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 ◽  
...  

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):  
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.


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 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.


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.


2012 ◽  
Vol 40 (11) ◽  
pp. 2578-2582 ◽  
Author(s):  
Masashi Nagao ◽  
Yoshitomo Saita ◽  
So Kameda ◽  
Hiroaki Seto ◽  
Ryo Sadatsuki ◽  
...  

Background: Internal fixation is advocated as the primary treatment for fifth metatarsal Jones fractures in athletes; however, screw insertion site discomfort and refracture can occur especially in competitive athletes. The ideal implant has not been determined. Hypothesis: Headless compression screw fixation of proximal fifth metatarsal Jones fractures is an effective treatment approach especially in competitive athletes. Study Design: Case series; Evidence level, 4. Methods: We studied 60 athletes treated surgically with a headless compression screw for fifth metatarsal Jones fractures (mean age, 19 years). The mean follow-up time was 178 weeks. We evaluated the clinical and radiographic outcomes of headless compression screw fixation of Jones fractures. Results: All athletes returned to full activity. The mean time to start running after surgery was 6.3 weeks (range, 3-12.7 weeks), and the mean time to full activity after surgery was 11.2 weeks (range, 6-25 weeks). One athlete suffered a delayed union, which healed uneventfully. One athlete suffered a nonunion and underwent reoperation for a screw exchange to an autogenous bone graft harvested from the iliac crest. No screw breakage was reported. No athlete suffered a refracture or discomfort in the screw insertion site. Conclusion: Headless compression screw fixation of fifth metatarsal Jones fractures provided excellent results, allowing athletes to return to full activity without both screw insertion site irritation and clinical refracture.


1996 ◽  
Vol 85 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Christopher G. Paramore ◽  
Curtis A. Dickman ◽  
Volker K. H. Sonntag

✓ Posterior transarticular screw fixation of the C1–2 complex has become an accepted method of rigid internal fixation for patients requiring posterior C1–2 fusion. The principal limitation of this procedure is the location of the vertebral artery, because an anomalous position may prohibit screw placement. In this study, a consecutive series of computerized tomography (CT) scans was reviewed, and the suitability of each patient for transarticular screw fixation was evaluated. All of the fine-slice axial C1–2 CT scans and reconstructions performed on a spiral scanner over 2 years were reviewed. A novel screw trajectory reconstruction was designed to visualize the potential path of a transarticular screw in the plane of the reconstruction. Scans were reviewed for bone anatomy and the position of the transverse foramen. Seventeen (18%) of 94 patients had a high-riding transverse foramen on at least one side of the C-2 vertebra that would prohibit the placement of transarticular screws. The left side was involved in nine patients and the right in five. Three patients had bilateral anomalies. The mean age of the group with anomalies (35.9 years, range 10–76) was not significantly different from the overall mean age (35.7 years, range 6–94). An additional five patients (5%) were considered to have anatomy in which screw placement was feasible but risky. On the basis of these data, it is postulated that 18% to 23% of patients may not be suitable candidates for posterior C1–2 transarticular screw fixation on at least one side.


2016 ◽  
Vol 37 (12) ◽  
pp. 1317-1325 ◽  
Author(s):  
Onur Kocadal ◽  
Mehmet Yucel ◽  
Murad Pepe ◽  
Ertugrul Aksahin ◽  
Cem Nuri Aktekin

Background: Among the most important predictors of functional results of treatment of syndesmotic injuries is the accurate restoration of the syndesmotic space. The purpose of this study was to investigate the reduction performance of screw fixation and suture-button techniques using images obtained from computed tomography (CT) scans. Methods: Patients at or below 65 years who were treated with screw or suture-button fixation for syndesmotic injuries accompanying ankle fractures between January 2012 and March 2015 were retrospectively reviewed in our regional trauma unit. A total of 52 patients were included in the present study. Fixation was performed with syndesmotic screws in 26 patients and suture-button fixation in 26 patients. The patients were divided into 2 groups according to the fixation methods. Postoperative CT scans were used for radiologic evaluation. Four parameters (anteroposterior reduction, rotational reduction, the cross-sectional syndesmotic area, and the distal tibiofibular volumes) were taken into consideration for the radiologic assessment. Functional evaluation of patients was done using the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale at the final follow-up. The mean follow-up period was 16.7 ± 11.0 months, and the mean age was 44.1 ± 13.2. Results: There was a statistically significant decrease in the degree of fibular rotation ( P = .03) and an increase in the upper syndesmotic area ( P = .006) compared with the contralateral limb in the screw fixation group. In the suture-button fixation group, there was a statistically significant increase in the lower syndesmotic area ( P = .02) and distal tibiofibular volumes ( P = .04) compared with the contralateral limbs. The mean AOFAS scores were 88.4 ± 9.2 and 86.1 ± 14.0 in the suture-button fixation and screw fixation group, respectively. There was no statistically significant difference in the functional ankle joint scores between the groups. Conclusion: Although the functional outcomes were similar, the restoration of the fibular rotation in the treatment of syndesmotic injuries by screw fixation was troublesome and the volume of the distal tibiofibular space increased with the suture-button fixation technique. Level of Evidence: Level III, retrospective comparative study.


2019 ◽  
Author(s):  
Bei Zhao ◽  
Weidong Mu

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.


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


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