BACKGROUND The Oxford Unicompartmental Knee Replacement (OUKR) uses a mobile bearing to minimise wear. Bearing dislocation is a problem in the lateral compartment as the ligaments are loose in flexion. A domed tibial component has been introduced to minimise the risk of dislocation, yet they still occur, particularly medially. The aim of this mechanical study was to compare the domed and flat t...

BACKGROUND Traumatic bilateral hip dislocation is a rare condition. Anterior shoulder dislocation combined with this condition is even a rare occurrence. A 57-year-old man had bilateral asymmetric hip dislocation with a posterior wall fracture of the left acetabulum associated with right shoulder anterior dislocation caused by falling down from a cherry tree. Traumatic hip dislocation and anter...

Dislocation interaction with and accumulation at twin boundaries have been reported to significantly improve the strength and ductility of nanostructured face-centered cubic (fcc) metals and alloys. Here we systematically describe plausible dislocation interactions at twin boundaries. Depending on the characteristics of the dislocations and the driving stress, possible dislocation reactions at ...

We introduce a continuum model to describe the phase separation of a binary alloy in the presence of mobile dislocations. The kinetics of the local composition and dislocation density are coupled through their elastic fields. We show both analytically and numerically that mobile dislocations modify the standard spinodal decomposition process, and lead to several regimes of growth. Depending on ...

The effect of electrically active VGa–ON threading edge dislocations on drift and Hall mobilities in n-type epitaxial wurtzite WZ GaN is investigated theoretically. The charge distribution along the dislocation core is first obtained by means of a density-functional theory atomistic calculation; the two N atoms near the missing Ga atom at the dislocation core are found to be electron acceptors....

During an eight month prospective study, 8240 newborns were examined for detection of congenital dislocation of the hip from Oct. 23, 1991 to June 22, 1992. On fIrst examination we found 1302 neonates (158/1000 live births) to have abnormal hips 1063 (81.6%) were prone to subluxation (subluxatable), 218 (16.81 %) prone to dislocation (dislocatable), 17 (1.3%) were dislocated and 4 (0.3%) w...

The problem of several finite moving cracks in a functionally graded material is solved by dislocation technique under the condition of anti-plane deformation. By using the Fourier transform the stress fields are obtained for a functionally graded strip containing a screw dislocation. The stress components reveal the familiar Cauchy singularity at the location of dislocation. The solution is em...

  Congenital dislocation of the knee (CDK) is a rare disorder. We report the case of a 7-year-old girl with bilateral knee stiffness, marked anterior bowing of both legs, and inability to walk without aid. Radiologic investigation revealed bilateral knee joint dislocation accompanied by severe anterior bowing of both tibia proximally and posterior bowing of both femur distally, demonstrating ...

In 1994, a register for cerebral palsy and a health-care programme were started in southern Sweden with the aim of preventing dislocation of the hip in children with cerebral palsy. It involved all children with cerebral palsy born in 1992 or later. None of the 206 affected children born between 1992 and 1997 has developed a dislocation following the introduction of the prevention programme. An...

Case History associated with poor outcome because as the time interval between dislocation and reduction increases, incidence of Traumatic dislocation of hip in children is a rare entity complications like avascular necrosis of femoral head, accounting for less than 5% of pediatric dislocation and redislocation, heterotopic ossification and chondrolysis neglected post traumatic dislocation of h...