The odontoid process fracture (also known as the PEG or dens fracture) occurs where there is a fracture through the odontoid process of C2.
Odontoid fractures are the most common geriatric cervical spine fractures.
The commonest classification of these fractures is the Anderson D'Alonzo classification:
type I: fracture of the upper part of the odontoid peg; it's rare and potentially unstable
persistent ossiculum terminale
Nonunion rates have been reported to be up to 40% and mortality up to 35%, and poor functional outcomes are common.
Atlantoaxial instability (AAI) may be more likely to experience nonunion and mortality, suggesting the possibility that aggressive management could be warranted. Further investigation with a large prospective study including patient-important functional outcomes is justified 1).
prospectively evaluated sixty-nine consecutive patients who presented to our institution with a dens fracture. The mean duration of follow-up was 9.7 months (range, six to fifty-eight months). Fractures were categorized as stable or unstable. Stable fractures were treated by immobilization in a rigid collar. Patients seventy-five years or older with unstable fractures, patients with a neurological deficit, and patients with Anderson and D'Alonzo type-III fractures underwent posterior transarticular C1-C2 stabilization. Unstable fractures in patients younger than seventy-five years were stabilized with direct anterior screw fixation. Thirty-one patients were treated with a Philadelphia collar, twenty-five with posterior transarticular fixation, and thirteen with direct anterior screw fixation. RESULTS: Fracture-healing or solid fusion of C1-C2 was documented in sixty-eight of sixty-nine treated patients at final follow-up. The remaining patient had a stable nonunion of the dens. Secondary procedures were performed in five patients. CONCLUSIONS: Our treatment algorithm based on dens fracture type, fracture stability, and patient age was associated with a high success rate. Evaluating fracture stability is crucial when considering nonoperative treatment. External stabilization with a rigid cervical collar was adequate for stable fractures of the dens and was associated with a high healing rate. Posterior transarticular screw fixation of C1-C2 was associated with a high success rate, including in elderly patients. LEVEL OF EVIDENCE: Therapeutic Level III 2).
From April 1997 to December 2008, we treated a total of 60 patients with upper cervical spine injuries. This study included 31 (51.7%) patients (22 men, 9 women; mean age, 39.3 years) with types II and III odontoid process fractures. The average follow-up was 25.1 months. We reviewed digital radiographs and analyzed images according to type of injury and treatment outcomes, following conservative treatment with HVI and surgical management with screw fixation. RESULTS: There were a total of 31 cases of types II and III odontoid process fractures (21 odontoid type II fractures, 10 type III fractures). Fifteen patients underwent HVI (10 type II fractures, 5 type III fractures). Nine (60%) out of 15 patients who underwent HVI experienced successful healing of odontoid fractures. The mean period for bone healing was 20.2 weeks. Sixteen patients underwent surgery including anterior screw fixation (6 cases), posterior C1-2 screw fixation (8), and transarticular screw fixation (2) for healing the odontoid fractures (11 type II fractures, 5 type III fractures). Fifteen (93.8%) out of 16 patients who underwent surgery achieved healing of cervical fractures. The average bone healing time was 17.6 weeks. CONCLUSION: The overall healing rate was 60% after HVI and 93.8% with surgical management. Patients treated with surgery showed a higher fusion rate and shorter bony healing time than patients who received HVI. However, prospective studies are needed in the future to define better optimal treatment and cost-effective perspective for the treatment of odontoid fractures 3).
Henry et al. reviewed 81 patients with fractures of the odontoid process treated between May 1983 and July 1997, by anterior screw fixation. There were 29 patients with Anderson and D'Alonzo type-II fractures and 52 with type III. Roy-Camille's classification identified the direction and instability of the fracture. Operative fixation was carried out on 48 men and 33 women with a mean age of 57 years. Associated injuries of the cervical spine were present in 15 patients, neurological signs in 13, and 18 had an Injury Severity Score of more than 15. Nine patients died and 11 were lost to follow-up. Of 61 patients, 56 (92%) achieved bony union at an average of 14.1 weeks. Two patients required a secondary posterior fusion after failure of the index operation. A full range of movement was restored in 43 patients; only six had a limitation of movement greater than 25%. We conclude that anterior screw fixation is effective and practicable in the treatment of fractures of the dens 4).