CASE 16999 Published on 21.10.2020

Unstable cervical fracture with a posterior epidural hematoma in ankylosing spondylitis


Musculoskeletal system

Case Type

Clinical Cases


Guillaume Vangrinsven1, Carine Petré1, Filip Vanhoenacker1,2,3

1Department of Radiology, Sint-Maarten General Hospital, Mechelen, Belgium

2Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium

3Department of Radiology and Faculty of Medicine and Health Sciences, Antwerp University Hospital, Antwerp, Belgium


80 years, male

Area of Interest Emergency, Musculoskeletal spine, Neuroradiology spine ; Imaging Technique CT, MR
Clinical History

The patient was admitted to the emergency department with neck pain after a minor fall. There was no relevant past medical history except atrial fibrillation for which he took anticoagulants. Repeated anamnesis after discharge, however, revealed a history of inflammatory back pain. Clinical examination revealed no neurological deficit.

Imaging Findings

Conventional radiography revealed bridging syndesmophytes and ankylosis of most apophyseal joints in the cervical spine and ankylosis of both sacro-iliac joints (SIJ), in keeping with previously unknown advanced ankylosing spondylitis (AS) (Fig. 1a-b). Cervical radiography was of poor quality due to difficult patient positioning related to spinal stiffness and high-riding shoulders. Subsequent CT confirmed the severe cervical changes and showed a fracture through the anterior column at level C5-C6, the C6 vertebral body, the spinous process of C5 and the left facet joint C5-C6, involving the three spinal columns (Fig. 2a-c). In addition, there was enlargement of the posterior epidural space from C2 to Th1 causing compression on the spinal cord (Fig. 2d). MRI confirmed the presence of an acute spinal epidural hematoma which was isointense to muscle on T1-weighted images (WI) and slightly hyperintense to the spinal cord on T2-WI and short tau inversion recovery (STIR) images (Fig. 3a-d).


AS is a seronegative spondyloarthropathy with chronic inflammation of the sacroiliac joints (SIJ) and the spine. Advanced disease is characterized by ankylosis, radiographically known as a “bamboo spine”. Ankylosis is associated with an increased risk of traumatic spinal fractures due to the rigid spine acting as a lever arm and the high prevalence of disuse osteopenia impairing vertebral mechanical strength. Fractures occurring even after minor trauma are often unstable. They most often involve the cervicothoracic junction and are prone to primary and secondary spinal cord injuries (SCI). The most common fracture mechanism is a hyperextension injury. Flexion injuries causing unstable chance-like fractures are less common. Unstable cervical fractures need urgent surgical fixation to prevent neurological damage [1-3].

Standard radiography has a low sensitivity and is of limited use for evaluation of spinal fractures in longstanding AS. Up to 60% of cervical fractures are missed due to the superimposition of the shoulders and distortion of normal cervical anatomy [2]. Multidetector computed tomography (MDCT) is the modality of choice for fracture. Vertebral body and spinous process fractures as well as tearing of ossified ligaments can be appreciated. Fracture extension should carefully be assessed to identify unstable fractures. MRI, however, is more valuable to evaluate soft tissue injuries and the contents of the spinal canal. Therefore, MRI should always be performed when a SCI is suspected [1,4,5].

Spinal epidural hematoma is an unusual complication of vertebral fractures although it is more common in patients with AS. The use of anticoagulants is an additional risk factor. The majority of posttraumatic spinal epidural hematomas are located posteriorly. A spinal epidural hematoma will appear spontaneously hyperdense compared to the spinal cord on CT. To evaluate spinal cord compression, extension of the hematoma and to assess any associated soft tissue injuries, MRI is the gold standard. Early detection and urgent decompression is needed to prevent further neurological damage [1,6].

Although our patient had no neurological deficit at presentation, the unstable fracture and spinal epidural hematoma required urgent surgical care. An anterior cervical fusion C5-C7 was successfully performed and the patient remained free of neurological symptoms.

In conclusion, patients with a rigid spine due to long-lasting AS should be considered at high- risk for unstable fractures, even after minor trauma. Standard radiography has low sensitivity, especially in the lower cervical spine. Whereas CT may evaluate the extent of the fracture, MRI is the preferred modality for evaluation of spinal cord damage.

Written informed patient consent for publication has been obtained.

Differential Diagnosis List
Unstable cervical fracture complicating ankylosing spondylitis
Unstable vertebral fracture complicating ankylosing spondylitis.
Unstable vertebral fracture complicating DISH
Pathological vertebral fracture
Osteoporotic compression fracture
Final Diagnosis
Unstable cervical fracture complicating ankylosing spondylitis
Case information
ISSN: 1563-4086