Occipital Condyle Fractures

Occipital condyle fractures should be considered a marker for potentially lethal trauma, with an 11% mortality rate from associated injuries. The incidence of associated cervical spine injury at another level is 31%.

The mechanism of injury involves compression and lateral bending; this causes either compression fracture of the condyle as it presses against the superior facet of C1 or avulsion of the alar ligament with extremes of atlanto-occipital rotation.

Occipital Condyle Fractures Diagnosis

Patient with Occipital Condyle Fractures presents with high cervical pain, reduced head/neck ROM, torticollis, lower cranial nerve deficits and motor paresis.

Cranial nerve palsies may develop days to weeks after injury and most frequently affect cranial nerves IX, X and XI.

The sensitivity of plain radiography for diagnosis is as low as 3% and a CT scan is frequently necessary for diagnosis.

See Also: Cranial Nerves

Occipital Condyle Fractures Classification

Occipital condyle fractures have been classified by Anderson and Montesano.

Anderson and Montesano Classification

Type I fractures (3% of occipital condyle fractures)

• They are comminuted impaction condyle fractures resulting from an axial load
• They are usually stable injury due to minimal fragment displacement into the foremen magnum. They result due to compression between the atlanto-odontoid joint.
• MRI shows craniocervical ligament injury.
• <2mm of cervical distraction with traction.

Type II fractures (22%)

• These fractures involve extension of a basilar skull fracture into the condyle that results from Due to a direct blow to skull
• These are also stable injury as the alar ligament and tectorial membrane are usually preserved.
• MRI shows craniocervical ligament injury.
• 2mm of cervical distraction with traction.

Type III fractures (75%)

• These fractures are condylar avulsion fractures in region of the alar ligament attachment, results from forced rotation with combined lateral bending.;
• They are potentially unstable and should raise clinical suspicion for an underlying occipitocervical dissociation.
• Craniocervical malalignment is greater than 2mm,
• >2mm of cervical distraction with traction.

See Also: Whiplash Injury

Occipital Condyle Fractures Treatment

Type I and II fractures are stable and managed nonoperatively in a rigid cervical collar or halo vest for 8 weeks.

Type III fractures are unstable and immobilization for 12 weeks in a halo vest is recommended. After the period of immobilization, if instability is observed on flexion and extension films, an occipital-to-C2 fusion may be necessary.

References & More

1. Anderson PA, Montesano PX. Morphology and treatment of occipital condyle fractures. Spine (Phila Pa 1976). 1988 Jul;13(7):731-6. doi: 10.1097/00007632-198807000-00004. PMID: 3194779. Pubmed
2. Occipital Condyle Fractures – Orthobullets
3. Mercer’s Textbook of Orthopaedics and Trauma, Tenth edition.