Shape Analysis of the Femoral Head: A Comparative Study Between Spherical, (Super)Ellipsoidal, and (Super)Ovoidal Shapes

Lopes, Daniel Simões; Neptune, Richard R.; Gonçalves, Artur; Ambrósio, Jorge; Silva, Miguel T.

doi:10.1115/1.4031650

Cited by 11 publications

(4 citation statements)

References 19 publications

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“…Thus, under the framework of multi-rigid body dynamics, Costa et al [346] studied the dynamics of a rigid human gait model with a HD lubricated planar revolute joint as its hip joint. However, the geometry of the revolute joint differs from the practical shape of the human hip joint [347,348]. Recently, Ebrahimi et al [349] used a multiple scales method to perform a nonlinear vibration analysis of a planar rigid sliding pendulum with dry and lubricated clearance joint between the slider and the guide.…”

Section: Planar Revolute Joint With Lubricationmentioning

confidence: 99%

A comprehensive survey of the analytical, numerical and experimental methodologies for dynamics of multibody mechanical systems with clearance or imperfect joints

Tian

Flores

Lankarani

2018

Mechanism and Machine Theory

317

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A comprehensive survey of the literature of the most relevant analytical, numerical, and experimental approaches for the kinematic and dynamic analyses of multibody mechanical systems with clearance joints is presented in this review. Both dry and lubricated clearance joints are addressed here, and an effort is made to include a large number of research works in this particular field, which have been published since the 1960's. First, the most frequently utilized methods for modeling planar and spatial multibody mechanical systems with clearance joints are analyzed, and compared. Other important phenomena commonly associated with clearance joint models, such as wear, non-smooth behavior, optimization and control, chaos, and uncertainty and links' flexibility, are then discussed. The main assumptions procedures and conclusions for the different methodologies are also examined and compared. Finally, future developments and new applications of clearance joint modeling and analysis are highlighted.

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Section: Planar Revolute Joint With Lubricationmentioning

confidence: 99%

A comprehensive survey of the analytical, numerical and experimental methodologies for dynamics of multibody mechanical systems with clearance or imperfect joints

Tian

Flores

Lankarani

2018

Mechanism and Machine Theory

317

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show abstract

“…As a result, a shorter distance of the lateral edge of the acetabulum to the inferior point of the weight-bearing area of the acetabular sourcil can be observed, which then leads to a steeper angle on plain x-ray. Likewise, the higher the acetabular torsion, the smaller the hip lateralization index gets which originates from a decreased distance between the center of the femoral head to the pelvic teardrop due to both increased anteversion and a relatively ovoid (as opposed to round) femoral head [ 40 ]. If the AIA from plain radiography is used to predict the acetabular anteversion, the x-ray must be taken very precisely.…”

Section: Discussionmentioning

confidence: 99%

Rotational abnormalities in dysplastic hips and how to predict acetabular torsion

et al. 2022

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Objectives The aim of this study was to investigate the degree to which conventional radiography can represent the acetabular and femoral rotational alignment profile between dysplastic and borderline-dysplastic hips. Methods A retrospective trial was conducted including 56 borderline-dysplastic and dysplastic hips at a mean age of 28.9 years (range from 18 to 46). Inclusion criteria consisted of symptomatic patients with hip dysplasia undergoing 2-dimensional radiography as well as computed tomography. On radiography, the lateral center edge angle, acetabular hip index, hip lateralization index, acetabular index angle, and the Sharp angle were measured, and the presence of a crossover sign was noted. In computed tomography, the full rotational profile of the lower limb was measured. Results Significant correlations were observed in the overall analysis between the anteversion of the acetabulum and the hip lateralization index (mean 0.56, coefficient of regression (CoR) −32.35, p = 0.011) as well as the acetabular index angle with a mean of 11.50 (CoR 0.544, p = 0.018). Similar results were found in the subgroup of dysplastic hips with an acetabular index angle of 13.9 (p = 0.013, CoR 0.74). For the borderline-dysplastic group, no significant correlations between the pelvis radiography and rotational CT were seen. Conclusion Although the femoral and acetabular torsion cannot be predicted from x-rays, the anteversion of the acetabulum correlates with the acetabular index angle, the hip lateralization index, and eventually the beta angle in dysplastic hips. For borderline-dysplastic hips, such results did not show up, which strongly illustrates the need for computed tomography in these cases. Key Points • Much of the current literature focuses on rotational alignment especially with respect to the femur and tibia in healthy patients, although little is known about the acetabular, femoral, and tibial torsion in dysplastic hips. • This is the first study showing significant correlations between the anteversion of the acetabulum and the hip lateralization index as well as the acetabular inclination angle. Also, it is the first study to provide a mechanism for estimation of the torsion of the acetabulum with plain radiography in dysplastic hips. • In borderline-dysplastic hips, no significant correlation was found, which raises the question if a simple x-ray has enough validity to address the acetabular deformity with surgery.

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“…The GH joint translations estimated in this study are considered valid based on their consistency with previous reports, but further experiments are still required to validate the musculoskeletal model developed [50] . Finally, the spherical shape of the GH joint can be questioned according to the observations of Lopes et al [28] , being additional research needed to assess its influence on the anatomical description of the joint.…”

Section: Discussionmentioning

confidence: 99%

“…The GH joint, which is originally described by a 3 DOF spherical joint [9] , is modeled here as a 6 DOF spherical joint with clearance [26,27] . Regardless of the fact that ovoids may reproduce better the humeral head geometry [28] , the shape of the humeral articular surface is described by a sphere with a curvature radius of 25 mm, located at the native GH joint centre, based on Garner and Pandy [29] . The shape of the scapular articular surface is reproduced by fitting a sphere to the 3D geometry of the glenoid cavity, generated from the visible human male dataset [30] .…”

Section: Upper Limb Model With a Biologically Inspired Glenohumeral Jmentioning

confidence: 99%

A new shoulder model with a biologically inspired glenohumeral joint

Quental

Folgado

Ambrósio

et al. 2016

Medical Engineering & Physics

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Shape Analysis of the Femoral Head: A Comparative Study Between Spherical, (Super)Ellipsoidal, and (Super)Ovoidal Shapes

Cited by 11 publications

References 19 publications

A comprehensive survey of the analytical, numerical and experimental methodologies for dynamics of multibody mechanical systems with clearance or imperfect joints

A comprehensive survey of the analytical, numerical and experimental methodologies for dynamics of multibody mechanical systems with clearance or imperfect joints

Rotational abnormalities in dysplastic hips and how to predict acetabular torsion

A new shoulder model with a biologically inspired glenohumeral joint

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