Accuracy of screw stabilization of the dorsal pelvic ring using a hybrid operating room: 5 Year experience in a level 1 trauma center

INTRODUCTION

Accuracy for screw placement in the dorsal pelvic ring can be enhanced using intraoperative 3D navigation. Advances in intraoperative imaging lead to benefits for pelvic surgery. New c-arms are equipped with flat panel detectors, which have a larger detector and assure higher image quality with accompanying dose reduction. A hybrid OR is defined by a fixed imaging system in an operating room providing the benefit of the surgical environment in combination with advanced intraoperative imaging. Aim of our investigation was to analyze the accuracy of navigated sacroiliac (SI) and transsacral transiliac (TSTI) screws in the dorsal pelvic ring, which were implanted with a hybrid OR in the first five years of use.

MATERIAL AND METHODS

All percutaneous SI or TSTI screws implanted in the hybrid OR using intraoperative navigation in the first 5 years of utilization (between June 2012 to June 2017) were included. Intraoperative 3D-scans and postoperative computed tomography were examined for screw perforation.

RESULTS

210 SI and TSTI screws were implanted in 187 patients using intraoperative navigation in the hybrid-OR. 90.6 % of SI screws showed no cortical perforation. 6,3 % had a grade 1, 2.4 % a grade 2 and 0.8 % a grade 3 perforation. In 80.7 % of TSTI screws no perforation and in 13.3 % a grade 1 perforation was detected. 3.6 % showed a grade 2 and 2.4 % a grade 3 perforation. No significant difference between both screw types regarding the grade of cortical perforation could be seen. No significant relation between perforation rate and year of operation could be detected.

CONCLUSION

Intraoperative navigation in a hybrid OR ensures a high accuracy for SI screws. Due to the large field of view and high image quality TSTI screws can be safely implanted in S1 and S2. Utilization of a hybrid-OR is accompanied with a steep learning curve.

Cement augmentation of the proximal femur nail antirotation: is it safe?

BACKGROUND

Cement augmentation of the proximal femur nail antirotation (PFNA; Fa. DePuy Synthes) showed good biomechanical and clinical results regarding increased stability and functional outcome [Linden et al. in J Orthop Res 24:2230-2237, 2006;Kammerlander et al. in Injury 49:1436-1444, 2018;]. Cement-associated complications are well known in orthopedic procedures like hip arthroplasty, vertebra- and kyphoplasty. This study investigates outcome and safety of augmentation of the proximal femur nail blade.

MATERIALS AND METHODS

The retrospective review of the 299 patients (mean age 80 ± 13 years; 205 women and 94 men) focused on perioperative complications after augmentation which was performed with Traumacem V+ Cement (Fa. DePuy Synthes) in 152 cases. The decision for augmentation of the blade was made by the attending surgeon and based on the factors age, bone quality, and fracture pattern. Primary outcome measures were changes in blood pressure, heart rate or oxygen saturation, and the number of needed vasoactive drugs during augmentation. Secondary outcome measures where the rate of cement leakage into the joint, mechanical failure, and perioperative complications like pulmonary embolism, stroke, or heart attack.

RESULTS

In 152 augmented cases, no leakage of cement into the joint could be detected. No signs of mechanical failure like cut-out of the blade were seen after 6 weeks and 3 months. Also, augmentation did not show a higher rate of mortality or postoperative complications like stroke, heart attack, embolism, or infection. 57 of 152 augmented cases received an intraoperative intervention with vasoactive medication at the time of augmentation either prophylactically or because of a blood pressure fall. Out of the non-augmented cases, 21 of 147 needed vasoactive medication in the second half of the operation. The difference between these groups was significant (p < 0.05). In the cases without an intervention, there was a significant blood pressure fall of about 8 ± 7.4 mmHg during the augmentation (p < 0.001). Still, none of the augmented cases showed a change in heart rate or oxygen saturation.

CONCLUSION

The augmentation of the PFNA blade proved to be a safe procedure. Cement augmentation will not increase postoperative complications or mortality. The risk for leakage of cement into the joint is low and mechanical cut-out might be prevented. The decision for augmentation should be made carefully and always be declared loud and in advance to allow the anesthetist to prepare, because blood pressure changes can occur.

Modified Candy-Package technique vs Cerclage technique for refixation of the lesser trochanteric fragment in pertrochanteric femoral fractures. A biomechanical comparison of 10 specimens

OBJECTIVES

Separation of the lesser trochanteric fragment in pertrochanteric 3-part fractures leads to a significant weakening of the medial cortical wall. Because of the attachment of the Iliopsoas muscle to this structure, the lesser trochanteric fragment tends to cranial dislocation along this muscle's action direction. Refixation of these fractures using an intramedullary nail and an additional wiring osteosynthesis can be considered an operative standard. Based on an intramedullary osteosynthesis procedure, the question was raised whether a 2-point fixation method was favourable over a 1-point method regarding the pull-out resistance of the lesser trochanteric fragment against the Iliopsoas muscle's force.

METHODS

Based on an intramedullary osteosynthesis (PFNA, DePuy/Synthes/SUI), two groups á five human femora were defined depending on the refixation technique of the lesser trochanteric fragment (1-point supertrochanteric "Cable" vs 2-point super/subtrochanteric fixation "Candy-Package" performed with a 1.25-mm steel cerclage). The specimens were tested using a novel traction setup, simulating the activity pattern of the Iliopsoas muscle. The target value was the resistance of the refixated lesser trochanteric fragment against a defined pull-out force produced by the Iliopsoas muscle. The main parameters considered were the peak traction force (Fmax) and the maximum summative work (WFmax) at construct failure.

RESULTS

The Fmax and WFmax displayed a significant difference in favour of the Candy-Package (2-point super/subtrochanteric fixation) group (822 N vs. 476 N, 13.8 k Nmm vs 4.4 k Nmm, respectively; P = 0.01).

CONCLUSIONS

The Candy-Package technique is a method that displays significantly more resistance than a single cerclage osteosynthesis regarding fragment loosening under the application of a simulated Iliopsoas muscle force in the course of a biomechanical proximal femoral 3-part fracture model.

Impact of oral anticoagulation on proximal femur fractures treated within 24 h - A retrospective chart review

BACKGROUND

About one third of all patients with proximal femur fractures take oral anticoagulation like aspirin (ASS), direct platelet aggregation inhibitors like Clopidogrel and Ticagrelor (PAI), vitamin-K-antagonists like Warfarin (VKA) and direct oral anticoagulants like Rivaroxaban, Dabigatran and Apixaban (DOAC). The management and timing of fracture stabilization of these patients is a rising challenge in orthopedic trauma. Our objective was to determine the effect of oral anticoagulation on patients with proximal femur fractures, which received a proximal femur nail antirotation (PFNA) within 24 h after trauma.

MATERIAL AND METHODS

A retrospective chart review of 327 patients (mean age 80 ± 13 years; 223 women and 104 men) with sub- or intertrochanteric fractures between January 2013 and December 2017 was performed. All patients underwent surgery in the first 24 h after admission. Solely patients without or with only one type of oral anticoagulation were included. There were 74 patients with ASS, 30 with PAI, 52 with DOAC and 25 with VKA medication. All patients taking VKA received high dose Vitamin K or coagulation factors to normalize INR prior to surgery. Primary outcome measures were transfusion rate and pre- and postoperative hemoglobin (Hb) difference. Secondary outcome measures were mortality and complications like infection, hematoma and acute cardiovascular events.

RESULTS

Patients undergoing treatment with DOAC had a 3.4-fold increased risk for intraoperative blood transfusion. The risk for blood transfusion for patients taking ASS, PAI or VKA did no differ from the control group. Patients without an intraoperative blood transfusion on oral anticoagulation showed no increase in pre- and postoperative Hb-difference compared with controls. Anticoagulation showed no significant effect on complication rates and mortality in patients operated within the first 24 h.

CONCLUSION

Early surgical care of proximal femur fractures is safe even in patients with anticoagulant medication. All patients should be preoperatively prepared for possibly intraoperative transfusion, especially patients on DOAC.

Correction to: Radiation exposure for intraoperative 3D scans in a hybrid operating room: how to reduce radiation exposure for the surgical team

The original version of this article unfortunately contained a mistake. In abstract, results section should read.

Cardiac Depression in Pigs after Multiple Trauma - Characterization of Posttraumatic Structural and Functional Alterations

The purpose of this study was to define the relationship between cardiac depression and morphological and immunological alterations in cardiac tissue after multiple trauma. However, the mechanistic basis of depressed cardiac function after trauma is still elusive. In a porcine polytrauma model including blunt chest trauma, liver laceration, femur fracture and haemorrhage serial trans-thoracic echocardiography was performed and correlated with cellular cardiac injury as well as with the occurrence of extracellular histones in serum. Postmortem analysis of heart tissue was performed 72 h after trauma. Ejection fraction and shortening fraction of the left ventricle were significantly impaired between 4 and 27 h after trauma. H-FABP, troponin I and extracellular histones were elevated early after trauma and returned to baseline after 24 and 48 h, respectively. Furthermore, increased nitrotyrosine and Il-1β generation and apoptosis were identified in cardiac tissue after trauma. Main structural findings revealed alteration of connexin 43 (Cx43) and co-translocation of Cx43 and zonula occludens 1 to the cytosol, reduction of α-actinin and increase of desmin in cardiomyocytes after trauma. The cellular and subcellular events demonstrated in this report may for the first time explain molecular mechanisms associated with cardiac dysfunction after multiple trauma.

Mesenchymal stem cells in peripheral blood of severely injured patients

PURPOSE

Mesenchymal stem cells (MSCs) are primarily stromal cells present in bone marrow and other tissues that are crucial for tissue regeneration and can be mobilized into peripheral blood after different types of organ damage. However, little is known about MSC appearance in blood in the setting of polytrauma.

METHODS

We conducted a monocentered and longitudinal observational clinical study in 11 polytraumatized patients with an injury severity score (ISS) ≥ 24 to determine the numbers of MSCs in peripheral blood. Blood was collected from healthy volunteers and patients after polytrauma in the emergency room and 4, 12, 24, 48 h, 5 and 10 day later, and cells carrying MSC-surface markers (negative for CD45, positive for CD29, CD73, CD90, CD105, and CD166 in different combinations also employing the more stringent markers STRO1 and MSCA1) were detected and characterized using flow cytometry. Relative numbers of MSC-like cells were correlated with clinical parameters to evaluate if specific injury patterns had an influence on their presence in the blood cell pool.

RESULTS

We were able to detect MSC marker-positive cells in both cohorts; however, the percentage of those cells present in the blood of patients during the first 10 day after injury was mostly similar to healthy volunteers, and significantly lowers starting at 4 h post trauma for one marker combination when compared to controls. Furthermore, the presence of a pelvis fracture was partly correlated with reduced relative numbers of MSC-like cells detectable in blood.

CONCLUSIONS

Polytrauma in humans was associated with partly reduced relative numbers of MSC-like cells detected in peripheral blood in the time course after injury. Further studies need to define if this reduction was due to lower mobilization from the bone marrow or to active migration to the sites of injury.

Complement C5a-Induced Changes in Neutrophil Morphology During Inflammation

The complement and neutrophil defence systems, as major components of innate immunity, are activated during inflammation and infection. For neutrophil migration to the inflamed region, we hypothesized that the complement activation product C5a induces significant changes in cellular morphology before chemotaxis. Exposure of human neutrophils to C5a dose- and time-dependently resulted in a rapid C5a receptor-1 (C5aR1)-dependent shape change, indicated by enhanced flow cytometric forward-scatter area values. Similar changes were observed after incubation with zymosan-activated serum and in blood neutrophils during murine sepsis, but not in mice lacking the C5aR1. In human neutrophils, Amnis high-resolution digital imaging revealed a C5a-induced decrease in circularity and increase in the cellular length/width ratio. Biomechanically, microfluidic optical stretching experiments indicated significantly increased neutrophil deformability early after C5a stimulation. The C5a-induced shape changes were inhibited by pharmacological blockade of either the Cl-/HCO3--exchanger or the Cl^- -channel. Furthermore, actin polymerization assays revealed that C5a exposure resulted in a significant polarization of the neutrophils. The functional polarization process triggered by ATP-P2X/Y-purinoceptor interaction was also involved in the C5a-induced shape changes, because pretreatment with suramin blocked not only the shape changes but also the subsequent C5a-dependent chemotactic activity. In conclusion, the data suggest that the anaphylatoxin C5a regulates basic neutrophil cell processes by increasing the membrane elasticity and cell size as a consequence of actin-cytoskeleton polymerization and reorganization, transforming the neutrophil into a migratory cell able to invade the inflammatory site and subsequently clear pathogens and molecular debris.

Feasibility of laser-guided percutaneous pedicle screw placement in the lumbar spine using a hybrid-OR

PURPOSE

Innovations in intraoperative imaging lead to major changes in orthopaedic surgery. In our setting, a 3D flat-panel c-arm (Artis zeego) is mounted on a robotic arm offering an integrated aiming tool (Syngo iGuide). Our aim was to investigate the feasibility of Syngo iGuide for pedicle screw placement in comparison with fluoroscopic screw implantation.

METHODS

In 10 lumbar models, 100 screws were implanted. In 5 models, a standard fluoroscopic technique was used. Syngo iGuide was used in all other models. Afterwards, CT-scans were performed and screw accuracy was investigated.

RESULTS

The procedure time for the new technique was significantly longer in comparison with the standard technique. The post-operative CT showed the same accuracy in both groups.

CONCLUSIONS

Syngo iGuide proofed feasible for percutaneous implantation of pedicle screws in anatomic models. Syngo iGuide can be a help for screw implantation in difficult anatomic regions without the need of an additional navigation system.

[Augmentation technique on the proximal humerus]

BACKGROUND AND OBJECTIVES

The treatment of osteoporotic fractures is still a challenge. The advantages of augmentation with respect to primary in vitro stability and the clinical use for the proximal humerus are presented in this article.

MATERIAL AND METHODS

In this study six paired human humeri were randomized into an augmented and a non-augmented group. Osteosynthesis was performed with a PHILOS plate (Synthes®). In the augmented group the two screws finding purchase in the weakest cancellous bone were augmented. The specimens were tested in a 3-part fracture model in a varus bending test.

RESULTS

The augmented PHILOS plates withstood significantly more load cycles until failure. The correlation to bone mineral density (BMD) showed that augmentation could partially compensate for low BMD.

CONCLUSION

The augmentation of the screws in locked plating in a proximal humerus fracture model is effective in improving the primary stability in a cyclic varus bending test. The targeted augmentation of two particular screws in a region of low bone quality within the humeral head was almost as effective as four screws with twice the amount of bone cement. Screw augmentation combined with a knowledge of the local bone quality could be more effective in enhancing the primary stability of a proximal humerus locking plate because the effect of augmentation can be exploited more effectively limiting it to the degree required. The technique of augmentation is simple and can be applied in open and minimally invasive procedures. When the correct procedure is used, complications (cement leakage into the joint) can be avoided.

Does the choice of mobile C-arms lead to a reduction of the intraoperative radiation dose?

INTRODUCTION

Mobile C-arm imaging is commonly used in operating rooms worldwide. Especially in orthopaedic surgery, intraoperative C-arms are used on a daily basis. Because of new minimally-invasive surgical procedures a development in intraoperative imaging is required. The purpose of this article is investigate if the choice of mobile C-arms with flat panel detector technology (Siemens Cios Alpha and Ziehm Vision RFD) influences image quality and dose using standard, commercially available test devices.

MATERIALS AND METHODS

For a total of four clinical application settings, two zoom formats, and all dose levels provided, the transmission dose was measured and representative images were recorded for each test device. The data was scored by four observers to assess low contrast and spatial resolution performance. The results were converted to a relative image quality figure allowing for a direct image quality and dose comparison of the two systems.

RESULTS

For one test device, the Cios Alpha system achieved equivalent (within the inter-observer standard error) or better low contrast resolution scores at significantly lower dose levels, while the results of the other test device suggested that both systems achieved similar image quality at the same dose. The Cios Alpha system achieved equivalent or better spatial resolution at significantly lower dose for all application settings except for Cardiac, where a comparable spatial resolution was achieved at the same dose.

CONCLUSION

The correct choice of a mobile C-arm is very important, because it can lead to a reduction of the intraoperative radiation dose without negative effects on image quality. This can be a big advantage to reduce intraoperative radiation not only for the patient but also for the entire OR-team.

Accuracy of computer-assisted iliosacral screw placement using a hybrid operating room

INTRODUCTION

In recent years hybrid operating rooms were established all over the world. In our setting we combined a 3D flat-panel c-arm (Artis zeego, Siemens) with a navigation system (BrainLab curve, BrainLab). This worldwide unique combination enables the surgeon to visualise an entire pelvis in CT-like image quality with a single 3D-scan. The aim of our study was to investigate, if utilisation of a hybrid operating room increases the accuracy of SI-screws in comparison to standard 3D-navigation.

MATERIAL AND METHODS

Retrospective, not randomised single centre case series at a level I trauma centre. Inclusion criterion was insertion of a percutaneous iliosacral screw using image-guidance in the hybrid operating room. 61 patients (35 female, 26 male) were included from June 2012 till October 2014. 65 iliosacral screws were inserted. Intraoperative 3D-scans and postoperative scans were examined to investigate screw placement. The results were compared to a preceding study performed in 2012 using conventional 3D-navigation. Statistical calculations were performed with Microsoft Excel 2011 and SPSS.

RESULTS

65 iliosacral screws were implanted. Two different types of screws were implanted: 1. "Standard" iliosacral screws stabilizing one joint/a unilateral fracture. 2. Single SI-screws stabilizing both SI-joints and if present a bilateral fracture. Forty one patients were included in group 1 (screws n=45). There was no perforation in 43 screws, grade 1 perforation in 2 screws. There was no grade 2 or 3 perforation in this group. Compared to the conventional 3D-navigated screws there was a highly significant difference (p<0.001). Twenty patients could be included in group 2. Eleven screws showed a complete intraosseous position. There was grade 1 perforation in 2 screws, grade 2 perforation in 5 screws and grade 3 perforation in 2 screws.

CONCLUSION

Improvements in image quality and enlargement of the display window lead to better intraoperative visualisation of the entire dorsal pelvis. Thereby the accuracy of computer-assisted iliosacral screws could be increased using a hybrid operating room. Furthermore difficult tasks like a single screw for both joints can be accomplished.

Unusual cutaneous features associated with a heterozygous gain-of-function mutation in IFIH1: overlap between Aicardi-Goutières and Singleton-Merten syndromes

Cutaneous lesions described as chilblain lupus occur in the context of familial chilblain lupus or Aicardi-Goutières syndrome. To date, seven genes related to Aicardi-Goutières syndrome have been described. The most recently described encodes the cytosolic double-stranded RNA receptor IFIH1 (also known as MDA5), a key component of the antiviral type I interferon-mediated innate immune response. Enhanced type I interferon signalling secondary to gain-of-function mutations in IFIH1 can result in a range of neuroinflammatory phenotypes including classical Aicardi-Goutières syndrome. It is of note that none of the patients with a neurological phenotype so far described with mutations in this gene was reported to demonstrate cutaneous involvement. We present a family segregating a heterozygous pathogenic mutation in IFIH1 showing dermatological involvement as a prominent feature, variably associated with neurological disturbance and premature tooth loss. All three affected individuals exhibited increased expression of interferon-stimulated genes in whole blood, and the mutant protein resulted in enhanced interferon signalling in vitro, both in the basal state and following ligand stimulation. Our results further extend the phenotypic spectrum associated with mutations in IFIH1, indicating that the disease can be confined predominantly to the skin, while also highlighting phenotypic overlap with both Aicardi-Goutières syndrome and Singleton-Merten syndrome.

Energy position of the transport path in disordered organic semiconductors

The concept of transport energy is the most transparent theoretical approach to describe hopping transport in disordered systems with steeply energy dependent density of states (DOS), in particular in organic semiconductors with Gaussian DOS. This concept allows one to treat hopping transport in the framework of a simple multiple-trapping model, replacing the mobility edge by a particular energy level called the transport energy. However, there is no consensus among researchers on the position of this transport level. In this article, we suggest a numerical procedure to find out the energy level most significantly contributing to charge transport in organic semiconductors. The procedure is based on studying the effects of DOS modifications on the charge carrier mobility in straightforward computer simulations. We also show why the most frequently visited energy, computed in several numerical studies to determine the transport energy, is not representative for charge transport.

Cell therapy for bone repair: narrowing the gap between vision and practice

This position paper summarises a vision of how cell-based therapies can be applied clinically to regenerate bone, as well as the steps needed to narrow the gap between that vision and clinical reality. It is a result of the presentations and discussion of the "Cell Therapy for Bone Repair" breakout session at the AO Foundation Symposium "Where Science Meets Clinics" in Davos, Switzerland from September 5-7, 2013. Participants included leaders from science, medicine, and industry from around the world. The session included clinical and scientific presentations, as well as an extended discussion among participants. Bone tissue has an innate regenerative capacity that in most cases allows functional healing at damage sites. However, there are a number of serious conditions in which bone does not fully heal and the result is significant morbidity. The clinical need for new therapies is clear, and the breakout session participants were enthusiastic about the potential impact on cell-based therapies for bone repair in the clinic. However, they also recognised the significant challenges that face the development of commercially viable cell therapy products. This paper outlines a vision in which patient selection is based on expected therapeutic outcome to create a consistently successful, cost-effective, cell-based therapy for bone repair. The need for a more complete understanding of bone repair, a better infrastructure for preclinical studies, and the need for collaboration among stakeholders is discussed.

Long-term results of the augmented PFNA: a prospective multicenter trial

BACKGROUND

Pertrochanteric fractures are increasing and their operative treatment remains under discussion. Failures needing reoperations such as a cut-out are reported to be high and are associated with multiple factors including poor bone quality, poor fracture reduction and improper implant placement. The PFNA(®) with perforated blade offers an option for standardized cement augmentation with a PMMA cement to provide more stability to the fracture fixation. It remains unclear if the augmentation of this implant does any harm in a longer time span. This prospective multicenter study shows clinical and radiological results with this implant with a mean follow-up time of 15 months.

METHODS

In 5 European clinics, 62 patients (79 % female, mean age 85.3 years) suffering from an osteoporotic pertrochanteric fracture (AO 31) were treated with the augmented PFNA(®). The primary objectives were assessment of activities of daily living, pain and mobility. Furthermore, the X-rays were analyzed for the cortical thickness index, changes of the trabecular structure around the cement and the hip joint space.

RESULTS

The mean follow-up time was 15.3 months. We observed callus healing in all cases. The surgical complication rate was 3.2 % with no complication related to the cement augmentation. A mean volume of 3.8 ml of cement was injected and no complication was reported due to this procedure. 59.9 % reached their prefracture mobility level until follow-up. The mean hip joint space did not change significantly until follow-up and there were no signs of osteonecrosis in the follow-up X-rays. Furthermore, no blade migration was assessed.

CONCLUSION

This study makes us believe that the standardized augmentation of the PFNA with a perforated blade is a safe method to treat pertrochanteric femoral fractures. It leads to good functional results and is not associated with cartilage or bone necrosis.

Mid term results of distal femoral fractures treated with a polyaxial locking plate: a multi-center study

Objective :

Locking plates have become a standard implant in the treatment of distal femoral fractures. Newer designs allow polyaxial screw placement as well as the ability to lock the lag screws.

Methods :

The consecutive multi-centre study cohort consists of all distal femoral fractures treated with the NCB® Distal Femur plate (Zimmer, Warsaw, USA) and a minimum follow-up of twelve months. Fracture classification according the AO/ OTA system and the trauma mechanism radiological evaluation and complications were documented. Clinical evaluation consisted of the Short Form SF12 questionnaire (SF12), the Hospital for Special Surgery Score (HSS) and clinical assessment of range of motion.

Results :

Twenty-five patients with twenty-six fractures were available for follow-up with a minimum required follow-up of twelve months. 81% of the fractures were intra-articular. 48% of the patients were multi-traumatised, 38% having open fractures. All except two went to union (92%) with the primary procedure. The HSS Score was 79 (32-99) and the SF 12 (physical and mental) 40 (19-57) and 54 (21-66) at follow-up. There were five patients requiring surgical revision (19%).

Conclusion :

These fractures are often combined with concomitant injuries. Using modern locked implants high union rates can be achieved with a good function and patient satisfaction when respecting biologic and biomechanical principles.

[Midterm results following denervation of the ankle]

BACKGROUND

Complications related to arthrodesis of the ankle or total ankle replacement require a critical assessment of the indication. Using denervation of the ankle, we have the possibility to delay the above-named surgical treatment for a number of years. The aim of this follow-up study was to review the results of ankle denervation after several years.

METHODS

Within a follow-up examination, we were able to evaluate the results of 45 patients an average of 102 months following ankle denervation.

RESULTS

A total of 82.2% of patients indicated an improvement of pain for an average of 60.9 months; 71.1% of patients reported that the operation was worthwhile. The AOFAS score improved from an average 37.9 (range 26-68) preoperatively to 55.6 (range 24-84) at follow-up.

CONCLUSIONS

Ankle denervation can achieve good ankle pain reduction in the treatment of ankle arthrosis. Denervation should be considered a long-term treatment concept.

[Reduced emergency room time for trauma patients by integrated CT]

BACKGROUND

A new emergency room (ER) has been established in our trauma centre including an integrated CT scanner. The former ER was located at a long distance from the CT. The aim of this study was to evaluate the influence of the integrated CT in the new ER on the time period from hospital admission to CT diagnostics as well as on the total ER time period.

MATERIAL AND METHODS

Data from the old ER (2005-2007) have been compared with those from the new ER (2009). All patients whose data have been transmitted to the German Trauma Registry (DGU) have been included. For statistics the Mann-Whitney U test has been used.

RESULTS

Data of 457 patients could be included. Time from admission to CT scan in the old ER had an average of 35 ± 27 min (4-240 min), in the new ER 13 ± 10 min (1-67 min; p < 0.001). The total ER time could be reduced from 86 ± 42 min (10-240) in the old ER to 61 ± 33 min (5-190; p < 0.001) in the new ER.

CONCLUSIONS

Time from hospital admission to CT scan as well as the total ER time period can be reduced by using an integrated CT scanner.

[Proximal tibia fracture treatment with a new locking device with polyaxial screw placement: technique and early results]

BACKGROUND

Surgical treatment of tibial head fractures can be challenging due to the close anatomic relationship to the knee joint which can be affected including its intraarticular structures. Frequently, soft tissue damages are present which can have a strong impact on the planning and choice of surgical technique. An important therapeutic requirement is the anatomic reconstruction and high primary stability to allow early functional treatment. The aim of the present study was to describe a recent locking device and its surgical technique and to analyse the early results.

MATERIAL AND METHODS

The Non-Contact-Bridging Plate for the proximal tibia (NCB® PT, Zimmer Inc.) features a polyaxial locking mechanism which allows both compression and locking with the same screw. The system can be applied both minimally invasively and open. 36 patients (16 female, 20 male; average age 53 years) with three type A, 21 type B and 12 type C fractures according to the AO classification were treated. In 22 cases the system was applied open and in 14 minimally invasively. Clinical and radiological follow-up was obtained at 6 weeks, 3, 6 and 12 months.

RESULTS

The handling of the system turned out to be straightforward after an initial learning curve. Implant failure was not detected in our sample. The minimally invasive technique can be beneficial in cases of severe soft tissue damage, but must not compromise the quality of reduction. The functional result at 1-year follow-up using a knee score was good or very good and comparable to the literature. The rate of general surgical complications was 11 % (haematoma, superficial or deep wound infection). Implant-related complications were not detected. At the 3-months' follow-up 44 % and at the 12-months' 100 % of the fractures were healed on X-ray.

CONCLUSION

The NCB PT plate offers a broad variety of treatment options due to the specific locking mechanism and the fact that it can be applied both minimally invasively and open. In cases of intraarticular involvement the application of compression and locking with the same screw turned out to be very beneficial. The primary stability of the system allows early functional treatment. Clinical results and complication rates of the present study are comparable to those in the literature.

[Development of intraoperative C-arm imaging in trauma surgery]

Since the earliest beginnings of using X-rays, two forms of examination techniques have been known: X-ray imaging and projection onto films. The new technology very rapidly became widespread. Just a few months after the discovery of the so-called X-rays, the first fluoroscopes (instruments for visualizing internal structures) were constructed and constantly improved upon. If the operation took place in bright light, a cryptoscope was needed for examination. Since 1984 fluoroscopic examinations or interventions performed under X-ray control are only permitted when systems are used that are equipped with an image intensifier video chain or a digital image receiver with TV monitor.At about the beginning of the new century the first digital imaging systems with solid-state detectors were put into service. Flat panel detectors offer high-quality imaging with good spatial resolution and contrast recognition. At the present time, storable intraoperative three-dimensional diagnostic imaging is available.

[Challenging the dogma on inferiority of stainless steel implants for fracture fixation. An end of the controversy?]

BACKGROUND

Titanium plates represent the predominant implants of choice for fracture care in Central Europe, based on the apparently favourable properties related to improved "biocompatibility". The present study was designed to test the hypothesis that the use of stainless steel implants for selected fractures represents a safe and efficient treatment modality, which is not associated with an increased rate of complications and surgical revisions.

METHODS

We conducted a retrospective analysis of a prospective database during a 5-year study period (01/01/2006-12/31/2010) at an academic Level 1 Trauma Center on all fractures treated by stainless steel plates. Inclusion criteria consisted of all consecutive patients >15 years of age whose fractures were fixated with a stainless steel plate. All fractures were classified according to the AO/OTA system. Outcome parameters consisted of the rate of complications and surgical revisions, and the data were placed into context with the published complication rates for titanium plates.

RESULTS

A total of 1,001 consecutive patients who underwent surgical fixation of fractures in the indication spectrum of this study were screened. Of these, 751 patients fulfilled the inclusion criteria. These patients had 774 fractures which were fixated with 859 stainless steel plates. Open fractures accounted for 9.6% of all injuries (n=74). The complication rate of the 774 fractures treated with stainless steel plates was 8.01% (n=62), with a surgical revision rate of 5.16% (n=40). These data are below the reported incidence of complications and surgical revisions for titanium plates in the identical indication spectrum in the pertinent literature published.

CONCLUSIONS

The fixation of selected fractures with stainless steel implants represents a safe and efficient treatment option, which does not appear to be associated with increased complication rates. These data challenge the anecdotal superiority of titanium plates and should spur a new discussion on the use of stainless steel implants, particularly under the aspect of cost savings in the DRG era.

[Early results after palmar multi-axial plate osteosynthesis for treatment of distal radius fractures]

In a prospective study a total of 49 fractures in 47 patients were treated with open reduction and palmar plate osteosynthesis. The results were evaluated radiologically, clinically and with the disability of arm-shoulder-hand (DASH) score. The emphasis was on early postoperative results. The patients consisted of 11 men and 36 women aged 21–85 years old. Very good or good results were achieved in 79.6% of the patients, a fair result in 16.3% and a poor result in 4.1% according to the Lidström criteria. In 65.9% of cases very good or good functional results were achieved, in 22.7% fair and in 11.4% only poor results. The DASH score showed high patient satisfaction in 70.2%, moderate satisfaction in 25.5% and only little satisfaction in 4.3% of patients. Complications occurred in 14.3% of patients and the average duration of sick leave was 45.8 days. Open reduction of distal radius fractures using palmar plates with multi-axial angular stability shows good radiological and functional results even shortly after the operation.

[Complications after pertrochanteric fractures]

Fractures at the coxal end of the femur have an incidence of almost 100.000 p.a. in Germany. Pertrochanteric femur fractures make up almost half of this collective. The highest incidence of 1.32% is seen in patients over the age of 85. Osteosynthesis is the treatment of choice. The options include extramedullary nail/screw systems or intramedullary nail systems. Study findings to date do not show a clear advantage of one procedure over another. The published complication rates remain high. The main complication is secondary reduction loss with cutout of the hip screw. Other complications include femoral neck shortening and lateralization of the hip screw with local irritation at the iliotibial tract. Functional outcomes after osteosynthesis are still less than satisfactory. Surgery only frees one third of patients from pain. In addition, a majority of patients also suffer loss of independence and social contacts. An alternative approach to treatment is total joint replacement. This is indicated in extreme cases of osteoporosis in combination with osteoarthritis. However, initial high stability must be weighed against an increased risk of dislocation and a higher rate of 1-year mortality.

Standardised cement augmentation of the PFNA using a perforated blade: A new technique and preliminary clinical results. A prospective multicentre trial

Pertrochanteric fractures are a rising major health-care problem in the elderly and their operative stabilisation techniques are still under discussion. Furthermore, complications like cut-out are reported to be high and implant failure often is associated with poor bone quality. The PFNA(®) with perforated blade offers a possibility for standardised cement augmentation using a polymethylmethacrylate (PMMA) cement which is injected through the perforated blade to enlarge the load-bearing surface and to diminish the stresses on the trabecular bone. The current prospective multicentre study was undertaken to evaluate the technical performance and the early clinical results of this new device. In nine European clinics, 59 patients (45 female, mean age 84.5 years) suffering from an osteoporotic pertrochanteric fracture (Arbeitsgemeinschaft für Osteosynthesefragen, AO-31) were treated with the augmented PFNA(®). Primary objectives were assessment of operative and postoperative complications, whereas activities of daily living, pain, mobility and radiologic parameters, such as cement distribution around the blade and the cortical thickness index, were secondary objectives. The mean follow-up time was 4 months where we observed callus healing in all cases. The surgical complication rate was 3.4% with no complication related to the cement augmentation. More than one-half of the patients reached their prefracture mobility level within the study period. A mean volume of 4.2ml of cement was injected. We did not find any cut-out, cut through, unexpected blade migration, implant loosening or implant breakage within the study period. Our findings lead us to conclude that the standardised cement augmentation using the perforated blade for pertrochanteric fracture fixation enhances the implant anchorage within the head-neck fragment and leads to good functional results.

[Mental practice has influence on limitation of motion and muscle atrophy following immobilisation of the radiocarpal joint - a prospective randomised experimental study]

PURPOSE

Distal radial fracture is the most common bony injury in man. Still there are unsatisfying treatment results, such as limited joint movement, muscle atrophy and pain, resulting from immobilisation while the fracture is healing. During this period, also joint movement seems to be "forgotten". This study experimentally examined if the method of mental practice, meaning the systematic repetition of a consciously imagined movement or action without simultaneous practical execution, can positively influence these findings.

MATERIALS AND METHODS

21 right-handed males had application of a circular forearm plaster for immobilisation of their left radiocarpal joint, simulating a distal radial fracture for three weeks. Following randomisation, half of the study participants learned mental practice for "virtual movement" of their radiocarpal joint and had to perform it, the others were not treated at all. At beginning and end of the experiment, joint movement was measured, and an MRI examination of the forearm muscles was performed. The brain (cortex) areas, responsible for radiocarpal joint movement, were examined concerning their activity with functional MRI at the beginning and also at the end of the three weeks. The experiment was also performed on three "real" patients suffering from a distal radial fracture demanding plaster immobilisation, all of them were mentally treated.

RESULTS

Mental practice significantly ameliorated dorsal extension and ulnar abduction after plaster removal in comparison to those not having been mentally trained. Muscle atrophy of forearm muscles, measured via MRI, was significantly less in those having mental training. The cortex areas responsible for radiocarpal joint movements (supplementary motor area, precentral gyrus, putamen, nucleus caudatus, prefrontal cortex, thalamus and cerebellum) showed significant signal changes at the end of the three weeks in those having been mentally trained. There were significant correlations between MRI and functional MRI findings. The findings in the three "real" patients were similiar.

CONCLUSIONS

The results of this experimental study show that mental practice can have a positive influence on the outcome of distal radial fractures demanding immobilisation. A study with a larger number of "real patients" should follow.

Antiferromagnetic order in multiband Hubbard models for iron pnictides

We investigate multiband Hubbard models for the three iron 3d t(2g) bands and the two iron 3d e(g) bands in LaOFeAs by means of the Gutzwiller variational theory. Our analysis of the paramagnetic ground state shows that neither Hartree-Fock mean-field theories nor effective spin models describe these systems adequately. In contrast to Hartree-Fock-type approaches, the Gutzwiller theory predicts that antiferromagnetic order requires substantial values of the local Hund's-rule exchange interaction. For the three-band model, the antiferromagnetic moment fits experimental data for a broad range of interaction parameters. However, for the more appropriate five-band model, the iron e(g) electrons polarize the t(2g) electrons and they substantially contribute to the ordered moment.

[Run-over injuries : causes, injury pattern, treatment and long-term sequelae]

BACKGROUND

The rate of long-term disability following run-over injuries has not been investigated so far. Therefore the aim of this study was to evaluate the long-term outcome following run-over injuries.

MATERIAL AND METHODS

A total of 71 patients were enrolled in the study. Data were collected regarding the injury pattern, surgical treatment and clinical outcome. The quality of life was measured with the POLO chart

RESULTS

The median ISS was 15. Eight patients died. The injuries were predominantly located at the lower extremities (39%) with severe soft tissue injuries in 68% of the cases. Patients were operated on a median of four times. In the follow-up evaluation with the SF36 7 years post-trauma, 57% of the patients had reduced physical functioning and 46% reduced psychological health.

CONCLUSIONS

The long-term disability following run-over injuries is severe and requires a multidisciplinary approach. Treatment should therefore be conducted in appropriate trauma centres.

[Results and complications in the treatment of periprosthetic femur fractures with a locked plate system]

BACKGROUND

Locked plate devices offer advantages in the treatment of periprosthetic femur fractures associated with fixed total hip or total knee arthroplasty. The purpose of this study was to evaluate the early results and complications with a locked plate system (NCB-DF(R)).

PATIENTS AND METHODS

A total of 31 patients (mean age 76 years, 7 males, 24 females) with a femur fracture above a fixed total knee arthroplasty (TKA, n=12) or a total hip arthroplasty (THA, n=19) were treated with a locked plate.

RESULTS

There were 11 complications necessitating revision: 6 implant failures, 2 in patients with a THA and 4 in patients with a TKA, 4 hematomas and 1 infection and 2 patients died. After 6 months all fractures had healed securely but a secondary correction was necessary in one patient.

CONCLUSION

Fixation of periprosthetic femur fractures with a locked plate system provided satisfactory results in patients with a THA, however, the relatively high implant failure rate in fractures above a stable TKA is a cause for concern.

[University benchmarking. A current status analysis]

Lump sum reimbursement and the resulting concentration of medical treatment in maximum care clinics have led to substantial increase in economic pressure on university hospitals. Nearly all hospitals have introduced business ratios to economically judge each department. In order to evaluate the validity and comparability the business ratios of seven university traumatology departments were evaluated. Structural data as well as cost calculation results in different cost groups were evaluated. Major differences could be identified despite the fact that the cost calculations were all based on the same method (InEK method). In particular the costs for distribution to other medical specialties such as radiology or anesthesiology differed widely. Costs for infrastructure also showed a great variation. Differences in efficiency cannot be the only cause for these discrepancies and lacking standardization of cost calculation methodology is also another major cause. All the business ratios analyzed must be looked at critically and unless a thoroughly standardized methodology of cost calculation is implemented, cost ratios will have a limited potential for hospital benchmarking.

Renormalization of bulk magnetic electron states at high binding energies

The quasiparticle dynamics of electrons in a magnetically ordered state is investigated by high-resolution angle-resolved photoemission of Ni(110) at 10 K. The self-energy is extracted for high binding energies reaching up to 500 meV, using a Gutzwiller calculation as a reference frame for correlated quasiparticles. Significant deviations exist in the 300 meV range, as identified on magnetic bulk bands for the first time. The discrepancy is strikingly well described by a self-energy model assuming interactions with spin excitations. Implications relating to different electron-electron correlation regimes are discussed.