{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,26]],"date-time":"2026-08-26T14:35:31Z","timestamp":1787754931237,"version":"build-2784847793"},"reference-count":31,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"19","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The Journal of Bone and Joint Surgery"],"published-print":{"date-parts":[[2019,10,2]]},"abstract":"<jats:sec>\n                    <jats:title>Background:<\/jats:title>\n                    <jats:p>Treatment outcomes and risk factors for neurological deficits in pediatric patients with an os odontoideum are unclear.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods:<\/jats:title>\n                    <jats:p>We reviewed the data for 102 children with os odontoideum who were managed at 11 centers between 2000 and 2016 and had a minimum duration of follow-up of 2 years. Thirty-one children had nonoperative treatment, and 71 underwent instrumented posterior cervical spinal arthrodesis for the treatment of C1-C2 instability. Nonoperative treatment consisted of observation (n = 29) or immobilization with a cervical collar (n = 1) or halo body jacket (n = 1). Surgical treatment consisted of atlantoaxial (n = 50) or occipitocervical (n = 21) arthrodesis. One patient also underwent transoral odontoidectomy.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>Thirty children (29%) presented with neurological deficits, 28 of whom had radiographic atlantoaxial instability (atlantoaxial distance &gt;5 mm) or limited space (\u226413 mm) available for the spinal cord (risk ratio, 7.8 [95% confidence interval, 2.0 to 31] compared with children with no radiographic risk factors). The 27 children without neurological deficits or atlantoaxial instability at presentation underwent nonoperative treatment and remained asymptomatic. Of the initial nonoperative cohort, one child developed atlantoaxial instability, and another had a persistent neurological deficit; both children underwent spinal arthrodesis during the study period. One child with cervical instability declined surgery and remained asymptomatic. Spinal fusion occurred in 68 patients in the surgical group by the end of the study period (mean, 3.7 years; range, 2.0 to 11.8 years). Surgical complications occurred in 21 children, including nonunion in 12, new neurological deficits in 4, cerebrospinal fluid leak in 2, symptomatic instrumentation requiring removal 2, and vertebral artery injury in 1. Nine children underwent revision surgery. In the surgical group, Japanese Orthopaedic Association neurological function scores improved significantly from preoperatively to the latest follow-up for the upper extremities (p = 0.026) and lower extremities (p = 0.007).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions:<\/jats:title>\n                    <jats:p>The risk of developing a neurological deficit was strongly associated with atlantoaxial instability and limited space available for the spinal cord in children with os odontoideum. Nonoperative treatment was safe for asymptomatic patients without atlantoaxial instability. Spinal arthrodesis resolved the neurological deficits of children with symptomatic os odontoideum.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Level of Evidence:<\/jats:title>\n                    <jats:p>\n                      Therapeutic\n                      <jats:underline>Level III<\/jats:underline>\n                      . See Instructions for Authors for a complete description of levels of evidence.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.2106\/jbjs.19.00314","type":"journal-article","created":{"date-parts":[[2019,10,11]],"date-time":"2019-10-11T11:59:35Z","timestamp":1570795175000},"page":"1750-1760","source":"Crossref","is-referenced-by-count":25,"title":["Os Odontoideum in Children"],"prefix":"10.2106","volume":"101","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5200-3279","authenticated-orcid":false,"given":"Ilkka J.","family":"Helenius","sequence":"first","affiliation":[{"name":"Department of Paediatric Orthopaedic Surgery, Turku University Hospital, Turku, Finland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5326-8383","authenticated-orcid":false,"given":"Jennifer M.","family":"Bauer","sequence":"additional","affiliation":[{"name":"Department of Orthopedics, Seattle Children\u2019s Hospital, Seattle, Washington"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8517-7195","authenticated-orcid":false,"given":"Bram","family":"Verhofste","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Boston Children\u2019s Hospital, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2934-6374","authenticated-orcid":false,"given":"Paul D.","family":"Sponseller","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, The Johns Hopkins University, Baltimore, Maryland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3076-1703","authenticated-orcid":false,"given":"Walter F.","family":"Krengel","sequence":"additional","affiliation":[{"name":"Department of Orthopedics, Seattle Children\u2019s Hospital, Seattle, Washington"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4067-5665","authenticated-orcid":false,"given":"Daniel","family":"Hedequist","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Boston Children\u2019s Hospital, Boston, Massachusetts"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7129-1007","authenticated-orcid":false,"given":"Patrick J.","family":"Cahill","sequence":"additional","affiliation":[{"name":"Division of Orthopaedics, Children\u2019s Hospital of Philadelphia, Philadelphia, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6542-6975","authenticated-orcid":false,"given":"A. Noelle","family":"Larson","sequence":"additional","affiliation":[{"name":"Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8965-354X","authenticated-orcid":false,"given":"Joshua M.","family":"Pahys","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Shiners Hospitals for Children, Philadelphia, Pennsylvania"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2866-1500","authenticated-orcid":false,"given":"John T.","family":"Anderson","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Children\u2019s Mercy, Kansas City, Missouri"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5768-6715","authenticated-orcid":false,"given":"Jeffrey E.","family":"Martus","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery and Rehabilitation, Vanderbilt Children\u2019s Hospital, Nashville, Tennessee"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9236-2284","authenticated-orcid":false,"given":"Burt","family":"Yaszay","sequence":"additional","affiliation":[{"name":"Department of Orthopaedic Surgery, Rady Children\u2019s Hospital, San Diego, California"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0647-7630","authenticated-orcid":false,"given":"Jonathan H.","family":"Phillips","sequence":"additional","affiliation":[{"name":"Department of Pediatric Orthopedics, Arnold Palmer Hospital for Children, Orlando, Florida"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","reference":[{"issue":"3","key":"bib1-20230810","doi-asserted-by":"crossref","first-page":"376","DOI":"10.2106\/00004623-198062030-00007","article-title":"Os odontoideum","volume":"62","author":"Fielding","year":"1980","journal-title":"J Bone Joint Surg Am."},{"issue":"6","key":"bib2-20230810","doi-asserted-by":"crossref","first-page":"e2","DOI":"10.3171\/foc.1999.6.6.5","article-title":"Pathogenesis, dynamics, and management of os odontoideum","volume":"6","author":"Menezes","year":"1999","journal-title":"Neurosurg Focus."},{"issue":"9","key":"bib3-20230810","doi-asserted-by":"crossref","first-page":"979","DOI":"10.1097\/01.brs.0000214935.70868.1c","article-title":"Os odontoideum revisited: the case for a multifactorial etiology","volume":"31","author":"Sankar","year":"2006","journal-title":"Spine (Phila Pa 1976)."},{"issue":"2","key":"bib4-20230810","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1097\/01241398-199103000-00017","article-title":"Natural history of os odontoideum","volume":"11","author":"Schuler","year":"1991","journal-title":"J Pediatr Orthop."},{"issue":"4","key":"bib5-20230810","doi-asserted-by":"crossref","first-page":"422","DOI":"10.1302\/0301-620X.64B4.7096415","article-title":"The management of os odontoideum. Analysis of 37 cases","volume":"64","author":"Spierings","year":"1982","journal-title":"J Bone Joint Surg Br."},{"issue":"2","key":"bib6-20230810","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/S0090-3019(99)00184-6","article-title":"Os odontoideum: etiology, diagnosis, and management","volume":"53","author":"Dai","year":"2000","journal-title":"Surg Neurol."},{"issue":"4","key":"bib7-20230810","doi-asserted-by":"crossref","first-page":"332","DOI":"10.3171\/SPI.2008.9.10.332","article-title":"Os odontoideum: presentation, diagnosis, and treatment in a series of 78 patients","volume":"9","author":"Klimo","year":"2008","journal-title":"J Neurosurg Spine."},{"issue":"7","key":"bib8-20230810","doi-asserted-by":"crossref","first-page":"706","DOI":"10.1097\/00007632-199107000-00003","article-title":"Os odontoideum with posterior atlantoaxial instability","volume":"16","author":"Shirasaki","year":"1991","journal-title":"Spine (Phila Pa 1976)."},{"issue":"12","key":"bib9-20230810","doi-asserted-by":"crossref","first-page":"1435","DOI":"10.1097\/00007632-199606150-00007","article-title":"Atlantoaxial instability in os odontoideum with myelopathy","volume":"21","author":"Watanabe","year":"1996","journal-title":"Spine (Phila Pa 1976)."},{"issue":"6","key":"bib10-20230810","doi-asserted-by":"crossref","first-page":"1180.e1","DOI":"10.1016\/j.wneu.2014.12.036","article-title":"Acute traumatic cervical cord injury in pediatric patients with os odontoideum: a series of 6 patients","volume":"83","author":"Zhang","year":"2015","journal-title":"World Neurosurg."},{"issue":"8","key":"bib11-20230810","doi-asserted-by":"crossref","first-page":"803","DOI":"10.1007\/s00247-005-1448-0","article-title":"Os odontoideum: a significant radiographic finding","volume":"35","author":"Choit","year":"2005","journal-title":"Pediatr Radiol."},{"issue":"3","key":"bib12-20230810","doi-asserted-by":"crossref","first-page":"252","DOI":"10.1097\/00000433-199009000-00016","article-title":"Fatal high cervical spinal cord injury in an automobile accident complicating os odontoideum","volume":"11","author":"Dempster","year":"1990","journal-title":"Am J Forensic Med Pathol."},{"issue":"2","key":"bib13-20230810","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1097\/00000658-191002000-00004","article-title":"Traumatic lesions of the atlas and axis","volume":"51","author":"Mixter","year":"1910","journal-title":"Ann Surg."},{"issue":"Suppl 2","key":"bib14-20230810","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1227\/NEU.0b013e318276ee69","article-title":"Os odontoideum","volume":"72","author":"Rozzelle","year":"2013","journal-title":"Neurosurgery."},{"issue":"3","key":"bib15-20230810","first-page":"S148","article-title":"Os odontoideum","volume":"50","author":"Hadley","year":"2002","journal-title":"Neurosurgery."},{"issue":"6","key":"bib16-20230810","doi-asserted-by":"crossref","first-page":"E10","DOI":"10.3171\/2011.9.FOCUS11227","article-title":"Incidental os odontoideum: current management strategies","volume":"31","author":"Klimo","year":"2011","journal-title":"Neurosurg Focus."},{"issue":"3","key":"bib17-20230810","doi-asserted-by":"crossref","first-page":"279","DOI":"10.2106\/00004623-197860030-00001","article-title":"Atlanto-axial arthrodesis by the wedge compression method","volume":"60","author":"Brooks","year":"1978","journal-title":"J Bone Joint Surg Am."},{"issue":"6","key":"bib18-20230810","doi-asserted-by":"crossref","first-page":"529","DOI":"10.3171\/2009.2.PEDS08149","article-title":"Screw fixation of the upper cervical spine in the pediatric population. Clinical article","volume":"3","author":"Haque","year":"2009","journal-title":"J Neurosurg Pediatr."},{"issue":"10","key":"bib19-20230810","doi-asserted-by":"crossref","first-page":"1265","DOI":"10.1007\/s00701-009-0277-6","article-title":"Reducible and irreducible os odontoideum in childhood treated with posterior wiring, instrumentation and fusion. Past or present?","volume":"151","author":"Visocchi","year":"2009","journal-title":"Acta Neurochir (Wien)."},{"issue":"21","key":"bib20-20230810","doi-asserted-by":"crossref","first-page":"1839","DOI":"10.1097\/BRS.0b013e3182578fd8","article-title":"Surgical management of symptomatic os odontoideum with posterior screw fixation performed using the Magerl and Harms techniques with intraoperative 3-dimensional fluoroscopy-based navigation","volume":"37","author":"Weng","year":"2012","journal-title":"Spine (Phila Pa 1976)."},{"issue":"5","key":"bib21-20230810","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1227\/NEU.0000000000000668","article-title":"Craniocervical instability in the setting of os odontoideum: assessment of cause, presentation, and surgical outcomes in a series of 279 cases","volume":"76","author":"Zhao","year":"2015","journal-title":"Neurosurgery."},{"issue":"7","key":"bib22-20230810","doi-asserted-by":"crossref","first-page":"695","DOI":"10.1097\/00007632-199107000-00001","article-title":"Fusion of the upper cervical spine in children and adolescents. 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