Uniaxial quasi-static, uniaxial dynamic and confined dynamic compression experiments have been performed to characterize the failure and deformation mechanisms of a sintered polycrystalline aluminum nitride using a servohydraulic machine and a modified Kolsky bar. Scanning electron microscopy and transmission electron microscopy (TEM) are used to identify the fracture and deformation mechanisms...

Residual stress present in coupons used for fracture testing will influence the experimental determination of fracture toughness. Triaxial residual stress (e.g., due to welding) can alter both the driving force for fracture and the crack-tip constraint at a specified load, so that the apparent toughness of a coupon depends on the residual stress present. In this paper, we employ a micromechanic...

BACKGROUND Angle-stable locking plates have improved the surgical management of fractures. However, locking implants are costly and removal can be difficult. The aim of this in vitro study was to evaluate the biomechanical performance of a newly proposed crossed-screw concept ("Fence") utilizing conventional (non-locked) implants in comparison to conventional LC-DCP (limited contact dynamic com...

BACKGROUND The risks associated with percutaneous vertebroplasty (PV) are low. Patients show marked improvement and are able to rapidly resume normal activities after PV. The sudden development of postoperative vertebral compression fracture (VCF) is a common complication, and additional PV is frequently performed in these cases. However, there have been no studies reporting acute compression f...

The effect of the direction of the impact and the presence of axial loading on fracture patterns have not yet been established in experimental 3-point bending studies. PURPOSE To reveal the association between the direction of the force and the fracture pattern, with and without axial loading. MATERIAL AND METHODS A Dynatup Model POE 2000 (Instron Co.) low energy pendulum impact machine was...

Fatigue fracture of the pelvis is the form of fracture due to repetitive micro-stress accumulation, can be affected by a number of factors such as patient's nutritional status, biomechanics, social status and so on. Still there is no study about precise standard degree of external force that lead to stress fracture, but it may caused by compression force, traction force or complex force and oth...

conclusions a clinical examination combined with a plain radiograph should be considered to improve the diagnostic precision for patients presenting with scaphoid fractures in an emergency department. in this way, both overtreatment and undertreatment of patients can be avoided. results scaphoid tubercle tenderness had a sensitivity of 95.23% and a specificity of 74.07% in the diagnosis of scap...

Open Access This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the source is credited. DOI 10.3109/17453670903317114 Sir—I have read with interest the article by Dr. Apelqvist et al. In their well-performed study they did not find pneumatic wound compres...

BACKGROUND Anterior bone grafts are used as struts to reconstruct the anterior column of the spine in kyphosis or following injury. An incomplete fusion can lead to later correction losses and compromise further healing. Despite the different stabilizing techniques that have evolved, from posterior or anterior fixating implants to combined anterior/posterior instrumentation, graft pseudarthrosi...

BACKGROUND Femoral stress fractures tend to occur at the neck, medial proximal-shaft, and distal-shaft. The purpose of this study was to determine the internal femoral forces and moments during running. It was expected that larger loads would occur at these common sites of femoral stress fracture. METHODS Ten subjects ran at their preferred running speed over a force platform while motion cap...