scholarly journals Measurement of lower limb alignment: there are within-person differences between weight-bearing and non-weight-bearing measurement modalities

2017 ◽  
Vol 25 (11) ◽  
pp. 3569-3575 ◽  
Author(s):  
Daphne A. L. Schoenmakers ◽  
Peter Z. Feczko ◽  
Bert Boonen ◽  
Martijn G. M. Schotanus ◽  
Nanne P. Kort ◽  
...  
Keyword(s):  
Lower Limb ◽  
Weight Bearing ◽  
Limb Alignment ◽  
Lower Limb Alignment

scholarly journals Can Deep Learning Using Weight Bearing Knee Anterio-Posterior Radiograph Alone Replace a Whole-Leg Radiograph in the Interpretation of Weight Bearing Line Ratio?

2021 ◽  
Vol 10 (8) ◽  
pp. 1772
Author(s):  
Hyun-Doo Moon ◽  
Han-Gyeol Choi ◽  
Kyong-Joon Lee ◽  
Dong-Jun Choi ◽  
Hyun-Jin Yoo ◽  
...  
Keyword(s):  
Deep Learning ◽  
Lower Limb ◽  
Assessment Tool ◽  
Weight Bearing ◽  
Absolute Error ◽  
Limb Alignment ◽  
Lower Limb Alignment ◽  
Test Set ◽  
Cumulative Score ◽  
Validation Set

Weight bearing whole-leg radiograph (WLR) is essential to assess lower limb alignment such as weight bearing line (WBL) ratio. The purpose of this study was to develop a deep learning (DL) model that predicts the WBL ratio using knee standing AP alone. Total of 3997 knee AP & WLRs were used. WBL ratio was used for labeling and analysis of prediction accuracy. The WBL ratio was divided into seven categories (0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6). After training, performance of the DL model was evaluated. Final performance was evaluated using 386 subjects as a test set. Cumulative score (CS) within error range 0.1 was set with showing maximum CS in the validation set (95% CI, 0.924–0.970). In the test set, mean absolute error was 0.054 (95% CI, 0.048–0.061) and CS was 0.951 (95% CI, 0.924–0.970). Developed DL algorithm could predict the WBL ratio on knee standing AP alone with comparable accuracy as the degree primary physician can assess the alignment. It can be the basis for developing an automated lower limb alignment assessment tool that can be used easily and cost-effectively in primary clinics.

scholarly journals Effects of Total Knee Arthroplasty on Coronal and Sagittal Whole-Body Alignments: Serial Assessments Using Whole-Body EOS

2021 ◽  
Vol 10 (15) ◽  
pp. 3242
Author(s):  
Seong-Chan Kim ◽  
Han-Gyeol Choi ◽  
Joo-Sung Kim ◽  
Tae-Woo Kim ◽  
Yong-Seuk Lee
Keyword(s):  
Knee Joint ◽  
Lower Limb ◽  
Weight Bearing ◽  
Whole Body ◽  
Limb Alignment ◽  
Lower Limb Alignment ◽  
Passive Motion ◽  
X Ray ◽  
Spinopelvic Alignment ◽  
Total Knee

Background: The aims of this study were to evaluate the effects of correcting lower limb alignment by total knee arthroplasty (TKA) on the spinopelvic alignment and to identify patients with difference in the knee joint between clinically measured passive motion and the actual standing posture. Methods: In this retrospective study, 101 patients who underwent TKA and whose serial whole-body EOS X-ray were available were included. The relationship of the knee and spinopelvic alignment was analyzed by evaluating the parameters of standing anterior-posterior and lateral whole-body EOS X-ray. The differences between postoperative passive motion and weight-bearing posture in the knee joint were assessed in both coronal and sagittal planes. Furthermore, the causes of such differences were analyzed. Results: Significant correlations between Δpelvic obliquity and coronal ΔHip-Knee-Ankle (HKA)Rt-Lt angle between the preoperative and 3-month and 1-year postoperative data (p < 0.001 and p < 0.005, respectively) and improved with coronal lower limb alignment close to neutral resulted in decreased pelvic obliquity (p < 0.001, ß = 0.085 and p = 0.005, ß = 0.065, respectively) were observed. The correlations between Δpelvic tilt (PT) and Δsacral slope (SS) and sagittal ΔHKARt-Lt angle were statistically significant (PT: p < 0.001 and p < 0.045; SS: p = 0.002 and p < 0.001, respectively). The improved sagittal alignment close to neutral resulted in decreased PT and increased SS. The difference between postoperative passive motion and the weight-bearing posture of the knee joint was correlated with lumbar lordosis and sagittal C7 plumb line-sacrum distance (p = 0.042 and p < 0.001, respectively). Conclusions: The correction of lower limb alignment with TKA affected pelvic parameters dominantly; however, there was little effect on the spinal alignment. Additionally, patients with anterior stooping or lumbar flat back demonstrated difference in extension between passive knee motion and standing. Therefore, rather than only focusing on changes in the knee alignment correction, knee surgeons should also evaluate the spinopelvic alignment before surgery to consider the prognosis of the standing and predict the possible changes in the whole-body alignment. This preoperative assessment may improve the prognosis of TKA.

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.

2D-3D registration for 3D analysis of lower limb alignment in a weight-bearing condition

2018 ◽  
Vol 33 (1) ◽  
pp. 59-70 ◽  
Author(s):  
Eungjune Shim ◽  
Youngjun Kim ◽  
Deukhee Lee ◽  
Byung Hoon Lee ◽  
Sungkyung Woo ◽  
...  
Keyword(s):  
Lower Limb ◽  
Weight Bearing ◽  
3D Analysis ◽  
3D Registration ◽  
Limb Alignment ◽  
Lower Limb Alignment

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

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

Abstract PurposeLong-leg-radiography (LLR) is commonly used for 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. MethodsForty-five lower limbs of thirty patients were scanned with CT. Virtual LLRs simulating 5 rotational positions (neutral, ±10°, and ±20° 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. ResultsThe measurement error of the HKA and FTA derived from limb rotation were up to 4.84±0.66° and 7.35±0.88° respectively, and were correlated with knee flexion (p＜0.001) and severe coronal deformity (p≤0.001). Compared with non-weight-bearing position, coronal deformity measured in weight-bearing condition was 2.62° greater, the correlation coefficients between the coronal deformity and the deviation ranges of HKA and FTA were also greater. ConclusionFlexion and severe coronal deformity have 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. The error of measurement of the anatomic axis is greater than the mechanical axis. Considering LLR is the gold standard image modality, attention should be paid to the measurement of knee alignment. Especially for the possible errors derives from weight-bearing long leg radiographs of patients with severe knee deformities.

The fracture sites of atypical femoral fractures are associated with the weight-bearing lower limb alignment

Bone ◽  
2014 ◽  
Vol 66 ◽  
pp. 105-110 ◽  
Author(s):  
Yoshitomo Saita ◽  
Muneaki Ishijima ◽  
Atsuhiko Mogami ◽  
Mitsuaki Kubota ◽  
Tomonori Baba ◽  
...  
Keyword(s):  
Lower Limb ◽  
Weight Bearing ◽  
Femoral Fractures ◽  
Limb Alignment ◽  
Lower Limb Alignment ◽  
Atypical Femoral Fractures
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