Type II odontoid fracture with complete posterior dens displacement: Manual reduction and anterior screw fixation

Abstract

Background:

Type II odontoid fractures with significant dens displacement are frequently treated with surgical fixation, most commonly through posterior cervical approaches. However, extensive posterior soft tissue injury may limit the feasibility of posterior fixation and require alternative anterior odontoid fixation.

Case Description:

A 61-year-old male sustained a type IIA odontoid fracture with complete posterior dens displacement following an electrical burn injury and fall. Extensive burns involving the posterior neck/back precluded posterior cervical fixation (i.e., high risk of infection and wound complications). Following manual reduction, a single anterior odontoid screw was placed for C1/C2 stabilization. Postoperative imaging demonstrated appropriate screw positioning and restoration of the atlantoaxial alignment complex with preservation of transverse ligament integrity.

Conclusion:

Anterior odontoid screw fixation provided effective C1-C2 stabilization in this 61-year-old male with a type II odontoid fracture where posterior fixation was contraindicated due to severe burns to the posterior cervical region.

INTRODUCTION

Type II odontoid fractures are associated with significant cervical instability and a high risk of nonunion.[1-3] Operative options include posterior cervical fusion with or without supplemental screw fixation, or anterior odontoid screw fixation (AOSF) when the fracture orientation is favorable (transverse/horizontal), the transverse ligament is intact, and reduction is achievable.[4,5,7,8] Here, we report a 61-year-old male with extensive posterior cervical burns who successfully underwent AOSF to achieve C1-C2 fusion.

CASE DESCRIPTION

A 61-year-old male sustained a posterior cervical electrical burn followed by a fall. He sustained a significant posterior scalp laceration accompanied by second-degree burns involving the posterior neck, back, buttocks, and right flank (20% total body surface area). On neurological exam, he exhibited a significant right-sided hemiplegia (i.e., 1/5 right upper and right lower extremity weakness). The cervical computed tomography (CT) scan demonstrated a transverse type II odontoid fracture, 100% posterior dense displacement, and atlantoaxial dislocation with locked lateral masses [Figure 1]. Notably, the cervical MRI confirmed transverse ligament integrity. Given the extent of posterior cervical burns, posterior cervical fixation was precluded, and AOSF was chosen for C1-C2 stabilization.

Figure 1:

Type II odontoid fracture with posterior displacement of the dense. (A) Sagittal cervical spine computed tomography reconstruction demonstrating a transverse type II odontoid fracture at the base of the dens with 100% posterior displacement of the dens. (B) Coronal reconstruction showing atlantoaxial dislocation with the C1 lateral masses completely locked over C2, consistent with locked faces and posteriorly displaced dense.

Surgery

A left-sided anterior cervical approach was chosen to access the upper cervical spine. Utilizing both O-Arm navigation system and intraoperative fluoroscopy, a pilot hole was created at the anterior border of the C2 inferior endplate. A guidewire was advanced, and a 38-mm partially threaded odontoid screw was placed over the wire [Figure 2]. The procedure was completed without incident, and the postoperative CT scan confirmed appropriate odontoid screw positioning (i.e., with minimal residual posterior dens displacement) [Figure 3].

Figure 2:

Intraoperative lateral fluoroscopy during anterior odontoid screw fixation. (A) Panel A shows the creation of a pilot hole with a surgical drill at the anterior–inferior C2 endplate. (B) Panel B shows that the guidewire is advanced across the fracture into the dens. (C) Panel C demonstrates the advancement of the odontoid screw over the guidewire. (D) Panel D shows the final construct with a 38-mm partially threaded odontoid screw placed across the fracture.

Figure 3:

Postoperative anterior odontoid screw placement. (A) Panel A (sagittal) demonstrates a Type II odontoid fracture stabilized with a well-positioned anterior odontoid screw. (B) Panel B (coronal) shows restored atlantoaxial alignment with C1 and C2 appropriately reduced.

DISCUSSION

AOSF was appropriate in this case where the patient had sustained a type II odontoid fracture with complete dens displacement. Notably, he had experienced extensive posterior soft tissue injury due to trauma/burns and could successfully be managed with an AOSF as the fracture was transverse, reducible, with an intact transverse ligament.[4,5,7,8] We utilized a single-screw technique (i.e., proven to be as successful as the 2-screw procedure, respectively 81% vs. 85%; P > 0.05 effective).[6]

Despite complete posterior dense displacement, manual reduction before AOSF restored atlantoaxial alignment and allowed for stable C1-C2 fixation.

CONCLUSION

This case illustrates that anterior odontoid screw fixation remains a viable option for Type II odontoid fractures even in the setting of complete posterior dens displacement. In patients where extensive posterior soft tissue injury precludes a posterior approach, AOSF offers a safe and effective alternative for restoring atlantoaxial stability.

Ethical approval:

Institutional Review Board approval is not required.

Declaration of patient consent:

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given consent for clinical information to be reported in the journal. The patient understands that the patient’s names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship:

Nil.

Conflicts of interest:

There are no conflicts of interest.

Use of artificial intelligence (AI)-assisted technology for manuscript preparation:

The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.

Disclaimer

The views and opinions expressed in this article are those of the authors and do not necessarily reflect the official policy or position of the Journal or its management. The information contained in this article should not be considered to be medical advice; patients should consult their own physicians for advice as to their specific medical needs.