The purpose of this study was to determine the change of fixation strength after adjusting the height of polymethylmethacrylate (PMMA)-augmented pedicle screws.Cement-augmented cannulated pedicle screws with or without PMMA augmentation with a radial hole in the distal third of the screw thread were inserted into synthetic bone blocks used to model osteoporosis. Screws were left unchanged (in s...

pedicle screws provide rigid fixation for instabilities in the lumbar and lumbosacral spine. anatomical consideration and potential risk of neurologic complications are the reasons to hesitate using pedicle screws in the thoracic spine. twenty moulages similar to human vertebrae were instrumented with cotrel-dubousset (cd) system pedicle screw by intratransverse process, extrapedicular and intr...

OBJECT In 2009, Santoni et al. reported cortical bone trajectory (CBT) as a method of inserting pedicle screws to obtain more solid fixation, and proposed the use of cortical trajectory screws with a more closely placed thread (cortical screws) for CBT. Since the entry trajectory in CBT differs from that in the traditional trajectory, it is unclear whether the increased strength derives from th...

This study presents the results from centrifuge modeling experiments performed to understand effects of temperature changes on vertical pullout capacity scale-model torpedo piles embedded in soft clay layers. The model pile is a pointed stainless-steel cylinder with fins at top, installed by self-weight base layer using stepper motor. An internal electrical resistance heater was used control te...

BACKGROUND CONTEXT Achieving solid implant fixation to osteoporotic bone presents a clinical challenge. New techniques and devices are being designed to increase screw-bone purchase of pedicle screws in the lumbar spine via a novel cortical bone trajectory that may improve holding screw strength and minimize loosening. Preliminary clinical evidence suggests that this new trajectory provides scr...

BACKGROUND AND PURPOSE Due to the known drawbacks of metal implants, new biomaterials for internal fracture fixation are attracting increasing interest, among them poly(lactic-co-glucolic) acids (PLGAs) and the recently developed silk-tenoin derived materials (STDMs). In accordance with the new philosophy of bio-derived biomaterials (BIODERIBIOs), I describe a novel innovative technology for us...

Marquees are temporary light structures that are connected to the ground by tensile anchors to resist forces imposed by wind acting on the structure. Failures of such structures are not rare and have resulted in deaths and tens of thousands of dollars of damage. Consequently, an accurate estimation of the ultimate pullout capacity of ground anchors is essential; however, current methods for est...

OBJECTIVE To study the impact of screw orientation on the pullout strength of OsteoMed M3 titanium screws in expansive unilateral open-door laminoplasty of the cervical spine. METHODS Six fresh human cervical spine specimens were randomly numbered and OsteoMed M3 plate and screws were used for an expansive unilateral open-door laminoplasty. The screws were inserted in the lateral mass at diff...

Expansive pedicle screws significantly improve fixation strength in osteoporotic spines. However, the previous literature does not adequately address the effects of the number of lengthwise slits and the extent of screw expansion on the strength of the bone/screw interface when expansive screws are used with or without cement augmentation. Herein, four designs for expansive pedicle screws with ...