-diameter screws is an option in cases with loosened thin-diameter screws. However, this is occasionally infeasible in patients with loosened thick-diameter screws. Therefore, this study aimed to biomechanically analyze whether loosened/pulled-out thick iliac screws regain strong anchorage following cement augmentation. METHODS: Six human pelvis specimens were dissected to isolate 12 hemipelves, and 9 × 80 mm iliac screws were implanted. The pullout maneuver was performed followed by cement augmentation of the same screw within the same screw hole. After cement hardening, pullout was performed again. Forces needed for pullout and the insertion torque were measured for the 12 iliac screws. FINDINGS: Cement augmentation significantly increased stability, with the pullout forces required being as high as 953.23 N (standard deviation [SD] 1070.46 N; median 306.30 N) for the uncemented screws and 2897.53 N (SD 585.83 N; median 2907.81 N) after cement augmentation (p < 0.001). No correlation was found between insertion torques and pullout forces. INTERPRETATION: While revision of loosened iliac screws can often be achieved using higher diameters, this method is limited by the thickness of the screws already in place. We demonstrated that cement augmentation significantly increases stability even in thick-diameter screws, achieving more pullout stability than before the initial pullout. This method may be a cost-effective and rapid option for revision, even with significant defects and with no thicker-diameter iliac screw being available.

A new minimally invasive U-shaped lumbopelvic stabilization technique.

Lumbopelvic stabilization is a surgical technique used frequently to treat lumbosacral fractures; however, it can also be used in revision cases, infections, or during deformity correction. However, the related soft tissue complication rates associated with open lumbopelvic stabilization are high. Different authors have recently reported minimally invasive surgical techniques. We developed a rigid minimally invasive technique for lumbopelvic stabilization. We present our technique and also present preliminary results from 10 cases. We did not observe soft tissue-related complications in any patient. Implant removal was performed twice, to release healthy disks and because of implant prominence. One patient required revision surgery because of implant loosening due to osteoporosis, and one patient required revision surgery due to screw cap loosening. Postsurgical mobilization was good in all patients without further injuries; however, polytraumatized patients were limited by additional injuries. Thus, minimally invasive U-shaped lumbopelvic stabilization is a useful technique combining the soft tissue-related advantages of minimally invasive surgical techniques as well as a theoretically very rigid construct caused by strong implants.

Recommendations for the Diagnostic Testing and Therapy of Atlas Fractures. / Empfehlungen zur Diagnostik und Therapie oberer Halswirbelsäulenverletzungen: Atlasfrakturen.

In a consensus process with four sessions in 2017, the working group on "the upper cervical spine" of the German Society for Orthopaedic and Trauma Surgery (DGOU) formulated "Therapeutic Recommendations for the Diagnosis and Treatment of Fractures to the Upper Cervical Spine", incorporating their own experience and current literature. The following article describes the recommendations for the atlas vertebra. About 10% of all cervical spine injuries include the axis vertebra. The diagnostic process primarily aims to detect the injury and to determine joint incongruency and integrity of the atlas ring. For classification purposes, the Gehweiler classification and the Dickman classification are suitable. The Canadian c-spine rule is recommended for clinical screening for c-spine injuries. CT is the preferred imaging modality; MRI is needed to determine the integrity of the Lig. transversum atlantis in complete atlas ring fractures. Conservative treatment is appropriate in very many atlas fractures. Surgical treatment is recommended in existing or potential joint incongruity or instability, which are frequently seen in Gehweiler IIIB or Gehweiler IV fractures. Posterior atlanto-axial stabilisation and fusion using transarticular screws or an internal fixator are regarded as a gold standard in the majority of surgical cases. Especially in young patients, the possibility of isolated atlas osteosynthesis should be checked. A possible option for Gehweiler IV fractures is halo-fixation with mild distraction for ligamentotaxis. Secondary dislocation should be checked for frequently. Involvement of the occipito-atlantal joint complex requires stabilisation of the occiput as well.

Treatment of Injuries to the Subaxial Cervical Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU).

STUDY DESIGN: Expert consensus. OBJECTIVES: To establish treatment recommendations for subaxial cervical spine injuries based on current literature and the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma. METHODS: This recommendation summarizes the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma. RESULTS: Therapeutic goals are a stable, painless cervical spine and protection against secondary neurologic damage while retaining maximum possible motion and spinal profile. The AOSpine classification for subaxial cervical injuries is recommended. The Canadian C-Spine Rule is recommended to decide on the need for imaging. Computed tomography is the favoured modality. Conventional x-ray is preserved for cases lacking a "dangerous mechanism of injury." Magnetic resonance imaging is recommended in case of unexplained neurologic deficit, prior to closed reduction and to exclude disco-ligamentous injuries. Computed tomography angiography is recommended in high-grade facet joint injuries or in the presence of vertebra-basilar symptoms. A0-, A1- and A2-injuries are treated conservatively, but have to be monitored for progressive kyphosis. A3 injuries are operated in the majority of cases. A4- and B- and C-type injuries are treated surgically. Most injuries can be treated with anterior plate stabilization and interbody support; A4 fractures need vertebral body replacement. In certain cases, additive or pure posterior instrumentation is needed. Usually, lateral mass screws suffice. A navigation system is advised for pedicle screws from C3 to C6. CONCLUSIONS: These recommendations provide a framework for the treatment of subaxial cervical spine Injuries. They give advice about diagnostic measures and the therapeutic strategy.

Classification of Osteoporotic Thoracolumbar Spine Fractures: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU).

STUDY DESIGN: Expert opinion. OBJECTIVES: Osteoporotic vertebral fractures are of increasing medical importance. For an adequate treatment strategy, an easy and reliable classification is needed. METHODS: The working group "Osteoporotic Fractures" of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU) has developed a classification system (OF classification) for osteoporotic thoracolumbar fractures. The consensus decision followed an established pathway including review of the current literature. RESULTS: The OF classification consists of 5 groups: OF 1, no vertebral deformation (vertebral edema); OF 2, deformation with no or minor (<1/5) involvement of the posterior wall; OF 3, deformation with distinct involvement (>1/5) of the posterior wall; OF 4, loss of integrity of the vertebral frame or vertebral body collapse or pincer-type fracture; OF 5, injuries with distraction or rotation. The interobserver reliability was substantial (κ = .63). CONCLUSIONS: The proposed OF classification is easy to use and provides superior clinical differentiation of the typical osteoporotic fracture morphologies.

Treatment of Fractures of the Thoracolumbar Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU).

STUDY DESIGN: consensus paper with systematic literature review. OBJECTIVE: The aim of this study was to establish recommendations for treatment of thoracolumbar spine fractures based on systematic review of current literature and consensus of several spine surgery experts. METHODS: The project was initiated in September 2008 and published in Germany in 2011. It was redone in 2017 based on systematic literature review, including new AOSpine classification. Members of the expert group were recruited from all over Germany working in hospitals of all levels of care. In total, the consensus process included 9 meetings and 20 hours of video conferences. RESULTS: As regards existing studies with highest level of evidence, a clear recommendation regarding treatment (operative vs conservative) or regarding type of surgery (posterior vs anterior vs combined anterior-posterior) cannot be given. Treatment has to be indicated individually based on clinical presentation, general condition of the patient, and radiological parameters. The following specific parameters have to be regarded and are proposed as morphological modifiers in addition to AOSpine classification: sagittal and coronal alignment of spine, degree of vertebral body destruction, stenosis of spinal canal, and intervertebral disc lesion. Meanwhile, the recommendations are used as standard algorithm in many German spine clinics and trauma centers. CONCLUSION: Clinical presentation and general condition of the patient are basic requirements for decision making. Additionally, treatment recommendations offer the physician a standardized, reproducible, and in Germany commonly accepted algorithm based on AOSpine classification and 4 morphological modifiers.

Recommendations for Diagnosis and Treatment of Fractures of the Ring of Axis. / Empfehlungen zur Diagnostik und Therapie oberer Halswirbelsäulenverletzungen: Axisringfrakturen.

In a consensus process with four sessions in 2017, the working group "upper cervical spine" of the German Society for Orthopaedics and Trauma Surgery (DGOU) formulated "Therapeutic Recommendations for the Diagnosis and Treatment of Upper Cervical Fractures", taking their own experience and the current literature into consideration. The following article describes the recommendations for axis ring fractures (traumatic spondylolysis C2). About 19 to 49% of all cervical spine injuries include the axis vertebra. Traumatic spondylolysis of C2 may include potential discoligamentous instability C2/3. The primary aim of the diagnostic process is to detect the injury and to determine potential disco-ligamentous instability C2/3. For classification purposes, the Josten classification or the modified Effendi classification may be used. The Canadian C-spine rule is recommended for clinical screening for C-spine injuries. CT is the preferred imaging modality and an MRI is needed to determine the integrity of the discoligamentous complex C2/3. Conservative treatment is appropriate in case of stable fractures with intact C2/3 motion segment (Josten type 2 and 2). Patients should be closely monitored, in order to detect secondary dislocation as early as possible. Surgical treatment is recommended in cases of primary severe fracture dislocation or discoligamentous instability C2/3 (Josten 3 and 4) and/or secondary fracture dislocation. Anterior cervical decompression and fusion (ACDF) C2/3 is the treatment of choice. However, in case of facet joint luxation C2/3 with looked facet (Josten 4), a primary posterior approach may be necessary.

Site-specific binding of a water molecule to the sulfa drugs sulfamethoxazole and sulfisoxazole: a laser-desorption isomer-specific UV and IR study.

To determine the preferred water molecule binding sites of the polybasic sulfa drugs sulfamethoxazole (SMX) and sulfisoxazole (SIX), we have studied their monomers and monohydrated complexes through laser-desorption conformer-specific UV and IR spectroscopy. Both the SMX and SIX monomer adopt a single conformer in the molecular beam. On the basis of their conformer-specific IR spectra in the NH stretch region, these conformers were assigned to the SMX and SIX global minimum structures, both exhibiting a staggered sulfonamide group and an intramolecular C-HO[double bond, length as m-dash]S hydrogen bond. The SMX-H2O and SIX-H2O complexes each adopt a single isomer in the molecular beam. Their isomeric structures were determined based on their isomer-specific IR spectra in the NH/OH stretch region. Quantum Theory of Atoms in Molecules analysis of the calculated electron densities revealed that in the SMX-H2O complex the water molecule donates an O-HN hydrogen bond to the heterocycle nitrogen atom and accepts an N-HO hydrogen bond from the sulfonamide NH group. In the SIX-H2O complex, however, the water molecule does not bind to the heterocycle but instead donates an O-HO[double bond, length as m-dash]S hydrogen bond to the sulfonamide group and accepts an N-HO hydrogen bond from the sulfonamide NH group. Both water complexes are additionally stabilized by a Cph-HOH2 hydrogen bond. Interacting Quantum Atoms analysis suggests that all intermolecular hydrogen bonds are dominated by the short-range exchange-correlation contribution.

Design considerations for a novel shape-memory-plate osteosynthesis allowing for non-invasive alteration of bending stiffness.

Biomechanical stimuli play a major role in fracture healing. Changing the fixation stiffness through the course of healing might accelerate bone healing and prevent healing complications. Shape memory alloy (SMA) based implants were developed to allow for non-invasive stiffness alteration during the fracture healing process. To gain a deeper understanding of the implant functionality based on the alloy characteristics and geometric design, the mechanical properties of different shape memory alloys where mechanically characterized. SMA bone plates were manufactured and the structural bending stiffness of the implants was determined at different temperatures and configurations. The temperature required for complete recovery of shape after deformation increased continuously with increasing pseudo-plastic deformation in SMA probes. Full recovery was observed at temperatures ranging from 38°C to 52°C after pseudo-plastic deformations ranging from 0.2% to 1.0% outer fibre strain, respectively. The small fragment inverse-dynamisation implants revealed bending stiffnesses ranging from 0.09Nm2 to 0.34Nm2 in the initial state and from 0.16Nm2 to 0.46Nm2 after shape alteration. Dependent on the design, a relative gain of the implant stiffness ranging from 18.8% to 115.0% could be observed. The large inverse-dynamisation implants revealed bending stiffnesses from 3.7Nm2 to 7.1Nm2 before and 4.1Nm2 to 12.6Nm2 after triggering the shape memory effect. Dependent on the design a gain in stiffness from 11.8% to 117.2% was observed. Warming the SMA implant to 40°C for a short period of time, leads to a moderate increase in implant stiffness of up to 64.5%, while triggering the implant with 50°C leads to a maximum increase in stiffness of up to 127.3%. The Nitinol shape memory bone plates have a huge potential for improving the treatment of long shaft fractures by allowing for the increase, decrease or incremental change of implant stiffness in fracture stabilization. However, the interaction between design, material properties, and manufacturing processes need to be carefully considered for each specific application to achieve optimum function of SMA-based, stiffness altering, fracture-fixation implants.

[Subaxial Cervical Spine Injuries: Treatment Recommendations of the German Orthopedic and Trauma Society]. / Therapieempfehlungen zur Versorgung von Verletzungen der subaxialen Halswirbelsäule.

In a consensus process during four sessions in 2016, the working group "lower cervical spine" of the German Society for Orthopedic and Trauma Surgery (DGOU), formulated "Therapeutic Recommendations for the Lower Cervical Spine", taking into consideration the current literature. Therapeutic goals are a permanently stable, painless cervical spine and the protection against secondary neurologic damage while retaining the greatest possible amount of motion and spinal profile. Due to its ease of use and its proven good reliability, the AOSpine classification for subaxial cervical injuries should be used. The Canadian C-Spine Rule is recommended as a clinical decision rule whether to perform imaging or not. If a structural or unstable injury is suspected by patient history or clinical findings, a spiral CT scan of the cervical spine is the favoured diagnostic modality. Conventional X-ray is reserved for patients in whom there is no "dangerous mechanism of injury". MR imaging is recommended in case of unexplained neurologic deficit, prior to closed reduction and open posterior surgery and to exclude disco-ligamentous injuries. Urgency of MR imaging depends on the specific findings. CT angiography is recommended in higher-grade facet joint injuries or in the presence of vertebra-basilar symptoms. Flexion-extension imaging is recommended only as a physician-guided dynamic fluoroscopy, when an unstable lesion is still suspected. The therapeutic strategy is mainly dependent on morphologic criteria, which are described using the AOSpine classification. A0-injuries are treated conservatively. A1- and A2-injuries are treated conservatively in the majority of cases, and in single cases a gross kyphotic deformity might indicate surgical stabilisation. A3-injuries do indicate a surgical therapy in the majority of cases, but certain cases might be treated conservatively. A4-fractures as well as B- and C-type injuries are to be treated surgically. Most injuries can be treated by anterior plate stabilisation with interbody support; when a complete burst fracture is present, corpectomy and vertebral body replacement is necessary. In certain cases, an additive posterior or pure posterior instrumentation might be possible or even mandatory. In most of these cases, lateral mass screws are sufficient; when pedicle screws are applied in C3 to C6, a 3D-navigation system is recommended. Injuries in an ankylosing spine (M3-modifier) should be treated preferably from posterior with long-segment instrumentation.

Laser desorption single-conformation UV and IR spectroscopy of the sulfonamide drug sulfanilamide, the sulfanilamide-water complex, and the sulfanilamide dimer.

We have studied the conformational preferences of the sulfonamide drug sulfanilamide, its dimer, and its monohydrated complex through laser desorption single-conformation UV and IR spectroscopy in a molecular beam. Based on potential energy curves for the inversion of the anilinic and the sulfonamide NH2 groups calculated at DFT level, we suggest that the zero-point level wave function of the sulfanilamide monomer is appreciably delocalized over all four conformer wells. The sulfanilamide dimer, and the monohydrated complex each exhibit a single isomer in the molecular beam. The isomeric structures of the sulfanilamide dimer and the monohydrated sulfanilamide complex were assigned based on their conformer-specific IR spectra in the NH and OH stretch region. Quantum Theory of Atoms in Molecules (QTAIM) analysis of the calculated electron density in the water complex suggests that the water molecule is bound side-on in a hydrogen bonding pocket, donating one O-HO[double bond, length as m-dash]S hydrogen bond and accepting two hydrogen bonds, a NHO and a CHO hydrogen bond. QTAIM analysis of the dimer electron density suggests that the Ci symmetry dimer structure exhibits two dominating N-HO[double bond, length as m-dash]S hydrogen bonds, and three weaker types of interactions: two CHO bonds, two CHN bonds, and a chalcogen OO interaction. Most interestingly, the molecular beam dimer structure closely resembles the R dimer unit - the dimer unit with the greatest interaction energy - of the α, γ, and δ crystal polymorphs. Interacting Quantum Atoms analysis provides evidence that the total intermolecular interaction in the dimer is dominated by the short-range exchange-correlation contribution.

BMP-2-transduced human bone marrow stem cells enhance neo-bone formation in a rat critical-sized femur defect.

Synthetic graft materials are considered as possible substitutes for cancellous bone, but lack osteogenic and osteoinductive properties. In this study, we investigated how composite scaffolds of ßTCP containing osteogenic human bone marrow mesenchymal stem cells (hBMSCs) and osteoinductive bone morphogenetic protein-2 (BMP-2) influenced the process of fracture healing. hBMSCs were loaded into ßTCP scaffolds 24 h before implantation in a rat critical-sized bone defect. hBMSCs were either stimulated with rhBMP-2 or transduced with BMP-2 by gene transfer. The effect of both protein stimulation and gene transfer was compared for osteogenic outcome. X-rays were conducted at weeks 0, 1, 3, 6, 9 and 12 post-operatively. In addition, bone-labelling fluorochromes were applied at 0, 3, 6 and 9 weeks. Histological analysis was performed for the amount of callus tissue and cartilage formation. At 6 weeks, the critical-sized defect in 33% of the rats treated with the Ad-BMP-2-transduced hBMSCs/ßTCP scaffolds was radiographically bridged. In contrast, in only 10% of the rats treated with rhBMP2/hBMSCs, 12 weeks post-treatment, the bone defect was closed in all treated rats of the Ad-BMP-2 group except for one. Histology showed significantly higher amounts of callus formation in both Ad-BMP-2- and rhBMP-2-treated rats. The amount of neocartilage was less pronounced in both BMP-2-related groups. In summary, scaffolds with BMP-2-transduced hBMSCs performed better than those with the rhBMP2/hBMSCs protein. These results suggest that combinations of osteoconductive biomaterials with genetically modified MSCs capable of secreting osteoinductive proteins may represent a promising alternative for bone regeneration. Copyright © 2015 John Wiley & Sons, Ltd.

A nickel-titanium shape memory alloy plate for contactless inverse dynamization after internal fixation in a sheep tibia fracture model: A pilot study.

BACKGROUND: Inverse dynamization has recently been proposed for the treatment of tibia non-unions. Nickel-titanium (NiTi) shape memory alloys (SMAs) may provide an opportunity for contactless non-invasive alteration of the stiffness of an implant after surgery. OBJECTIVE: The aim of this pilot study was to analyze the feasibility of the one way shape memory effect in a large animal as well as the feasibility of our ovine large animal fracture model. METHODS: A tibia osteotomy was performed in three sheep, followed by NiTi plate osteosynthesis in two cases and standard locking compression plate (LCP) osteosynthesis in one sheep. Contactless induction heating was performed after 3 weeks in order to alter the stiffness of the NiTi plates. Euthanasia was followed by biomechanical analysis after 8 weeks. RESULTS: Successful change of configuration through contactless induction heating was shown in both SMA plates by image intensifier control. Although large differences in bending and torsional stiffness were observed between the operated and contralateral tibia, the sheep ambulated almost normally at six weeks post-operative. CONCLUSION: We were able to trigger the one way shape memory effect which non-invasively altered the stiffness of the plate osteosynthesis.

A Novel Shape Memory Plate Osteosynthesis for Noninvasive Modulation of Fixation Stiffness in a Rabbit Tibia Osteotomy Model.

UNLABELLED: Nickel-titanium shape memory alloy (NiTi-SMA) implants might allow modulating fracture healing, changing their stiffness through alteration of both elastic modulus and cross-sectional shape by employing the shape memory effect (SME). HYPOTHESES: a novel NiTi-SMA plate stabilizes tibia osteotomies in rabbits. After noninvasive electromagnetic induction heating the alloy exhibits the SME and the plate changes towards higher stiffness (inverse dynamization) resulting in increased fixation stiffness and equal or better bony healing. In 14 rabbits, 1.0 mm tibia osteotomies were fixed with our experimental plate. Animals were randomised for control or induction heating at three weeks postoperatively. Repetitive X-ray imaging and in vivo measurements of bending stiffness were performed. After sacrifice at 8 weeks, macroscopic evaluation, µCT, and post mortem bending tests of the tibiae were carried out. One death and one early implant dislocation occurred. Following electromagnetic induction heating, radiographic and macroscopic changes of the implant proved successful SME activation. All osteotomies healed. In the treatment group, bending stiffness increased over time. Differences between groups were not significant. In conclusion, we demonstrated successful healing of rabbit tibia osteotomies using our novel NiTi-SMA plate. We demonstrated shape-changing SME in-vivo through transcutaneous electromagnetic induction heating. Thus, future orthopaedic implants could be modified without additional surgery.

Incidence of posttraumatic stress disorder after traffic accidents in Germany.

Posttraumatic stress disorder (PTSD) is possibly an overlooked diagnosis of victims suffering from traffic accidents sustaining serious to severe injuries. This paper investigates the incidence of PTSD after traffic accidents in Germany. Data from an accident research unit were analyzed in regard to collision details, and preclinical and clinical data. Preclinical data included details on crash circumstances and estimated injury severity as well as data on victims' conditions (e.g. heart rate, blood pressure, consciousness, breath rate). Clinical data included initial assessment in the emergency department, radiographic diagnoses, and basic life parameters comparable to the preclinical data as well as follow-up data on the daily ward. Data were collected in the German-In-Depth Accident Research study, and included gender, type of accident (e.g. type of vehicle, road conditions, rural or urban area), mental disorder, and AIS (Abbreviated Injury Scale) head score. AIS represent a scoring system to measure the injury severity of traffic accident victims. A total 258 out of 32807 data sets were included in this analysis. Data on accident and victims was collected on scene by specialized teams following established algorithms. Besides higher AIS Head scores for male motorcyclists compared to all other subgroups, no significant correlation was found between the mean maximum AIS score and the occurrence of PTSD. Furthermore, there was no correlation between higher AIS head scores, gender, or involvement in road traffic accidents and PTSD. In our study the overall incidence of PTSD after road traffic accidents was very low (0.78% in a total of 32.807 collected data sets) when compared to other published studies. The reason for this very low incidence of PTSD in our patient sample could be seen in an underestimation of the psychophysiological impact of traffic accidents on patients. Patients suffering from direct experiences of traumatic events such as a traffic accident and presenting with signs of clinically significant distress or impairment in social interactions should be treated in a team approach including not only trauma surgeons and surgical skilled staff but also psychophysiological experienced physicians.

Transcutaneous electromagnetic induction heating of an intramedullary nickel-titanium shape memory implant.

PURPOSE: Inadequate mechanical stimuli are a major cause for nonunions following surgery for femoral and tibial shaft fractures. Adapting fixation rigidity during the course of fracture healing requires additional surgery. Nickel-titanium (NiTi) implants can change shape and rigidity by employing a temperature-dependent shape-memory effect. As a first step in the development of advanced intramedullary (IM) NiTi devices for fracture healing, this study aimed to test the feasibility and safety of transcutaneous electromagnetic induction heating of an IM NiTi implant in a rat model. METHODS: In 51 rats, NiTi implants were introduced into the left distal femur. Forty-four animals were transferred to an induction coil, and the implant was electromagnetically heated to temperatures between 40° and 60 °C Blood samples were drawn before and four hours after the procedure. Interleukin (IL)-1, IL-4, IL-10, tumour necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) were measured. Animals were sacrificed at three weeks. Histological specimens from the hind leg and liver were retrieved and examined for inflammatory changes, necrosis or corrosion pits. RESULTS: All animals successfully underwent the surgical procedure. Following transcutaneous induction heating, target temperature was confirmed in 37/44 rats. Postoperative controls showed no signs of undue limitations. Neither cytokine measurements nor histological specimens showed any significant differences between groups. There were no corrosion pits or necrosis. CONCLUSION: We conclude that electromagnetic induction heating of IM NiTi implants is feasible and safe in a rat femur model. These findings reflect a further step in the development of novel concepts for IM fracture fixation that might lead to better fracture healing, less patient discomfort and less need for surgical interventions.