The variability in width, height, and spatial orientation of a spinal pedicle makes pedicle screw insertion a delicate operation. The aim of the current paper is to describe a computer-assisted surgical navigation system based on fluoroscopic X-ray image calibration and three-dimensional optical localizers in order to reduce radiation exposure while increasing accuracy and reliability of the su...

Objectives: To evaluate the accuracy and the operative complications of implanting pedicle screws in the thoracic and lumbar spine, using computer-assisted surgery compared to the implantation technique using fluoroscopy. Methods: A retrospective study was conducted at the Hospital Universitário Cajuru PUC-PR from January 2000 to January 2009. Two groups of patients undergoing implant pedicle s...

AIM To improve the strength of stabilization systems currently used in osteoporotic spinal fractures, essentially by increasing the fixation force of pedicle screws. MATERIAL AND METHODS Six human cadaveric vertebrae were used. Bone mineral densities of the specimens were measured with Dual Energy X-ray Absorptiometry in order to assess the osteoporosis. All vertebrae were found to be severel...

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-...

Stabilization of unstable thoracic fractures with transpedicular screws is widely accepted. However, placement of transpedicular screws can cause complications, particularly in the thoracic spine with physiologically small pedicles. Hybrid stabilization, a combination of sublaminar bands and pedicle screws, might reduce the rate of misplaced screws and can be helpful in special anatomic circums...

Expansive pedicle screws significantly improve fixation strength in osteoporotic spines. However, the previous literature does not adequately address the effects of the number of lengthwise slits and the extent of screw expansion on the strength of the bone/screw interface when expansive screws are used with or without cement augmentation. Herein, four designs for expansive pedicle screws with ...

The use of pedicle screw instrumentation in the spine has evolved over the last two decades. The initial use of pedicle screws began in the lumbar spine. As surgeons have become more comfortable with the complex anatomy required for accurate screw placement, the use of pedicle instrumentation has evolved to include their use in the thoracolumbar and thoracic spine. The impetus behind their incr...

An alternative cement augmentation technique for pedicle screws is described, which was applied in two patients with mono- and bisegmental non-union after preceding multisegmental lumbar fusion. The correctly placed pedicle screws in S1 with diameters of 6 and 8.5 mm had severely enlarged the screw cavities due to segmental instability. Revision screws with 10 mm diameter demonstrated sufficien...

Many successful attempts to increase pullout strength of pedicle screws in osteoporotic bone have been accompanied with an increased risk of catastrophic damage to the patient. To avoid this, a single-armed expansive pedicle screw was designed to increase fixation strength while controlling postfailure damage away from the nerves surrounding the pedicle. The screw was then subsequently tested i...

Surgical training using simulators has been shown to be highly effective but is not available for some applications and is too expensive for many programs. The authors piloted a cadaver-based module with the goal of objectively measuring and significantly improving orthopedic residents' surgical skills in placing thoracic pedicle screws, an advanced procedure. An experienced spine surgeon place...