The objective of this study is to present a new radiographic method for the assessment of vertebral rotation from an antero-posterior view of conventional X-rays which is sufficiently precise in comparison with radiographic methods presently used in clinical practice (methods of Nash-Moe and Perdriolle). This method is based on the properties of the geometric shape of vertebrae and their shared...

BACKGROUND Patellofemoral complications are one of the main problems after Total Knee Arthroplasty (TKA). Retropatellar pressure distribution after TKA can contribute to these symptoms. Therefore we evaluated retropatellar pressure distribution subdivided on the ridge, medial and lateral surface on non-resurfaced patella before and after TKA. Additionally, we analyzed axial femorotibial rotatio...

Knee arthroplasties are designed to accommodate flexion, axial rotation and anteroposterior (AP) translation. Axial rotation during extension varies, with some rotating platform devices allowing unrestricted rotation while some conforming fixed-bearing designs almost none. The purpose of this study was to examine in vivo kinematics of a fixed-bearing medial rotation-type arthroplasty (MRK) duri...

To explain the cause of axial rotation in a scoliotic vertebral column, the influence of the gravitation force on a spine with a C-scoliosis has been investigated by means of a mechanical model. In this model the gravitation force takes hold of the three-dimensionally curved vertebral column eccentrically. From these reflections it appears that the axial rotation in the scoliotic spine can be e...

To compare the biomechanical characters of three-level anterior cervical fusion and hybrid constructs by measuring coupled motion changes of the cervical spine, Eighteen adult human cadaveric cervical spines were biomechanically investigated under eccentric displacement control in lateral bending and axial rotation by measuring vertebral motion (X, Y, Z -axis).The 3DPD condition displayed simil...

Kyphoplasty is a therapeutic option for pain relief in the setting of compression fractures. Cement extravasation into adjacent disks is a common occurrence. The biomechanical and clinical consequences of cement in the disks currently are unknown. This study investigated the biomechanical effects of cement extravasation into the intervertebral disk in a human cadaveric model. Seven thoracolumba...

PURPOSE To measure the optic disc rotation around the vertical and horizontal disc axis and to evaluate associations with general and ocular parameters. DESIGN Population-based study. METHODS In the Beijing Eye Study, 3468 participants (mean age:64.6±9.8 years; range:50-93 years) underwent an ophthalmological examination which included spectral-domain optical coherence tomography (OCT) with...

Aims. The stability of dissipative Taylor-Couette flows with an axial stable density stratification and a prescribed azimuthal magnetic field is considered. Methods. Global nonaxisymmetric solutions of the linearized MHD equations with toroidal magnetic field, axial density stratification and differential rotation are found for both insulating and conducting cylinder walls. Results. Flat rotati...

Mechanical alignment with conventional total knee arthroplasty (TKA) instruments often requires collateral ligament releases, which result in a high prevalence of adduction and reverse axial rotation (external rotation) of the tibial component during knee flexion with a variety of component designs. We used a radiographic image-matching technique to determine the contact kinematics during stand...

The purpose of this study was to better understand how lower body kinematics relate to peak glenohumeral compressive force and develop a regression model accounting for variability in peak glenohumeral compressive force. Data were collected for 34 pitchers. Average peak glenohumeral compressive force was 1.72% ± 33% body weight (1334.9 N ± 257.5). Correlation coefficients revealed 5 kinematic v...