title: Novel treatment of basilar invagination resulting from an untreated C-1 fracture associated with transverse ligament avulsion. Case report and description of surgical technique.
abstract: The authors describe the case of a traumatic C-1 ring fracture and transverse ligament injury in an otherwise healthy adult woman; the lesion was essentially untreated for 3 months and resulted in basilar invagination. On presentation 3 months postinjury, the patient complained of severe increasing suboccipital pain and a grinding sensation in her upper neck. Axial computerized tomography (CT) scans revealed a C-1 ring fracture, basilar invagination with the dens abutting the clivus, and significant lateral splaying of the C-1 lateral masses. Flexion-extension radiography demonstrated abnormal motion at the atlantoaxial junction. A unique surgical technique was used to address simultaneously the C1-2 instability, the displaced C-1 fracture, and basilar invagination without having to perform occipital fixation. The authors believe that an understanding of the mechanism of the cranial settling in this case (further splaying of the C-1 lateral masses and downward migration of the occipital condyles) permitted full reduction of the deformity; this was accomplished by performing a horizontal reduction of the C-1 lateral masses, using direct C-1 lateral mass screws, a rod compressor, and a cross-link. Postoperative CT scanning confirmed the success of reduction. The results in this report highlight a rare but important complication of untreated C-1 fracture and ligament disruption, and the authors describe a novel treatment technique with which to restore vertical alignment and preserve occipital C-1 motion. A variation of this technique may also be used to treat Type II transverse ligament injuries associated with C-1 ring fractures as an alternative to halo immobilization.
authors.affiliation: Department of Neurological Surgery, University of California at San Francisco, California 94122, USA. AmesC@neurosurg.ucsf.edu
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Ames
authors.forename: Frank
authors.initials: F
authors.lastname: Acosta
authors.forename: Eric
authors.initials: E
authors.lastname: Nottmeier
mesh_terms: D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D002574:Cervical Vertebrae / Q000293:injuries* / Q000601:surgery*; D005260:Female; D005592:Fracture Fixation / Q000379:methods*; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008022:Ligaments / Q000000981:diagnostic imaging / Q000293:injuries* / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D019838:Neck Injuries / Q000150:complications / Q000175:diagnosis; D013536:Suture Techniques; D014057:Tomography, X-Ray Computed