BACKGROUND We wanted to investigate the leading cause of failed vertebroplasty or kyphoplasty. METHODS Twelve patients (10 females and 2 males) who underwent revision surgery after vertebroplasty or kyphoplasty were included. In 4 cases, vertebroplasty was done for two or more levels. Six cases with kyphoplasty were included. Through the retrospective review of the radiographic studies and me...

Figure 1. Preoperative posteroanterior radiographs showing progressive fragmentation and collapse of the lunate, as well as subsequent pathologic fracture of the scaphoid.

This paper investigates the set of all selectively refined meshes that can be obtained from a progressive mesh. We call the set the transitive mesh space of a progressive mesh and present a theoretical analysis of the space. We define selective edge collapse and vertex split transformations, which we use to traverse all selectively refined meshes in the transitive mesh space. We propose a compl...

The paper applies a computer-based method involving stochastic search, multi-criteria optimization and color filtering to investigate the tradeoff between the life-cycle profitability of highrise commercial office buildings and their load-path safety against progressive collapse under abnormal loading. The study was motivated by the progressive-collapse failure of the twin towers of the World T...

Pitressin is frequently used in the treatment of circulatory collapse. Evaluation of its usefulness has been hindered by the difficulty of interpreting symptoms and of obtaining circulatory measurements in critically ill patients. Previous studies on normal subjects in the upright position (1) (2) have demonstrated that sodium nitrite produces a type of collapse, often ending in syncope, which ...

The collapse behaviour of the World Trade Centre (WTC) towers is considered formally as a propagating instability phenomenon. The application of associated concepts enables the residual capacities of both towers after the onset of collapse to be formally estimated. This information is combined into a simplified variable-mass collapse model of the overall dynamical behaviour. The resulting, non-...

Progressive collapse of framed structures is a complex topic going beyond the usual tools of structural mechanics. The analogy with the propagation of damage in the framework of fracture mechanics has already brought some theoretical results, especially when the energy fluxes are analyzed. Nevertheless, the difficulty to get representative experimental data avoids proposing and eventually provi...

The paper presents the results of a comprehensive study on evaluation effectiveness retrofit strategy existing steel buildings against progressive collapse. In this respect, it investigates performance and design solution to increase robustness Moment Resisting Frame buildings. A truss system added at building's rooftop level (i.e., ‘roof-truss’), intended define an alternative load path, was i...

Corrosion causes reduction in cross-sectional area of reinforcement, deterioration mechanical properties, and degradation bonding properties between reinforced concrete, which are the most important factors leading to structural service performance. In order investigate progressive collapse mechanism a corroded concrete frame structure, failure modes, characteristics vertical displacement, load...