Carpal instability is a rare injury of the wrist, but it can cause adverse disability and morbidity of the patient. Lunate dislocation is the fourth and last stage of perilunate dislocation. Bilateral perilunate dislocation is an even more uncommon injury, and only several cases have been reported in literature. We are presenting a case of bilateral perilunate dislocation of wrists in 27-year-o...

The article describes a model of interaction dynamics between a dislocation and dipolar dislocation loops. The interaction is essential for dipolar dislocation structure formation in early stages of a hardening process. For the description of the dislocation curve a direct parametric approach is employed whereas the loops are treated as rigid objects. The model equations are solved approximatel...

To determine the natural history of dislocation of the hip in cerebral palsy, and to evolve methods to predict dislocation, the notes and radiographs of 462 patients with cerebral palsy were reviewed. Dislocation occurred in 10% of patients by progressive migration and subluxation of the proximal femur in the presence of acetabular dysplasia. Statistical analysis identified the radiographic fea...

The correspondence theorem which relates the solutions of displacement boundary value problems in classical and couple stress elasticity is formulated and applied to derive the solutions for edge and screw dislocations in an infinite medium. The effects of couple stresses on the dislocation strain energy is evaluated for both types of dislocations. It is shown that within a radius of influence ...

Anterior dislocation of the hip is uncommon compared with posterior dislocation. Thompson and Epstein (1951) collected 204 cases of dislocation of the hip from the Los Angeles Hospital records in twenty-one years. Of these, 180 cases were posterior whereas only eighteen were anterior. In the last ten years seven cases of anterior dislocation presented themselves to us. Three dislocationswereacu...

A new approach to the description of processes of plastic defonnation is developed. Within this approach, the evolution of a dislocation ensemble is detennined by both dislocation multiplication and dislocation transfonnations with both the processes occurring against the background of elastic stresses produced by the dislocation ensemble itself. Apart from the equations of detailed balance tha...

Late presentation of congenital patellar dislocation with advanced osteoarthritis is rare. This article presents a case of 56-year-old woman with advanced osteoarthritis due to right neglected congenital patellar dislocation treated with total knee arthroplasty (TKA) with release of the lateral retinaculum and proximal extensor mechanism realignment. One year later, the patient had improvement ...

Dislocation is a major complication of total hip arthroplasty (THA), whose frequency has been unaffected by improvements in surgical techniques and implants. The dislocation rate depends on multiple factors related to the patient, hip disease, and surgical procedure and is therefore also dependent on the surgeon. The many published studies on THA dislocation, its causes, and its treatment have ...

The misfit dislocations and strain fields at a Ge/Si heterostructure interface were investigated experimentally using a combination of high-resolution transmission electron microscopy and quantitative electron micrograph analysis methods. The type of misfit dislocation at the interface was determined to be 60° dislocation and 90° full-edge dislocation. The full-field strains at the Ge/Si hetero...

Solution strengthening is a well-known approach to tailoring the mechanical properties of structural alloys. Ultimately, the properties of the dislocation/solute interaction are rooted in the electronic structure of the alloy. Accordingly, we compute the electronic structure associated with, and the energy barriers to dislocation cross-slip. The energy barriers so obtained can be used in the de...