PURPOSE OF THE STUDY The aim of the study was to assess the accuracy of axis deformity correction achieved by high-tibial valgus osteotomy either without or with a computer-assisted kinematic navigation system, on the basis of comparing the planned and the achieved frontal axis of the leg. Comparisons of mechanical axis deviation were made using both pre- and post-operative measurements with the planning software and intra-operative measurements with the navigation system before and after osteotomy. In addition, the aim was to test the hypothesis that the use of 3D navigation, as compared with 2D navigation, would help reduce changes in the tibial plateau slope. MATERIAL AND METHODS In the period 2008-2011, high-tibial osteotomy was performed in 68 patients. Twenty-one patients (group 1) underwent osteotomy without the use of navigation and 47 patients (group 2) had osteotomy with a computer-assisted navigation system (32 with 2D navigation and 15 with 3D navigation). Using the planning software, the mechanical leg axis before and after surgery and the anatomical dorsal proximal tibial angle in the sagittal plane were assessed. Medial opening-wedge high-tibial valgus osteotomy was carried out in all patients. When using 2D navigation, the mechanical leg axis was measured intra-operatively before osteotomy and then after osteosynthesis which included a simulated axial load of the heel. When using 3D navigation, the procedure was identical and furthermore involved a measurement of the tibial plateau slope obtained with an additional probe in the proximal fragment. The results were characterised using descriptive statistics and their significance was evaluated using the Mann-Whitney U test and Wilcoxon's test, with the level of significance set at p < 0.05. RESULTS In group 1, osteotomy resulted in good correction of the mechanical axis in nine patients (43%), inadequate correction in nine (43%) and overcorrection and three (14%) patients. In group 2 with the use of navigation, accurate correction of the mechanical leg axis was achieved in 24 patients (51%), undercorrection was recorded in 21 (45%) and overcorrection in two (4%) patients. The difference in outcomes between the two groups was not statistically significant (p = 0.73). The average correction of the mechanical axis based on comparing measurements on pre- and post-operative radiographs was 9.1 degrees (range, 5-27 degrees); the average correction of the axis visualised intra-operatively was 8.7 degrees (range, 4-27 degrees). The difference was not significant (p = 0.1615) and confirmed our hypothesis that the accuracy of measuring the mechanical axis was not influenced by the method used. The average change in the dorsal slope of the tibial plateau following osteotomy without navigation was 0.9 degrees (range, -8.9 to 9.0 degrees) and that after osteotomy with intra-operative visualisation of the proximal tibial slope was 0.3 degrees (range, -4 to 4 degrees). This difference was not statistically significant (p = 0.813). DISCUSSION A good clinical outcome of high-tibial valgus osteotomy depends on achieving accurate correction of the mechanical leg axis with partial load transfer to the lateral compartment of the knee. CONCLUSIONS Although the number of cases with good correction was slightly higher in the patients undergoing osteotomy with navigation, the difference was not significant. Intra-operative visualisation of the mechanical axis proved sufficiently accurate on comparison with the pre-operative planning based on weight-bearing radiography of the leg. A simulated axial load of the heel included in the kinematic navigation system does not sufficiently correspond to normal weight-bearing and therefore an undercorrection of the deformity might occur. Using 3D navigation had no marked effect on a change in the slope of the tibial plateau.

• MeSH
• Surgery, Computer-Assisted * MeSH
• Adult MeSH
• Genu Valgum surgery   MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Osteotomy * MeSH
• Aged MeSH
• Tibia surgery   MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Young Adult MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• English Abstract MeSH
• Journal Article MeSH

PURPOSE: Treatment of pelvic fractures is often complicated. Here, we intended to evaluate the intraoperative benefits of using 2D computer navigation when compared with traditional fluoroscopy on X-ray burden, surgical time and screw placement accuracy. METHODS: In this study, we retrospectively evaluated the records of 25 patients who underwent osteosynthesis of a posterior pelvic fracture using fluoroscopy at the University Hospital Ostrava, Czech Republic between 2011 and 2019, and 32 patients from the same department and period in whom 2D computer navigation was used. RESULTS: Intraoperative X-ray burden was significantly lower in the group with 2D computer navigation (median 650 vs 1024 cGy/cm2), as was the duration of the surgery (41 vs 45 min). This was most obvious where two screws were inserted (X-ray dose of 994 vs 1847 cGy/cm2 and 48 vs 70 min, respectively). Correction of the path for wire placement after the original drilling was necessary in 2 patients (6%) from the 2D computer navigation group and 15 patients from the fluoroscopy group (60%). Still, no malposition of the screws nor dislocation of the posterior pelvic segment after 12 months was observed in any patient of either group; of complications, only three superficial infections in the 2D navigation group and 2 in the fluoroscopy group were observed. CONCLUSION: 2D computer navigation is a safe and accurate method for placement of screws during posterior pelvic fracture osteosynthesis, associated with lower intraoperative radiation burden and shorter surgical times compared to standard fluoroscopy, especially if two screws are inserted.

• MeSH
• Surgery, Computer-Assisted * methods   MeSH
• Fluoroscopy methods   MeSH
• Fractures, Bone * diagnostic imaging   surgery   MeSH
• Bone Screws MeSH
• Humans MeSH
• Computers MeSH
• Retrospective Studies MeSH
• Fracture Fixation, Internal methods   MeSH
• Imaging, Three-Dimensional methods   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH

INTRODUCTION: For fractures of the posterior part of the pelvis and disjunction of the sacroiliac joint, iliosacral screws are used, which transfix the sacral process of the hip bone with the sacrum in the region of the S1 or S2 segment. The correct placement of these screws in the sacrum is important in order to avoid injury to the sacral nerve fibres or soft tissue injury ventrally and dorsally to the sacrum. 3D navigation provides the possibility of more precise control of drilling and screw insertion. It works on the basis of a 3D scan taken directly in the operating room using a C-arm with the possibility of 3D scanning. The aim of the work is to determine the operating times, the dose of intraoperative X-ray radiation and also the occurrence of postoperative complications during the introduction of iliosacral screws into the posterior segment of the pelvis under the control of 3D navigation. MATERIAL AND METHODS: In the years 2014–2020, we performed 13 osteosyntheses of the posterior segment of the pelvis using iliosacral screws under the control of 3D navigation at the Department of Surgery and Trauma and Emergency Surgery. We performed osteosynthesis using one or two cannulated screws with a diameter of 7.0 mm. The Ziehm Flat panel 3D fluoroscopy device and Vector Vision computer navigation were used during the surgery. For individual surgeries, we monitored the operating time in minutes, the dose of intraoperative X-ray radiation in cGY per cm2, as well as the time of intraoperative fluoroscopy in seconds. Postoperatively, we performed an X-ray check of the location of the iliosacral screws in four projections, in case of uncertainty, we clarified the position of the screws by CT examination. We monitored the incidence of postoperative complications within 90 days after surgery. One year after the surgery, we performed a control X-ray of the pelvis in four projections with the aim of detecting possible migration of osteosynthetic material or dislocation of the posterior segment of the pelvis after osteosynthesis. RESULTS: The group of 13 patients consisted of eight men and five women. All fractures were type C according to the AO-OTA classification. Eight patients (74 %) underwent osteosynthesis with one screw and five patients (26 %) with two screws. The median age of all patients in the cohort is 51 years (range: 33–73 years). The median weight of all patients in the cohort is 83 kg (range: 65–107 kg). The median intraoperative X-ray time of all patients is 1.14 min (range: 0.50–2.35 min). The median X-ray radiation dose is 853 cGy/cm2 (range: 591–1369 cGy/cm2). The median total operative time is 42 minutes (range: 28–62 min). CONCLUSION: Osteosynthesis of the posterior segment of the pelvis using 3D navigation is more accurate than fluoroscopic control of this surgical procedure and also 2D navigation because it allows drilling to be monitored in individual sections of the sacral bone. It is possible to assess the intraosseous position throughout the drilling of the channel for the iliosacral screw. In a small group of patients, we did not observe post-operative complications in the sense of injury to neurovascular structures and also malposition of screws.

• Keywords
• Vector Vision,
• MeSH
• Surgery, Computer-Assisted methods   MeSH
• Bone Screws MeSH
• Humans MeSH
• Sacroiliac Joint surgery   injuries   MeSH
• Sacrococcygeal Region surgery   injuries   MeSH
• Fracture Fixation, Internal * methods   MeSH
• Treatment Outcome MeSH
• Imaging, Three-Dimensional MeSH
• Check Tag
• Humans MeSH

Intraoperativní sonografické zobrazení (IOS) v neurochirurgii představuje standardní nástroj pro aktuální a reálné zobrazení mozkové tkáně a zájmových struktur. Technologický rozvoj sonografické techniky vedl k miniaturizaci sond a umožnil jejich použití v omezeném prostoru kraniotomie. Kvalita zobrazení se zvýšila zavedením vysokofrekvenčních sond s vysokým prostorovým rozlišením. Prostředí mozkové tkáně je z hlediska insonačních podmínek příznivé a umožňuje přesnou lokalizaci a navigaci operačního přístupu u všech běžných druhů mozkových nádorů, jako jsou gliomy, metastázy, meningeomy a kavernomy. Základní zobrazení je B mód (2D zobrazení), které lze pro zlepšení orientace doplnit o rekonstruované 3D zobrazení. Tumorózní expanze se v IOS jeví proti mozkové tkáni jako hyperechogenní struktury. Další usnadnění orientace v IOS přináší integrace sonografického přístroje s optickou neuronavigací. Vedle navigační funkce je IOS výhodné při detekci a lokalizaci reziduí při resekcích gliálních nádorů a metastáz. Přispívá tak k dosažení co největší radikality resekce. Použití sonografické kontrastní látky při IOS zlepšuje dále kvalitu obrazu a snižuje vliv artefaktů na kvalitu zobrazení během resekce nádoru. Duplexní zobrazení v barevném dopplerovském nebo energetickém módu umožňuje lokalizovat cévní struktury, vyhodnotit jejich vztah k tumoru nebo lokalizovat cévní zásobení. Kromě lokalizace tumoru lze posoudit vnitřní strukturu tumoru a navigovat podle toho biopsie a přístup. Hlavními přednostmi IOS jsou přesné a aktuální zobrazení, dostupnost, libovolná opakovatelnost a vysoká kvalita zobrazení. Předpokladem vysoké výtěžnosti IOS je dlouhodobá zkušenost s tímto zobrazením. Nedostatkem je nemožnost navigovat kraniotomii a výskyt artefaktů při kontrole resekce.

Intraoperative sonography (IOS) in neurosurgery is a standard acquisition tool for real-time imaging of brain tissue and target structures. The technological advance of ultrasound devices has led to miniaturisation of ultrasound probes and enabled their use in the limited space of craniotomy. The quality of IOS imaging improved after introducing high-frequency probes with high spatial resolution. The environment of brain tissue provides favourable insonation conditions and enables precise localisation and navigation of surgical access to all com­mon brain tumours, including gliomas, metastases, meningiomas and cavernomas. The basic imaging is B-mode (two-dimensional; 2D) and can be supplemented by 3D (three-dimensional; 3D) reconstruction to improve orientation. Brain tumours are displayed as hyperechoic structures compared to the brain tissue. The integration of ultrasound devices with optical neuronavigation facilitates the orientation in IOS even more. Besides the navigational function, the IOS is suitable for detection and localisation of tumour remnants during removal of gliomas and metastases. In this way the IOS contributes to maximum extent of resection. The contrast-enhanced IOS further improves image quality and reduces the impact of artefacts. Duplex ultrasonography using colour Doppler or power Doppler makes it possible to localise vessels and to evaluate their relation to the tumour or to localise its vessel supply. In addition to localisation of tumours, it is possible to assess their internal structure and lead biopsies and navigate access. The main advantages of IOS are precise real-time information, availability, easy repeatability and high-quality imaging. The prerequisite for effective IOS imaging is long-term experience with this imaging modality. The drawbacks of the IOS include the impossibility to navigate craniotomy and the occurrence of artefacts during resection control.

• MeSH
• Glioma surgery   therapy   MeSH
• Intraoperative Neurophysiological Monitoring MeSH
• Humans MeSH
• Magnetic Resonance Imaging utilization   MeSH
• Meningioma MeSH
• Brain Neoplasms diagnostic imaging   surgery   therapy   MeSH
• Neuronavigation * MeSH
• Ultrasonography, Doppler, Transcranial MeSH
• Ultrasonography * methods   instrumentation   utilization   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Examination Questions MeSH

Cognitive deficits in older adults attributable to Alzheimer's disease (AD) pathology are featured early on by hippocampal impairment. Among these individuals, deterioration in spatial navigation, manifested by poor hippocampus-dependent allocentric navigation, may occur well before the clinical onset of dementia. Our aim was to determine whether allocentric spatial navigation impairment would be proportional to right hippocampal volume loss irrespective of general brain atrophy. We also contrasted the respective spatial navigation scores of the real-space human Morris water maze with its corresponding 2D computer version. We included 42 cognitively impaired patients with either amnestic mild cognitive impairment (n = 23) or mild and moderate AD (n = 19), and 14 cognitively intact older controls. All participants underwent 1.5T MRI brain scanning with subsequent automatic measurement of the total brain and hippocampal (right and left) volumes. Allocentric spatial navigation was tested in the real-space version of the human Morris water maze and in its corresponding computer version. Participants used two navigational cues to locate an invisible goal independent of the start position. We found that smaller right hippocampal volume was associated with poorer navigation performance in both the real-space (β = -0.62, P < 0.001) and virtual (β = -0.43, P = 0.026) versions, controlling for demographic variables, total brain and left hippocampal volumes. In subsequent analyses, the results were significant in cognitively impaired (P ≤ 0.05) but not in cognitively healthy (P > 0.59) subjects. The respective real-space and virtual scores strongly correlated with each other. Our findings indicate that the right hippocampus plays a critical role in allocentric navigation, particularly when cognitive impairment is present.

• MeSH
• Hippocampus anatomy & histology   pathology   MeSH
• Humans MeSH
• Magnetic Resonance Imaging MeSH
• Case-Control Studies MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Computer-assisted orthopedic surgery (CAOS) systems have become one of the most important and challenging types of system in clinical orthopedics, as they enable precise treatment of musculoskeletal diseases, employing modern clinical navigation systems and surgical tools. This paper brings a comprehensive review of recent trends and possibilities of CAOS systems. There are three types of the surgical planning systems, including: systems based on the volumetric images (computer tomography (CT), magnetic resonance imaging (MRI) or ultrasound images), further systems utilize either 2D or 3D fluoroscopic images, and the last one utilizes the kinetic information about the joints and morphological information about the target bones. This complex review is focused on three fundamental aspects of CAOS systems: their essential components, types of CAOS systems, and mechanical tools used in CAOS systems. In this review, we also outline the possibilities for using ultrasound computer-assisted orthopedic surgery (UCAOS) systems as an alternative to conventionally used CAOS systems.

• MeSH
• Surgery, Computer-Assisted trends   MeSH
• Humans MeSH
• Musculoskeletal Diseases physiopathology   surgery   MeSH
• Orthopedic Procedures trends   MeSH
• Tomography, X-Ray Computed trends   MeSH
• Robotics trends   MeSH
• Imaging, Three-Dimensional trends   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Cíl: Zhodnotit superioritu předoperačního trojrozměrného (3D) plánování pomocí CT nad dvojrozměrným (2D) plánováním z hlediska přesnosti umístění pedikulárních šroubů. Materiál a metody: Ve virtuálním prostředí umístili tři chirurgové osmi pacientům ve skupině 2D pedikulární šrouby do bederní páteře po konvenčním 2D plánování. Ve skupině 3D umístili pedikulární šrouby po 3D plánování na základě CT. Po virtuálních operacích byly zaznamenány úhly trajektorie, vzdálenost míst narušení pedikulární stěny a vzdálenost odchylek od místa vstupu šroubu. Výsledky: V 2D skupině pedikulární stěnu penetrovalo 69 šroubů (28,8 %) a v 3D skupině 37 šroubů (15,5 %). Porovnání těchto dvou skupin ukázalo významnou výhodu ve prospěch předoperačního 3D plánování (p = 0,003). V 2D skupině byl průměrný úhel trajektorie šroubu vypočítaný před operací 19,65 ± 6,35° a průměrný úhel vložených šroubů měřený po operaci byl 20,79 ± 5,95°. Ve skupině 3D byl průměrný úhel trajektorie šroubu vypočítaný předoperačně 20,18 ± 5,67° a průměrný úhel vloženého šroubu změřený pooperačně byl 20,07 ± 5,85°. V porovnání s předoperačním plánováním ve skupině 3D byly šrouby vloženy v podobné orientaci (p = 0,655), ale pooperačně nebylo možné ve skupině 2D podobné orientace dosáhnout u všech úrovní (p ≤ 0,001). Závěr: Předoperační 3D plánování zlepšuje přesnost tím, že pomáhá určit bod vstupu pedikulárního šroubu a jeho směr.

Aim: To evaluate the superiority of preoperative three-dimensional (3D) CT-based planning over two-dimensional (2D) planning in terms of pedicle screw placement accuracy. Materials and methods: In a virtual environment, three surgeons placed pedicle screws in the lumbar region of eight patients in the 2D group after conventional 2D planning. In the 3D group, they placed pedicle screws after 3D CT-based planning. Trajectory angles, distance of the wall breach and distance of the screw entry point deviation were recorded after virtual surgeries. Results: In the 2D group, 69 screws (28.8%) penetrated the pedicle wall and 37 screws (15.5%) penetrated the pedicle wall in the 3D group. Comparing these two groups, preoperative 3D planning showed a signifi cant advantage (P = 0.003). In the 2D group, the mean angle of the screw trajectory preoperatively calculated was 19.65 ± 6.35°, and the mean angle of the inserted screws was postoperatively measured at 20.79 ± 5.95°. In the 3D group, the mean angle of the screw trajectory calculated preoperatively was 20.18 ± 5.67°, and the mean angle of the inserted screws postoperatively was 20.07 ± 5.85°. The screws were inserted in the similar orientation comparing to preoperative planning in the 3D group (P = 0.655), but a similar orientation could not be obtained postoperatively in the 2D group (P ≤ 0.001) for all levels. Conclusion: Preoperative 3D planning improves accuracy by helping determine the pedicle screw entry point and direction.

• Keywords
• plánování operace,
• MeSH
• Lumbar Vertebrae * surgery   MeSH
• Surgery, Computer-Assisted * MeSH
• Clinical Studies as Topic MeSH
• Humans MeSH
• Pedicle Screws * MeSH
• Virtual Reality MeSH
• Imaging, Three-Dimensional MeSH
• Check Tag
• Humans MeSH

Intracardiac echocardiography (ICE) broadens the spectrum of echocardiographic techniques. Modern 10F sector echocardiographic catheters introduced into the right atrium allow high quality imaging of all cardiac structures, including pulse and continuous wave Doppler and/or color Doppler. The main indication for ICE appears to be monitoring of catheter ablation of complex arrhythmic substrates such atrial fibrillation, postincisional tachycardias and ventricular tachycardias. The other important role of ICE is the early diagnosis and prevention of complications during ablation procedures. These include those occurring during transseptal catheterization, damage to cardiac structures, left atrial thrombus formation, pulmonary venous stenosis, esophageal injury and pericardial effusion.

• MeSH
• Surgery, Computer-Assisted methods   MeSH
• Echocardiography methods   MeSH
• Financing, Organized MeSH
• Ultrasonography, Interventional methods   MeSH
• Humans MeSH
• Body Surface Potential Mapping methods   MeSH
• Heart Conduction System surgery   ultrasonography   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Review MeSH

The variability in width, height, and orientation of spinal pedicles makes pedicle screw insertion a delicate operation. Fluoroscopic guidance often exposes the patient and especially surgeons to relatively high doses of ionising radiation. The use of pulsed fluoroscopy is safer, as compared to continuous fluoroscopy, because of reduced radiation exposure. There are increasing numbers of literature reports regarding the high doses of radiation to which orthopaedic and spine surgeons are exposed during surgical procedures. Spine surgery can be associated with significant radiation exposure to the surgical staff. The purpose of this prospective study was to compare a computer-assisted navigation with a conventional procedure in order to assess if it is possible to reduce radiation exposure while preserving the accuracy of screw placement. MATERIAL AND METHODS: The first "conventional" group consisted of 30 patients, with an average of 1.9 segments of the lumbar spine stabilised. Screws were inserted transpedicularly under image intensifier guidance. In the second "navigated" group of 30 patients, stabilisation of 1,8 segments was performed on average. A CT-free fluoroscopic 2D spinal navigation system (VectorVision, Brain LAB, Germany) was used intra-operatively. It combines image-guided surgery with C-arm fluoroscopy. For each surgery (navigated or not), the duration of irradiation was recorded. The irradiation duration was collected from the X-ray image intensifier. In both groups the screw positioning accuracy was controlled intra-operatively according to Learch's, Acikbas's, and Whitecloud's methods from AP and lateral images and by meticulous pedicle palpation. RESULTS: The irradiation duration calculated to one vertebra (two screws) was significantly shorter in the second (navigated) group (3.4 s) than in the first (conventional) group (14.4 s). The mean duration of data registration was 6.0 minutes (range, 3 to 11 minutes). The mean ratio according to Acikbas's calculation method was 43.2 % (range, 32 % to 74 %) in the first (conventional) group and 44.1 % (range, 35 % to 76 %) in the second (navigated) group. DISCUSSION: During a conventional surgical procedure many X-ray images are made to control the accuracy of screw insertion. If the trajectory is not satisfying, it must be corrected or the pedicle is drilled again, always with a new fluoroscopic control. The process is repeated until satisfactory orientation is achieved. This is the explanation for a much longer duration of irradiation in conventional procedures. Navigation facilitates the surgical act, enabling us to acquire the right position of all screws, with only an AP image and a lateral image at the beginning of instrumentation for data registration; prolongation of the operative time is irrelevant. CONCLUSIONS: Navigation allows us to keep the same accuracy of pedicle screw placement while reducing radiation exposure of the surgeons and operating room staff by about one quarter. In multiple-level vertebral instrumentations this reduction is more pronounced. In centres where many procedures involving spine instrumentation are done every day, the "saved" exposure time can amount to hours.

• MeSH
• Surgery, Computer-Assisted methods   MeSH
• Adult MeSH
• Fluoroscopy methods   MeSH
• Spinal Fusion methods   instrumentation   MeSH
• Bone Screws MeSH
• Middle Aged MeSH
• Humans MeSH
• Spine surgery   radiography   MeSH
• Computer Graphics MeSH
• Computer Simulation MeSH
• Prospective Studies MeSH
• Radiographic Image Interpretation, Computer-Assisted methods   MeSH
• Robotics methods   MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH

• MeSH
• Surgery, Computer-Assisted MeSH
• Echocardiography standards   MeSH
• Endocardium pathology   MeSH
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Postoperative Care MeSH
• Aged MeSH
• Heart Transplantation MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Adolescent MeSH
• Aged MeSH