BACKGROUND Screw length pertains to stability in various orthopedic fixation devices. There is little or no information on the relationship between plate pullout strength and screw length in anterior lumbar interbody fusion (ALIF) plate constructs in the literature. Such a description may prove useful, especially in the treatment of osteoporotic patients where maximizing construct stability is ...

A large scale experimental program using vertical and batter model piles in sand subjected to pull out loads has been carried out in a model tank of size 1m x 1m x 1m. Mild steel pipes of varying diameters, lengths, and shapes are used as model piles. A poorly graded river sand having specific gravity G= 2.67, Uniformity coefficient= 3.53, emax = 0.81, emin = 0.54 has been used as foundation me...

INTRODUCTION: Rotator cuff injuries account for more than 4.5 million physician visits annually in the U.S. Injuries to the rotator cuff are typically treated arthroscopically by using implanted suture anchors for the repair. Common suture anchor designs include variations in thread design and the material used. The primary objective of this study was to understand and model the effects of fron...

Many successful attempts to increase pullout strength of pedicle screws in osteoporotic bone have been accompanied with an increased risk of catastrophic damage to the patient. To avoid this, a single-armed expansive pedicle screw was designed to increase fixation strength while controlling postfailure damage away from the nerves surrounding the pedicle. The screw was then subsequently tested i...

The adhesion between a polymer melt and substrate is studied in the presence of chemically attached chains on the substrate surface. Extensive molecular dynamics simulations have been carried out to study the effect of temperature, tethered chain areal density (Σ), tethered chain length (Nt), chain bending energy (kθ) and tensile pull velocity (v) on the adhesive failure mechanisms of pullout a...

Materials and methods Eighteen vertebrae were harvested from the lumbar section of six porcine spines ranged from L1 to L3. All vertebrae were instrumented on both pedicles using pedicle screws. Quantitative CT scans were used before instrumentation in order to assess the bone density of each vertebra. Cyclic bending (toggling) load of ± 1mm displacement at 3Hz for 5000 cycles were assigned in ...

This paper investigated the effect of residual thermal stresses on carbon fibre pullout by using cohesive zone modelling. The finite element method was applied to analyse the residual thermal stress components along the interface between the fibre and matrix due to curing. A comparison study on the anisotropic and isotropic material properties are considered using four typical carbon fibres, T3...

Antler bone displays considerable toughness through the use of a complex nanofibrous structure of mineralized collagen fibrils (MCFs) bound together by non-collagenous proteins (NCPs). While the NCP regions represent a small volume fraction relative to the MCFs, significant surface area is evolved upon failure of the nanointerfaces formed at NCP-collagen fibril boundaries. The mechanical proper...