title: Migration of titanium cable into spinal cord and spontaneous C2 and C3 fusion: Case report of possible causes of fatigue failure after posterior atlantoaxial fixation.
abstract: BACKGROUND
  Atlantoaxial instability is a common and serious injury of the upper cervical spine. Brooks' procedure is widely used to reconstruct the unstable atlantoaxial joint. The migration into spinal cord of titanium cable and spontaneous fusion between C2 and C3 has been little reported and the management of such a patient is difficult. We describe an unusual case of fatigue failure of posterior titanium atlantoaxial cable fixation with migration into the spinal cord and spontaneous fusion between C2 and C3.
  
  
  METHODS
  A 16-year-old girl complained of cervico-occipital pain with numbness and weakness of extremities 3 months ago. The girl underwent posterior C1-C2 arthrodesis with titanium cables and autogenous iliac crest bone grafting when she was 6 years old. When presented to our emergency department, imaging revealed the cracked titanium atlantoaxial cable and the spontaneous fusion between C2 and C3. Computed tomography demonstrated a broken wire with anterior migration of the cable into the spinal cord. The patient underwent posterior approach cervical spinal surgery to remove the broken cables. She remains neurologically intact a year following the posterior approach cervical spine surgery.
  
  
  CONCLUSIONS
  Brooks' posterior stabilization could not effectively control rotation at the atlantoaxial articulation, so surgeons must be aware of the potential of fatigue failure of cables as well as the possibility of its migration into the spinal cord when using Brooks' posterior stabilization. Bilateral C1 lateral mass and C2 pedicle screw fixation or transarticular screw fixation are recommended by the authors in the event of rotatory instability.
authors.affiliation: Department of Orthopedics, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Huibo
authors.initials: H
authors.lastname: Li
authors.forename: Jigang
authors.initials: J
authors.lastname: Lou
authors.forename: Hao
authors.initials: H
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D001268:Atlanto-Axial Joint; D001368:Axis, Cervical Vertebra; D005260:Female; D005547:Foreign Bodies / Q000000981:diagnostic imaging*; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects*; D007593:Joint Instability / Q000601:surgery*; D011475:Prosthesis Failure / Q000009:adverse effects* / Q000209:etiology; D013116:Spinal Cord / Q000000981:diagnostic imaging*; D013123:Spinal Fusion; D014057:Tomography, X-Ray Computed