Study Design Biomechanical analysis of lateral mass screw pullout strength. Objective We compare the pullout strength of our bone cement-revised lateral mass screw with the standard lateral mass screw. Methods In cadaveric cervical spines, we simulated lateral mass screw "cutouts" unilaterally from C3 to C7. We salvaged fixation in the cutout side with polymethyl methacrylate (PMMA) or Cortoss ...

We examined the radiographs from a prospective clinical study of fixation by pedicle screws and those from an experimental study in a sheep model. In the clinical study, instruments were removed from 21 patients after implantation for 11 to 16 months and the extraction torques of the screws were recorded. A structured protocol was used for the radiological examinations. In the experimental stud...

While the biomechanical properties of pedicle screws have proven to be superior in the lumbar spine, little is known concerning pullout strength of pedicle screws in comparison to hooks in the thoracic spine. In vitro biomechanical pullout testing was performed to evaluate the axial pullout strength of pedicle screws versus pedicle and laminar hooks in the thoracic spine with regard to surgical...

OBJECTIVE The objective of this paper is to measure the volume occupied by the most widely used internal fixation devices for treating femoral neck fractures, using the first 30, 40 and 50 mm of insertion of each screw as an approximation. The study aimed to observe which of these implants caused least bone aggression. METHODS Five types of cannulated screws and four types of dynamic hip scre...

The fundamental problem in osteoporotic fracture treatment is significant decrease in bone mass and bone tissue density resulting in decreased firmness and elasticity of osteoporotic bone. Application of standard implants and standard surgical techniques in osteoporotic bone fracture treatment makes it almost impossible to achieve stable osteosynthesis sufficient for early mobility, verticaliza...

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...

PURPOSE The purpose of this study was to simulate and calculate the probability of iatrogenic perforation of the scaphoid cortical bone when internal fixation appeared to be safe on radiographs. The results will assist surgeons in determining proper screw placement. METHODS Thirty scaphoids were reconstructed using computed tomography data and image-processing software. Different central axes...

OBJECTIVES Osteosynthesis of anterior pubic ramus fractures using one large-diameter screw can be challenging in terms of both surgical procedure and fixation stability. Small-fragment screws have the advantage of following the pelvic cortex and being more flexible.The aim of the present study was to biomechanically compare retrograde intramedullary fixation of the superior pubic ramus using ei...

STUDY DESIGN Biomechanical analysis. OBJECTIVE To determine the relative strengths of 2 different forms of revision spinal instrumentation using a validated, constant load, cyclic testing mechanism. SUMMARY OF BACKGROUND DATA Spinal fusion with instrumentation procedures are on the rise. As such, so are revision procedures. A few studies have looked at revision instrumentation techniques. B...

PURPOSE Previous studies have proved that vascular endothelial growth factor (VEGF) has a dual role in the promotion of new bone formation and blood vessel repair during fracture healing. However, how to introduce VEGF to a fracture site safely and effectively is still a challenge. This study aimed to prepare a VEGF-loaded nanographene coated internal fixation screw and to evaluate its effects ...