{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T17:22:21Z","timestamp":1787764941738,"version":"build-2784847793"},"reference-count":27,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"4","content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2023,10]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>Excess flexion or extension during occipitocervical fusion (OCF) can lead to postoperative complications, such as dysphagia, respiratory problems, line of sight issues, and neck pain, but posterior fossa decompression (PFD) and OCF require different positions that require intraoperative manipulation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objective:<\/jats:title>\n                    <jats:p>The objective of this study was to describe quantitative fluoroscopic morphometrics in Chiari malformation (CM) patients with symptoms of craniocervical instability (CCI) and demonstrate the intraoperative application of these measurements to achieve neutral craniocervical alignment while leveraging a single axis of motion with the Mayfield head clamp locking mechanism.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>A retrospective cohort study of patients with CM 1 and 1.5 and features of CCI who underwent PFD and OCF at a single-center institution from March 2015 to October 2020 was performed. Patient demographics, preoperative presentation, radiographic morphometrics, operative details, complications, and clinical outcomes were analyzed.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      A total of 39 patients met the inclusion criteria, of which 37 patients (94.9%) did not require additional revision surgery after PFD and OCF. In this nonrevision cohort, preoperative to postoperative occipital to C2 angle (O-C2a) (13.5\n                      <jats:sup>\u00b0<\/jats:sup>\n                      \u00b1 10.4\n                      <jats:sup>\u00b0<\/jats:sup>\n                      vs. 17.5\n                      <jats:sup>\u00b0<\/jats:sup>\n                      \u00b1 10.1\n                      <jats:sup>\u00b0<\/jats:sup>\n                      ,\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      = 0.047) and narrowest oropharyngeal airway space (nPAS) (10.9 \u00b1 3.4 mm vs. 13.1 \u00b1 4.8 mm,\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      = 0.007) increased significantly. These measurements were decreased in the two patients who required revision surgery due to postoperative dysphagia (mean difference \u2013 16.6\n                      <jats:sup>\u00b0<\/jats:sup>\n                      \u00b0 in O C2a and 12.8\n                      <jats:sup>\u00b0<\/jats:sup>\n                      \u00b0 in occipital and external acoustic meatus to axis angle). Based on these results, these fluoroscopic morphometrics are intraoperatively assessed, utilizing a locking Mayfield head clamp repositioning maneuver to optimize craniocervical alignment prior to rod placement from the occipital plate to cervical screws.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>Establishing a preoperative baseline of reliable fluoroscopic morphometrics can guide surgeons intraoperatively in appropriate patient realignment during combined PFD and OCF, and may prevent postoperative complications.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.4103\/jcvjs.jcvjs_59_23","type":"journal-article","created":{"date-parts":[[2023,11,29]],"date-time":"2023-11-29T00:00:50Z","timestamp":1701216050000},"page":"365-372","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":2,"title":["Intraoperative occipital to C2 angle and external acoustic meatus-to-axis angular measurements for optimizing alignment during posterior fossa decompression and occipitocervical fusion for complex Chiari malformation"],"prefix":"10.4103","volume":"14","author":[{"given":"Rachael K.","family":"Han","sequence":"first","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"John K.","family":"Chae","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew L. A.","family":"Garton","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amanda","family":"Cruz","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rodrigo","family":"Navarro-Ramirez","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA"},{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York Presbyterian-Och Spine, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ibrahim","family":"Hussain","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA"},{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York Presbyterian-Och Spine, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roger","family":"H\u00e4rtl","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, USA"},{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York Presbyterian-Och Spine, New York, NY, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jeffrey P.","family":"Greenfield","sequence":"additional","affiliation":[{"name":"Department of Neurological Surgery, Weill Cornell Medicine, New York-Presbyterian Hospital, New York, NY, 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hypermobility connective tissue disorders: 5-year follow-up after craniocervical reduction, fusion, and stabilization","volume":"42","author":"Henderson","year":"2019","journal-title":"Neurosurg Rev"},{"key":"R4-20240904","doi-asserted-by":"crossref","first-page":"601","DOI":"10.3171\/SPI-07\/12\/601","article-title":"Syndrome of occipitoatlantoaxial hypermobility, cranial settling, and chiari malformation type I in patients with hereditary disorders of connective tissue","volume":"7","author":"Milhorat","year":"2007","journal-title":"J Neurosurg Spine"},{"key":"R5-20240904","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1016\/j.nec.2015.06.011","article-title":"Ventral decompression in chiari malformation, basilar invagination, and related disorders","volume":"26","author":"Ridder","year":"2015","journal-title":"Neurosurg Clin N Am"},{"key":"R6-20240904","doi-asserted-by":"crossref","first-page":"e546","DOI":"10.1016\/j.wneu.2022.02.068","article-title":"Craniocervical 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angle is associated with clinical improvement in children undergoing occipitocervical fusion for complex Chiari malformation: Patient series","volume":"2","author":"Marianayagam","year":"2021","journal-title":"J Neurosurg Case Lessons"},{"key":"R10-20240904","doi-asserted-by":"crossref","first-page":"103","DOI":"10.4103\/jcvjs.jcvjs_55_21","article-title":"Indicators of atlantoaxial instability","volume":"12","author":"Goel","year":"2021","journal-title":"J Craniovertebr Junction Spine"},{"key":"R11-20240904","doi-asserted-by":"crossref","first-page":"116","DOI":"10.3171\/2014.10.SPINE14176","article-title":"Is atlantoaxial instability the cause of Chiari malformation?Outcome analysis of 65 patients treated by atlantoaxial fixation","volume":"22","author":"Goel","year":"2015","journal-title":"J Neurosurg Spine"},{"key":"R12-20240904","doi-asserted-by":"crossref","first-page":"100221","DOI":"10.1016\/j.wnsx.2023.100221","article-title":"Treatment of Chiari malformations with craniovertebral junction anomalies: Where do we stand today?","volume":"20","author":"Vazquez","year":"2023","journal-title":"World Neurosurg X"},{"key":"R13-20240904","doi-asserted-by":"crossref","first-page":"820","DOI":"10.3171\/2015.3.SPINE15233","article-title":"Chiari malformation Type 1 and atlantoaxial instability: A letter from the Pediatric Craniocervical Society","volume":"23","author":"Brockmeyer","year":"2015","journal-title":"J Neurosurg Spine"},{"key":"R14-20240904","doi-asserted-by":"crossref","first-page":"1553","DOI":"10.1007\/s00701-020-04429-z","article-title":"Chiari malformation type I and basilar invagination originating from atlantoaxial instability: a literature review and critical analysis","volume":"162","author":"Wagner","year":"2020","journal-title":"Acta Neurochir (Wien)"},{"key":"R15-20240904","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1007\/978-3-319-62515-7_15","article-title":"Atlantoaxial fixation for treatment of Chiari formation and 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Plast Surg"},{"key":"R24-20240904","doi-asserted-by":"crossref","first-page":"S201","DOI":"10.1097\/SAP.0000000000003176","article-title":"Myofascial flap closure decreases complications in complex surgery of the craniocervical junction in Ehlers-Danlos patients","volume":"88","author":"Norman","year":"2022","journal-title":"Ann Plast Surg"},{"key":"R25-20240904","doi-asserted-by":"crossref","first-page":"30","DOI":"10.4103\/2152-7806.66461","article-title":"Deformative stress associated with an abnormal clivo-axial angle: A finite element analysis","volume":"1","author":"Henderson","year":"2010","journal-title":"Surg Neurol Int"},{"key":"R26-20240904","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1007\/s10143-017-0830-3","article-title":"Utility of the clivo-axial angle in assessing brainstem deformity: Pilot study and literature review","volume":"41","author":"Henderson","year":"2018","journal-title":"Neurosurg 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Spine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.ovid.com\/10.4103\/jcvjs.jcvjs_59_23","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T16:52:21Z","timestamp":1787763141000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ovid.com\/10.4103\/jcvjs.jcvjs_59_23"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,10]]},"references-count":27,"journal-issue":{"issue":"4","published-print":{"date-parts":[[2023]]}},"URL":"https:\/\/doi.org\/10.4103\/jcvjs.jcvjs_59_23","relation":{},"ISSN":["0974-8237","0976-9285"],"issn-type":[{"value":"0974-8237","type":"print"},{"value":"0976-9285","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,10]]},"assertion":[{"value":"2023-05-31","name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2023-08-21","name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}}]}}