The spine journal : official journal of the North American Spine Society
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Pedicle screw malposition rates using conventional techniques have been reported to occur with a frequency of 6% to 41%. The upper thoracic spine (T1-T3) is a challenging area for pedicle screw placement secondary to the small size of the pedicles, the inability to visualize this area with lateral fluoroscopy, and significant consequences for malpositioned screws. We describe our experience placing 150 pedicle screws in the T1-T3 levels using three-dimensional (3D) image guidance. ⋯ Upper thoracic pedicle screw placement is technically demanding as a result of variable pedicle anatomy and difficulty with two-dimensional visualization. This study demonstrates the accuracy and reliability of 3D image guidance when placing pedicle screws in this region. Advantages of this technology in our practice include safe and accurate placement of spinal instrumentation with little to no radiation exposure to the surgeon and operating room staff.
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The prevalence of scoliosis in Prader-Willi syndrome (PWS) is high; however, the prevalence of PWS is rare, with one person in 10,000 to 20,000 affected. The etiology and characteristics of scoliosis associated with PWS remain unidentified. In addition, it is believed that the speedup of growth associated with growth hormone (GH) supplement treatment may influence the deterioration of scoliosis in PWS. ⋯ Scoliosis in PWS can be classified into three types. A lumbar curve convex on the left side was found in most patients. In addition, severe deterioration of scoliosis was found in Type 2 patients. Therefore we recommend careful, ongoing observations for patients showing double curve tendencies.
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From a biomechanical perspective, the successful outcome of total disc replacement is largely based on the mechanisms of acute fixation obtained at the index procedure and the extent of porous biological osseointegration at the prosthesis-bone interface, ensuring long-term device fixation. ⋯ The present study represents the largest analysis to date of any retrieved porous ingrowth disc replacement prostheses. A trend was observed of increase porous osseointegration with improved implant positioning; however, the small sample size and high standard deviations account for lack of statistical significance. Although osseointegration occurs despite nonideal intraoperative positioning, it remains imperative that surgeons strive for Ideal implant position.