scholarly journals Anatomical axis validation of lower extremity for different deformities: A radiological study

2020 ◽  
Vol 8 ◽  
pp. 205031212092382
Author(s):  
Meric Unal ◽  
Sabriye Ercan ◽  
Aydin Budeyri ◽  
Uğur Toprak ◽  
Abdülkerim Şalkaci
Keyword(s):  
Lower Limb ◽  
Mechanical Axis ◽  
Correlation Coefficients ◽  
Strong Positive Correlation ◽  
Knee Alignment ◽  
Intra Class Correlation ◽  
X Ray ◽  
The Past ◽  
Radiology Assistant ◽  
Anatomical Axis

Aim: The aim of this study was to derive a pure, unbiased, reliable and accurate objective relationship between the local knee axis measurements through a short knee anteroposterior roentgenogram and the lower limb axis measurement through an orthoroentgenogram. Patients and Methods: Radiographs of 114 patients (114 knees) were evaluated by two independent raters for measurement of lower limb axis on an orthoroentgenogram and the local knee axis on short knee anteroposterior X-ray, which was derived by cropping the orthoroentgenogram by a blinded radiology assistant. The raters measured at two different time-points separated by an interval of 30-day period. Intra-rater and inter-rater reliabilities were calculated by intra-class correlation coefficients and three models were built to establish the relationships of X-ray anatomical axis with orthoroentgenogram anatomical axis, orthoroentgenogram anatomical axis with orthoroentgenogram mechanical axis and X-ray anatomical axis with orthoroentgenogram mechanical axis. Results: For three different measurements, intra-class correlation coefficients of Rater 2 were higher than 0.90 which shows perfect reliability, while that for Rater 1 was low. Furthermore, first measurements were more consistent than the second measurement. There was a strong positive correlation in all the three models except for varus cases in the last. Conclusion: The standardized correlation derived between the two different techniques for measuring knee alignment is fairly comparable with the studies in the past and would serve as a reliable template for future studies concerning relationships between the two, in addition to helping knee surgeons make more reliable and accurate interpretations through local knee axis measurements.

scholarly journals Mechanical and Anatomical Axis in Total Ankle Arthroplasty

2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0008
Author(s):  
Ali-Asgar Najefi ◽  
Andrew Goldberg
Keyword(s):  
Lower Limb ◽  
Mechanical Axis ◽  
Normal Group ◽  
Total Ankle Arthroplasty ◽  
Coronal Plane ◽  
Patient Specific ◽  
Ankle Arthroplasty ◽  
Patient Specific Instrumentation ◽  
Significant Difference ◽  
Anatomical Axis

Category: Ankle Arthritis Introduction/Purpose: Inadequate correction of alignment in the coronal, sagittal or axial planes will inevitably lead to failure of the Total Ankle Arthroplasty (TAA). The mechanical axis of the lower limb (MAL), the mechanical axis of the tibia (MAT) and the anatomical axis of the tibia (AAT) are three recognized coronal plane measurements using plain radiography. The relationship between anatomical and mechanical axes depends on the presence of femoral or tibial deformities from trauma or inherited conditions, or previous corrective or replacement surgery. Ankle arthroplasty relies heavily on preoperative radiographs or CT scans and the purpose of this study was to assess whether MAL, MAT and AAT are the same in a cohort of patients upon which placement of TAA is considered. Methods: We analysed 75 patients operated on between 2015 and 2016 at a specialist tertiary centre for elective orthopaedic surgery. All patients had a pre-operative long leg radiograph. They were split into 2 groups. The first group had known deformity proximal to the ankle (such as previous tibial or femoral fracture, severe arthritis, or previous reconstructive surgery) and the second group had no clinically detectable deformity. The MAL, MAT and AAT were assessed and the difference between these values was calculated. Results: There were 54 patients in the normal group, and 21 patients in the deformity group. Overall, 25 patients(33%) had a difference between all three axes of less than 1 degree. In 33 patients(44%), there was a difference in one of the axes of ≥2 degrees. There was no significant difference between MAT and AAT in patients in the normal group(p=0.6). 95% of patients had a difference of <1 degree. There was a significant difference between the MAT and AAT in patients in the deformity group(p<0.01). In the normal group, 39 patients(73%) had a difference of <2 degrees between the AAT and MAL. In the deformity group, only 10 patients (48%) had a difference of <2 degrees.In fact, 24% of patients had a difference ≥3 degrees. Conclusion: Malalignment in the coronal plane in TAA may be an issue that we have not properly addressed. Up to 66% of patients without known deformity may have a TAA that is placed at least 1 degree incorrectly relative to the MAL. We recommend the use of full-length lower limb radiographs when planning a TAA in order to plan the placement of implants. The decision to perform extramedullary referencing, intramedullary referencing, or patient specific Instrumentation must be part of the pre-operative planning process.

Cross-cultural adaptation and clinical evaluation of a Korean version of the Work, Osteoarthritis or joint-Replacement Questionnaire

2019 ◽  
Vol 26 (5) ◽  
pp. 1-8
Author(s):  
Gyu-wan Lee ◽  
Chung-hwi Yi ◽  
Gyoung-mo Kim ◽  
Young-jung Lee ◽  
Jang-whon Yoon
Keyword(s):  
Factor Analysis ◽  
Internal Consistency ◽  
Joint Replacement ◽  
Cultural Adaptation ◽  
Assessment Tool ◽  
Correlation Coefficients ◽  
Cross Cultural ◽  
Strong Positive Correlation ◽  
Intra Class Correlation ◽  
Cross Cultural Adaptation

Background and aim The Work Osteoarthritis or joint-Replacement Questionnaire (WORQ) is a new assessment tool developed in the Netherlands. It needs translation and cross-cultural adaptation for use in each country. The aim of this study was to translate the Work Osteoarthritis or joint-Replacement Questionnaire into Korean and to verify its reliability and validity. Methods To evaluate the clinimetric quality of the Korean-WORQ, we performed tests for internal consistency (Cronbach's alpha), reliability (intra-class correlation coefficients) and concurrent validity (Spearman's correlation coefficient). Factor analysis was carried out to identify the principal components of the questionnaire. Findings Both the internal consistency and intra-class correlation coefficients showed the reliability of the Korean-WORQ to be excellent. The Korean-WORQ had a strong positive correlation with the Western Ontario and McMaster Universities Osteoarthritis Index and three components were extracted in factor analysis. Conclusions Based on these results, the Korean-WORQ seems to be a suitable questionnaire for assessing the disability levels of patients with knee injuries.

The Reliability of an Isokinetic Knee Muscle Endurance Test in Young Children

2003 ◽  
Vol 15 (3) ◽  
pp. 313-323 ◽  
Author(s):  
Mark B.A. De Ste Croix ◽  
Neil Armstrong ◽  
Joanne R. Welsman
Keyword(s):  
Sex Differences ◽  
Young Children ◽  
Correlation Coefficients ◽  
Knee Extension ◽  
Muscle Endurance ◽  
Strong Positive Correlation ◽  
Intra Class Correlation ◽  
Isokinetic Muscle Actions ◽  
Knee Muscle ◽  
Muscle Actions

The purpose of this study was to examine the reliability of repeated isokinetic knee extension and flexion in young children and to examine sex differences in 30 untrained subjects (16 boys and 14 girls) aged 12.2 ± 0.3 years. Total work and the percentage decline in average torque and work were recorded during 50 repetitions. Intra-class correlation coefficients indicated a strong positive correlation between test 1 and 2 for all parameters ranging from 0.36–0.95. Coefficient of variation data ranged from ± 0% to ± 5.4%. Repeatability coefficients and limits of agreement indicated that the extensors were more reliable than the flexors for both torque and work. There were no significant sex differences in any of the parameters measured. This study suggests that repeated isokinetic muscle actions of the knee, as a function of muscle endurance, can be reliably assessed in young people.

Using the Anatomical Axis as an Alternative to the Mechanical Axis to Assess Knee Alignment

Orthopedics ◽  
2015 ◽  
Vol 38 (12) ◽  
pp. e1115-e1120 ◽  
Author(s):  
Shane C. Tipton ◽  
John Sutherland ◽  
Ran Schwarzkopf
Keyword(s):  
Mechanical Axis ◽  
Knee Alignment ◽  
Anatomical Axis

Reliability of Roentgenographic Knee Alignment Measurements in Gonarthrosis

2017 ◽  
Vol 31 (04) ◽  
pp. 302-305
Author(s):  
Teng-Le Huang ◽  
Chen-Chie Wang ◽  
Kai-Chiang Yang ◽  
Chang-Chin Wu
Keyword(s):  
Lower Limb ◽  
Estimating Equation ◽  
Equation Model ◽  
Generalized Estimating Equation ◽  
Tibial Osteotomy ◽  
Knee Alignment ◽  
Ankle Joints ◽  
Medial Gonarthrosis ◽  
Anatomical Axis ◽  
Better Than

AbstractA reliable method of measuring knee alignment is critical in the preoperative planning of high tibial osteotomy (HTO). This radiological study, based on the measurements of the mechanical and anatomical axes of the lower limb, aimed to determine which method would be more reliable and reproducible. From 2004 to 2013, 50 consecutive patients (50 knees) with medial gonarthrosis were treated with valgus-producing HTO. Four independent investigators assessed preoperative standing lower limb radiography (including hip, knee, and ankle joints) to measure both anatomical and mechanical axes. We defined a response as a difference in the angle measured by the same investigator using the same method. The covariates were the investigators and methods. To account for both inter- and intraobserver variabilities, all data were evaluated using a generalized estimating equation model. The results revealed that the effect of the investigators was not statistically significant; however, the effect of the measurement method was highly significant (p < 0.0001). The estimated coefficient of the anatomical axis method was negative, indicating that the reproducibility of the anatomical axis method was better than that of the mechanical axis.

scholarly journals Effect of limb rotation on radiographic alignment measurement in mal-aligned knees

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaoshu Sun ◽  
Bin Yang ◽  
Shengzhao Xiao ◽  
Yichen Yan ◽  
Zifan Liu ◽  
...  
Keyword(s):  
Lower Limb ◽  
Knee Flexion ◽  
Measurement Errors ◽  
Mechanical Axis ◽  
Weight Bearing ◽  
Correlation Coefficients ◽  
Lower Limbs ◽  
Limb Alignment ◽  
Lower Limb Alignment ◽  
Accuracy Of Measurements

Abstract Purpose Long-leg-radiography (LLR) is commonly used for the measurement of lower limb alignment. However, limb rotations during radiography may interfere with the alignment measurement. This study examines the effect of limb rotation on the accuracy of measurements based on the mechanical and anatomical axes of the femur and tibia, with variations in knee flexion and coronal deformity. Methods Forty-five lower limbs of 30 patients were scanned with CT. Virtual LLRs simulating five rotational positions (neutral, ± 10$$^{\circ }$$ ∘ , and ± 20$$^{\circ }$$ ∘ internal rotation) were generated from the CT images. Changes in the hip–knee–ankle angle (HKA) and the femorotibial angle (FTA) were measured on each image with respect to neutral values. These changes were related to knee flexion and coronal deformity under both weight- and non-weight-bearing conditions. Results The measurement errors of the HKA and FTA derived from limb rotation were up to 4.84 ± 0.66$$^{\circ }$$ ∘ and 7.35 ± 0.88$$^{\circ }$$ ∘ , respectively, and were correlated with knee flexion (p < 0.001) and severe coronal deformity (p < 0.001). Compared with the non-weight-bearing position, the coronal deformity measured in the weight-bearing condition was 2.62$$^{\circ }$$ ∘ greater, the correlation coefficients between the coronal deformity and the deviation ranges of HKA and FTA were also greater. Conclusions Flexion and severe coronal deformity have a significant influence on the measurement error of lower limb alignment. Errors can be amplified in the weight-bearing condition compared with the non-weight-bearing condition. When using HKA and FTA to represent the mechanical axis and the anatomical axis on LLR, limb rotation impacts the anatomic axis more than the mechanical axis in patients with severe deformities. Considering LLR as the gold standard image modality, attention should be paid to the measurement of knee alignment. Especially for the possible errors derived from weight-bearing long-leg radiographs of patients with severe knee deformities.

scholarly journals Comparison of Accuracy for HKA by X-ray and Knee Motion Analysis System and the Relationships between HKA and Gait Posture

2021 ◽  
Author(s):  
Hui Zhang ◽  
Yanan Chen ◽  
Huiquan Jiang ◽  
Wenqing Yan ◽  
Yuanming Ouyang ◽  
...  
Keyword(s):  
Knee Joint ◽  
Lower Limb ◽  
Degrees Of Freedom ◽  
Mechanical Axis ◽  
Movement Analysis ◽  
X Rays ◽  
Joint Movement ◽  
X Ray ◽  
Posterior Displacement ◽  
Analysis System

Abstract This study is aimed at obtaining the accuracy of the lower limb mechanical axis (Hip-Knee-Ankle, HKA) by the six degrees of freedom (6DOF) of the knee and ground gait data and analyzing the correlation between the lower limb mechanical axis and 6DOF. We analyzed 3D knee kinematics during ground gait of 99 patients with KOA and 80 patients 6 months after the operations with the vivo infrared navigation 3D portable knee joint movement analysis system (Opti-Knee®, Innomotion Inc, Shanghai, China). Significant correlations with low coefficients (r = -0.19, p = 0.01) between HKA value and anterior-posterior displacement for the whole cohort were found. There were significant correlations with moderate to high coefficients (r = 0.784 to 0.976) between the comparisons of HKA measured on the full-length alignment radiographs and 3D knee joint movement analysis system (Opti-Knee). The further linear correlation analysis showed that there was a significant correlation between the values of HKA measured by X-ray and movement analysis system(R2 = 0.90, p < 0.01). Data with equivalent results as HKA could be provided by knee joint movement analysis system comparing with the conventional X-rays. Nonetheless, there was low significance between the HKA and ground gait data .

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Prediction of lymph node metastase in NSCLC

2010 ◽  
Vol 01 (05) ◽  
pp. 219-226 ◽  
Author(s):  
F. Beyer ◽  
B. Buerke ◽  
J. Gerss ◽  
K. Scheffe ◽  
M. Puesken ◽  
...  
Keyword(s):  
Lymph Nodes ◽  
Fdg Pet ◽  
Automatic Segmentation ◽  
Correlation Coefficients ◽  
Mediastinal Lymph Nodes ◽  
Intra Class Correlation ◽  
Axial Diameter ◽  
Pet Ct ◽  
Fdg Pet Ct

SummaryPurpose: To distinguish between benign and malignant mediastinal lymph nodes in patients with NSCLC by comparing 2D and semiautomated 3D measurements in FDG-PET-CT.Patients, material, methods: FDG-PET-CT was performed in 46 patients prior to therapy. 299 mediastinal lymph-nodes were evaluated independently by two radiologists, both manually and by semi-automatic segmentation software. Longest-axial-diameter (LAD), shortest-axial-diameter (SAD), maximal-3D-diameter, elongation and volume were obtained. FDG-PET-CT and clinical/FDG-PET-CT follow up examinations and/or histology served as the reference standard. Statistical analysis encompassed intra-class-correlation-coefficients and receiver-operator-characteristics-curves (ROC). Results: The standard of reference revealed involvement in 87 (29%) of 299 lymph nodes. Manually and semi-automatically measured 2D parameters (LAD and SAD) showed a good correlation with mean

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