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Spine
implant has zero profile, it may reduce the occurrence of adjacent level ossification and postoperative dysphagia. The device is designed as a plate/spacer combination with four rigid screws so that it provides similar stability to a traditional cervical plate and spacer [3]. Zero-P is the first implant on the market offering both a zero anterior profile as well as a biomechanical stability similar to a plate-spacer construct. Implants and instrumentation For optimal adoption to the patient’s anatomy, Zero-P is available in three different spacer shapes (convex, lordodic, and parallel), two different footprint sizes (standard and large) and eight different heights (5–12 mm). Zero-P is delivered preassembled and sterilely packaged. After the removal of the cervical disc, trial spacers are used to determine implant height, shape, and footprint size. After the correct trial spacer is fitted, the corresponding Zero-P implant is inserted using the aiming device. Because plate and spacer are preassembled, the plate is automatically aligned upon implant insertion. This avoids the process of aligning and realigning an anterior cervical plate. To prepare the screw holes, instruments for awling and drilling are available. For anatomically challenging situations like patients with short necks, angled instruments are available. The Zero-P screws have a one-step locking conical head, which locks the screw to the plate by simply inserting and tightening the screw. Bibliography 1 Kaiser MG, Haid RW Jr, Subach BR, et al (2002) Anterior cervical plating enhances arthrodesis after discectomy and fusion with cortical allograft. Neurosurgery; 50(2):229–236. 2 Fraser JF, Härtl R (2007) Anterior approaches to fusion of the cervical spine: a metaanalysis of fusion rates. J Neurosurg Spine; 6(4):298–303. 3 Scholz M, Reyes PM, Schleier P, et al (2009) A new stand-alone cervical anterior interbody fusion device: biomechanical comparison with established anterior cervical fixation devices. Spine; 34(2):156–160.
59-year-old female with neck pain and right radicular arm pain C5 and C6 and weakness during walking. An MRI was performed and a severe DDD with soft spinal stenosis C3–C6 was diagnosed. Neurophysiology revealed myelopathic spinal cord changes. Decompression and stabilization C3/4, C4/5, and C5/6 using Zero-P was performed. After surgery the patient was nearly free of pain, had no complains regarding dysphagia, and was neurologically improved. a
Case provided by Frank Kandziora, Frankfurt, Germany
b
Fig 1a–b Preoperative x-rays.
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Fig 2a–b Postoperative x-rays.