scholarly journals A Novel Patient-Specific Three-Dimensional Printing Template Based on External Fixation for Pelvic Screw Insertion

2020 ◽  
Author(s):  
Kaihua Zhou ◽  
Xingguang Tao ◽  
Fugen Pan ◽  
Congfeng Luo ◽  
Huilin Yang
Keyword(s):  
Radiation Exposure ◽  
External Fixation ◽  
Exposure Time ◽  
Patient Specific ◽  
Mean Deviation ◽  
Surgical Time ◽  
X Ray ◽  
Screw Insertion ◽  
Navigation Group ◽  
The Mean

Abstract (1) Background: To investigate the clinical effect of the novel patient-specific 3D printing templates based on external fixation for pelvic screw insertion. (2) Methods: We retrospectively studied 8 patients with pelvic fractures who were treated using this novel template from July 2017 to July 2018. During the operation, the screws were inserted with the aid of the template. The operative time per screw, radiation exposure time, and accuracy of the screw insertions as evaluated by post-operative CT scans were analyzed statistically and compared with previous outcomes using the fluoro-navigation technique. (3) Results: In the template group, a total of 9 pubis screws and 6 sacroiliac screws were inserted. The mean surgical time was 11.3 min/screw and the mean X-ray exposure time was 11.8 ± 3.9 s/screw. The mean deviation distance and angle between the actual and planned screw position was 2.6 ± 0.2 mm and 2.0 ± 0.3 degrees, and blood loss during the surgery was 12.2 ml/screw. No superficial and deep infections and no patient sustained recognized neurologic, vascular, or urologic injury occurred in the template group. The surgical time and X-ray exposure time was less than that in the fluoro-navigation group((P < 0.05) (4) Conclusions: The patient-specific template based on external fixation can guide the insertion of the pelvic screw accurately, safely and invasively and significantly reduce operation and radiation exposure time.

scholarly journals A novel patient-specific three-dimensional printing template based on external fixation for pelvic screw insertion

2020 ◽  
Author(s):  
kaihua Zhou ◽  
Xingguang Tao ◽  
Fugen Pan ◽  
Congfeng Luo ◽  
Huilin Yang
Keyword(s):  
Radiation Exposure ◽  
External Fixation ◽  
Exposure Time ◽  
Patient Specific ◽  
Mean Deviation ◽  
Surgical Time ◽  
X Ray ◽  
Screw Insertion ◽  
Navigation Group ◽  
The Mean

Abstract (1) Background: To investigate the clinical effect of the novel patient-specific 3D printing templates based on external fixation for pelvic screw insertion. (2) Methods: We retrospectively studied 8 patients with pelvic fractures who were treated using this novel template from July 2017 to July 2018. During the operation, the screws were inserted with the aid of the template. The operative time per screw, radiation exposure time, and accuracy of the screw insertions as evaluated by post-operative CT scans were analyzed statistically and compared with previous outcomes using the fluoro-navigation technique. (3) Results: In the template group, a total of 9 pubis screws and 6 sacroiliac screws were inserted. The mean surgical time was 11.3 min/screw and the mean X-ray exposure time was 11.8 ± 3.9 s/screw. The mean deviation distance and angle between the actual and planned screw position was 2.6 ± 0.2 mm and 2.0 ± 0.3 degrees, and blood loss during the surgery was 12.2 ml/screw. No superficial and deep infections and no patient sustained recognized neurologic, vascular, or urologic injury occurred in the template group. The surgical time and X-ray exposure time was less than that in the fluoro-navigation group((P < 0.05) (4) Conclusions: The patient-specific template based on external fixation can guide the insertion of the pelvic screw accurately, safely and invasively and significantly reduce operation and radiation exposure time.

scholarly journals Patient-specific template-guided versus standard freehand lumbar pedicle screw implantation: a randomized controlled trial

2021 ◽  
pp. 1-7
Author(s):  
José Miguel Spirig ◽  
Shayan Golshani ◽  
Nadja A. Farshad-Amacker ◽  
Mazda Farshad
Keyword(s):  
Randomized Controlled Trial ◽  
Radiation Exposure ◽  
Pedicle Screw ◽  
Controlled Trial ◽  
Patient Specific ◽  
Pedicle Screw Placement ◽  
Surgical Time ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Randomized Controlled

OBJECTIVE Patient-specific template-guided (TG) pedicle screw placement currently achieves the highest reported accuracy in cadaveric and early clinical studies, with reports of reduced use of radiation and less surgical time. However, a clinical randomized controlled trial (RCT) eliminating potential biases is lacking. This study compares TG and standard freehand (FH) pedicle screw insertion techniques in an RCT. METHODS Twenty-four patients (mean age 64 years, 9 men and 15 women) scheduled consecutively and independently from this study for 1-, 2-, or 3-level lumbar fusion were randomized to either the FH (n = 12) or TG (n = 12) group. Accuracy of pedicle screw placement, intraoperative parameters, and short-term complications were compared. RESULTS A total of 112 screws (58 FH and 54 TG screws) were implanted in the lumbar spine. Radiation exposure was significantly less in the TG group (78.0 ± 46.3 cGycm2) compared with the FH group (234.1 ± 138.1 cGycm2, p = 0.001). There were 4 pedicle screw perforations (6.9%) in the FH group and 2 (3.7%) in the TG group (p > 0.99), with no clinical consequences. Clinically relevant complications were 1 postoperative pedicle fracture in the FH group (p > 0.99), 1 infection in the FH group, and 2 infections in the TG group (p > 0.99). There were no significant differences in surgical exposure time, screw insertion time, overall surgical time, or blood loss between the FH and TG groups. CONCLUSIONS In this RCT, patient-specific TG pedicle screw insertion in the lumbar region achieved a high accuracy, but not better than a standardized FH technique. Even if intraoperative radiation exposure is less with the TG technique, the need for a preoperative CT scan counterbalances this advantage. However, more difficult trajectories might reveal potential benefits of the TG technique and need further research.

Abstract 2598: Radiation Exposure, Procedure Time And Contrast Load In Patients Referred For Coronary Angiography: Head-to-head Comparison Of Dual Source Ct With Conventional Coronary Angiography.

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Carlos A Van Mieghem ◽  
Annick C Weustink ◽  
Marcel Kofflard ◽  
A. Schreve-Steensma ◽  
Niels A Matheijssen ◽  
...  
Keyword(s):  
Coronary Angiography ◽  
Radiation Exposure ◽  
Contrast Material ◽  
Conventional Coronary Angiography ◽  
Dual Source Ct ◽  
Procedure Time ◽  
X Ray ◽  
Iodinated Contrast ◽  
Dual Source ◽  
The Mean

Introduction and aim: Dual Source CT (DSCT) scanners, with an increased temporal resolution (83 ms), are becoming widely available. To evaluate the current potential of this scanner in the clinical arena, we performed a head-to-head comparison with conventional coronary angiography (CCA) taking into account the following parameters: radiation exposure, procedure time and contrast load. Methods: During a one-year period (april 2006 to march 2007) we compared a consecutive patient group who underwent DSCT (318 patients, 222 male, mean age 68±11 years) and CCA (352 patients, 258 male, mean age 61±12) respectively. Patients with previous bypass surgery were excluded. In DSCT, the volume of iodinated contrast material was adapted to the scan time. A contrast bolus was injected in an antecubital vein at a flow rate of 5.0 ml/s followed by a saline chaser of 40 ml at 5.0 ml/s. Each tube provided 412 mAs/rot (maximum), and full X-ray tube current was given during 25–70% of the RR-interval. Exposure data were collected using the x-ray dosimetrical reports from DSCT and CCA. Results: The mean procedure time using DSCT and CCA was 16.1±4.7 min and 44.1±25.5 min (p<0.001), respectively. The mean contrast load in DSCT and CCA was 77.9±7.6 ml and 175.3±4.3ml (p<0.001), respectively. The overall radiation exposure for DSCT and CCA was calculated as 15.3±4.0 mSv and 5.7±4.3 mSv, respectively. Radiation exposure with DSCT was significantly lower (p<0.001) in patients with a heart rate of >70 bpm (12.9±3.1 mSv ) as compared with patients with heart rates <70 bpm (16.4±3.8 mSv). Conclusion: In today’s practice currently available DSCT scanners perform favorably as compared with CCA, considering procedure time and patient contrast load. Radiation exposure with DSCT remains higher but should not be considered a major disadvantage taking into account the relatively old age group that generally undergoes coronary angiography and the major benefit of not being exposed to the risks of an invasive procedure.

Impact of considering non-occupational radiation exposure on the association between occupational dose and solid cancer among French nuclear workers

2017 ◽  
Vol 75 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Lucie Fournier ◽  
Enora Cléro ◽  
Eric Samson ◽  
Sylvaine Caër-Lorho ◽  
Dominique Laurier ◽  
...  
Keyword(s):  
Occupational Exposure ◽  
Cancer Risk ◽  
Radiation Exposure ◽  
Cancer Mortality ◽  
Environmental Radiation ◽  
Occupational Radiation Exposure ◽  
X Ray ◽  
Work Related ◽  
The Mean ◽  
Occupational Radiation

ObjectivesThe French nuclear worker cohort allows for the assessment of cancer risk associated with occupational radiation exposure, but workers are also exposed to medical and environmental radiation which can be of the same order of magnitude. This study aims to examine the impact of non-occupational radiation exposures on the dose-risk analysis between occupational radiation exposure and cancer mortality.MethodsThe cohort included workers employed before 1995 for at least one year by CEA, AREVA NC or EDF and badge-monitored for external radiation exposure. Monitoring results were used to calculate occupational individual doses. Scenarios of work-related X-ray and environmental exposures were simulated. Poisson regression was used to quantify associations between occupational exposure and cancer mortality adjusting for non-occupational radiation exposure.ResultsThe mean cumulative dose of external occupational radiation was 18.4 mSv among 59 004 workers. Depending on the hypotheses made, the mean cumulative work-related X-ray dose varied between 3.1 and 9.2 mSv and the mean cumulative environmental dose was around 130 mSv. The unadjusted excess relative rate of cancer per Sievert (ERR/Sv) was 0.34 (90% CI −0.44 to 1.24). Adjusting for environmental radiation exposure did not substantially modify this risk coefficient, but it was attenuated by medical exposure (ERR/Sv point estimate between 0.15 and 0.23).ConclusionsOccupational radiation risk estimates were lower when adjusted for work-related X-ray exposures. Environmental exposures had a very slight impact on the occupational exposure risk estimates. In any scenario of non-occupational exposure considered, a positive but insignificant excess cancer risk associated with occupational exposure was observed.

Crystalline microstructure of sepiolite influenced by grinding

2005 ◽  
Vol 38 (6) ◽  
pp. 888-899 ◽  
Author(s):  
Marek Andrzej Kojdecki ◽  
Joaquín Bastida ◽  
Pablo Pardo ◽  
Pedro Amorós
Keyword(s):  
Specific Surface ◽  
Mean Value ◽  
Crystalline Lattice ◽  
Mean Deviation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystallite Shape ◽  
The Mean ◽  
Crystalline Microstructure ◽  
Grinding Time

The crystalline microstructure of ground sepiolite has been investigated. A reference sample of sepiolite and products of its comminution by dry grinding were studied through X-ray diffraction pattern analysis, specific surface measurements by nitrogen adsorption and complementary analysis of field emission scanning electron microscope images. A statistical model of polycrystals was applied to describe and determine the crystalline microstructure of the studied specimens. The model parameters characterizing the microstructure were prevalent crystallite shape, volume-weighted crystallite size distribution and second-order crystalline lattice strain distribution, and they were determined for each sample by modelling a selected part of the X-ray diffraction pattern and fitting the simulated pattern to a measured one. A strict correlation of microstructure parameters with grinding time and with specific surface magnitudes was observed. A parallelepiped with edge-length ratios almost independent of grinding time (for longer times) was found to be the predominant crystallite shape. The crystallite size distributions were found to be close to logarithmic normal ones, with the mean values decreasing with increasing grinding time and the standard-deviation-to-mean-value ratios approximately constant. The second-order crystalline lattice strain distributions were found to be close to some simple function with the mean value equal to zero, the mean deviation increasing with increasing grinding time and the standard-to-mean-deviation ratios approximately constant. It was demonstrated that the specific surface can be calculated on the basis of the microstructure characteristics. Some details of the relation between crystallites and crystalline grains were explained by comparing the results of analysesviaX-ray diffraction and scanning electron microscopy.

Multistep pedicle screw insertion procedure with patient-specific lamina fit-and-lock templates for the thoracic spine

2013 ◽  
Vol 19 (2) ◽  
pp. 185-190 ◽  
Author(s):  
Taku Sugawara ◽  
Naoki Higashiyama ◽  
Shuichi Kaneyama ◽  
Masato Takabatake ◽  
Naoko Watanabe ◽  
...  
Keyword(s):  
Pedicle Screw ◽  
Thoracic Spine ◽  
Operating Time ◽  
Spinal Instrumentation ◽  
Ct Scans ◽  
Patient Specific ◽  
Mean Deviation ◽  
Screw Insertion ◽  
Pedicle Screw Insertion ◽  
Adjacent Structures

Object Pedicle screw fixation is a standard procedure of spinal instrumentation, but accurate screw placement is essential to avoid injury to the adjacent structures, such as the vessels, nerves, and viscera. The authors recently developed an intraoperative screw guiding method in which patient-specific laminar templates were used, and verified the accuracy of the multistep procedure in the thoracic spine. Methods Preoperative bone images of the CT scans were analyzed using 3D/multiplanar imaging software and the trajectories of the screws were planned. Plastic templates with screw guiding structures were created for each lamina by using 3D design and printing technology. Three types of templates were made for precise multistep guidance, and all templates were specially designed to fit and lock on the lamina during the procedure. Plastic vertebra models were also generated and preoperative screw insertion simulation was performed. Surgery was performed using this patient-specific screw guide template system, and the placement of screws was postoperatively evaluated using CT scanning. Results Ten patients with thoracic or cervicothoracic pathological entities were selected to verify this novel procedure. Fifty-eight pedicle screws were placed using the screw guide template system. Preoperatively, each template was found to fit exactly and to lock on the lamina of the vertebra models, and screw insertion simulation was successfully performed. Intraoperatively the templates also fit and locked on the patient lamina, and screw insertion was completed successfully. Postoperative CT scans confirmed that no screws violated the cortex of the pedicles, and the mean deviation of the screws from the planned trajectories was 0.87 ± 0.34 mm at the coronal midpoint section of the pedicles. Conclusions The multistep, patient-specific screw guide template system is useful for intraoperative pedicle screw navigation in the thoracic spine. This simple and economical method can improve the accuracy of pedicle screw insertion and reduce the operating time and radiation exposure of spinal fixation surgery.

scholarly journals The accuracy and safety of patient-specific 3D printing screws insertion templates based on external fixation for pelvic screw insertion

10.29007/96k5 ◽  
2018 ◽  
Author(s):  
Xing-Guang Tao ◽  
Hui Liang ◽  
Fu-Gen Pan ◽  
Kai Hua Zhou
Keyword(s):  
3D Printing ◽  
External Fixation ◽  
Pelvic Fractures ◽  
Patient Specific ◽  
Sacroiliac Screw ◽  
Screw Insertion ◽  
Sacroiliac Screws ◽  
New Type ◽  
Printing System ◽  
Moderate Cost

Objective: To explore the feasibility and accuracy of the new technique of patient-specific 3D printing screws insertion template in the pelvic fractures.Methods: From January to June in 2017, 6 patients with pelvic fractures were treated by this new type of screw guide templates. Pubis screws and sacroiliac screws were inserted. The patients with external fixation were examined by CT scan before surgery. The patients-specific 3D printing templates were made with photosensitive resin by a 3D printing system to ensure the trajectory of the screws. The templates were sterilized by ethylene oxide and used during surgery. The accuracy and safety of the templates were evaluated by CT scans after surgery.Results: Totally 10 screws were inserted, including 5 pubis screws and 5 sacroiliac screws. The average surgical time for pubis screw was 12.7 min/screw, and 9.2 min/screw for sacroiliac screw. The average time of X-ray exposure was 13.3±3.6s/screw for public screw and 9.6±4.5s/screw for sacroiliac screw. All the screws were inserted in the trajectory as preoperative design and the screw axis deviation was 1.60 ± 0.2mm and 2 ± 0.3 degrees angle deviation by preoperative and postoperative CT verification. Blood loss during the surgery was minimal (12.2ml/screw). Vascular of neurologic complications or injuries did not happen. And no infection, broken screws or screw pullout occurred.ConculsionThe patient-specific screw guide template based on the external fixation can insert the screw accurately and safely with very small incision. This technique is a new kind of intraoperative screw navigations. The patient-specific 3D printing screw insertion template was user-frindly, moderate cost and enabled a radiation-reduced pelvic screw insertion.

scholarly journals Delayed Internal Fixation of Distal Radius and Bimalleolar Ankle Fractures Does Not Increase Surgical Time

2019 ◽  
Vol 13 (1) ◽  
pp. 42-46
Author(s):  
Aman Chopra ◽  
Paul Hoogervorst ◽  
Meir Marmor
Keyword(s):  
Radiation Exposure ◽  
Distal Radius ◽  
Ankle Fracture ◽  
Callus Formation ◽  
Ankle Fractures ◽  
Surgical Time ◽  
Fracture Care ◽  
Significant Difference ◽  
Duration Of Surgery ◽  
The Mean

Introduction: It is commonly believed that delay in fracture fixation of more than two weeks results in increased Surgical Time (ST), due to scar and callus formation at the fracture site. Reducing ST can lower hospital costs and decrease radiation exposure. Methods and Results: A retrospective chart review was conducted to investigate whether early fracture care (up to 2 days after injury) results in decreased ST and radiation exposure compared to delayed fracture care (> 14 days after injury) for distal radius and bimalleolar ankle fractures. A total of 581 radius and ankle fractures that underwent surgical fixation between 2014 and 2017 were identified from the OR registry. Cases with only a single volar locking plate for the distal radius and constructs consisting of 2 medial malleolar screws, third tubular plate, and up to 1 syndesmotic screw for the ankle were included. The mean ST for distal radius cases done up to 2 days after injury was significantly greater than ST for distal radius cases done > 14 days after injury (125.78±29.75 minutes versus 105.83±24.82 minutes respectively , p=0.06). The mean ST for ankle fracture cases done less than 2 days did not differ from ST for ankle fracture cases done > 14 days after injury (140.86±28.15 minutes versus 173.22±39.98 minutes respectively, p=0.06). Conclusion: There was no significant difference in radiation exposure. Delaying surgery for distal radius and bimalleolar ankle fractures > 14 days after injury does not seem to significantly affect the duration of surgery or radiation exposure.

Radiation Exposure in the Neonatal Intensive Care Unit in Newborns and Staff

2021 ◽  
Author(s):  
Salih Cagri Cakir ◽  
Bayram Ali Dorum ◽  
Nilgun Koksal ◽  
Hilal Ozkan ◽  
Zeynep Yazici ◽  
...  
Keyword(s):  
Intensive Care ◽  
Radiation Exposure ◽  
Premature Infants ◽  
Neonatal Intensive Care ◽  
Diagnostic Procedures ◽  
Skin Dose ◽  
X Rays ◽  
X Ray ◽  
Radiation Induced ◽  
The Mean

Objective Portable X-rays remain one of the most frequently used diagnostic procedures in neonatal intensive care units (NICU). Premature infants are more sensitive to radiation-induced harmful effects. Dangers from diagnostic radiation can occur with stochastic effects. We aimed to determine the radiation exposure in premature infants and staff and determine the scattering during X-ray examinations in the NICU. Study Design In this prospective study, dosimeters were placed on premature infants who were ≤1,250 g at birth and ≤30 weeks of gestational age who stayed in the NICU for at least 4 weeks. The doses were measured at each X-ray examination during their stay. The measurements of the nurses and the doctors in the NICU were also performed with dosimeters over the 1-month period. Other dosimeters were placed in certain areas outside the incubator and the results were obtained after 1 month. Results The mean radiation exposure of the 10 premature infants, monitored with dosimeters, was 3.65 ± 2.44 mGy. The mean skin dose of the six staff was 0.087 ± 0.0998 mSV. The mean scattered dose was 67.9 ± 26.5 µGy. Conclusion Relatively high exposures were observed in 90% of the patients and two staff. The radiation exposure levels of premature infants and staff may need to be monitored continuously. Key Points

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