Radiographs, stability dictate management of craniocervical junction injuries

Craniocervical junction injuries occur in patients of all ages and can be successfully treated either surgically or non-surgically, a presenter said.

Injuries that occur at the craniocervical junction have increased in the past decade, and the frequency of odontoid fractures, in particular, has increased more than three-fold in patients older than 85 years of age, according to data presented here.

Radiographs, imaging and stability are critical in determining the treatment plan for a craniocervical junction injury, Richard A. Davis, MD, said at the American Spinal Injury Association section of the Federation of Spine Associations Specialty Day Meeting.

“Radiographs are critical to identify an injury and form a treatment plan. Stable fracture patterns, once we determine that off of radiographic studies, are usually best treated with a cervical collar. Unstable fracture patterns, we will operate on,” Davis said.

Injuries in young and old

Typically, injuries from high-energy events occur in younger patients, but elderly patients with osteoporosis or spondylosis can sustain the same injuries from low-energy events. Therefore, a diagnosis from MRI is important, he said. Physicians should look for increased signal intensity in several locations, including the spinal cord, prevertebral soft tissues and the C1-2 joint.

Normal radiographic evaluation is also possible for these injuries. Physicians should look for markers such as prevertebral swelling, soft tissue shadow (normal is less than 6 mm of space at C2) and some other factors that indicate there is an injury at the craniocervical junction, he said.

According to Davis, surgeons use several measurements to identify an occipital cervical disassociation that are easy to use. Known as Harris’ measurements, or the Rule of Twelves, the Basion-Dens interval and Basion-Axis interval should not exceed 12 mm.

“Anything above that, there is a high suspicion for a highly unstable cervical spine,” he said.

Treatment depends on injury

Once the diagnosis is made and the type of fracture is identified, the surgeon should develop a treatment plan. For an Atlas fracture displaced less than 6.9 mm, the patient should be put in a halo vest for 3 months. For a fracture displaced more than that, the patient can undergo halo traction for several weeks and then be placed into a halo vest. After brace treatment, the physician should confirm the C1-2 stability, and if the atlanto-dens interval is greater than 5 mm, a C1-2 fusion may be required.

Odontoid fractures, which are the most common fractures of the axis, account for 10% to 20% of all cervical fractures. These injuries are most common at C2 and often occur in older patients, Davis said.

Determining the displacement of an odontoid fracture is essential in determining how to treat the patient, he said.

Based on the displacement and the stability of the fracture, “I order an MRI on all patients with an odontoid fracture, regardless of whether surgical treatment is likely,” Davis said, noting the imaging helps him predict when and if the odontoid fracture of the subaxial spine is at risk of becoming symptomatic.

Surgery indicated for instability

Type 2 odontoid fractures are the hardest to treat, according to Davis. Type 1 fractures are extremely rare, and type 3 fractures typically heal well. Determining if a type 2 fracture is stable or unstable may help the surgeon determine whether surgery is necessary. In addition, the patient’s age is also a factor in whether surgery is necessary or the type of surgery the patient should undergo.

When it is decided to address an unstable fracture surgically, an anterior or posterior approach is possible. However, anterior procedures allow for more maintenance of C1-2 rotation, Davis said, whereas posterior procedures, particularly a posterior arthrodesis, have a fusion rate that approaches 100%. Patients may lose some C1-2 motion, but that is usually acceptable and tolerated in older patients.

According to Davis, collars provide a reasonable treatment for stable fractures. Patients with unstable fractures are good surgical candidates, and surgeons have at their disposal a number of fusion techniques that offer different rates of union. – by Robert Linnehan

Reference:
Davis RA. Presentation #28. Presented at: Federation of Spine Associations Specialty Day; March 28, 2015; Las Vegas.

For more information:
Richard A. Davis, MD, can be reached at Regions Hospital, 640 Jackson St., Saint Paul, MN, 55101.

Disclosure: Davis reports he is a paid presenter/ speaker for DePuy, a Johnson & Johnson Company, and he receives IP royalties from Stryker.