scholarly journals Assessment of acetabulum anteversion aligned with the transverse acetabulum ligament: cadaveric study using image-free navigation system

2013 ◽  
Vol 5 (1) ◽  
pp. 5 ◽  
Author(s):  
Tomokazu Fukui ◽  
Shigeo Fukunishi ◽  
Shoji Nishio ◽  
Yuki Fujihara ◽  
Shohei Okahisa ◽  
...  
Keyword(s):  
Gender Difference ◽  
Navigation System ◽  
Posterior Wall ◽  
Safe Zone ◽  
Anatomical Landmark ◽  
Cadaveric Study ◽  
Whole Body ◽  
Male Population ◽  
Anteversion Angle ◽  
Inclination Angles

The transverse acetabulum ligament (TAL) has been used as an intraoperative anatomical landmark to position the acetabulum cup in total hip arthroplasty (THA). However, the validity of the use of TAL has not been clarified. The purpose of this study was to examine the orientation of the cup component aligned with the TAL in <em>cadaveric study</em>. The 31 hips in 25 whole-body embalmed cadavers were examined. The donors were 12 men and 13 women. Simulated THA procedure using image-free navigation system was performed and a trial cup with a diameter of approximately 2 mm less than the size of the acetabulum were inserted and snugly fitted on the TAL through the posterior wall of acetabulum. The orientation of the cup component was measured using an image-free THA navigation system. The measured radiographic anteversion and inclination angles averaged 18.2±7.2° (range: 2.0-33.2°) and 43.5±4.2° (range: 33.1-51.0°) respectively. Based on the Lewinnek’s<em> safe zone</em> criteria, 26 hips (80.6%) were judged to be within the. Moreover, in the analysis of the gender difference of TAL angles, the average anteversion angle was shown to be significant larger in female than male population. The TAL can be effectively used an intraoperative landmark to align the acetabulum component helping reduce the risk of dislocation after surgery. In the intraoperative judgment, a gender difference in the alignment of the TAL should be taken into consideration.

scholarly journals Accuracy of cup placement in total hip arthroplasty by means of a mechanical positioning device: a comprehensive cadaveric 3d analysis of 16 specimens

2019 ◽  
pp. 112070001987482
Author(s):  
Arthur J Kievit ◽  
Johannes G G Dobbe ◽  
Wouter H Mallee ◽  
Leendert Blankevoort ◽  
Geert J Streekstra ◽  
...  
Keyword(s):  
3D Models ◽  
Safe Zone ◽  
3D Analysis ◽  
Anterior Pelvic Plane ◽  
Mechanical Device ◽  
Acetabular Cup ◽  
Anteversion Angle ◽  
Positioning Device ◽  
The Mean ◽  
Safe Zones

Introduction: We tested whether a mechanical device (such as Hipsecure) to pinpoint the anterior pelvic plane (APP) as a guide can improve acetabular cup placement. To assess accuracy we asked: (1) is the APP an effective guide to position acetabular cup placement within acceptable ° of divergence from the optimal 40° inclination and 15° anteversion; (2) could a mechanical device increase the number of acetabular cup placements within Lewinnek’s safe zone (i.e. inclination 30° to 50°; anteversion 5° to 25°)? Methods: 16 cadaveric specimens were used to assess the 3D surgical success of using a mechanical device APP to guide acetabular cup placement along the APP. We used the Hipsecure mechanical device to implant acetabular cups at 40° inclination and 15° anteversion. Subequently, all cadaveric specimens with implants were scanned with a CT and 3D models were created of the pelvis and acetabular cups to assess the outcome in terms of Lewinnek’s safe zones. Results: The mean inclination of the 16 implants was 40.6° (95% CI, 37.7–43.4) and the mean anteversion angle was 13.4° (95% CI, 10.7–16.1). All 16 cup placements were within Lewinnek’s safe zone for inclination (between 30° and 50°) and all but 2 were within Lewinnek’s safe zone for anteversion (between 5° and 25°). Conclusion: In cadaveric specimens, the use of a mechanical device and the APP as a guide for acetabular cup placement resulted in good positioning with respect to both of Lewinnek’s safe zones.

A Whole-Body Registration-Free Navigation System for Image-Guided Surgery and Interventional Radiology

2000 ◽  
Vol 35 (5) ◽  
pp. 279-288 ◽  
Author(s):  
AUGUSTINUS LUDWIG JACOB ◽  
PETER MESSMER ◽  
ACHIM KAIM ◽  
NORBERT SUHM ◽  
PIETRO REGAZZONI ◽  
...  
Keyword(s):  
Interventional Radiology ◽  
Navigation System ◽  
Whole Body ◽  
Image Guided Surgery ◽  
Guided Surgery ◽  
Image Guided

A Study for IGSO Inclination Angles in the Transmitting Satellite Navigation Constellation

2011 ◽  
Vol 64 (S1) ◽  
pp. S73-S82 ◽  
Author(s):  
Lihua Ma ◽  
Guoxiang Ai ◽  
Haifu Ji
Keyword(s):  
Southern Hemisphere ◽  
High Latitude ◽  
Navigation System ◽  
Satellite Navigation ◽  
Geosynchronous Orbit ◽  
High Quality ◽  
Satellite Navigation System ◽  
Inclination Angles ◽  
Navigation Signals ◽  
China Mainland

Unlike a direct broadcasting satellite navigation system, the transmitting satellite navigation system developed in China uses transponders onboard communication satellites to retransmit navigation signals generated at a ground master station. The transmitting navigation satellite constellation consists of a number of inclined geosynchronous orbit (IGSO) satellites. Considering China's mainland coverage in the northern hemisphere occupies some 62 degrees in longitude, the inclination of the IGSO satellites cannot be too high, or its signals would not be received by the users in the middle and high latitude areas when the IGSO satellite travels over the southern hemisphere. Meanwhile, the latitude of the most southerly station in China mainland that can uplink navigation signals is about 18°N when the IGSO satellite travels to the southern hemisphere. Therefore, there is a need to consider the IGSO inclination to achieve balance between uplinking high-quality navigation signals and covering the high-latitude area. In this work, the navigation performance and availability of the IGSO satellite are examined when navigation signals are uplinked from the stations Lintong and Sanya.

scholarly journals Calcaneal Osteotomy “Safe Zone” for Avoiding Injury to the Lateral Plantar Artery: A Fresh Cadaveric Study

2020 ◽  
Author(s):  
Ichiro Tonogai ◽  
Koichi Sairyo ◽  
Yoshihiro Tsuruo Tsuruo
Keyword(s):  
External Iliac Artery ◽  
Plantar Fascia ◽  
Safe Zone ◽  
Cadaveric Study ◽  
Medial Side ◽  
Calcaneal Osteotomy ◽  
Plantar Artery ◽  
Perpendicular Distance ◽  
Risk Of Rupture ◽  
Enhanced Computed Tomography

Abstract Background Calcaneal osteotomy is used to correct hindfoot deformity. Pseudoaneurysms of the lateral plantar artery (LPA) have been reported following calcaneal osteotomy and are at risk of rupture. The vascular structures in close proximity to the calcaneal osteotomy have variable courses and branching patterns. However, there is little information on the “safe zone” during calcaneal osteotomy. This study aimed to identify the safe zone that avoids LPA injury during calcaneal osteotomy.Methods Enhanced computed tomography scans of 25 fresh cadaveric feet (13 male and 12 female specimens; mean age 79.0 years at time of death) were assessed. The specimens were injected with barium via the external iliac artery. A landmark line (line A) connecting the posterosuperior aspect of the calcaneal tuberosity and the origin of the plantar fascia was drawn and the shortest perpendicular distance between the LPA and line A was measured on sagittal images.Results The average perpendicular distance between the LPA and line A at its closest point was 15.2 ± 2.9 mm. In 2 feet (8.0%), the perpendicular distance between the LPA and line A at its closest point was very short (approximately 9 mm). In 18 of the 25 feet (72.0%), the point where the perpendicular distance from line A to the LPA was closest was the bifurcation of one of the medial calcaneal branches of the LPA, and in 7 feet (28.0%) the shortest perpendicular distance from line A to the LPA was the trifurcation of the LPA, medial plantar artery, and one of the medial calcaneal branches.Conclusion Calcaneal osteotomy performed more than 9 mm from line A could damage the LPA by overpenetration on the medial side. Calcaneal osteotomy on the medial side should be performed with caution to avoid iatrogenic injury to the LPA.Level of Evidence: IV, cadaveric study

Radiological and cadaveric study of anatomical safe zone for transoral base of tongue surgery

2020 ◽  
Author(s):  
Ameena Ibrahim ◽  
Swetha Kumar ◽  
Aruna R. Patil ◽  
J. G. Aishwarya ◽  
Ashish S. Shah ◽  
...  
Keyword(s):  
Safe Zone ◽  
Cadaveric Study ◽  
Base Of Tongue

scholarly journals Retroversion of the hemipelvis rather than hypoplastic posterior wall decreases acetabular anteversion in hips affected by Perthes disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shijie Liao ◽  
Manjun Zhao ◽  
Tiantian Wang ◽  
Boxiang Li ◽  
Chengsen Lin ◽  
...  
Keyword(s):  
Linear Regression ◽  
Linear Regression Analysis ◽  
Posterior Wall ◽  
Anterior Wall ◽  
Contralateral Side ◽  
Acetabular Retroversion ◽  
Perthes Disease ◽  
Acetabular Anteversion ◽  
Anteversion Angle ◽  
The Mean

AbstractThe acetabular retroversion has a moderate incidence of 31–60% in all patients of the Perthes disease. It might be caused by posterior wall dysplasia based on recent animal researches. However, some studies support that hemipelvic retroversion is the main factor for the acetabular retroversion. The primary pathological factor of increasing retroversion angle is still controversial anatomically. This study aimed to identify whether there is acetabular retroversion in children with Perthes disease,and to find a method to distinguish version types. Forty children with unilateral Perthes disease who were admitted to our hospital from January 1, 2012 to December 31, 2018 were enrolled, and 40 controls were matched based on sex and age. The acetabular anteversion angle (AAA), internal wall anteversion angle (IWAA), anterior wall height of the acetabulum (A), acetabular posterior wall height (P), and acetabular width (W) were assessed on computed tomography (CT) at the level of the femoral head center. The acetabular wall difference index (AWDI; AWDI = P-A)/W*100) was calculated. The mean AAA was significantly lower in Perthes disease hips (10.59 (8.05–12.46)) than in contralateral hips (12.04 (9.02–13.33)) (p = 0.002) but did not differ from control hips (9.68 ± 3.76) (p = 0.465). The mean IWAA was significantly lower in Perthes hips (9.16 ± 3.89) than in contralateral hips (11.31 ± 4.04) (p = 0.000) but did not differ from control hips (9.43 ± 3.82) (p = 0.753). The mean AWDI did not differ between Perthes hips (0.41 ± 4.94) and contralateral hips (− 1.12 (− 4.50, 2.17)) (p = 0.06) or control hips (− 0.49 ± 5.46) (p = 0.437). The mean W was significantly higher in Perthes hips (44.61 ± 5.06) than in contralateral hips (43.36 ± 4.38) (p = 0.000) but did not differ from control hips (45.02 ± 5.01) (p = 0.719). The mean A and P did not differ between Perthes hips and contralateral hips or control hips. Correlation analysis of all hip joints revealed a significant correlation between AAAs and IWAAs (r = 0.772; r = 0.643; r = 0.608; and r = 0.540). Linear regression analysis revealed that AAAs increased with IWAAs. Multiple linear regression showed that IWAAs and AWDIs have good predictive value for AAAs in both Perthes and control hips (R2 = 0.842, R2 = 0.869). In patients with unilateral Perthes disease, the affected acetabulum is more retroverted than that on the contralateral side, which may be caused by hemipelvic retroversion. The measurements in this study could distinguish the form of acetabular retroversion. IWAAs and AWDIs can be used as new observations in future studies of acetabular version.

Imaging studies of the hindlimbs of pacas (Cuniculus paca) bred in captivity

2010 ◽  
Vol 23 (06) ◽  
pp. 439-443 ◽  
Author(s):  
S. C. Rahal ◽  
D. P. Doiche ◽  
M. R. F. Machado ◽  
L. C. Vulcano ◽  
C. R. Teixeira ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Mean Value ◽  
Imaging Studies ◽  
Anteversion Angle ◽  
Future Studies ◽  
Significant Difference ◽  
In Captivity ◽  
Inclination Angles ◽  
Norberg Angle ◽  
Ct Studies

Summary Objective: To evaluate the hindlimbs of pacas bred in captivity using radiographic and computed tomography (CT) studies. Animals: Nine mature pacas (Cuniculus paca) 5.9–8.2 kg in body weight. Methods: Radiographical aspects of the bones of the hindlimbs were evaluated, and the Norberg angle and inclination angle were measured for each hindlimb. Anteversion angle were measured in CT examination. Results: The bone anatomy of the hindlimb of the paca was similar to that of the guinea pig, apart from two lunulae and a single fabella (lateral) which were observed. The Norberg angle had mean value of 130.56º ±13.81 without any significant difference between testers. Inclination angles ranged from 142.44º ±4.82 to 145.44º ±4.09 by Hauptman’s method, and from 144.94º ±3.13 to 148.22º ±3.25 by Montavon’s method, for right and left hindlimbs respectively. Average values for the anteversion angles measured with CT ranged from 28.56º ±5.56 to 32.91º ± 2.62. Clinical significance: The data may be used in future studies comparing the paca to other rodent species. In addition, the paca could be used as an animal model in orthopaedic research.

Examination of Safe Zone to Avoid Injury of the Lateral Plantar Artery During Calcaneal Osteotomy: A Fresh Cadaveric Study

2020 ◽  
pp. 193864002096508
Author(s):  
Ichiro Tonogai ◽  
Yoshihiro Tsuruo ◽  
Koichi Sairyo
Keyword(s):  
External Iliac Artery ◽  
Plantar Fascia ◽  
Safe Zone ◽  
Cadaveric Study ◽  
Medial Side ◽  
Calcaneal Osteotomy ◽  
Plantar Artery ◽  
Perpendicular Distance ◽  
Hindfoot Deformities ◽  
Enhanced Computed Tomography

Background: Calcaneal osteotomy are used to treat various pathologies in the correction of hindfoot deformities. But lateral plantar artery (LPA) pseudoaneurysms have been reported following calcaneal osteotomy, and LPA pseudoaneurysms may be at risk for rupture. Although the vascular structures in close proximity to calcaneal osteotomies have variable courses and branching patterns, there is little information on safe zone for LPA during calcaneal osteotomy. The aims of this study were to identify the safety zone to avoid the LPA injury during calcaneal osteotomy. Methods: Enhanced computed tomography scans of 25 fresh cadaveric feet (male, n = 13; female, n = 12; mean age 79.0 years at the time of death) were assessed. The specimens were injected with barium via the external iliac artery. Line A is the landmark line and extends from the posterosuperior aspect of the calcaneal tuberosity to the plantar fascia origin, and the perpendicular distance between the LPA and line A at its closest point was measured on sagittal images. Results: The average perpendicular distance between the LPA and line A at its closest point was 15.2 ± 2.9 mm. In 2 cases (8.0 %), the perpendicular distance between the LPA and line A at its closest point was very close, approximately 9 mm. In 18 of 25 feet (72.0%), the point where perpendicular distance from the line A to LPA is the closest was the bifurcation of one of the medial calcaneal branches from LPA, and in 7 feet in 25 feet (28.0%) feet the point where perpendicular distance from the line A to LPA is the closest was the trifurcation of LPA, medial plantar artery, and one of the medial calcaneal branches. Conclusions: Calcaneal osteotomy approximately more than 9 mm from the line A could injure the LPA in overpenetration into the medial aspect of tcalcaneal osteotomy. Completion of the osteotomy on the medial side should be performed with caution to avoid iatrogenic injury of the LPA. Levels of Evidence:: Level IV, Cadaveric study

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