A preliminary study of acoustic emission during orthopaedic screw fixation was performed using polyurethane foam as the bone-simulating material. Three sets of screws, a dynamic hip screw, a small fragment screw and a large fragment screw, were investigated, monitoring acoustic-emission activity during the screw tightening. In some specimens, screws were deliberately overtightened in order to i...

BACKGROUND Tibial fixation of hamstring tendon grafts has been the weak link in anterior cruciate ligament reconstruction. HYPOTHESIS Use of a central four-quadrant sleeve and screw provides superior fixation when compared with standard interference screw fixation. STUDY DESIGN Controlled laboratory study. METHODS In eight pairs of cadaveric knees each anterior cruciate ligament was recon...

Objective Among the various sacropelvic fixation methods, S2 alar-iliac (S2AI) screw fixation has several advantages compared to conventional iliac wing screw. However, the placement of S2AI screw still remains a challenge. The purpose of this study was to describe a novel technique of free hand S2AI screw insertion using a K-wire and cannulated screw, and to evaluate the accuracy of the techni...

Pedicle screws are the main fixation devices for certain surgeries. Pedicle screw loosening is a common problem especially for osteoporotic incidents. Cannulated screws with cement augmentation are widely used for that kind of cases. Dual lead dual cored pedicle screw has already given promising pullout values without augmentation. This study concentrates on the usage of dual lead dual core wit...

BACKGROUND The objective of this study is to investigate the outcomes and safety of using percutaneous anterior C1/2 transarticular screw fixation as a salvage technique for odontoid fracture if percutaneous odontoid screw fixation fails. METHODS Fifteen in 108 odontoid fracture patients (planned to be treated by percutaneous anterior odontoid screw fixation) were failed to introduce satisfac...

BACKGROUND Complications related to extensor tendons have begun to increase with the use of volar plates in the treatment of distal radius fractures. In this study, we aimed to compare four-plane radiography and ultrasonography in the evaluation of dorsal cortex screw penetration following volar plate fixation. METHODS We recruited 47 patients (33 males, 14 females, mean age 37.4 years; range...

In this work, the design and analysis of new Level Shifter with Gate Driver for Li-Ion battery charger is proposed for high speed and low area in 180nm CMOS technology. The new proposed level shifter is used to raise the voltage level and significantly reduces transfer delay 1.3ns (transfer delay of conventional level shifter) to 0.15ns with the same input signal. Also, the level shifter with g...

Since Bra�nemark et al published the results of a 10-year study on osseointegration in 1977, dental implants have increasingly been used to replace missing teeth. The use of osseointegrated implants had become a successful procedure for the treatment of complete, partial edentulism, and single-tooth replacements in both the anterior and posterior regions of the mouth. Although improvements in m...

PURPOSE This study was conducted to assess the effect of using a double screw on the prevention of abutment screw loosening. MATERIALS AND METHODS Internal connected abutment with a single screw (IS), internal connected abutment with a double screw (ID), external connected abutment with a single screw (ES), and external connected abutment with a double screw (ED) groups were prepared (n = 10 ...

statement of the problem: one disadvantage of cement-retained crowns is the lack of predictable irretrievability. this problem can be overcome through designing a screw access hole in the metal substructure of cement-retained restoration and using porcelain stain to define this area. purpose: this study aimed to evaluate the influence of existence of screw access hole on porcelain fracture resi...