C2 (Axis) Fractures Treatment & Management

Updated: Apr 07, 2022
  • Author: Igor Boyarsky, DO, FACEP, FAAEM; Chief Editor: Jeffrey A Goldstein, MD  more...
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Nonoperative vs Operative Treatment

Odontoid fractures

Treatment for type I C2 (axis) fractures is hard-collar immobilization for 6-8 weeks, which usually is quite successful.

Type II fractures can be managed conservatively or surgically. Treatment options include the following:

  • Halo immobilization
  • Internal fixation (odontoid screw fixation) [11]
  • Posterior atlantoaxial arthrodesis

Arthrodesis can be accomplished by C1-C2 transarticular screw fixation, interlaminar clamps, or wiring techniques such as the Gallie or the Brooks method. [12, 13, 3, 14]

Management with the halo vest usually is considered if the initial dens displacement is less than 5 mm, the reduction is performed within 1 week of the injury and is able to be maintained, and the patient is younger than 60 years. During immobilization, alignment is assessed to ensure that reduction is maintained. Displacement of less than 20% is acceptable. The halo vest is in place for 12-16 weeks and the fusion rate is over 90%. [15]

Wiring techniques, such as Gallie or Brooks methods, offer a high fusion rate (~95%); however, the posterior arch needs to be intact and a halo vest must be worn postoperatively. Transarticular screw fixation provides a high fusion rate and the posterior arch need not be intact. Although posterior surgical fusion techniques provide high fusion success rates, they do so at the expense of cervical rotation. Generally, up to 50% of rotation is lost with these techniques.

Nonunion, malunion, and pseudarthrosis formation are potential major complications. Factors affecting this are amount and position of displacement, degree of angulation, ability to obtain and hold a reduced fracture, age of the patient, and tolerance to halo immobilization. However, some reports have demonstrated nonunion rates approaching 80% in certain subsets of patients. Shilpakar et al looked at all treatment options and associated rates of complications. [16]  On the basis of a meta-analysis of previously published studies, they concluded that type II fractures are best managed with odontoid screw fixation.

Anterior odontoid single screw fixation is noted to preserve normal rotation at C1-C2, provide immediate stability, and obviate the need for postoperative halo immobilization. Furthermore, rates of malunion, nonunion, and pseudarthrosis formation are very low. There are limitations to this approach, namely, the age of the fracture and the patient's body habitus. If the fracture is older than 4 weeks or if the patient possesses a short neck and barrel-shaped chest, consider an alternative treatment approach, such as transarticular screw fixation or Brooks sublaminar fusion.

There has been some controversy regarding operative versus nonoperative management of type II fractures. Vaccaro et al, in a study of 159 elderly patients with type II dens fractures, reported a significant benefit with surgical treatment and recommended that elderly patients with such fractures who are healthy enough for general anesthesia be considered for surgical stabilization. [17]

The investigators from the AOSpine North America Geriatric Odontoid Fracture Mortality Study did not find operative treatment of type II fractures to have a negative impact on survival in 322 elderly patients with type II fractures, even after age, sex, and comorbidities had been adjusted for. [18]  In this study, operative treatment had a significant advantage in 30-day survival advantage, and a trend toward improved longer-term survival was noted.

Paolo et al examined 108 consecutive type II fractures, of which 60 were conservatively treated with external immobilization and 48 surgically treated . [19]  They concluded that all odontoid fractures without dislocation should be treated with rigid external immobilization and that all odontoid fractures with dens dislocation exceeding 5 mm should be considered for surgery. They further suggested that type II fractures in patients older than 50 years should also be considered for surgery; outcomes with conservative treatment are better for patients younger than 50 years.

Type III fractures are treated with halo immobilization, odontoid screw fixation, or C1-C2 arthrodesis. Deep, displaced, or angulated fractures are treated with closed reduction and halo thoracic immobilization. Uncomplicated shallow type III fractures are treated with odontoid screw fixation. Nonunion and malunion are potential complications. The vertical type of odontoid process fractures is addressed in the treatment section on traumatic spondylolisthesis.

A prospective, controlled study (N = 42) evaluated the safety and efficacy of percutaneous anterior screw fixation versus open screw fixation for type II and rostral type III odontoid fractures. [20] Clinical and radiographic resultsshowed significantly less operating time and less blood loss in the percutaneous anterior screw fixation group. Both groups experienced satisfactory bony union, similar radiation time, and clinical outcome, and no evidence of abnormal movement at the fracture site was noted. These data suggest that percutaneous anterior screw fixation may be a safe and reliable alternative with potential advantages for treatment of type II and rostral type III odontoid fractures.

Another study evaluated the outcomes after anterior screw fixation of type II and rostral shallow type III fractures. The study found that the risk of fusion failure was 37.5 times greater in patients in whom surgery was delayed for more than 1 week and 21 times greater in patients with a fracture gap of greater than 2 mm. [21]

Lateral mass fractures

Treatment ranges from collar immobilization for uncomplicated minimally depressed fractures to cervical traction followed by halo immobilization for more extensive fractures. Complications secondary to posttraumatic degenerative changes may eventually warrant atlantoaxial arthrodesis.

Extension teardrop fractures

Treatment of these fractures is cervical orthosis, unless more aggressive measures are needed to secure a concomitant unstable fracture.

Traumatic spondylolisthesis

Treatment of type I fractures usually is with a Philadelphia collar or halo.

Several treatment options are available for type II fractures, the first being conservative external fixation with halo or tong traction in weighted extension for 1 week. If reduction is acceptable (with less than 4 mm of displacement and less than 10º of angulation), treatment progresses with halo-vest immobilization for 12-16 weeks. If reduction is unacceptable, weighted extension traction resumes for up to 6 weeks, followed by halo treatment for 6 weeks. If adequate results are not achieved after closed reduction and traction, open reduction with anterior cervical plating is the next step.

The other surgical treatment option consists of weighted extension traction to accomplish adequate reduction, followed by internal fixation with a C2 transpedicular screw. Conservative and surgical treatments typically yield excellent results. [11, 15]

Treatment options for type IIA fractures include both conservative and surgical measures. Conservative treatment consists of closed reduction that is obtained under fluoroscopic guidance via application of compression and extension and is followed by halo-vest immobilization. Repeated imaging is used to monitor the healing process with a variable time course. Surgical options include C2 transpedicular screws and anterior cervical plating. Conservative and surgical treatments typically yield very good results. Malunion is a potential complication.

For type III fractures, surgery is indicated if the fracture line extends anteriorly to the facet dislocation, at the level of the dislocation, or just posterior to it. Any of these locations make reduction unlikely secondary to instability. In this case, surgical reduction and stabilization is mandated and is accomplished with lateral mass plates, interspinous wiring, or bilateral oblique wiring. Once accomplished, bilateral pedicle fractures can be addressed with C2 transpedicular screws, or treated conservatively with traction or a halo/vest. Lateral mass plating of C2 by placing lateral mass screws in C3 in conjunction with C2 transpedicular screws may make postoperative halo immobilization unnecessary.

Atypical traumatic spondylolisthesis fractures are managed on a case-by-case basis, weighing the need for more aggressive stabilization against the likelihood of fragment dislodgment and subsequent spinal cord injury. Surgical treatment options for these fractures include C2 transpedicular screw fixation along with odontoid screw fixation.

For all types of traumatic spondylolisthesis fractures, nonunion and malunion are the major complications of nonoperative treatment, but, fortunately, these are rare occurrences.

In March 2022, the American College of Surgeons (ACS) published guidelines on management of spine injuries. [22]



Complications of C2 fracture treatment include nonunion, malunion, pseudoarthrosis formation, infection, neurovascular injury, acute airway compromise, and hardware failure.

The risks of nonunion, malunion, and pseudoarthrosis formation are lessened with surgical treatment. [23]

As with any surgical procedure, risk of infection always exists. Osteomyelitis is a rare, but not unknown, complication. Some authors recommend the use of prophylactic antibiotics for up to 72 hours following surgery, and continuation if there is evidence of an infection.

Neurovascular injury is a risk associated with any surgical intervention and is a function of both surgical acumen and anatomic variability.

Airway compromise is a risk associated with any anterior surgical approach, and prolonged endotracheal intubation may be necessary.

Common hardware failures include screw bending and breaking, loosening of implants, and hardware failure secondary to osteoporotic bone.