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Is the human acetabulofemoral joint spherical?

Authors:
  • University of Rome Foro Italico

Abstract

The human acetabulofemoral joint is commonly modelled as a pure ball-and-socket joint, but there has been no quantitative assessment of this assumption in the literature. Our aim was to test the limits and validity of this hypothesis. We performed experiments on four adult cadavers. Cortical pins, each equipped with a marker cluster, were implanted in the pelvis and the femur. Movements were recorded using stereophotogrammetry while an operator rotated the cadaver’s acetabulofemoral joint, exploiting the widest possible range of movement. The functional consistency of the acetabulofemoral joint as a pure spherical joint was assessed by comparing the magnitude of the translations of the hip joint centre as obtained on cadavers, with the centre of rotation of two metal segments linked through a perfectly spherical hinge. The results showed that the radii of the spheres containing 95% of the positions of the estimated centres of rotation were separated by less than 1 mm for both the acetabulofemoral joint and the mechanical spherical hinge. Therefore, the acetabulofemoral joint can be modelled as a spherical joint within the considered range of movement (flexion/extension 20° to 70°; abduction/adduction 0° to 45°; internal/external rotation 0° to 30°).
... Andersen et al., 2009;Duprey et al., 2010;Reinbolt et al., 2005) : n'autorise qu'une rotation autour d'un seul axe prédéfini (un degré de liberté) et aucune translation • Rotule à doigt, ellipsoïde et joint de cardan(Andersen et al., 2009;Duprey et al., 2010;Reinbolt et al., 2005) : autorise la rotation autour de deux axes (deux degrés de liberté) et aucune translation.• Rotule ou sphéroïde(Cereatti et al., 2010) : autorise les trois rotations dans l'espace (3 degrés de liberté), mais aucune translation.• Sphère sur plan ou ponctuelle (Parenti-Castelli et al., 2004) : autorise les trois rotations et deux translations sur le plan (cinq degrés de liberté). ...
Thesis
L’analyse du mouvement humain est un paramètre clé pour comprendre les différentes problématiques de la locomotion humaine. Qui plus est, il est nécessaire que ces analyses soient effectuées au plus proche de la locomotion réelle. L’essor de la miniaturisation des capteurs et des technologies sans fil a permis d’offrir la possibilité d’utiliser les centrales inertielles sur le terrain. Mais différentes problématiques existent encore pour obtenir la cinématique des membres inférieurs avec les centrales inertielles.La première étude de ce manuscrit aborde une comparaison des différents calibrages centrale-à-segment pour définir le passage entre l’orientation de la centrale inertielle et le segment sous-jacent. Nous avons mis en avant une méthode qui valide ces critères au mieux et ne demande que deux postures et un dispositif simple. Mais la cinématique obtenue reste entachée d’erreurs qui pourraient être dues à la présence d’artefacts de tissu mou.C’est pourquoi dans une seconde partie nous étudions la possibilité de diminuer ces effets par l’intermédiaire de l’optimisation multisegmentaire. Ainsi nous avons pu mettre en avant la nécessité de bien paramétrer le modèle derrière l’optimisation sans pour autant présenter un apport significatif. Enfin, en dernière partie, nous proposons d’appliquer la méthodologie de traitement de la cinématique articulaire sur une population pathologique, en collaboration avec le laboratoire de cinésiologie Willy Taillard des HUG et de l’Université de Genève. En conclusion cette thèse propose un processus méthodologique et des recommandations pour développer des analyses de la cinématique en milieu écologique avec des centrales inertielles.
... The joints of a lower limb can be modeled as a spherical joint within the considered range of movement. 36 Referring to the fundamental and basic axes defined in the anatomy, the basic forms of joint motion can be classified into three categories: flexion/extension (FE) around the frontal axis, abduction/adduction (AA) around the sagittal axis, and internal/external (IE) around the vertical axis. Degrees of freedom (DOF) is used as a term to describe the freedom of motion. ...
Article
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The lower limb exoskeleton robot is capable of providing assisted walking and enhancing exercise ability of humans. The coupling human–machine model has attracted a lot of research efforts to solve the complex dynamics and nonlinearity within the system. This study focuses on an approach of gait trajectory optimization of lower limb exoskeleton coupled with human through genetic algorithm. The human–machine coupling system is studied in this article through multibody virtual simulation environment. Planning of the motion trajectory is carried out by the genetic algorithm, which is iteratively generated under optimization of a set of specially designed fitness functions. Human motion captured data are used to guide the evolution of gait trajectory generation method based on genetic algorithm. Experiments are carried out using the MATLAB/Simulink Multibody physical simulation engine and genetic algorithm-toolbox to generate a more natural gait trajectory, the results show that the proposed gait trajectory generation method can provide an anthropomorphic gait for lower limb exoskeleton device.
... Hip joint stability is achieved mainly by the contribution of static stabilizers [1]. The high anatomical congruence between the femoral head and the acetabulum has been described as the most important static stabilizer [2]. This bony congruence allows the hip joint to achieve large range of motion in three different axes [3]. ...
Article
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Hip joint instability has been targeted as an important issue that affects normal hip function. The diagnosis of hip instability could be very challenging and currently, there is no definitive diagnostic test. Hip instability results in an excessive amount of translation of femoroacetabular articulation, leading to changes on the dynamic loading of the hip. These changes in femoroacetabular translation could be evaluated by human movement analysis methods. The purpose of this study was to describe the triaxial and overall magnitude of acceleration in patients diagnosed with hip instability during gait cycle and compare those results with a control group. Our hypothesis was that acceleration values obtained from the instability group would be higher than asymptomatic controls. Ten patients with previously diagnosed hip instability were included and 10 healthy and asymptomatic subjects were enrolled as control group. Triaxial accelerometers attached bilaterally to the skin over the greater trochanter were used to record acceleration during walking on a treadmill. The overall magnitude of acceleration and the axial, anteroposterior and mediolateral accelerations (x/y/z) were obtained during gait. Mean overall magnitude of acceleration was higher in the hip instability group compared with the control group, 1.51 g (SD: 0.23) versus 1.07 g (SD: 0.16) (P = 0.022). The axial, anteroposterior and mediolateral accelerations significantly differed between the two groups. The axial and mediolateral accelerations showed to be higher for the hip instability group while the anteroposterior axis acceleration was lower.
... The normal hip joint is inherently stable primarily because of the bony anatomy. 6 However, recent studies have highlighted the role of the capsule and labrum as significant contributors to hip stability. 33 Natural history studies have shown that patients with true acetabular dysplasia are predisposed to developing early coxarthrosis. ...
Article
Background: The arthroscopic management of hip dysplasia has been controversial and has historically demonstrated mixed results. Studies on patients with borderline dysplasia, emphasizing the importance of the labrum and capsule as secondary stabilizers, have shown improvement in patient-reported outcomes (PROs). Purpose/Hypothesis: The purpose was to assess whether the results of hip arthroscopic surgery with labral preservation and concurrent capsular plication in patients with borderline hip dysplasia have lasting, positive outcomes at a minimum 5-year follow-up. It was hypothesized that with careful patient selection, outcomes would be favorable. Study design: Case series; Level of evidence, 4. Methods: Data were prospectively collected and retrospectively reviewed for patients aged <40 years who underwent hip arthroscopic surgery for intra-articular abnormalities. Inclusion criteria included lateral center-edge angle (LCEA) between 18° and 25°, concurrent capsular plication and labral preservation, and minimum 5-year follow-up. Exclusion criteria were severe dysplasia (LCEA ≤18°), Tönnis grade ≥2, pre-existing childhood hip conditions, or prior hip surgery. PRO scores including the modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), and Hip Outcome Score Sport-Specific Subscale (HOS-SSS) and the visual analog scale (VAS) score for pain were collected preoperatively, at 3 months, and annually thereafter. Complications and revisions were recorded. Results: Twenty-five hips (24 patients) met the inclusion criteria. Twenty-one hips (19 patients, 84%) were available for follow-up. The mean age at surgery was 22.9 years. The mean preoperative LCEA and Tönnis angle were 21.7° (range, 18° to 24°) and 6.9° (range, -1° to 16°), respectively. The mean follow-up was 68.8 months. The mean mHHS increased from 70.3 to 85.9 ( P < .0001), the mean NAHS from 68.3 to 87.3 ( P < .0001), and the mean HOS-SSS from 52.1 to 70.8 ( P = .0002). The mean VAS score improved from 5.6 to 1.8 ( P < .0001). Four hips (19%) required secondary arthroscopic procedures, all of which resulted in improved PRO scores at latest follow-up. No patient required conversion to total hip arthroplasty. Conclusion: While periacetabular osteotomy remains the standard for treating true acetabular dysplasia, hip arthroscopy may provide a safe and durable means of managing intra-articular abnormalities in the setting of borderline acetabular dysplasia at midterm follow-up. These procedures should be performed by surgeons with expertise in advanced arthroscopic techniques, using strict patient selection criteria, with emphasis on labral preservation and capsular plication.
... Commonly, human joints are modelled either as spherical or hinge joints. Whereas for the hip joint, the functional consistency between the actual joint and the spherical joint model is almost perfect [90] and therefore a unique centre of rotation exists, this is not true for other human joints. For instance, it was demonstrated that in the knee joint during normal gait the tibiofemoral contact loads contribute substantially to both net extension and adduction moments [5]. ...
Article
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Quantitative gait analysis can provide a description of joint kinematics and dynamics, and it is recognized as a clinically useful tool for functional assessment, diagnosis and intervention planning. Clinically interpretable parameters are estimated from quantitative measures (i.e. ground reaction forces, skin marker trajectories, etc.) through biomechanical modelling. In particular, the estimation of joint moments during motion is grounded on several modelling assumptions: (1) body segmental and joint kinematics is derived from the trajectories of markers and by modelling the human body as a kinematic chain; (2) joint resultant (net) loads are, usually, derived from force plate measurements through a model of segmental dynamics. Therefore, both measurement errors and modelling assumptions can affect the results, to an extent that also depends on the characteristics of the motor task analysed (i.e. gait speed). Errors affecting the trajectories of joint centres, the orientation of joint functional axes, the joint angular velocities, the accuracy of inertial parameters and force measurements (concurring to the definition of the dynamic model), can weigh differently in the estimation of clinically interpretable joint moments. Numerous studies addressed all these methodological aspects separately, but a critical analysis of how these aspects may affect the clinical interpretation of joint dynamics is still missing. This article aims at filling this gap through a systematic review of the literature, conducted on Web of Science, Scopus and PubMed. The final objective is hence to provide clear take-home messages to guide laboratories in the estimation of joint moments for the clinical practice. Electronic supplementary material The online version of this article (doi:10.1186/s12938-017-0396-x) contains supplementary material, which is available to authorized users.
... In some cases, functionally defined centers and/or axes of rotation can be used as well. This approach is viable when there is a constant and generalizable relationship between anatomy and function among individuals, such as for the hip center of rotation [74,142]. ...
Article
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Gait analysis is recognized as a useful assessment tool in the field of human movement research. However, doubts remain on its real effectiveness as a clinical tool, i.e. on its capability to change the diagnostic-therapeutic practice. In particular, the conditions in which evidence of a favorable cost-benefit ratio is found and the methodology for properly conducting and interpreting the exam are not identified clearly. To provide guidelines for the use of Gait Analysis in the context of rehabilitation medicine, SIAMOC (the Italian Society of Clinical Movement Analysis) promoted a National Consensus Conference which was held in Bologna on September 14th, 2013. The resulting recommendations were the result of a three-stage process entailing i) the preparation of working documents on specific open issues, ii) the holding of the consensus meeting, and iii) the drafting of consensus statements by an external Jury. The statements were formulated based on scientific evidence or experts' opinion, when the quality/quantity of the relevant literature was deemed insufficient. The aim of this work is to disseminate the consensus statements. These are divided into 13 questions grouped in three areas of interest: 1) General requirements and management, 2) Methodological and instrumental issues, and 3) Scientific evidence and clinical appropriateness. SIAMOC hopes that this document will contribute to improve clinical practice and help promoting further research in the field.
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Purpose: In the setting of acetabular dysplasia, the increased translational motion of the femur may damage the labrum and cartilage, as well as stretch the capsule. The purpose of the study was to investigate the relationship between the acetabular coverage and the capsular stiffness by assessing the distension of anterior and posterior joint recesses on the hip computed tomography arthrography. Methods: One hundred thirty-three patients (138 hips) with a median age of 36 years (range 18-50 years) who received the computed tomography arthrography for evaluation of nonarthritic hip pain in our institute between 2015 and 2017 were retrospectively reviewed. The maximal distance between the anterior/posterior capsule and the anterior femoral head-neck junction/posterior femoral head on the axial imaging of computed tomography arthrography was defined as the width of anterior/posterior joint recess. The width of anterior/posterior joint recess was adjusted with the diameter of the femoral head and was then compared between acetabular dysplasia (lateral center-edge angle < 25°), normal acetabulum (lateral center-edge angle between 25 and 39°), and deep acetabulum (lateral center-edge angle > 39°). In addition, the standard univariate linear regression analysis was used to investigate the relationship between the adjusted width of anterior/posterior joint recess and anterior/posterior coverage of the hip, determined by the anterior/posterior wall index. Results: The adjusted width of posterior joint recess was significantly greater in the acetabular dysplasia group than the normal acetabulum and deep acetabulum groups (p < 0.01 and p = 0.02, respectively). There was no significant difference of the adjusted width of anterior joint recess between the groups (n.s.). The adjusted width of posterior joint recess had a significant but weak negative correlation with the anterior wall index (r = - 0.25, p < 0.001), and no correlation with the posterior wall index (r = - 0.0004, n.s.). There was no significant correlation between the adjusted width of anterior joint recess and the anterior/posterior wall index (r = 0.05, n.s./r = 0.07, n.s.). Conclusions: The distension of posterior capsule on the computed tomography arthrography was significantly greater in acetabular dysplasia. In addition, there was a significant but weak negative correlation between the distension of posterior capsule and the anterior coverage of the hip. It indicated a looser posterior capsule was observed in a dysplastic hip. The relevance of posterior capsular laxity to clinical outcomes warrants further investigation. Given the fact that the distension of anterior capsule was not significantly higher in acetabular dysplasia, the need of anterior capsular plication in a dysplastic hip should be carefully evaluated. Level of evidence: Level III.
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Chapter
The injuries sustained by dance students are mainly the result of overuse (excessive quantity) or abuse (incorrect technique); thus, they could be prevented. The outcome of a dance injury can either affect participation in dance for a given time or bring the student’s potential development as a dancer to an end. In order to predict who is prone to what injuries the medical profession has developed screening processes by which one can draw conclusions for individual dance students regarding their risk factors for certain injuries, and also accumulate data regarding this specific population and establish “norms” and objective parameters to compare between individuals. This chapter will address the differences between specific age groups and describe the correlation between body structure, dance technique, and some pathologies. It should provide tools to empower students and teachers, and enhance medical professionals’ knowledge of the specific issues relevant to dance students.
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