scholarly journals The largest secure corridor of the infra-acetabular screw — a 3-D axial perspective analysis

2020 ◽  
Author(s):  
Bei Zhao ◽  
Wei Zhang ◽  
Hao Li ◽  
Liren Han ◽  
Shizhang Han ◽  
...  
Keyword(s):  
Maximum Length ◽  
Posterior Column ◽  
Chinese Patients ◽  
Maximum Diameter ◽  
Insertion Point ◽  
Screw Insertion ◽  
The Mean ◽  
The Right ◽  
Perspective Analysis ◽  
The Ideal

Abstract Background The infra-acetabular screw is placed from the pubis to the ischium and can be used as a special lag screw of the posterior column of the acetabulum. This study was performed to simulate the surgical procedure and try to obtain the ideal insertion point, diameter, length and angle of the screw through the method of axial perspective in Chinese patients. Methods We randomly collected the pelvic computed tomography (CT) scans of 100 adults. DICOM-formatted CT-scan images were imported into Mimics software. The 3D digital model of the right semi-pelvic was established. A virtual cylinder representing the screw was placed from the pubis to the ischium to fix the posterior column. The largest secure diameter and length of the virtual screw were measured. The position of the insertion point and the directions of the screw were also researched. Results The screw insertion safe zone can exhibit an irregular “tear drop” from the reconstructed pelvic model. The mean maximum diameter of screws was 4.03 ± 0.93 mm, and the mean maximum length of screws was 96.05 ± 7.19 mm. The screw insertion corridor with a diameter of at least 3.5 mm was found in 48 of 50 males (96%). We found gender-dependent differences for the mean maximum diameter and the maximum length of the screw. The position between insertion point and eminelntia iliopectinea was statistically significant in different genders. Conclusions The study provides a valuable guideline for the largest secure corridor of infra-acetabular screw. We suggest an individual preoperative 3D reconstruction simulation for the ideal screw placement. Further biomechanical studies are needed to verify the function of the screw.

scholarly journals The largest secure corridor of the infra-acetabular screw—a 3-D axial perspective analysis

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Bei Zhao ◽  
Wei Zhang ◽  
Hao Li ◽  
Liren Han ◽  
Shizhang Han ◽  
...  
Keyword(s):  
Maximum Length ◽  
Posterior Column ◽  
Chinese Patients ◽  
Maximum Diameter ◽  
Insertion Point ◽  
Screw Insertion ◽  
Significant Difference ◽  
The Mean ◽  
The Right ◽  
Perspective Analysis

Abstract Background The infra-acetabular screw which is placed from the pubis to the ischium can be used as a special positional screw of the posterior column of the acetabulum. This study was performed to simulate the surgical procedure and obtain the ideal insertion point, diameter, length and angle of the screw through the method of axial perspective in Chinese patients. Methods We randomly collected the pelvic computed tomography (CT) scans of 200 adults. DICOM-formatted CT-scan images were imported into Mimics software to establish the 3D digital model of the right semi-pelvic was established. A virtual cylinder representing the screw was placed from the pubis to the ischium to fix the posterior column. The largest secure diameter and length of the virtual screw were measured and the position of the insertion point and the directions of the screw were also researched. Results The screw insertion safe zone exhibits an irregular shape of “tear drop” in the reconstructed pelvic model. The mean maximum diameter of screws was 5.01 ± 1.28 mm, and the mean maximum length of screws was 93.99 ± 8.92 mm. The screw insertion corridor with the least diameter 3.5 mm was found in 94 of 100 males (94%) and 86 of 100 females (86%). We found gender-dependent differences for the mean maximum diameter and the maximum length of the screw. There was statistically significant difference between genders in the position of insertion point. Conclusions In this study, we suggest an individual preoperative 3D reconstruction simulation to develop better screw placement plans, which provides a valuable guideline for seeking the largest secure corridor of infra-acetabular screw. Further biomechanical studies are needed to verify the function of the screw.

scholarly journals The Largest Secure Corridor of the Infra-acetabular Screw—a 3-D Axial Perspective Analysis

2020 ◽  
Author(s):  
Bei Zhao ◽  
Wei Zhang ◽  
Hao Li ◽  
Liren Han ◽  
Shizhang Han ◽  
...  
Keyword(s):  
Safe Zone ◽  
Maximum Length ◽  
Posterior Column ◽  
Maximum Diameter ◽  
Insertion Point ◽  
Screw Insertion ◽  
The Mean ◽  
The Right ◽  
Perspective Analysis ◽  
The Ideal

Abstract Background The infra-acetabular screw is placed from the pubis to the ischium and can be used as a special lag screw of the posterior column of the acetabulum. This study was performed to simulate the surgical procedure and try to obtain the ideal insertion point, diameter, length and angle of the screw through the method of axial perspective in Chinese patients.Methods We randomly collected the pelvic computed tomography (CT) scans of 200 adults. DICOM-formatted CT-scan images were imported into Mimics software. The 3D digital model of the right semi-pelvic was established. A virtual cylinder representing the screw was placed from the pubis to the ischium to fix the posterior column. The largest secure diameter and length of the virtual screw were measured. The position of the insertion point and the directions of the screw were also researched.Results The screw insertion safe zone can exhibit an irregular “tear drop” from the reconstructed pelvic model. The mean maximum diameter of screws was 5.01±1.28 mm, and the mean maximum length of screws was 93.99±8.92 mm. The screw insertion corridor with a diameter of at least 3.5mm was found in 94 of 100 males (94%) and 86 of 100 females (86%). We found gender-dependent differences for the mean maximum diameter and the maximum length of the screw. The position of insertion point was statistically significant in different genders.Conclusions The study provides a valuable guideline for the largest secure corridor of infra-acetabular screw. We suggest an individual preoperative 3D reconstruction simulation for the ideal screw placement. Further biomechanical studies are needed to verify the function of the screw.

scholarly journals A guideline for screw fixation of coracoid process base fracture by 3D simulation

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Zhongye Sun ◽  
Hao Li ◽  
Bei Wang ◽  
Jun Yan ◽  
Liren Han ◽  
...  
Keyword(s):  
Screw Fixation ◽  
Safe Zone ◽  
Coracoid Process ◽  
Chinese Patients ◽  
Ct Scans ◽  
Insertion Point ◽  
Screw Insertion ◽  
The Mean ◽  
The Right ◽  
The Ideal

Abstract Background Fractures of the base of the coracoid process are relatively rare, but an increasing number of studies have reported using screws to fix coracoid process base fractures. This study was performed to simulate the surgical procedure and obtain the ideal diameter, length, insertion point and angle of the screw from a 3-D axial perspective in Chinese patients. Methods We randomly collected right scapula computed tomography (CT) scans from 100 adults. DICOM-formatted CT scan images were imported into Mimics software. A 3D digital model of the right scapula was established. Two virtual cylinders representing two screws were placed from the top of the coracoid process to the neck of the scapula and across the base of the coracoid process to fix the base of the coracoid process. The largest secure diameters and lengths of the virtual screws were measured. The positions of the insertion points and the directions of the screws were also examined. Results The screw insertion safe zone can exhibit an irregular fusiform shape according to the reconstructed scapula model. The mean maximum diameters of the medial and lateral screws were 7.08 ± 1.19 mm and 7.34 ± 1.11 mm, respectively. The mean maximum lengths of the medial and lateral screws were 43.11 ± 6.31 mm and 48.16 ± 6.94 mm, respectively. A screw insertion corridor with a diameter of at least 4.5 mm was found in all patients. We found sex-dependent differences in the mean maximum diameters and maximum lengths of the two screws. The positions of the two insertion points were statistically different across sexes. Conclusions The study provides a valuable guideline for determining the largest secure corridor for two screws in fixing a fracture at the base of the coracoid process. For ideal screw placement, we suggest individualised preoperative 3D reconstruction simulations. Further biomechanical studies are needed to verify the function of the screws.

scholarly journals A guideline for screw fixation of coracoid process base fracture by 3D technology

2020 ◽  
Author(s):  
Zhongye Sun ◽  
Hao Li ◽  
Bei Wang ◽  
Jun Yan ◽  
Liren Han ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Screw Fixation ◽  
Safe Zone ◽  
Coracoid Process ◽  
Ct Scans ◽  
Insertion Point ◽  
Screw Insertion ◽  
The Mean ◽  
The Right ◽  
The Ideal

Abstract BackgroundFractures of the base of the coracoid process are relatively rare, but an increasing number of studies have reported using screws to fix basal coracoid process fractures. This study was performed to simulate the surgical procedure and obtain the ideal diameter, length, insertion point and angle of the screw through the method of 3-D axial perspective in Chinese patients.MethodsWe randomly collected the right scapula computed tomography (CT) scans of 100 adults. DICOM-formatted CT-scan images were imported into Mimics software. The 3D digital model of the right scapula was established. Two virtual cylinders representing two screws were placed from the top of the coracoid process to the neck of the scapula and across the base of the coracoid process to fix the basal coracoid process. The largest secure diameters and lengths of the virtual screws were measured. The positions of the insertion points and the directions of the screws were also researched.ResultsThe screw insertion safe zone can exhibit an irregular fusiform shape from the reconstructed scapula model. The mean maximum diameters of the medial and lateral screws were 7.08 ± 1.19 mm and 7.34 ± 1.11 mm, respectively. The mean maximum lengths of the medial and lateral screws were 43.11 ± 6.31 mm and 48.16 ± 6.94 mm, respectively. The screw insertion corridor with a diameter of at least 4.5 mm was found in anyone. We found gender-dependent differences for the mean maximum diameters and the maximum lengths of the two screws. The positions of the two insertion points were statistically significant in different genders.ConclusionsThe study provides a valuable guideline for the largest secure corridor of two screws that fixed the fracture at the base of the coracoid process. For the ideal screw placement, we suggest an individual preoperative 3D reconstruction simulation. Further biomechanical studies are needed to verify the function of the screws.

scholarly journals Digital anatomical study of screw placement for quadrilateral plate through the middle window of ilioinguinal approach

2019 ◽  
Author(s):  
Bei Zhao ◽  
Weidong Mu
Keyword(s):  
Inclination Angle ◽  
Three Dimensional ◽  
Anatomical Study ◽  
Chinese Patients ◽  
Screw Placement ◽  
Insertion Point ◽  
Ilioinguinal Approach ◽  
Quadrilateral Plate ◽  
Dimensional Reconstruction ◽  
The Mean

Abstract Background Screw placement directly for quadrilateral plate fractures of the acetabulum is very difficult. This study was performed to simulate the surgical procedure and try to obtain effective and safe screw angles through the middle window of ilioinguinal approach in Chinese patients. Methods We randomly collected the pelvic computed tomography (CT) scans of 50 adults. DICOM-formatted CT-scan images were imported into Mimics software. The three-dimensional reconstruction (3D) digital model of the semi-pelvic was established. In the coronal and sagittal planes, a 3.5 mm cylinder was used to simulate the pathway of the screw from the designated insertion point. The angles of insertion and intersex differences were explored by statistical analyses. Results The screws could be inserted via four angles: medial inclination, lateral inclination, anterior inclination and posterior inclination. The mean minimum medial inclination angle (MIMIA) of insertion point A was 4.96°±1.11° in males and 8.66°±3.40° in females, and the intersex difference was significant. The mean minimum medial inclination angle (MIMIA) of insertion point C was -5.31°±3.69° in males and 1.75°±8.95° in females, and the intersex difference was significant. There were no differences in all the angles between males and females in insertion point B. Conclusions Preoperative measurement and calculation by digital tools before the screw placement for quadrilateral plate fractures of the acetabulum are feasible. Double cortical screws could be placed safely through the middle window of ilioinguinal approach to increase the stability of acetabulum.

Evaluation of a screw insertion landmark for a minimally invasive repair technique in induced bilateral sacroiliac luxation in feline cadavers

2021 ◽  
pp. 1098612X2110107
Author(s):  
Cheol-kyu Han ◽  
Jinsu Kang ◽  
Haebeom Lee ◽  
Namsoo Kim ◽  
Suyoung Heo
Keyword(s):  
Minimally Invasive ◽  
Iliac Crest ◽  
The Body ◽  
Insertion Point ◽  
Screw Insertion ◽  
Repair Technique ◽  
Canal Diameter ◽  
Significant Difference ◽  
Reduction Methods ◽  
The Right

Objectives The aim of this study was to describe an alternative landmark for screw insertion into the body of the ilium with bilateral sacroiliac luxation in cats. Methods Seven cat cadavers with artificially induced bilateral sacroiliac luxation were used. The screw insertion point was determined using the caudal iliac crest and cranial acetabular rim. These two points make the first guideline; a second guideline ran perpendicular to the caudal iliac crest point. The screw insertion point was halfway along the second guideline across the ilium body. Surgery was performed in a minimally invasive manner using fluoroscopy. Results Postoperative radiographs and CT were performed. In the postoperative evaluation, the sacroiliac joint reduction percentage was almost 90% and there was no significant difference in pelvic canal diameter ratio before and after surgery. Screw depth/sacral width was >60% in all cadavers. On CT, the angle between the screw and sacrum wing was within the normal range of 96.24° to the left and 98.65° to the right, except in one case. Conclusions and relevance In previous studies, surgical repair was based on having an intact contralateral ilium. However, this method is not applicable to patients with bilateral sacroiliac luxation and is mostly performed using open reduction methods. The screw insertion point suggested in this study offers a potential alternative repair technique for patients with bilateral sacroiliac luxation.

scholarly journals Digital anatomical study and clinical application of screw placement for quadrilateral plate fractures in the danger zone

2020 ◽  
Author(s):  
Bei Zhao ◽  
Zhongye Sun ◽  
Wei Zhang ◽  
Zhongbao Xu ◽  
Xiaofei Yang ◽  
...  
Keyword(s):  
Inclination Angle ◽  
Three Dimensional ◽  
Anatomical Study ◽  
Chinese Patients ◽  
Screw Placement ◽  
Insertion Point ◽  
Danger Zone ◽  
Ilioinguinal Approach ◽  
Quadrilateral Plate ◽  
The Mean

Abstract Background Direct screw placement for quadrilateral plate fractures in the danger zone of the acetabulum is very difficult. This study was performed to simulate the surgical procedure and try to obtain effective and safe screw angles through the middle window of the ilioinguinal approach in Chinese patients. Methods We randomly collected the pelvic computed tomography (CT) scans of 50 adults. DICOM-formatted CT-scan images were imported into Mimics software. The three-dimensional reconstruction (3D) digital model of the semi-pelvi s was established. A 3.5 mm cylinder was used to simulate the pathway of the screw from the designated insertion point . The angles of insertion and intersex differences were explored by statistical analyses. Results The screws could be inserted via three angles: medial inclination , anterior inclination and posterior inclination. The mean minimum medial inclination angle (MIMIA) of insertion point A was 4.96°±1.11° in males and 8.66°±3.40° in females, and the intersex difference was significant. The mean minimum medial inclination angle (MIMIA) of insertion point B was -5.31°±3.69° in males and 1.75°±8.95° in females, and the intersex difference was significant. There were no differences between any of the angles for males and females at insertion point O. Conclusions Preoperative measurement and calculation by digital tools before screw placement for quadrilateral plate fractures of the acetabulum are feasible. Double cortical screws could be placed safely in the danger zone through the middle window of the ilioinguinal approach to increase the stability of the acetabulum.

scholarly journals Extra-articular Portion of the Sacroiliac Joint—Between the Sacral and Pelvic Tuberosities: An Anatomical Guide for the S2-Alar-Iliac Screw Trajectory

2020 ◽  
pp. 219256822090303
Author(s):  
Yasunori Tatara ◽  
Takanori Niimura ◽  
Tatsuhiro Sekiya ◽  
Hisanori Mihara
Keyword(s):  
Sacroiliac Joint ◽  
Screw Placement ◽  
Anatomical Landmarks ◽  
Related Complication ◽  
Screw Insertion ◽  
Iliac Screw ◽  
The Individual ◽  
The Right ◽  
Navigation Software ◽  
The Ideal

Study Design: A novel technique for S2-alar-iliac (S2AI) screw placement was analyzed. Objectives: Accurate confirmation of the S2AI screw trajectory with free-hand techniques is not simple, although some anatomical landmarks have been reported. To overcome the drawback, we aimed to introduce our technique for S2AI screw placement assisted with a guidewire using a new anatomical landmark. Methods: A total of 104 S2AI screws of 52 patients who underwent S2AI screw placement were investigated. Navigation software was used to simulate S2AI screw placement preoperatively. Screw placement was performed with the nonfluoroscopic free-hand technique. In this technique, a guidewire is inserted into the ilium from the extra-articular portion of the sacroiliac joint just lateral to the ideal screw entry point toward the tip of the greater trochanter and guides the screw trajectory. If the direction of the guidewire is satisfactory, all procedures of screw insertion are performed accordingly. The screw accuracy was assessed with computed tomography. Results: The modal size of the screw was 9.5 mm × 90 mm. The average horizontal angle was 42.0° (SD = 5.1°) on the right and 40.7° (SD = 4.7°) on the left. Of the 104 screws, 4 screws (3.9%) breached dorsally. No screw-related complication was observed. Conclusions: Because the guidewire can be inserted at an angle according to the individual morphology of the sacroiliac joint, it will be a reliable guide for the screw trajectory. This technique with a guidewire would help improve the accuracy of S2AI screw placement.

scholarly journals The effect of pH decline rate on the meat and eating quality of beef carcasses

2014 ◽  
Vol 54 (4) ◽  
pp. 407 ◽  
Author(s):  
D. L. Hopkins ◽  
E. N. Ponnampalam ◽  
R. J. van de Ven ◽  
R. D. Warner
Keyword(s):  
Eating Quality ◽  
Rapid Decline ◽  
Effect Of Ph ◽  
Beef Carcasses ◽  
Temperature Window ◽  
The Mean ◽  
The Right ◽  
Beef Steer ◽  
The Ideal

An experiment was undertaken to examine the effect of rapid pH fall at a high muscle temperature on meat and eating quality of two beef cuts (striploin and cube roll). From 115 beef steer carcasses of which the right side of each carcass was subjected to electrical stimulation, 25 carcasses which exhibited the largest difference in the rate of pH fall in the M. longissimus between sides were selected for subsequent sampling. All of the stimulated sides missed the ‘ideal’ pH/temperature window (defined as temperature at pH 6 in the M. longissimus <35°C and >12°C) at the upper end, as did several of the non-stimulated sides. The mean temperature at pH 6 for stimulated sides from modelling was 40.9 versus 33.3°C for non-stimulated sides. Despite the significant effect of stimulation on pH decline there was no statistically significant impact on shear force or sensory traits of the M. longissimus, but there was a significant effect of aging on these traits. There was no effect of stimulation or pH decline on drip loss of the striploin. After 14 days of aging there was no effect of stimulation or ultimate pH on striploin purge, but there was a significant effect of pH decline. This was not, however, evident for purge of the cube roll aged for either 4 or 42 days. The redness of the cube rolls as reflected by a* values declined with days of display, with the decline more rapid for samples aged for 42 days compared with those aged for 4 days. For meat aged and displayed identically, the a* values were on average significantly lower for meat from non-stimulated carcasses, but apart from aging there was no effect on the wavelength ratio 630/580 nm, an indicator of the formation of metmyoglobin. There was also evidence that a rapid decline in pH increased the onset of lipid oxidation.

DMSA-scintigraphy in paediatrics: Is the evaluation of the geometric mean necessary for the calculation of the differential renal function?

2001 ◽  
Vol 40 (04) ◽  
pp. 107-110 ◽  
Author(s):  
B. Roßmüller ◽  
S. Alalp ◽  
S. Fischer ◽  
S. Dresel ◽  
K. Hahn ◽  
...  
Keyword(s):  
Renal Function ◽  
Geometric Mean ◽  
Region Of Interest ◽  
Posterior View ◽  
Renal Abnormality ◽  
Anterior View ◽  
Differential Renal Function ◽  
The Mean ◽  
The Right ◽  
To Receive

SummaryFor assessment of differential renal function (PF) by means of static renal scintigraphy with Tc-99m-dimer-captosuccinic acid (DMSA) the calculation of the geometric mean of counts from the anterior and posterior view is recommended. Aim of this retrospective study was to find out, if the anterior view is necessary to receive an accurate differential renal function by calculating the geometric mean compared to calculating PF using the counts of the posterior view only. Methods: 164 DMSA-scans of 151 children (86 f, 65 m) aged 16 d to 16 a (4.7 ± 3.9 a) were reviewed. The scans were performed using a dual head gamma camera (Picker Prism 2000 XP, low energy ultra high resolution collimator, matrix 256 x 256,300 kcts/view, Zoom: 1.6-2.0). Background corrected values from both kidneys anterior and posterior were obtained. Using region of interest technique PF was calculated using the counts of the dorsal view and compared with the calculated geometric mean [SQR(Ctsdors x Ctsventr]. Results: The differential function of the right kidney was significantly less when compared to the calculation of the geometric mean (p<0.01). The mean difference between the PFgeom and the PFdors was 1.5 ± 1.4%. A difference > 5% (5.0-9.5%) was obtained in only 6/164 scans (3.7%). Three of 6 patients presented with an underestimated PFdors due to dystopic kidneys on the left side in 2 patients and on the right side in one patient. The other 3 patients with a difference >5% did not show any renal abnormality. Conclusion: The calculation of the PF from the posterior view only will give an underestimated value of the right kidney compared to the calculation of the geometric mean. This effect is not relevant for the calculation of the differntial renal function in orthotopic kidneys, so that in these cases the anterior view is not necesssary. However, geometric mean calculation to obtain reliable values for differential renal function should be applied in cases with an obvious anatomical abnormality.

Sign in / Sign up

Export Citation Format

Share Document