This study aims to evaluate the effect of nanosilica (NS) and metakaolin (MK) as binder replacement materials on fresh hardened characteristics slag (GGBS)-based alkali-activated self-compacting concretes (A-ASCC). Therefore, nine A-ASCC mixes, with without metakaolin, were prepared, well mixes NS incorporation. In production GGBS was used a material. The properties determined using L-box, V-fu...

PURPOSE The aim of this study was to test a simple technique to augment the pullout resistance of an anchor in an over-drilled sheep humerus model. METHODS Sixty-four paired sheep humeri were harvested from 32 male sheep aged 18 months. Specimens were divided into an augmented group and non-augmented group. FASTIN RC 5-mm titanium screw anchors (DePuy Mitek, Raynham, MA) double loaded with su...

BACKGROUND Expandable screws have greater pullout strength than conventional screws. The purpose of this study was to compare the biomechanical stability provided by a new built-in expandable anterior spinal fixation system with that of 2 commonly used anterior fixation systems, the Z-Plate and the Kaneda, in a porcine partial vertebral corpectomy model. METHODS Eighteen porcine thoracolumbar...

The mechanical behavior of carbon nanotube (CNT)-based fibers and nanocomposites depends intimately on the shear interactions between adjacent tubes. We have applied an experimental-computational approach to investigate the shear interactions between adjacent CNTs within individual double-walled nanotube (DWNT) bundles. The force required to pull out an inner bundle of DWNTs from an outer shell...

PURPOSE Pedicle screw fixation of osteoporotic bone in the elderly is a challenge. Various augmentation methods have been studied by many authors. Although polymethylmethacrylate (PMMA) augmentation is believed to be a standard method, its usage is fraught with complications. Butyl-2-cyanoacrylate is an alternative to PMMA as it is bioresorbable, biocompatible, inexpensive, and noninfective. Th...

BACKGROUND Immobilization after tendon transfers has been the conventional postoperative management. Several recent studies suggest early mobilization does not increase tendon pullout. QUESTIONS/PURPOSES To confirm those studies we determined whether when compared with immobilization early active mobilization after a tendon transfer for foot-drop correction would (1) have a similar low rate o...

BACKGROUND Pedicle screws with PMMA cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques, namely solid screws with retrograde cement pre-filling versus cannulated screws with cement injection through perforation, remains unknown. This study aimed t...

STUDY DESIGN Biomechanical evaluation using porcine spines. OBJECTIVE Compare the fixation strength of two currently used fusionless adolescent idiopathic scoliosis correction techniques following cyclic loading using porcine spines. SUMMARY OF BACKGROUND DATA The ability of fusionless implants to control or correct scoliosis in a growing patient requires such implants to maintain spinal fi...

OBJECTIVE This study was undertaken to quantify the in vitro range of motion (ROM) of oblique as compared with anterior lumbar interbody devices, pullout resistance, and subsidence in fatigue. METHODS Anterior and oblique cages with integrated plate fixation (IPF) were tested using lumbar motion segments. Flexibility tests were conducted on the intact segments, cage, cage + IPF, and cage + IP...