title: Occipitocervical fusion with relief of odontoid invagination: atlantoaxial distraction method using cylindrical titanium cage for basilar invagination--case report.
abstract: A 65-year-old woman presented with basilar invagination manifesting as neck pain, dysesthesia around the lips, and truncal ataxia. The radiological findings demonstrated invagination of the odontoid process into the medulla oblongata and vertical atlantoaxial subluxation with C1 assimilation. The clivo-axial angle was 88° and the cervicomedullary angle was 115°, indicating severe basilar invagination. We planned occipitocervical fusion with atlantoaxial distraction using a cylindrical titanium cage. C2 pedicle screws were inserted, and the atlantoaxial joint was opened to translocate the odontoid process downward. A cylindrical titanium cage packed with local bone graft was inserted into the opened facet joint space. Occipital-C2 fusion was completed by fastening the occipital bone plates with pedicle screws using titanium rods. Postoperatively, the apex of the odontoid process descended by 7 mm, and the clivo-axial and cervicomedullary angles opened to 112° and 125°, respectively. Invagination of the odontoid process into the medulla oblongata was relieved. The preoperative symptoms improved, and she remained symptom-free without requiring anterior decompression over 2 years. Bone fusion of the atlantoaxial joints was completed with sustained facet distraction 12 months after the surgery, and adequate relief of the basilar invagination was maintained. The atlantoaxial distraction method using a cylindrical titanium cage can be a useful option in posterior fusion surgery for basilar invagination.
authors.affiliation: Department of Neurosurgery, Yokohama City University Graduate School of Medical Sciences, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Kanawaga, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Yoshizumi
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Murata
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Ikenishi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Sato
authors.forename: Hajime
authors.initials: H
authors.lastname: Takase
authors.forename: Kensuke
authors.initials: K
authors.lastname: Tateishi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nakanowatari
authors.forename: Jun
authors.initials: J
authors.lastname: Suenaga
authors.forename: Nobutaka
authors.initials: N
authors.lastname: Kawahara
mesh_terms: D000368:Aged; D001860:Bone Plates; D001863:Bone Screws; D019299:Decompression, Surgical / Q000379:methods; D005260:Female; D006801:Humans; D009777:Occipital Bone / Q000601:surgery*; D019736:Prostheses and Implants; D019651:Plastic Surgery Procedures; D013116:Spinal Cord / Q000473:pathology*; D013123:Spinal Fusion; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D014025:Titanium