Patient head and neck position need to be considered in the context of anaesthesia, fracture reduction, and steps to optimize spinal precautions. Several critical steps in odontoid fixation warrant discussion. C1-C2 fusion is often an easier procedure to perform technically, while acknowledging that the procedure significantly reduces neck motion, particularly in rotation, by about 50%. The ability to achieve proper fracture realignment, as well as the ability to achieve screw fixation that satisfactorily stabilizes the fracture adhering to AO principles in lag screw fixation, will influence surgical success. The risk of fracture non-union can be significant, particularly in some displaced Type II odontoid fractures. While odontoid screw fixation may be an attractive option to many patients presenting with Type II odontoid fractures, its practical use may be tempered by the aforementioned factors, as the procedure does present technical challenges even in experienced hands. Plain lateral (Figure 2a, top) and open-mouth odontoid AP (Figure 2b, bottom) view of the same patient 9 months after fracture reduction performed under image guidance and general anaesthesia followed by anterior odontoid screw fixation with two AO small fragment terminally threaded lag screws. Computed tomography scan coronal (Figure 1A, top) and sagittal (Figure 1B, bottom) reformatted images of a 26-year-old female with a displaced Type II odontoid fracture following a high-energy motor-vehicle accident.įigure 2. Issues relating to fracture configuration, the size of the remaining "peg" in achieving distal fixation, the need for and ease of fracture reduction, and bone density are all variables to consider in the ability to properly place screw(s) with sufficient fixation to encourage fracture healing (Figures 1 and 2).įigure 1. Patient selection in odontoid fracture care is critical.
Fracture healing rates of this procedure has been demonstrated, in observational studies, to be comparable to atlantoaxial fusion rates, with a similar complication rate between procedures, although patient numbers in these studies are small and randomized studies are lacking. Lessening or obviating the need for halo immobilization is desirable additionally, autologous bone graft harvest is not needed. The desire to maintain cervical motion following an odontoid fracture is attractive, and, thus, odontoid screw fixation has been increasingly reported. In odontoid fractures, surgical stability can be achieved by either fracture fixation of the C2 body to the odontoid process or by arthrodesis of the C1-C2 motion segment. 5,6 An overwhelming goal of surgery in spinal fracture care is to restore mechanical stability. The bimodal pattern of patient age (young or old) presenting with these injuries that result from either high- or low-energy trauma is important to consider when planning treatment. 2-4 The decision regarding whether to operate and, if so, what type of procedure to perform, is subject to much discussion. 1 The optimal treatment of Type II fractures remains controversial: The evidence suggests no standards or guidelines, but rather presents options in care. Odontoid Fractures - Anterior Odontoid Screw Fixationįractures of the odontoid account for approximately 20% of all cervical fractures, with approximately 70% being Type II fractures (ie, fracture crossing the base of the odontoid process at the junction with the axis body).
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