C2-fractures: part II. A morphometrical analysis of computerized atlantoaxial motion, anatomical alignment and related clinical outcomes

Abstract

Knowledge on the outcome of C2-fractures is founded on heterogenous samples with cross-sectional outcome assessment focusing on union rates, complications and technical concerns related to surgical treatment. Reproducible clinical and functional outcome assessments are scant. Validated generic and disease specific outcome measures were rarely applied. Therefore, the aim of the current study is to investigate the radiographic, functional and clinical outcome of a patient sample with C2-fractures. Out of a consecutive series of 121 patients with C2 fractures, 44 met strict inclusion criteria and 35 patients with C2-fractures treated either nonsurgically or surgically with motion-preserving techniques were surveyed. Outcome analysis included validated measures (SF-36, NPDI, CSOQ), and a functional CT-scanning protocol for the evaluation of C1-2 rotation and alignment. Mean followup was 64 months and mean age of patients was 52 years. Classification of C2-fractures at injury was performed using a detailed morphological description: 24 patients had odontoid fractures type II or III, 18 patients had fracture patterns involving the vertebral body and 11 included a dislocated or a burst lateral mass fracture. Thirty-one percent of patients were treated with a halo, 34% with a Philadelphia collar and 34% had anterior odontoid screw fixation. At follow-up mean atlantoaxial rotation in left and right head position was 20.2°and 20.6°, respectively. According to the classification system of posttreatment C2-alignment established by our group in part I of the C2-fracture study project, mean malunion score was 2.8 points. In 49% of patients the fractures healed in anatomical shape or with mild malalignment. In 51% fractures healed with moderate or severe malalignment. Self-rated outcome was excellent or good in 65% of patients and moderate or poor in 35%. The raw data of varying nuances allow for comparison in future benchmark studies and metaanalysis. Detailed investigation of C2-fracture morphology, posttreatment C2-alignment and atlantoaxial rotation allowed a unique outcome analysis that focused on the identification of risk factors for poor outcome and the interdependencies of outcome variables that should be addressed in studies on C2-fractures. We recognized that reduced rotation of C1-2 per se was not a concern for the patients. However, patients with worse clinical outcomes had reduced total neck rotation and rotation C1-2. In turn, C2-fractures, especially fractures affecting the lateral mass that healed with atlantoaxial deformity and malunion, had higher incidence of atlantoaxial degeneration and osteoarthritis. Patients with increased severity of C2-malunion and Electronic supplementary material The online version of this article

Pooled Analysis of Non-Union, Re-Operation, Infection, and Approach Related Complications after Anterior Odontoid Screw Fixation

“…Six studies [21], [52], [61], [72], [74], [75] were excluded from data synthesizing because of potential patients overlapping. Imaging methods used for fusion assessment included radiograph (static and/or dynamic) and CT scan.…”

Unstable atlas fracture treatment by anterior plate C1-ring osteosynthesis using a transoral approach

“…By reconstructing C1-C2 congruency, important joint motion is preserved while late sequelae from malunion are prevented [40][41][42]. Whether an MRIproven incompetency of the transverse atlantal ligament is a contraindication for C1-ring osteosynthesis (thereby indicating fusion of C1-C2 to prevent late translational instability) has not been thoroughly investigated, although studies indicate that C1-ring osteosynthesis restores sufficient stability at C1-C2 to prevent significant translation under physiologic loads [37,39].…”

Unstable Jefferson fractures: Results of transoral osteosynthesis

“…Definitive fusion was identified by the formation of bridging bone across the fracture. The rotational capacity of the C 1 -C 2 joints was measured by functional CT scans in the supine position as described by Koller et al 12. and patients were treated with therapy focusing on restoring rotation.…”