title: Evaluation of the Efficacy of Titanium Mesh Cages with Posterior C1 Lateral Mass and C2 Pedicle Screw Fixation in Patients with Atlantoaxial Instability.
abstract: BACKGROUND
  Atlantoaxial fusion is a surgical technique that is performed for the treatment of atlantoaxial instability. The standard surgical procedure is fixation of the atlantoaxial complex via a C1 lateral mass and C2 pedicle screw with posterior wiring. Bone grafting material may still be biomechanically suboptimal, such as autologous bone obtained from osteoporotic patients, and may result in collapse and loosening of posterior wiring.
  
  
  METHODS
  Fourteen patients with C1 lateral mass and C2 pedicle fixation as a result of atlantoaxial instability were included in this study. All patients were treated by a single surgeon using a titanium mesh cage with demineralized bone matrix packing. Patient clinical history, imaging data, and medical records were reviewed. To evaluate bony fusion, measurement of the atlantodental interval and computed tomography were performed in the preoperative period, immediate postoperative period, and at 1, 3, 6, and 12 months postoperatively. The Wilcoxon signed-rank test was used to compare differences in the radiologic evaluation at 1 and 12 months postoperatively.
  
  
  RESULTS
  Bone fusion was achieved in all patients (100%). Of the 14 patients, 11 had rheumatoid arthritis and 3 had trauma. The mean atlantodental interval of patients with rheumatoid arthritis was 1.85 mm in the immediate postoperative period, 1.96 mm at 1 month postoperatively, 1.98 mm at 3 months postoperatively, 1.96 mm at 6 months, and 1.93 mm at 12 months. Hardware failure and other complications were not observed.
  
  
  CONCLUSIONS
  The titanium mesh cage has several advantages compared with bone autografts, including reduced donor-site morbidity, immediate rigid fixation, and successful bone fusion.
authors.affiliation: Department of Neurosurgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Republic of Korea.
authors.forename: Je Il
authors.initials: JI
authors.lastname: Ryu
authors.affiliation: Department of Neurosurgery, Hanyang University Seoul Hospital, Hanyang University College of Medicine, Sungdong-gu, Seoul, Republic of Korea.
authors.forename: Koang Hum
authors.initials: KH
authors.lastname: Bak
authors.affiliation: Department of Neurosurgery, Hanyang University Seoul Hospital, Hanyang University College of Medicine, Sungdong-gu, Seoul, Republic of Korea.
authors.forename: Hyoung-Joong
authors.initials: HJ
authors.lastname: Yi
authors.affiliation: Department of Neurosurgery, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Republic of Korea.
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Hanyang University Seoul Hospital, Hanyang University College of Medicine, Sungdong-gu, Seoul, Republic of Korea. Electronic address: tdy815@hanyang.ac.kr.
authors.forename: Hyoung-Joon
authors.initials: HJ
authors.lastname: Chun
mesh_terms: D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging / Q000601:surgery*; D001860:Bone Plates; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws; D011474:Prosthesis Design; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000295:instrumentation* / Q000379:methods; D013526:Surgical Mesh; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D014025:Titanium
keywords: Atlantoaxial instability; Autologous iliac bone graft; C1 lateral mass; C2 pedicle screw; Titanium mesh cage