C1-C2 Fracture with Atlantoaxial Subluxation

History

The patient is an 87-year-old man who was struck by a car while on a crosswalk. He presented to the ER as a poly-trauma patient. Work-up revealed an anterior C1 arch and Type II C2 dens fracture with atlantoaxial subluxation (in addition to multiple cervical spinous process fractures).

Examination

Awake and alert but confused. No focal motor or sensory deficits. No evidence of myelopathy.

Pre-treatment Images

Figure 1: Sagittal CT of the cervical spine demonstrating Type II dens fracture with posterior listhesis and slight angulation.

Figure 2: Axial CT demonstrating subtle C1 anterior arch non-displaced fracture

Diagnosis

C1-C2 Fracture with atlantoaxial subluxation

Selected Treatment

We elected a posterior occiput-cervical fixation (O-C3). Given that he was an otherwise healthy and relatively high-functioning individual according to family, and given the degree of listhesis, we elected to surgically stabilize this fracture.

Dens fractures in octogenarians are increasingly common. Treatment options include 1) rigid collar 2) halo orthosis 3) surgical stabilization. Direct surgical fixation is the optimal choice in patients who have a Type II dens fracture (especially with angulation/listhesis).

In our practice, it’s extremely uncommon to utilize halos in the elderly population. If a patient is otherwise a high-risk surgical candidate, and does not have gross instability, we may consider a rigid collar only with close radiographic and clinical follow-up. 

Surgical stabilization typically involves anterior odontoid screw fixation or posterior atlantoaxial fixation. In this case, the anterior C1 arch fracture, though linear and non-displaced, precluded fixation to the atlas and instead an O-C fixation procedure was pursued.

Intraoperative and Post-operative Images

Figure 3: Intraoperative lateral x-ray demonstrating O-C3 instrumented fusion. The occipital plate accommodated two 10 mm screws and one 8 mm screw. We used 3.5 x 22 mm pedicle screws at C2 and 3.5 x 14 mm lateral mass screws at C3.

Figure 4: Post-operative sagittal CT demonstrating improved alignment of the C2 dens fracture after stabilization.

Outcome

The patient tolerated the procedure well without any postoperative deficits. He was in preparation for discharge to a skilled nursing facility.

Case Discussion

Robert E. Isaacs, MD

Director of Spine Surgery

Duke University Medical Center

Odontoid fractures in the elderly are very common. Although the disease process is well understood and the treatment strategies well described in the case study presented, the correct choice is often difficult to determine. This is not due to the lack of understanding of the options, but that the treatment is often a decision on determining which is the best of many evils.

The risks of placing this near 90-year-old in a halo carries a significant chance of ending in death (Horn EM, Theodore N, Feiz-Erfan I, Lekovic GP, Dickman CA, Sonntag VK. Complications of halo fixation in the elderly. J Neurosurg Spine. 2006;5(1):46-9) or major morbidity during the time it takes to heal. The bone quality in this age group may not tolerate an anterior screw placement, and significant displacement may preclude this option.

Posterior approaches are associated with significant perioperative risks far exceeding anterior surgical options (Shamji MF, Cook C, Pietrobon R, Tackett S, Brown C, Isaacs RE. Impact of surgical approach on complications and resource utilization of cervical spine fusion: a nationwide perspective to the surgical treatment of diffuse cervical spondylosis. Spine. 2009;9(1):31-8) and leave the patient permanently disabled in terms of neck range of motion. Placing the patient in a rigid cervical collar is frequently associated in a non-union, which can lead to a delayed myelopathy, although is frequently well tolerated in the short-term.

In short, no clear treatment choice is either ideal or clearly the correct choice when dealing with an odontoid fracture in the extreme elderly.