This paper studies the vectors of cofactors in a screw matrix assembled by n screws and investigates the properties and different arrangements of cofactors. An augmentation screw which is linearly independent of n screws in the screw matrix is proposed and is used to relate the vector of cofactors to a reciprocal screw and subsequently to the reciprocal screw system. The paper proposes a new al...

STUDY DESIGN The loosening rates of two monocortical pedicle screw designs (hollow and solid) were compared in a cadaveric sacrum model subjected to cyclic loading. OBJECTIVE To determine if a hollow screw would be more resistant to loosening than a solid pedicle screw when placed into the pedicles of S1 and tested under stair-cased cyclic loading. SUMMARY OF BACKGROUND DATA Screw loosening...

STUDY DESIGN Biomechanical study. PURPOSE To determine the effect of density, insertion angle and reinsertion on pull-out strength of pedicle screw in single and two screw-rod configurations. OVERVIEW OF LITERATURE Pedicle screw pull-out studies have involved single screw construct, whereas two screws and rod constructs are always used in spine fusions. Extrapolation of results using the si...

STUDY DESIGN Clinical case series. PURPOSE In the posterior lumbar interbody fusion (PLIF) procedure in our institute, the cephalad screw trajectory follows a mediolateral and caudocephalad directed path according to the original cortical bone trajectory (CBT) method. However, the starting point of the caudal screw is at the medial border of the pedicle on an articular surface of the superior...

introduction ophthalmomyiasis is a rare disorder that is caused by invasion of dipterous larvae to necrotic tissues. case presentation an 80-year-old woman with invasive basal cell carcinoma (bcc) presented anabnormal growth of worm in her eye. she had ophthalmomyiasis caused by lucilia sericata larva in here nucleated eye. l. sericata is common all over the temperate and tropical regions, main...

INTRODUCTION: In a pedicle screw fixation, the degree of osseointegration between a screw and the bone is an essential factor for the stability and fusion. In patients with osteoporosis, however, there is a high possibility for a pedicle screw loosening. Owing to this, there is a difficulty in determining the surgical indications. Previous biomechanical studies have reported that a pedicle scre...

background appropriate treatment of acromioclavicular joint dislocation is controversial. acroplate fixation is one of the most common treatment methods of acromioclavicular joint (acj) dislocation. based on the risk of re-dislocation after acroplate fixation, we assumed that combined fixation with an acroplate and a coracoclavicular screw helps improve the outcome. objectives the main purpose ...

We analyze screw, edge and mixed screw-edge dislocations in monochromatic light waves. Methods for the experimental dete~nation of the topological charge value and helicity of screw dislocations are elaborated. By use of computer-synthesized binary gratings waves with edge and mixed screw-edge disl~ations were obtained and studied ~xpe~mentally. The transformation of a mixed screw-edge distocat...

BACKGROUND Tibial aperture fixation with a bioabsorbable interference screw is a popular fixation method in anterior cruciate ligament reconstruction (ACLR). An interference screw containing β-tricalcium phosphate (β-TCP) to improve bony integration and biocompatibility was recently introduced. This study aims to compare the clinical outcomes and radiological results of tunnel enlargement effec...