Medial swivel type dislocation of the talonavicular joint with associated cuboid fracture: a case report

Medial Swivel-type dislocation are dislocation of talonavicular joint (TNJ) medially and the calcaneus swivels under the talus, with the calcaneocuboid joint intact. This is a rare injury due to the strong network of ligament and tendinous structures. An 11-year-old girl presented after 1 week of injury to the left foot. She had pain, swelling on the mid-foot and inability to weight bearing. X-ray and computerized tomography (CT) scan showed medial dislocation of TNJ, with fracture of cuboid body. A closed reduction was attempted but it failed. Patient then underwent open reduction with K-wire fixation and immobilization by below knee cast for 3 weeks. After K-wire removal, the foot was stable with near normal ankle and sub-talar joint range of motion and patient started to partial weight bearing Midtarsal dislocations of the foot are rare injuries. In this case dislocation is resulted from high-energy medial forces to the forefoot. The associated cuboid fracture possibly as a result of tensile forces through the lateral structure of midfoot with adduction. ‘Swivel dislocation’ in which the TNJ dislocates, usually medially, and the calcaneus swivels under the talus, with the calcaneocuboid joint intact. A careful assessment of initial radiograph and CT scan should be done to determine type of dislocation and associated fracture. An open reduction K-wire fixation bring a stable reduction. Talonavicular dislocations are rare injuries, occur as a result of high-energy trauma. A stable reduction and good outcome are anticipated.

In Situ Synchrotron X-ray Study of the Mechanical Properties of Pure Mg Produced by Powder Metallurgy

In this study, in situ synchrotron X-ray experiments with wide-angle X-ray scattering (WAXS) and small-angle X-ray scattering (SAXS) detectors were performed on two pure magnesium materials produced by powder metallurgy. According to SAXS analysis, each of the two materials has a porosity of less than 0.5%. Line broadening analysis was performed on diffraction patterns collected by WAXS to analyze the dislocation evolution during material deformation. In both materials, <a>-type dislocation activities dominate the tensile deformation. The influence of grain size and texture on the different tensile behaviors of these two materials is also discussed.

An Ulnar-Type Dislocation of Fifth Carpometacarpal Joint: Case Report and Review of the Literature

Unilateral pure dislocation of the fifth carpometacarpal joint (CMCJ) is a very rare injury. We are reporting the second case of an ulnar type of unilateral dislocation of a fifth CMCJ. Indian salutation (Namaskar) test and radiographs aid in diagnosis. Closed reduction and internal fixation by K-wires restored the normal anatomic relationships of the fifth CMC joint. This type of injury is prone to be missed in an emergency room due to soft tissue swelling, and particular attention should be paid to diagnose it in polytrauma patients. A review of the literature is presented.

Образование дислокационных пар в гетероструктуре Ge/GeSi/Si(001)

In the Ge/LTGe/GeSi/Si(001) heterostructures, the GeSi buffer layer remains pseudomorphic in a certain range of the heterostructure parameters and growth regimes, while the Ge film is completely relaxed owing to the edge dislocation network at the Ge/GeSi interface. It has been experimentally shown that, along with edge dislocations, dislocations with the Burgers vectors of the a _0〈100〉-type form. Their formation is caused by the reaction of 60° dislocations with a unidirectional screw component. In this case, if during the buffer layer relaxation the edge dislocations split with the formation of an edge-type dislocation complex, in which the 60° dislocations remained bound, the dislocations with the Burgers vectors a _0〈001〉 split into two independent 60° dislocations.