OBJECT Intraoperative imaging often does not provide adequate visualization to ensure safe placement of screws. Therefore, the authors investigated the accuracy of a freehand technique for placement of pars, pedicle, and intralaminar screws in C-2. METHODS Sixteen cadaveric specimens were instrumented freehand by 2 experienced cervical spine surgeons with either a pars or pedicle screw, and b...

P edicle screw fixation for spinal stabilization is now commonplace in spine surgery. Traditionally, pedicle screws are placed through a trajectory in which screw insertion utilizes a transpedicular path through the axis of the pedicle, either paralleling the end plate, as in the straightforward trajectory, or following the anatomic axis of the pedicle with an approximately 22° cephalocaudal tr...

Results: The review of the literature yielded 15 studies on the effect of treatment options for osteoporosis on lumbar fusion rates. One study demonstrated an association between low bone mass as measured by Hounsfield Units and lower fusion rates. Six studies evaluated perioperative medical treatment of osteoporosis and showed higher fusion rates in patients treated with alendronate and teripa...

STUDY DESIGN Prospective clinical study with postoperative radiologic control of pedicle screw placement in the cervical spine. OBJECTIVES To evaluate whether cervical pedicle screws can be placed safely in a conventional technique when using cannulated screws and separate stab incisions. Also, to evaluate if accuracy and safety of pedicle screw placement can be improved using a computer-assi...

OBJECTIVE To determine if image-guided spine surgery is cost effective. METHODS A prospective case series of the first 100 patients undergoing thoracolumbar pedicle screw instrumentation under image-guidance was compared to a retrospective control group of the last 100 patients who underwent screw placement prior to the use of image-guidance. The image-guidance system was NaviVision (Vector V...

STUDY DESIGN An in vitro biomechanical comparison of four posterior fixation techniques in the setting of an anterior lumbar interbody fusion (ALIF). OBJECTIVE To compare the initial stability, in terms of range of motion and neutral zone, provided by pedicle screws, facet screws, translaminar facet screws, and H-graft plus interspinous cables in the presence of an anteriorly placed femoral r...

BACKGROUND More studies report the intraoperative benefits vs. risks of utilizing the O-Arm in performing pedicle screw insertion in spinal surgery. METHODS/RESULTS Several studies document the utility of CT-guided O-arm placement of pedicle/lateral mass screws. Singh et al. documented the efficacy of CT guided-O Arm placement of pedicle screws and lateral mass screws in the upper cervical sp...

BACKGROUND Pedicle screws are biomechanically superior over other spinal fixation devices. When improperly positioned, they lose this advantage and put adjacent structures at risk. Accurate placement is therefore critical. Postoperative computed tomography (CT) scans are the imaging gold standard and have shown malposition rates ranging from 2% to 41%. The O-arm (Medtronic Navigation, Louisvill...

Multiple techniques exist for the fixation of C2, including axial pedicle screws and bilateral translaminar screws. We describe a novel method of incorporating both the translaminar and pedicle screws within C2 to improve fixation to the subaxial spine in patients requiring posterior cervical instrumentation for deformity correction or instability. We report three cases of patients with cervica...

BACKGROUND Pedicle screw insertions are commonly used for posterior fixation to treat various spine disorders. However, the misplacement of pedicle screws can lead to disastrous complications. Inaccurate pedicle screw placement is relatively common even when placement is performed under fluoroscopic control. In order to improve the accuracy of the screw placement, we applied a technique using g...