Spine
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We present the positional magnetic resonance imaging findings of a prospective case series of patients undergoing surgery with the Dynesys spinal stabilization device (Zimmer, Inc., Warsaw, IN). ⋯ In vivo, the Dynesys Stabilization System allows movement at the instrumented level, albeit reduced, with no significant increased mobility at the adjacent segments. There was reduction of the anterior disc height without a significant increase of the posterior disc height.
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Retrospective review of the medical, radiographic, surgical, and postoperative records of patients who underwent resection of multilevel intradural extramedullary spinal cord tumors of the ventral cervical and cervicothoracic spine via a modified paramedian transpedicular approach at the University of California, San Francisco, between 2003 and 2005. ⋯ The modified paramedian transpedicular approach with partial dorsal corpectomy we describe here is a variation of traditional thoracic posterolateral transpedicular extracavitary approaches and offers direct access to lesions of the ventral cervicothoracic spinal canal. This approach avoids the morbidity of anterior transcervical, transoral, or transthoracic procedures, while providing a view of the entire ventral cervicothoracic canal, and can be performed safely and effectively in select patients.
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This is an in vitro biomechanical study. ⋯ Results from our study revealed greater adjacent level motion following all 3 fixation types. No consistent significant intergroup differences in neighboring segment kinematics were detected among reconstructions. Circumferential fixation provided the greatest level of segmental stability without additional significant increase in adjacent level ROM.
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Case Reports Multicenter Study Comparative Study
Surgical strategy for cervical myelopathy due to ossification of the posterior longitudinal ligament: Part 2: Advantages of anterior decompression and fusion over laminoplasty.
Retrospective study of 27 patients who underwent anterior decompression and fusion (ADF) for treatment of cervical myelopathy due to ossification of the posterior longitudinal ligament (OPLL). ⋯ Although ADF is technically demanding and has a higher incidence of surgery-related complications, it is preferable to laminoplasty for patients with occupying ratio of OPLL > or =60%.
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Randomized Controlled Trial
Magnetic resonance imaging clarity of the Bryan, Prodisc-C, Prestige LP, and PCM cervical arthroplasty devices.
Prospective, randomized, controlled and double-blinded study on imaging of artificial discs. ⋯ Preoperative and postoperative magnetic resonance imaging scans of 20 patients who had undergone cervical arthroplasty were assessed for imaging quality. Five cases each of the Bryan (Medtronic Sofamor Danek, Memphis, TN), Prodisc-C (Synthes Spine, Paoli, PA), Prestige LP (Medtronic Sofamor Danek), and PCM devices (Cervitech, Rockaway, NJ) were analyzed. Six blinded spinal surgeons scored twice sagittal and axial T2-weighted images using the Jarvik 4-point scale. Statistical analysis was performed comparing quality before surgery and after disc implantation at the operated and adjacent levels and between implant types. RESULTS.: Moderate intraobserver and interobserver reliability was noted. Preoperative images of patients in all implant groups had high-quality images at operative and adjacent levels. The Bryan and Prestige LP devices allowed satisfactory visualization of the canal, exit foramina, cord, and adjacent levels after arthroplasty. Visualization was significantly impaired in all PCM and Prodisc-C cases at the operated level in both the spinal canal and neural foramina. At the adjacent levels, image quality was statistically poorer in the PCM and Prodisc-C than those of Prestige LP or Bryan. CONCLUSIONS.: Postoperative visualization of neural structures and adjacent levels after cervical arthroplasty is variable among current available devices. Devices containing nontitanium metals (cobalt-chrome-molybdenum alloys in the PCM and Prodisc-C) prevent accurate postoperative assessment with magnetic resonance imaging at the surgical and adjacent levels. Titanium devices, with or without polyethylene (Bryan disc or Prestige LP), allow for satisfactory monitoring of the adjacent and operated levels. This information is crucial for any surgeon who wishes to assess adequacy of neural decompression and where monitoring of adjacent levels is desired.