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Advances in fractures and dislocations of the hip joint
Published in K. Mohan Iyer, Hip Joint in Adults: Advances and Developments, 2018
Thomas Pepper, Philip Ahrens, M. Zahid Saeed
This type forms the vast majority of hip dislocations and is frequently associated with a road traffic accident involving a headon force that causes the knee to strike against the dashboard of the vehicle, forcing the femur backwards. Acetabular injury depends on the position at the time of impact. If the hip is abducted at the time of posterior dislocation, a simultaneous acetabular fracture will occur. However, if the hip is adducted it is unsupported posteriorly and acetabular fracture may be avoided. In isolated posterior hip dislocation, clinically the leg appears shortened and the hip will be held adducted and internally rotated. This picture may be complicated if there is a concomitant femoral shaft fracture. Plain radiographs will show the femoral head to be displaced from and superior to the acetabulum (Fig. 2.5). A computed tomography (CT) scan will better demonstrate any acetabular fracture.
Paediatrics
Published in David A Lisle, Imaging for Students, 2012
Developmental dysplasia of the hip (DDH) occurs in 1–2 per 1000 births. Females are more commonly affected than males with a ratio of 8:1. Left hip is more commonly involved than the right. Previously known as congenital hip dislocation, the term DDH more accurately reflects the underlying disorder, which is dysplasia of the acetabulum. Dysplasia of the acetabulum may lead to varying degrees of hip joint subluxation, dislocation and dysfunction. Risk factors for the development of DDH include family history, breech presentation, neuromuscular disorders and foot deformities. Early diagnosis is essential to the prevention of long-term complications including worsening dysplasia, abnormal gait and premature osteoarthritis. Conservative measures, such as splinting for a few weeks, are usually successful in all but the most severe cases.
Finite element modelling and biodynamic response prediction of the seated human body exposed to whole-body vibration
Published in Ergonomics, 2023
Kaizhan Gao, Zhifei Zhang, Hongwei Lu, Zhongming Xu, Yansong He
The previous human model derived from the literature (Gao et al. 2021) was combined with the FE model of the L1-pelvis. The pelvis and femur were connected with the hip joint at the acetabulum. The upper torso and lower torso were connected with the lumbar joint between the bottom of the upper torso and L1. The position of the lumbar joint and hip joint is shown in Figure 4(d). The joint parameters of the present model referred to the literature (Gao et al. 2021). Tetrahedral elements were filled around the pelvis, femur, and lumbar spine to simulate the muscle tissues of the human body. Tetrahedral elements were connected with the pelvis, femur, and lumbar spine in the form of co-nodes. Automatic surface-to-surface contact algorism was applied between the upper torso and lower torso. The static and dynamic friction coefficients were 0.3 and 0.2, respectively.
Evolution of different designs and wear studies in total hip prosthesis using finite element analysis: A review
Published in Cogent Engineering, 2022
Chethan K N, Shyamasunder Bhat N, Mohammad Zuber, Satish Shenoy B
Usually, the average male femur is about 480 mm in length with a diameter of 23.4 mm (Nakabayashi et al., 1994; Chethan, Bhat et al., 2019; Portigliatti-Barbos et al., 1987). The hip joint is a classic example of a ball and socket joint where the head of the femur articulates in the acetabulum of the pelvis. The head of the femur and acetabulum are covered by a 63.5 mm thick shiny white hyaline which acts as a smooth cushion to the joint (Chethan, Shyamasunder Bhat et al., 2019). This joint has synovial fluid articulated in the mating surface which allows the joint to flex under different pressures without causing wear and tear. The synovial fluid and the hyaline help the bones move each other at different degrees of freedom without causing pain to the human.
Musculoskeletal models with generic and subject-specific geometry estimate different joint biomechanics in dysplastic hips
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Ke Song, Andrew E. Anderson, Jeffrey A. Weiss, Michael D. Harris
Developmental dysplasia of the hip (DDH) is a structural disease characterized by a shallow acetabulum, insufficient femoral coverage, and abnormal intra-articular loading (Leunig et al. 2001; Henak et al. 2014; Gala et al. 2016). Abnormal hip loads may contribute to acetabular labrum and articular cartilage damage (Cooperman 2013), which often progresses to early osteoarthritis (Jessel et al. 2009; Harris-Hayes and Royer 2011). Reliable quantification of hip loads, including joint reaction forces (JRFs) and muscle forces, may improve our understanding of tissue damage and the pathogenesis of osteoarthritis among patients with DDH.