STUDY DESIGN Using fresh cadavers, the biomechanical testing were used to examine the pullout strength of each pedicle screw. OBJECTIVE The aim of this study was to evaluate pullout strength of (1) a redirected pedicle screw following lateral wall breach; (2) a redirected pedicle screw following end-plate breach; and (3) a pedicle without redirection after end-plate breach without redirection...

Background: The purpose of this prospective study was to determine the accuracy of pedicular screw insertion withoutthe use of fluoroscopy.Methods: This study was conducted on patients with spinal diseases in need of pedicular screw fixation and fusion.The included patients suffered from such conditions as vertebral fracture, spinal stenosis, kyphosis, tumor, and pelvicf...

STUDY DESIGN Case report. OBJECTIVE To describe the technique used to place bilateral lumbar transfacet pedicle screws. SUMMARY OF BACKGROUND DATA Transfacet pedicle screw fixation is a growing alternative and biomechanically comparable with traditional pedicle screw fixation. There is no clear description of technique steps for placing transfacet pedicle screws available in the literature,...

INTRODUCTION Many case reports have documented the successful use of titanium miniscrews for orthodontic anchorage. However, the literature lacks a well-controlled study examining the effect of miniscrew diameter on anchorage force resistance. The purpose of this in-vitro study was to compare the force resistance of larger-diameter monocortical miniscrews to smaller-diameter monocortical minisc...

The geometric optimization of orthopedic screws can considerably increase their orthopedic efficiency. Due to the high geometric parameters of orthopedic screws, a finite element simulation is an effective tool for analyzing and forecasting the effect of the parameters on the load-bearing capacity of different types of screws and bones. Thus, in the present study, the tensile strength of a typi...

Study Design Mechanical study. Purpose To compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model. Overview of Literature Adequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone-...

OBJECTIVE To determine if 1) angularly stable devices created by compressing ("locking") proximal locking screws to intramedullary nails using end caps or compression screws or 2) increasing the number of proximal screws from two to three increases the stiffness of intramedullary constructs that stabilize proximal third tibia fractures in a nonosteopenic bone model. METHODS Four proximal lock...

BACKGROUND Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. PURPOSE To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous sc...

BACKGROUND Screws placed in the distal fibula may not have satisfactory purchase during internal fixation of an osteoporotic ankle fracture. Tibia-pro-fibula screws that extend from the fibula into the distal tibial metaphysis provide additional purchase. The purpose of this study was to investigate if purchase of these screws can be enhanced further by injecting calcium sulfate and calcium pho...