{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,26]],"date-time":"2025-10-26T22:51:45Z","timestamp":1761519105656},"reference-count":41,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"5","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["SPI"],"published-print":{"date-parts":[[2014,11]]},"abstract":"<jats:sec>\n<jats:title>Object<\/jats:title>\n<jats:p>Single-level anterior cervical discectomy and fusion (ACDF) is an established surgical treatment for cervical myelopathy. Within 10 years of undergoing ACDF, 19.2% of patients develop symptomatic adjacent-level degeneration. Performing ACDF adjacent to prior fusion requires exposure and removal of previously placed hardware, which may increase the risk of adverse outcomes. Zero-profile cervical implants combine an interbody spacer with an anterior plate into a single device that does not extend beyond the intervertebral disc space, potentially obviating the need to remove prior hardware. This study compared the biomechanical stability and adjacent-level range of motion (ROM) following placement of a zero-profile device (ZPD) adjacent to a single-level ACDF against a standard 2-level ACDF.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Methods<\/jats:title>\n<jats:p>In this in vitro biomechanical cadaveric study, multidirectional flexibility testing was performed by a robotic spine system that simulates flexion-extension, lateral bending, and axial rotation by applying a continuous pure moment load. Testing conditions were as follows: 1) intact, 2) C5\u20136 ACDF, 3) C4\u20135 ZPD supraadjacent to simulated fusion at C5\u20136, and 4) 2-level ACDF (C4\u20136). The sequence of the latter 2 test conditions was randomized. An unconstrained pure moment of 1.5 Nm with a 40-N simulated head weight load was applied to the intact condition first in all 3 planes of motion and then using the hybrid test protocol, overall intact kinematics were replicated subsequently for each surgical test condition. Intersegmental rotations were measured optoelectronically. Mean segmental ROM for operated levels and adjacent levels was recorded and normalized to the intact condition and expressed as a percent change from intact. A repeated-measures ANOVA was used to analyze the ROM between test conditions with a 95% level of significance.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Results<\/jats:title>\n<jats:p>No statistically significant differences in immediate construct stability were found between construct Patterns 3 and 4, in all planes of motion (p &gt; 0.05). At the operated level, C4\u20135, the zero-profile construct showed greater decreases in axial rotation (\u201345% vs \u201336%) and lateral bending (\u201355% vs \u201338%), whereas the 2-level ACDF showed greater decreases in flexion-extension (\u201340% vs \u201334%). These differences were marginal and not statistically significant. Adjacent-level motion was nearly equivalent, with minor differences in flexion-extension.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Conclusions<\/jats:title>\n<jats:p>When treating degeneration adjacent to a single-level ACDF, a zero-profile implant showed stabilizing potential at the operated level statistically similar to that of the standard revision with a 2-level plate. Revision for adjacent-level disease is common, and using a ZPD in this setting should be investigated clinically because it may be a faster, safer alternative.<\/jats:p><\/jats:sec>","DOI":"10.3171\/2014.7.spine131059","type":"journal-article","created":{"date-parts":[[2014,8,29]],"date-time":"2014-08-29T14:07:26Z","timestamp":1409321246000},"page":"753-760","source":"Crossref","is-referenced-by-count":10,"title":["Zero-profile hybrid fusion construct versus 2-level plate fixation to treat adjacent-level disease in the cervical spine"],"prefix":"10.3171","volume":"21","author":[{"given":"Andrew T.","family":"Healy","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Swetha J.","family":"Sundar","sequence":"additional","affiliation":[{"name":"Case Western Reserve University School of Medicine, Cleveland, Ohio;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Raul J.","family":"Cardenas","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Mischer Neuroscience Associates, The Woodlands, Texas; and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Prasath","family":"Mageswaran","sequence":"additional","affiliation":[{"name":"Head, Neck & Spine Research Laboratory, Cleveland Clinic, Cleveland, Ohio"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Edward C.","family":"Benzel","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio;"},{"name":"Head, Neck & Spine Research Laboratory, Cleveland Clinic, Cleveland, Ohio"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Thomas E.","family":"Mroz","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio;"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Todd B.","family":"Francis","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio;"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1754","reference":[{"key":"b1-spine131059","series-title":"Spine J","doi-asserted-by":"publisher","first-page":"711","DOI":"10.1016\/j.spinee.2007.06.018","article-title":"The prevalence of indications and contraindications to cervical total disc replacement","volume":"8","author":"Auerbach","year":"2008"},{"key":"b2-spine131059","series-title":"Turk Neurosurg","first-page":"611","article-title":"Outcome evaluation of a zero-profile implant for anterior cervical diskectomy with fusion","volume":"22","author":"Azab","year":"2012"},{"key":"b3-spine131059","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"2167","DOI":"10.1097\/00007632-199311000-00004","article-title":"Late radiographic findings after anterior cervical fusion for spondylotic myeloradiculopathy","volume":"18","author":"Baba","year":"1993"},{"issue":"3","key":"b4-spine131059","series-title":"Neurosurg Focus","first-page":"E14","article-title":"Postoperative wound infections of the spine","volume":"15","author":"Beiner","year":"2003"},{"key":"b5-spine131059","series-title":"Biomechanics of Spine Stabilization","first-page":"189","article-title":"Quantitative attributes of spinal implants","author":"Benzel","year":"2001"},{"key":"b6-spine131059","series-title":"Biomechanics of Spine Stabilization","first-page":"431","article-title":"Subsidence and dynamic spine stabilization","author":"Benzel","year":"2001"},{"key":"b7-spine131059","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"915","DOI":"10.1097\/01.brs.0000158949.37281.d7","article-title":"Biomechanical analysis of rigid stabilization techniques for three-column injury in the lower cervical spine","volume":"30","author":"Bozkus","year":"2005"},{"key":"b8-spine131059","series-title":"Spine Surgery: Techniques, Complications, Avoidance and Management","first-page":"e2221","article-title":"Cervical disc herniation with radiculopathy","volume":"2","author":"Branch","year":"2012"},{"key":"b9-spine131059","series-title":"Clin Neurol Neurosurg","doi-asserted-by":"publisher","first-page":"2049","DOI":"10.1016\/j.clineuro.2013.07.013","article-title":"Alternative grafts in anterior cervical fusion","volume":"115","author":"Chen","year":"2013"},{"key":"b10-spine131059","series-title":"Spine J","doi-asserted-by":"publisher","first-page":"157","DOI":"10.1016\/j.spinee.2012.01.011","article-title":"The biomechanical stability of a novel spacer with integrated plate in contiguous two-level and three-level ACDF models: an in vitro cadaveric study","volume":"12","author":"Clavenna","year":"2012"},{"key":"b11-spine131059","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"1023","DOI":"10.1097\/00007632-199015100-00008","article-title":"Anterior cervical discectomy and fusion","volume":"15","author":"Clements","year":"1990"},{"key":"b12-spine131059","series-title":"Spine (Phila Pa 1976)","doi-asserted-by":"publisher","first-page":"E188","DOI":"10.1097\/01.brs.0000257577.70576.07","article-title":"Stabilizing potential of anterior, posterior, and circumferential fixation for multilevel cervical arthrodesis: an in vitro human cadaveric study of the operative and adjacent segment kinematics","volume":"32","author":"Dmitriev","year":"2007"},{"key":"b13-spine131059","series-title":"Arch Orthop Trauma Surg","doi-asserted-by":"publisher","first-page":"247","DOI":"10.1007\/BF00450219","article-title":"Instability of the cervical spine after anterior interbody fusion. 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