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

Author(s):  
Zhongye Sun ◽  
Hao Li ◽  
Bei Wang ◽  
Jun Yan ◽  
Liren Han ◽  
...  

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.

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Zhongye Sun ◽  
Hao Li ◽  
Bei Wang ◽  
Jun Yan ◽  
Liren Han ◽  
...  

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.


2020 ◽  
Author(s):  
Bei Zhao ◽  
Wei Zhang ◽  
Hao Li ◽  
Liren Han ◽  
Shizhang Han ◽  
...  

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.


2020 ◽  
Author(s):  
Bei Zhao ◽  
Wei Zhang ◽  
Hao Li ◽  
Liren Han ◽  
Shizhang Han ◽  
...  

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.


2021 ◽  
Vol 104 (3) ◽  
pp. 475-481

Objective: Atlantoaxial instability can be caused by various etiologies and surgical fixation is often required. Various methods have been described for atlantoaxial fixation. Screw fixation is associated with an increased risk of vertebral artery injury especially in patients with an anomalous vertebral artery location or abnormal bony anomalies. A new C1 posterior arch crossing screw fixation technique was proposed to reduce the risk of vertebral artery injury. The present study aimed to assess morphometric CT analysis of atlas for C1 posterior arch crossing screw fixation in Thai people. Materials and Methods: The present research was an observational study that reviewed 150 computed tomography (CT) scans of the patients who had neck trauma or any other complaint requiring craniocervical investigations. Atlantoaxial articulation deformities due to trauma, infections, neoplasm, congenital anomaly, inflammatory disease, incomplete CT scan analysis, and history of surgical intervention of the cervical spine were excluded. All the images were measured for the height of the posterior tubercle, the width of the posterior arch was measured bilaterally in three parts on the axial plane, part 1: medial of the VA groove, where the arch transforms into the VA groove, part 2: the middle part between the posterior tubercle and medial of the VA, and part 3: posterior tubercle, length of the screw, and the screw projection angle was calculated. Results: Out of the 139 CT scans analyzed, the mean measurement of posterior arch height was 7.45±1.03 mm, wherein 73.3% exceed 7 mm. The mean width of the left posterior arch in part 1, 2, and 3 was 4.50±0.70 mm, 4.90±0.70 mm, and 5.70±0.80 mm, respectively, and the width of the right posterior arch in part 1, 2, and 3 was 4.50±0.70 mm, 4.80±0.70 mm, and 5.60±0.80 mm, respectively. The mean crossing screw length of the Left and Right was 17.02±3.04 mm and 17.37±2.75 mm, respectively. The mean angle of screw of the Left and Right was 24.62±3.38 degrees and 24.78±3.57 degrees, respectively. There were no significant differences in these variables between gender or sides (p>0.05) except the mean angle of the screw between gender (p<0.05). Conclusion: C1 posterior arch screw fixation is feasible in the adult Thai population. Preoperative thin-cut CT is essential for planning successful posterior arch crossing screws placement. Keywords: C1 posterior arch, Computed tomography, Crossing screw fixation


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Bei Zhao ◽  
Wei Zhang ◽  
Hao Li ◽  
Liren Han ◽  
Shizhang Han ◽  
...  

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.


2018 ◽  
Vol 45 (8) ◽  
pp. 1116-1123 ◽  
Author(s):  
Jonneke S. Kuperus ◽  
Constantinus F. Buckens ◽  
Jurica Šprem ◽  
F. Cumhur Oner ◽  
Pim A. de Jong ◽  
...  

Objective.Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by flowing bony bridges on the right side of the spine. Knowledge of the development of these spinal bridges is limited. The current longitudinal computed tomography (CT) study was designed to bridge this gap.Methods.Chest CT scans from elderly males with 2 scans (interval ≥ 2.5 yrs) were retrospectively included. Using the Resnick criteria, a pre-DISH group and a definite DISH group were identified. A scoring system based on the completeness of a bone bridge (score 0–3), extent of fluency, and location of the new bone was created to evaluate the progression of bone formation.Results.In total, 145 of 1367 subjects were allocated to the DISH groups with a mean followup period of 5 years. Overall prevalence of a complete bone bridge increased in the pre-DISH group (11.3% to 31.0%) and in the definite DISH group (45.0% to 55.8%). The mean bridge score increased significantly in both the pre-DISH and definite DISH group (p < 0.001). The new bone gradually became more flowing and expanded circumferentially.Conclusion.Over the mean course of 5 years, the new bone developed from incomplete, pointy bone bridges to more flowing complete bridges. This suggests an ongoing and measurable bone-forming process that continues to progress, also in established cases of DISH.


2019 ◽  
Vol 12 (S 01) ◽  
pp. S39-S44
Author(s):  
Michael Okoli ◽  
Kevin Lutsky ◽  
Michael Rivlin ◽  
Brian Katt ◽  
Pedro Beredjiklian

Abstract Introduction The purpose of this study is to determine the radiographic dimensions of the finger metacarpals and to compare these measurements with headless compression screws commonly used for fracture fixation. Materials and Methods We analyzed computed tomography (CT) scans of the index, long, ring, and small metacarpal bones and measured the metacarpal length, distance from the isthmus to the metacarpal head, and intramedullary diameter of the isthmus. Metacarpals with previous fractures or hardware were excluded. We compared these dimensions with the size of several commercially available headless screws used for intramedullary fixation. Results A total of 223 metacarpals from 57 patients were analyzed. The index metacarpal was the longest, averaging 67.6 mm in length. The mean distance from the most distal aspect of the metacarpal head to the isthmus was 40.3, 39.5, 34.4, and 31 mm for the index, long, ring, and small metacarpals, respectively. The narrowest diameter of the isthmus was a mean of 2.6, 2.7, 2.3, and 3 mm for the index, long, ring, and small metacarpals, respectively. Of 33 commercially available screws, only 27% percent reached the isthmus of the index metacarpal followed by 42, 48, and 58% in the long, ring, and small metacarpals, respectively. Conclusion The index and long metacarpals are at a particular risk of screw mismatch given their relatively long lengths and narrow isthmus diameters.


2019 ◽  
Vol 47 ◽  
Author(s):  
Viviane Motta dos Santos Moretto ◽  
Luciana Maria Curtio Soares ◽  
Esthefanie Nunes ◽  
Uiara Hanna Araújo Barreto ◽  
Valéria Régia Franco Sousa ◽  
...  

Background: Cerebral cavernous hemangioma is a rare neoplasm of vascular origin in the brain, characterized by abnormally dilated vascular channels surrounded by endothelium without muscle or elastic fibers. Presumptive diagnosis is performed by magnetic resonance or computed tomography (CT) scanning and can be confirmed by histopathology. The prognosis of intracranial cavernous hemangioma is poor, with progression of clinical signs culminating in spontaneous death or euthanasia. The purpose of this paper is to report a case of cerebral cavernous hemangioma in a dog, presenting the clinical findings, tomographic changes, and pathological findings.Case: This case involved a 2-year-old medium sized mixed breed female dog presenting with apathy, hyporexia, ataxia, bradycardia, dyspnea, and seizure episodes for three days. Hemogram and serum biochemistry of renal and hepatic function and urinalysis did not reveal any visible changes. CT scanning was also performed. The scans revealed a hyperdense nodule of 15.9 x 14 mm, with well defined borders, and a hypodense halo without post-contrast enhancement and mass effect in the right parietal lobe was observed in both transverse and coronal sections. Based on the image presented in the CT scans, the nodule was defined as a hemorrhagic brain lesion. The animal died after a seizure. The right telencephalon was subjected to necropsy, which revealed a reddish-black wel-defined nodule 1.7 cm in diameter extending from the height of the piriform lobe to the olfactory trine at the groove level and extending towards the lateral ventricle, with slight compression and deformation of the thalamus but no other macroscopic alterations in the other organs. The histopathology indicated that this nodular area in the encephalus contained moderate, well-delimited but unencapsulated cellularity, composed of large vascular spaces paved with endothelial cells filled with erythrocytes, some containing eosinophilic fibrillar material (fibrin) and others with organized thrombus containing occasional neutrophil aggregates. The endothelial cells had cytoplasm with indistinct borders, elongated nuclei, scanty crust-like chromatin, and cellular pleomorphism ranging from discrete to moderate, without mitotic figures.Discussion: The histological findings characterized the morphological changes in the brain as cavernous hemangioma, and the growth and compression of this neoplasm were considered the cause of the clinical signs of this dog. The main complaint was seizures, although ataxia and lethargy were also noted. These clinical signs are often related to changes in the anterior brain and brainstem. The literature does not list computed tomography as a complementary diagnostic method in cases of cerebral cavernous hemangioma in dogs, but CT scanning was useful in confirming cerebral hemorrhage. The main differential diagnosis for cerebral cavernous hemangioma would be a hamartoma, but what differentiates them histologically is the presence of normal interstices between the blood vessels, since no intervening neural tissue occurs in the case of cerebral hemangioma. Therefore, even in the absence of immunohistochemistry to more confidently confirm a cavernous hemangioma, the clinical signs, CT scans and especially the pathological findings were consistent with a case of cerebral cavernous hemangioma, a benign neoplasm with a poor prognosis due to the severe neurological changes it causes and its difficult treatment.


2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Lubna Bushara ◽  
Mohamed Yousef ◽  
Ikhlas Abdelaziz ◽  
Mogahid Zidan ◽  
Dalia Bilal ◽  
...  

This study aimed to determine the measurements of the cochlea among healthy subjects and hearing deafness subjects using a High Resolution Computed Tomography (HRCT). A total of 230 temporal bone HRCT cases were retrospectively investigated in the period spanning from 2011 to 2015. Three 64-slice units were used to examine patients with clinical complaints of hearing loss conditions at three Radiology departments in Khartoum, Sudan. For the control group (A) healthy subjects, the mean width of the right and left cochlear were 5.61±0.40 mm and 5.56±0.58 mm, the height were 3.56±0.36 mm and 3.54±0.36 mm, the basal turn width were 1.87±0.19 mm and 1.88 ±0.18 mm, the width of the cochlear nerve canal were 2.02±1.23 and 1.93±0.20, cochlear nerve density was 279.41±159.02 and 306.84±336.9 HU respectively. However, for the experimental group (B), the mean width of the right and left cochlear width were 5.38±0.46 mm and 5.34±0.30 mm, the height were 3.53±0.25 mm and 3.49±0.28mm, the basal turn width were 1.76±0.13 mm, and 1.79±0.13 mm, the width of the cochlear nerve canal were 1.75±0.18mm and 1.73±0.18mm, and cochlear nerve density were 232.84±316.82 and 196.58±230.05 HU, respectively. The study found there was a significant difference in cochlea’s measurement between the two groups with a p-value < 0.05. This study had established baseline measurements for the cochlear for the healthy Sudanese population. Furthermore, it found that HRCT of the temporal bone was the best for investigation of the cochlear and could provide a guide for the clinicians to manage congenital hearing loss.


SICOT-J ◽  
2020 ◽  
Vol 6 ◽  
pp. 9
Author(s):  
Hatem Galal Said ◽  
Tarek Nabil Fetih ◽  
Hosam Elsayed Abd-Elzaher ◽  
Simon Martin Lambert

Introduction: Coracoid fractures have the potential to lead to inadequate shoulder function. Most coracoid base fractures occur with scapular fractures and the posterior approaches would be utilized for surgical treatment. We investigated the possibility of fixing the coracoid through the same approach without an additional anterior approach. Materials and methods: Multi-slice CT scans of 30 shoulders were examined and the following measurements were performed by an independent specialized radiologist: posterior coracoid screw entry point measured form infraglenoid tubercle, screw trajectory in coronal plane in relation to scapular spine and lateral scapular border, screw trajectory in sagittal plane in relation to glenoid face bisector line and screw length. We used the results from the CT study to guide postero-anterior coracoid screw insertion under fluoroscopic guidance on two fresh frozen cadaveric specimens to assess the reproducibility of accurate screw placement based on these parameters. We also developed a novel fluoroscopic projection, the anteroposterior (AP) coracoid view, to guide screw placement in the para-coronal plane. Results: The mean distance between entry point and the infraglenoid tubercle was 10.8 mm (range: 9.2–13.9, SD 1.36). The mean screw length was 52 mm (range: 46.7–58.5, SD 3.3). The mean sagittal inclination angle between was 44.7 degrees (range: 25–59, SD 5.8). The mean angle between screw line and lateral scapular border was 47.9 degrees (range: 34–58, SD 4.3). The mean angle between screw line and scapular spine was 86.2 degrees (range: 75–95, SD 4.9). It was easy to reproduce the screw trajectory in the para-coronal plane; however, multiple attempts were needed to reach the correct angle in the parasagittal plane, requiring several C-arm corrections. Conclusion: This study facilitates posterior fixation of coracoid process fractures and will inform the “virtual visualization” of coracoid process orientation.


Sign in / Sign up

Export Citation Format

Share Document