STUDY DESIGN Axial pullout tests using fresh cadaveric thoracolumbar vertebral bodies. OBJECTIVES To evaluate the effect of a new injectable calcium phosphate cement on the axial pullout strength of both revised and augmented pedicle screws in comparison with polymethyl methacrylate and in terms of injection method. SUMMARY OF BACKGROUND DATA Failure of pedicle screws by loosening and back ...

STUDY DESIGN Pedicle screw strength or load to failure was biomechanically evaluated, and the geometric characteristics of pedicle screw instrumentation systems were compared. OBJECTIVES To compare the features of pedicle screw systems, and to demonstrate the failure point of the polyaxial pedicle screw head. SUMMARY OF BACKGROUND DATA Many pedicle screw instrumentation systems are currentl...

BACKGROUND Posterior vertebral column resection (PVCR) is an effective alternative for treating rigid and severe spinal deformities. Accurate placement of pedicle screws, especially apically, is crucial. As morphologic evaluations of thoracic pedicles have not provided objective criteria, we propose a thoracic pedicle classification for treating rigid and severe spinal deformities. METHODS A ...

BACKGROUND Some early studies with robotic-assisted pedicle screw implantation have suggested these systems increase accuracy of screw placement. However, the relationship between the success rate of screw placement and the learning curve of this new technique has not been evaluated. QUESTIONS/PURPOSES We determined whether, as a function of surgeon experience, (1) the success rate of robotic...

Background: To analyse use of monopolar diathermy stimulation of pedicle screws in order to improve breach detection. Methods: Prospective single-blind study. Patients with preoperative neurological deficit excluded. Pedicle screws inserted freehand into thoracic and lumbar spine. Monopolar diathermy in “cutting” mode at half the strength used for actual cutting purpose was used to stimulate th...

STUDY DESIGN The shape of the L5 vertebral body was analyzed using a computerized tomography (CT) scan. OBJECTIVE The aim of this study is to determine if the vertebral L5 body shape varies depending on the height of the CT slices through the L5 pedicle. SUMMARY OF BACKGROUND DATA The morphometry of L5 has been studied to help the introduction of pedicular screws. The shape of the vertebral...

Introduction Pedicle screw insertion is the mainstay of thora-cic and lumbosacral posterior spinal instrumentation. However, it may be associated with complications such as screw mal-positioning. The purpose of this study was to develop a pilot study to compare the accuracy of robot-guided screw insertion versus hand-guided screw placement for spinal instrumentation. The hand-guided screws were...

Background Data: Various methods to help guidance of screw purchase in AIS have been described the literature. Free-hand technique is a relatively easy and as accurate other methods. MSCT scan, most method postoperative evaluation still needs more research. Purpose: The aim this study evaluate accuracy safety pedicle fixation (PSF) with free-hand using scan. Study Design: Prospective clinical c...

background & aims: thuracolumbar unstable fractures (t, l.u.f) are common after spine truma. posterior pedicular fixation is a technique that is use for fixation of these fractures. this study evaluates the accuracy of pedicular screw placement in t, luf with the assistance of plain radiography in operation rooms. materials & methods: this study is a case-control and analytical study. 35 patien...

Lumbar fusion using the pedicle screw system is a popular operative procedure, with favorable clinical results and high fusion rates. However, the risk of adjacent segment disease after lumbar fusion is problematic. We report a complicated case of severe retrolisthesis at L3-4 level following dynamic interspinous process stabilization at L2-3 level and a fusion at L4-5 level. The radiological a...