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.

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.

Radiation exposure for the surgical team in a hybrid-operating room.

Hybrid-operating rooms enable the surgeon to acquire intraoperative high-resolution 2- and 3D images and use them for navigation. The radiation dose of the operating personal and the patient remains the major concern. In 9 months, 109 pelvic and spine cases were performed using a hybrid operating room. Radiation dose of the surgeon and the assisting nurse was recorded using real-time dosimeters. Lower radiation doses for the main surgeon in navigated dorsal instrumentations of the thoracic spine were recorded. Standing between the C-arm during screw placement increased the radiation dose sixfold. Lumbar dorsal instrumentation showed a similar radiation dose compared to the previous studies in traditional operating room settings. The use of a hybrid-operating room for dorsal spine instrumentation showed no increase in radiation dose compared to traditional settings. Intraoperative navigation can help to reduce the radiation dosage for the operating personnel.

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.

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

BACKGROUND: Hybrid operating rooms are used in different fields of surgery. In orthopedic surgery, the possibility of a 3D scan of difficult anatomical regions (spine, pelvis) showed promising results not only in navigated screw placement. The associated exposure to radiation raises questions regarding potential risks for the operating room personal and the patient. The present study focuses on scatter radiation during 3D scans in a hybrid operating room, the adjacent rooms, and methods to reduce radiation exposure. MATERIAL AND METHODS: [Formula: see text] i2 dosimeters were used to measure scatter radiation during 3D scans of different anatomical regions in different distances and heights in a hybrid operating room. The 3D scans were performed with a floor-based flat-panel robotic C-arm with 3D scan capability (Artis Zeego, Siemens; Germany). The 3D scans were performed using a human cadaver. The 3D scans were performed using a standard and a dose reduction protocol (DRP). RESULTS: The highest scatter radiation was measured during 3D scans of the pelvis on the side of the surgical assistant (39.5 µSv in height of 1 m) compared to the side of the main surgeon (23 µSv in height of 1 m). Scatter radiation was less on the position of the scrub nurse (6.8 µSv in height of 1 m) and during 3D scans of the other anatomical regions. The radiation dosage was about 66% less with the DRP. Low values of scatter radiation were measured behind a radiation protection wall and with open doors in the adjacent rooms. CONCLUSION: While performing a scan scatter radiation was measured everywhere in the operating room especially during 3D scans of the pelvic girdle. Therefore, settings with lower dosage should be used whenever possible. Personnel should stand behind a radiation safety wall or leave the operating room and close the doors. For this study, six behavioral rules to avoid radiation in a hybrid operating room were established.

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.

The evolution of 3D imaging in orthopedic trauma care.

Three-dimensional (3D) imaging can enhance trauma care by allowing better evaluation of bony detail and implant position compared to conventional fluoroscopy or x­ray. Intraoperative 3D imaging further improves this evaluation by allowing any necessary revisions to be made in the operating room prior to the patient emerging from anesthesia. This revision, if necessary, better achieves the surgical goals and alleviates the stressful situation of obtaining postoperative 3D imaging, where the benefit of revision must be balanced against the cost and risk of returning to the operating room. Improved image volume, resolution, and software capability have allowed surgeons to obtain high-quality, wide field views of bony anatomy that can include the uninjured side as a comparison. In this paper, the evolution of intraoperative 3D imaging over the past 25 years is discussed.

[The evolution of 3D imaging in orthopedic trauma care. German version]. / Entwicklung der 3­D-Bildgebung in der Versorgung orthopädischer Verletzungen.

Three-dimensional (3D) imaging can enhance trauma care by allowing better evaluation of bony detail and implant position compared to conventional fluoroscopy or x­ray. Intraoperative 3D imaging further improves this evaluation by allowing any necessary revisions to be made in the operating room prior to the patient emerging from anesthesia. This revision, if necessary, better achieves the surgical goals and alleviates the stressful situation of obtaining postoperative 3D imaging, where the benefit of revision must be balanced against the cost and risk of returning to the operating room. Improved image volume, resolution, and software capability have allowed surgeons to obtain high quality, wide field views of bony anatomy that can include the uninjured side as a comparison. In this paper, the evolution of intraoperative 3D imaging over the past 25 years is discussed.

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.

[Impact of Spinal Fractures in Horseback Riding]. / Verletzungsfolgen nach Wirbelsäulenfrakturen im Reitsport.

BACKGROUND: Injuries to the spinal cord are not only dreaded because of the high risks existing during the acute phase, but also because of their potential long-term sequelae. Horseback riding also poses a high risk of spinal injuries. We therefore evaluated the most frequent characteristics of accidents leading to long-term sequelae, the primary long-term discomfort resulting from such injuries caused by horseback riding accidents and the way injured persons changed their behaviour after the accidents. PATIENTS: Our study included all cases of horseback riding injuries registered in the Department of Trauma, Hand, Plastic and Restorative Surgery at the University Hospital of Ulm between May 2005 and October 2012. Sequelae of the accidents were examined via follow-up interviews by phone. These included questions about protective gear worn during the accident as well as behavioural changes after the injury. In addition, a spine-specific questionnaire based on the Visual Analogue Scale (VAS) was used to assess long-term complications. RESULTS: Overall, we recorded 50 cases of spinal injuries caused by horseback riding accidents over a time span of 7 years and 5 months. 41 (82 %) of the patients were female and 9 (18 %) were male. The average patient age was 32.0 ±â€Š15.2 years. All in all, the 50 patients sustained 84 injuries: 59 fractures and 25 other injuries such as distorsions or discoligamentous injuries. Most injuries were located in the lumbar spine (n = 43), corresponding to 51 % of all recorded injuries, followed by 32 % in the thoracic spine (n = 27) and 17 % in the cervical spine (n = 14). After sustaining a fracture to the spine, 9 out of 24 patients quit horseback riding. All patients used a helmet after the accident, but only 7 out of 15 used back protection. 11 out of 24 patients suffer from back pain while resting with a mean VAS score of 3.4 ±â€Š1.9. More than half (17 out of 24) have back pain while working with a VAS score of 4.8 ±â€Š2.2. CONCLUSION: The frequency and severity of back injuries sustained by horseback riders increases with age. This can be due to various reasons such as biomechanical factors. The low acceptance of back protection is remarkable.

[Importance of intraoperative navigation in spinal surgery]. / Bedeutung der intraoperativen Navigation in der Wirbelsäulenchirurgie.

The number of spinal operations carried out per year is steadily increasing. Pedicle screw placement is the standard procedure for spinal stabilization but can be associated with severe complications. Intraoperative navigation can increase the accuracy of placement of the screws and a decisive role is played by the improvement in imaging devices. Nowadays, 3D-navigation is performed using intraoperative computed tomography or a flatpanel-3D C-arm. Computer navigation is a crucial aid especially for complex deformities or tumor cases. However, as yet no statistically significant reduction of complications could be shown using navigation compared to conventional procedures. With continuing development of intraoperative imaging and navigation it is hoped that screw positioning can be improved further.

[The interdisciplinary hybrid operation theatre. Current experience and future]. / Der interdisziplinäre Hybridoperationssaal. Erfahrungen und Zukunft.

Since June 2013 a hybrid operation theatre is used interdisciplinary in the department for surgery of Ulm University. In this operation theatre a floor-based flat panel c-arm, which is mounted on a robotic arm that can be controlled by the surgeon in a sterile environment, is linked to the operating table. Furthermore for the first time it was possible to integrate a navigation system in this setting. The interdisciplinary utilization (trauma, neurosurgery, cardiac and vascular surgery) makes this hybrid operation theatre very time and cost effective. In the orthopedic trauma department this system is mainly used for traumatic and oncologic pelvic and spinal injuries. In these anatomical regions the excellent image quality and large field of view of the robotic flat panel detector based 3D imaging combined with an intraoperative navigation system is a huge advantage. The system can also be used for complex fractures of the extremities. In the future there will be an integration of further imaging modalities and referenced holding devices in this setting.

[Anti-arrhythmia action of amidinohydrazone substituted benzophenones. 6. Parenteral drug forms of (Z)-2-amino-5-chlorobenzophenone amidinohydrazone acetate (G 256)]. / Antiarrhythmisch wirksame Amidinohydrazone substituierter Benzophenone. 6. Mitteilung: Parenterale Arzneiformen für des (Z)-2-Amino-5- chlorbenzophenonamidino-hydrazonacetat (G 256).

The combination of lyophilized G 256 and a solvent ampoule is recommended as an optimal variant for the application of the compound. In the lyophilized substance both the hydrolysis and the isomerisation are reduced so it is stable enough for the required period of usability.

Cytochrome P450-dependent N-hydroxylation of an aminoguanidine (amidinohydrazone) and microsomal retroreduction of the N-hydroxylated product.

1. The first example of a P450-dependent N-hydroxylation of an aminoguanidine (amidinohydrazone) is reported for 2-amino-5-chlorobenzophenone amidinohydrazone 1 (G 256) as substrate. 2. The N-hydroxylated metabolite 2 (2-amino-5-chlorobenzophenone N-hydroxyamidinohydrazone NOH-G256) and a further metabolite of 1, the phenol 3, were identified by tlc and ms analysis. 3. The microsomal reduction of an N-hydroxyaminoguanidine (N-hydroxy-amidino-hydrazone) was also demonstrated for the transformation of 2 to 1. 4. Both the N-hydroxylation of the aminoguanidine and the retroreduction of the N-hydroxyaminoguanidine were characterized by quantitative hplc analysis. 5. The conversion of the aminoguanidine 1 to N-hydroxyaminoguanidine 2 may be considered as an analogue of the physiological N-hydroxylation of arginine to N-hydroxyarginine by NO synthases.