{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T09:25:39Z","timestamp":1748597139427},"reference-count":26,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["SPI"],"published-print":{"date-parts":[[2013,4]]},"abstract":"<jats:sec>\n<jats:title>Object<\/jats:title>\n<jats:p>Endoscopic endonasal approaches to the craniovertebral junction (CVJ) and clivus are increasingly performed for ventral skull-base pathology, but the biomechanical implications of these approaches have not been studied. The aim of this study was to investigate the spinal biomechanics of the CVJ after an inferior-third clivectomy and anterior intradural exposure of the foramen magnum as would be performed in an endonasal endoscopic surgical strategy.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Methods<\/jats:title>\n<jats:p>Seven upper-cervical human cadaveric specimens (occiput [Oc]\u2013C2) underwent nondestructive biomechanical flexibility testing during flexion-extension, axial rotation, and lateral bending at Oc\u2013C1 and C1\u20132. Each specimen was tested intact, after an inferior-third clivectomy, and after ligamentous complex dissection simulating a wide intradural exposure using an anterior approach. Angular range of motion (ROM), lax zone, and stiff zone were determined and compared with the intact state.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Results<\/jats:title>\n<jats:p>Modest, but statistically significant, hypermobility was observed after inferior-third clivectomy and intradural exposure during flexion-extension and axial rotation at Oc\u2013C1. Angular ROM increased incrementally between 6% and 12% in flexion-extension and axial rotation. These increases were primarily the result of changes in the lax zone. No significant changes were noted at C1\u20132.<\/jats:p><\/jats:sec>\n<jats:sec>\n<jats:title>Conclusions<\/jats:title>\n<jats:p>Inferior-third clivectomy and an intradural exposure to the ventral CVJ and foramen magnum resulted in hypermobility at Oc\u2013C1 during flexion-extension and axial rotation. Although the results were statistically significant, the modest degree of hypermobility observed compared with other well-characterized CVJ injuries suggests that occipitocervical stabilization may be unnecessary for most patients.<\/jats:p><\/jats:sec>","DOI":"10.3171\/2013.1.spine12835","type":"journal-article","created":{"date-parts":[[2013,2,15]],"date-time":"2013-02-15T15:01:47Z","timestamp":1360940507000},"page":"327-332","source":"Crossref","is-referenced-by-count":13,"title":["Biomechanical evaluation of the craniovertebral junction after inferior-third clivectomy and intradural exposure of the foramen magnum: implications for endoscopic endonasal approaches to the cranial base"],"prefix":"10.3171","volume":"18","author":[{"given":"Andrew S.","family":"Little","sequence":"first","affiliation":[{"name":"Barrow Pituitary and Cranial Base Center, Division of Neurosurgery, and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Luis","family":"Perez-Orribo","sequence":"additional","affiliation":[{"name":"Spinal Biomechanics Research Laboratory, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona; and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nestor G.","family":"Rodriguez-Martinez","sequence":"additional","affiliation":[{"name":"Spinal Biomechanics Research Laboratory, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona; and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Phillip M.","family":"Reyes","sequence":"additional","affiliation":[{"name":"Spinal Biomechanics Research Laboratory, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona; and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anna G. 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