A three-dimensional simulation of trabecular surface remodeling was performed to investigate the basic effects of a fixation screw on the trabecular structural changes in a vertebral body. Voxel-based finite elements were used to construct computational models of the bone and screw for an entire vertebral body with the screw and for the bone-screw interface. The remodeling simulation for the en...

STUDY DESIGN Evaluation using 3-dimensional screw trajectory software and computed tomographic scans. OBJECTIVE To investigate the anatomic feasibility of laminar screw placement in the upper thoracic spine compared with pedicle screw placement. SUMMARY OF BACKGROUND DATA Although laminar screws have been suggested as an alternative to pedicle screws in the upper thoracic spine, previous an...

We report a case of fixation of a scaphoid fracture using an Acutrak(®) screw. This screw is cannulated and headless, which allows it to be implanted below the surface of the bone. It uses the same concept of variable thread pitch as the Herbert screw, but unlike the Herbert screw, is fully threaded, with continuously varying pitch along its length. This variable pitch creates constant compress...

the potential use of nano technology for improving of withdrawal resistance of nail and screw in wood was evaluated. for this, the maintenance strength of nail and screw was measured under dry and wet conditions for poplar wood (populus nigra) coated with common paints in furniture industry and nano-particles. specimens with dimensions of 15×5×5 cm3 (l×r×t) were cut from poplar wood (populus ni...

AIM In unique clinical situations where C1-C2 posterior fixation is not available or has previously failed, an anterior transarticular screw (ATAS) may be a viable alternative. However, there are no previous reports that investigate possible screw angles, screw entry points, and screw length based on computed tomography (CT) multiplanar reconstruction images in Turkish patients. The aim of this...

Introduction: Anterior spinal instrumentation of the thoracic and lumbar spine has gained in popularity since Dwyer et al [1] developed the cable system in 1964. However, implant loosening, screw breakage and cut-throughs have been noted clinically when using Dwyer or Zielke's Ventrale Derotations Spondylodese (VDS) instrumentations [2,3]. To avoid these complications and pseudarthrosis, one ma...

A 27-year-old woman with a type II odontoid fracture was treated by anterior odontoid screw fixation. Radiographic union at the fracture site was obtained 3 months after surgery. Nearly 3 years after surgery, she presented at a local Ear, Nose, and Throat (ENT) clinic with a 2-month history of dysphagia. Laryngoscopy identified the head of the odontoid lag screw. Plain radiography showed that t...

According to the problem of screw fracture of electric submersible pump unit in Shengtuo oilfield, the reasons for the screw fracture are analyzed from three aspects: material, strength and pretightening force. The preliminary result shows that the imbalanced pretightening force of screw is the main reason of screw fracture. By means of Ansys software, the static and modal analyses for the elec...

The aim is to present our new method of compression, a compression tube instead of conventional compression screw and to investigate the difference of proximal locking screw bending resistance between compression screw application (6 mm wide contact) and compression tube (two contact points with 13 mm gap) application. We formed six groups each consisting of 10 proximal locking screws. On metal...

This report describes an eddy current system for locating distal transverse screw holes of an intramedullary nail. In fracture surgery, screw holes on an intramedullary nail are in invisible situation. Although conventional X-ray methods can visualize screw holes in bone, they pose a danger due to X-ray exposure. Therefore, a system to find screw holes without X-ray exposure is required. We sol...