title: Comparison of fusion rates between rod-based laminar claw hook and posterior cervical screw constructs in Type II odontoid fractures.
abstract: BACKGROUND
  This study was aimed (i) to compare the fusion rates of rod-based laminar claw hook constructs to that of posterior C1/C2 screw constructs in odontoid fractures, and (ii) to evaluate any complications associated with claw hook/rod constructs. To our knowledge, no study in contemporary literature has presented the effects of using modern rod-based laminar claw hooks for treating odontoid fractures. Unlike laminar clamps from the 1980s, contemporary laminar hook-rod instrumentation systems provide better immobilisation of the cervical spine and allows for building reliable frame-like constructs similar to cervical screw-rod systems.
  
  
  METHODS
  A retrospective review of a series of 167 consecutive odontoid fractures from a single-institution was conducted. 30 cases from the series were treated using posterior atlantoaxial fusion, 12 using C1/C2 posterior screws (control group), and 18 with rod-based laminar claw hooks (study group). Hooks were mounted bilaterally in a claw manner on each individual lamina and were rigidly fixed to perpendicular rods with a transverse connector whenever feasible. The minimum follow-up period was one year. Bony union was determined using computed tomography (CT) scan, while stability at the fusion site was assessed using dynamic radiograms.
  
  
  RESULTS
  The study group had an overall fusion rate of 89% (non-geriatric 93% while geriatric subgroup 75%) with a 100% stability rate at the fusion site in all cases. In the control group fusion rate was 100%. There were no major complications in both control and study groups. Four minor complications, three in the control and one in the study group, were noted in 3 patients.
  
  
  CONCLUSIONS
  Preliminary results of this study suggest that laminar claw hook-rod systems are useful alternatives to posterior screw techniques. Moreover, the fusion rate in non-geriatric patients is comparable to that of posterior screws. Importantly, they are devoid of the disadvantages and complications posed by screw constructs. Further studies are necessary to confirm these promising results.
authors: Department of Neurosurgery, St Luke Hospital, Tarnow, Poland; Faculty of Medicine, University of Rzeszow, Rzeszow Poland. Electronic address: amac@mp.pl.
authors: Andrzej
authors: A
authors: Maciejczak
authors: Faculty of Medicine, University of Rzeszow, Rzeszow Poland.
authors: Andzelina
authors: A
authors: Wolan-Nieroda
authors: Faculty of Medicine, University of Rzeszow, Rzeszow Poland.
authors: Katarzyna
authors: K
authors: Jabłońska-Sudoł
mesh_terms: D001696:Biomechanical Phenomena; D001863:Bone Screws; D006801:Humans; D009809:Odontoid Process / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery*; D009984:Orthopedic Fixation Devices; D011859:Radiography; D016059:Range of Motion, Articular; D012189:Retrospective Studies; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods*; D016896:Treatment Outcome
keywords: Atlantoaxial fusion; Claw hook fixation; Odontoid fractures; Odontoid screw