NCBI Bookshelf. Steven Tenny ; Matthew Varacallo. Authors Steven Tenny 1 ; Matthew Varacallo 2. The odontoid process, or dens, is a superior projecting bony element from the second cervical vertebrae C2, or the axis. The first cervical vertebrae atlas rotates around the odontoid process to provide the largest single component of lateral rotation of the cervical spine.
L2 - PGY3. URL of Article. By System:. Odontoid peg fracture C. If a T ype II Odontoid Fracture is suspected, the doctor frqcture order the following diagnostic procedures: X-rays — test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs on film. The imaging modality of choice is a CT of the cervical spine. From the case: Odontoid fracture classification: diagram. Sign Up. Some fractures are considered stable, and some are unstable. Loading Stack - 0 images remaining.
Tantra mediation. Loading Stack -
L7 - years in practice. Non-rigid external immobilisation The use of non-rigid external immobilisation using a Doctoral oral history cervical collar is a recognised form of treatment for type II odontoid fractures in the elderly. Other authors believe that as osteoporosis is mainly a cancellous disease and since Odontoid peg fracture technique of anterior odontoid screw fixation is dependent on the distal tip of screw purchasing the dense cortical bone, it may not significantly affect the manner of screw purchase [ 8 ]. They concluded that the management of type II odontoid fractures in the octogenarian population are associated with substantial morbidity and mortality, irrespective of Odontoid peg fracture management method. J Bone Odontoid peg fracture Surg Am. This arrangement allows for a lot of freedom of motion between the combination of the head, first vertebra atlasand 2nd vertebra axis. Wolfgang et al. Injury films are shown in Figure A and B. Variations in injury patterns, treatment and outcome for spinal fractures and paralysis in adult versus geriatric patients. L2 - PGY3. L6 - years in practice. The patients typically heal well with the proper treatment. Displaced fracture with fracture line from anterosuperior to posteroinferior. However, in their recent study, Odontoid peg fracture Middendorp et al. The amount of radiation is small—less than the radiation in half of one CT scan.
- Albert J.
- A type II odontoid fracture is a break that occurs through a specific part of C2, the second bone in the neck.
NCBI Bookshelf. Steven Tenny ; Matthew Varacallo. Authors Steven Tenny 1 ; Matthew Varacallo 2. The odontoid process, or dens, is a superior projecting bony element from the second cervical vertebrae C2, or the axis.
The first cervical vertebrae atlas rotates around the odontoid process to provide the largest single component of lateral rotation of the cervical spine. Fracture of the odontoid process is classified into one of three types which are type I, type II, or type III fractures, depending on the location and morphology of the fracture. Odontoid fractures occur as a result of trauma to the cervical spine.
In younger patients, they are typically the result of high-energy trauma which occurs as a result of motor vehicle or diving accidents. In the elderly population, the trauma can occur after lower energy impacts such as falls from a standing position. The odontoid fracture can also occur with hyperflexion of the cervical spine.
The transverse ligament runs dorsal to behind the odontoid process and attaches to the lateral mass of C1 on either side. If the cervical spine is excessively flexed, then the transverse ligament can transmit the excessive anterior forces to the odontoid process and cause an odontoid fracture. MVA , followed by elderly patient populations ages 70 to 80 years secondary to compromised bone density and low energy impact falls. Type I odontoid fractures are rare. A type I odontoid fracture occurs when the rostral tip of the odontoid process is avulsed broken or torn off.
The apical ligament attaches the tip of the odontoid process to the foramen magnum skull base. A type II odontoid fracture is a fracture through the base of the odontoid process. Type II odontoid fractures can also occur with hyperflexion of the neck and the transverse ligament pushing the odontoid process forward to the point of fracture.
A type III odontoid fracture is a fracture through the body of the C2 vertebrae and may involve a variable portion of the C1 and C2 facets. Type III odontoid fractures occur secondary to hyperextension or hyperflexion of the cervical spine in a similar manner to type II odontoid fractures.
The difference is where the fracture line occurs. Younger patients with an odontoid fracture typically have identifiable recent trauma motor vehicle accident, sports-related impact, diving accident, fall from a height or down stairs. However, older individuals can also sustain an odontoid fracture from recent injuries similar to those of younger people.
On physical exam, patients may note cervical neck pain which is worse with motion. They can also have dysphagia due to a retropharyngeal hematoma or associated parapharyngeal swelling. Fewer spinal cord injuries in odontoid fractures are due to the relatively large cross-sectional diameter of the spinal canal at the level of the odontoid process compared to the diameter of the spinal cord. Although radiographs yield lower sensitivity and specificity rates when compared to CT scans, experienced clinicians and practitioners can still appreciate suspected injury without CT utilization.
The imaging modality of choice is a CT of the cervical spine. The CT provides the best resolution of the bony elements allowing for identification and characterization of an odontoid fracture. If there is neurologic injury paresthesia, weakness , then an MRI without contrast of the cervical spine should be obtained to assess the cervical cord for injuries.
Some surgeons also order a CT angiogram of the cervical spine if posterior instrumentation is planned. The CT angiogram allows for better identification of the course of the vertebral arteries for surgical planning of posterior instrumentation. Type II odontoid fractures are inherently unstable and have a lower union rate than type III odontoid fractures due to the lower surface area of fractured bone in type II versus type III odontoid fractures.
The configuration of type II odontoid fracture and age of patient also play important roles in treatment decisions. The current treatment options for a type II odontoid fracture include rigid cervical orthosis, halo vest immobilization, odontoid screw, transoral odontoidectomy, and posterior instrumentation.
A type II odontoid fracture is inherently unstable, and a rigid cervical orthosis is not the ideal treatment for such an injury. In the elderly population many are not surgical candidates due to comorbidities or poor bone quality , and the elderly typically poorly tolerate a halo vest immobilization.
In such situations, a practitioner may attempt a rigid cervical orthosis, although union rates are low. Some authors have argued that a fibrous union will form with the use of a rigid cervical orthosis with time and this may provide sufficient stability in the elderly population while avoiding the morbidity of surgery or halo vest immobilization. If a patient is relatively young and healthy, and there is low risk for nonunion, then halo vest immobilization may be the best treatment for a type II odontoid fracture.
Elderly patients poorly tolerate halo vest immobilization and have increased the risk of death with halo-vest immobilization. Younger patients typically spend six to 12 weeks in halo vest immobilization with frequent x-rays to check alignment and healing.
An anterior odontoid osteosynthesis odontoid screw is a screw placed from the inferior anterior aspect of the C2 vertebral body, in a superior trajectory, and capturing the odontoid process and affixing it in place to allow bony fusion to occur.
A surgeon can only place the odontoid screw if there are acceptable alignment and minimal displacement of the odontoid process, the fracture line is oblique or perpendicular to the screw trajectory, the injury is relatively recent, and the patient has acceptable body habitus to place the odontoid screw.
Due to the relatively vertical orientation of an odontoid screw a person with a short neck or large chest or sternum may not allow the surgeon an adequate trajectory for placement of the odontoid screw.
Odontoid screws have a lower union rate and higher failure rate than posterior instrumentation. In some situations, the odontoid process dens may be severely posteriorly displaced and compressing the spinal cord causing neurologic deficits. It is difficult and dangerous to reduce the odontoid process in a closed manner, so surgical removal of the odontoid process is required to relieve the compression of the spinal cord.
If the odontoid process is removed, the cervical spine remains unstable, and the patient requires instrumented fusion, commonly from a posterior or combined anterior-posterior approach. The risk factors include:. It is important to recognize these to avoid unnecessary interventions.
During the development, there are multiple ossification centers in the spine with one being in the odontoid process, one in the odontoid tip, and one in the vertebral body. If the ossification centers in the odontoid process and vertebral body fail to fuse then the odontoid process dens can appear to be detached from the vertebral body and mimic a type II odontoid fracture.
In younger children, the complete ossification of the spine has not yet occurred, and normal growth pattern and ossification can also mimic a type II odontoid fracture. The rostral tip of the odontoid process has a separate ossification center during development from the remaining odontoid process. When the two ossification centers fail to fuse there can be a persistent gap between the odontoid process and the tip of the odontoid process which can mimic a type I odontoid fracture.
Patients are often younger. To access free multiple choice questions on this topic, click here. Anderson and D'Alonzo classification of odontoid fractures.
This book is distributed under the terms of the Creative Commons Attribution 4. Turn recording back on. National Center for Biotechnology Information , U. StatPearls [Internet]. Search term.
Affiliations 1 University of Nebraska Medical Center. Introduction The odontoid process, or dens, is a superior projecting bony element from the second cervical vertebrae C2, or the axis. Etiology Odontoid fractures occur as a result of trauma to the cervical spine. History and Physical Younger patients with an odontoid fracture typically have identifiable recent trauma motor vehicle accident, sports-related impact, diving accident, fall from a height or down stairs.
Halo Vest Immobilization If a patient is relatively young and healthy, and there is low risk for nonunion, then halo vest immobilization may be the best treatment for a type II odontoid fracture. Questions To access free multiple choice questions on this topic, click here. Figure Anderson and D'Alonzo classification of odontoid fractures. References 1. Biomed Res Int. Guan J, Bisson EF. Treatment of Odontoid Fractures in the Aging Population.
Fractures of the axis: a review of pediatric, adult, and geriatric injuries. Curr Rev Musculoskelet Med. Surgical treatment of type II odontoid fractures in elderly patients: a comparison of anterior odontoid screw fixation and posterior atlantoaxial fusion using the Magerl-Gallie technique.
Eur Spine J. Baogui L, Juwen C. Fusion rates for odontoid fractures after treatment by anterior odontoid screw versus posterior C1-C2 arthrodesis: a meta-analysis. Arch Orthop Trauma Surg. In: StatPearls [Internet]. In this Page. Related information. Similar articles in PubMed. Acta Chir Orthop Traumatol Cech. Analysis of predisposing factors in elderly people with type II odontoid fracture. Spine J. Epub Sep Review Odontoid screw fixation for fresh and remote fractures.
The procedure is technically demanding and carries the risk of vertebral artery injury [ 75 , 80 ]. Cancel Save. Os odontoideum Os odontoideum. Ogden , Christopher E. Odontoid fractures: high complication rate associated with anterior screw fixation in the elderly. Non-rigid external immobilisation The use of non-rigid external immobilisation using a hard cervical collar is a recognised form of treatment for type II odontoid fractures in the elderly.
Odontoid peg fracture. Introduction
Odontoid (peg) fracture | Radiology Case | aupetitchavignol.com
Oblique linear fracture noted in the odontoid process and lower part of the anterior tubercle of C2. It has the highest rates of non-union. Differential diagnosis includes Bergmann's ossicle. Support Radiopaedia and see fewer ads. Updating… Please wait. Unable to process the form. Check for errors and try again.
Thank you for updating your details. Log In. Sign Up. Log in Sign up. Articles Cases Courses Quiz. About Blog Go ad-free. Diagnosis certain. Presentation Road traffic accident, neck pain, no neurological deficits. Patient Data Age: 30 years. From the case: Odontoid peg fracture. Loading images Loading Stack - 0 images remaining. Odontoid fracture. Musculoskeletal Imaging Spine Trauma.
Related Radiopaedia articles Anderson and D'Alonzo classification of odontoid process fracture Cervical spine fractures Odontoid fracture Persistent ossiculum terminale Promoted articles advertising. Full screen case. Case with hidden diagnosis. Full screen case with hidden diagnosis. Case information.
Systems: Musculoskeletal , Spine , Trauma. Inclusion in quiz mode: Included. By System:. Patient Cases.