Medical Apparatus: Imaging Guide to Orthopedic Devices

Neck & Spine

Overlying Materials

Neck Apparatus

Cervical Spine

Thoracic and Lumbar Spine





Medical Devices of the Neck and Spine...cervical spine continued

by Tim B Hunter, MD, MSc and Mihra S Taljanovic, MD, PhD


Cervical Spine Instrumentation...continued


Cervical Collars and Halo Vests

There are many kinds of cervical spine immobilization devices, including cranial (head) tongs (figure: cranial tongs), cervical collars, neck braces, and halo vests. Cervical collars are ubiquitous and are commonly placed on trauma patients in the emergency department. The most frequent cervical collar design is the Philadelphia collar, which is molded from plastic and has chin and occipital supports. Although it is effective in stabilizing the neck to prevent harmful motion, it is uncomfortable, and patients want to remove it as soon as possible.

A more comfortable collar for patients is a soft foam collar covered by cotton. Although this collar is ineffective in controlling neck motion, it is useful as a reminder to the patient that neck motion must be avoided.

No neck collar provides adequate long-term neck stabilization for unstable cervical spine fractures. Unlike cervical collars, cervical braces are designed for the long-term treatment of cervical spine fractures. They consist of chin and occipital supports that are connected to a thoracic vest by metal rods. Cervical braces do provide good prevention against harmful flexion, but they are not as effective in preventing harmful extension.

The halo vest contains a metallic ring (the halo) that is attached to the outer table of the skull by screws (Bucholz, 1989; Kostuik, 1981; Whitehill, 1986) (figure: halo vest and brace). The halo is connected to a padded fiberglass or plastic thoracic cast by metal rods (the struts), which hold up the patient’s head. Although halo vests involve placement of screws into the skull and are a major undertaking for both the patient and the physician, they provide the best long-term fixation of the cervical spine. They are especially indicated for unstable fractures and dislocations and work best in the upper cervical spine. 

Cervical spine disk cages Cervical spine "corpectomy" and fusion  
Cervical disk cages Cervical disk cages Cervical spine fusion and corpectomy cage at C4-5 Cervical spine fusion and corpectomy cage at C4-5
65 year-old woman with vertebral disk cages at C3-4, C4-5, and C5-6. A previous anterior C4-6 fusion plate has been removed. The disk cages are probably composed of PEEK. Elderly woman with diskitis at C4-5 and adjacent bony destruction by osteomyelitis at C4 and C5. Initial cervical fusion failed. A corpectomy cage was placed at C4-5 with posterior spinal fusion from the occiput to T2. A crosslink is at C6.
Cervical spine PEEK disk cages Occipital strut and posterior cervical spine fixation for C1-2 subluxation Zero-profile ACDF
Cervical spine PEEK disk cages Cervical spine PEEK disk cages Occipital stut and posterior cervical spine fixation Zero profile ACDF
56 year-old man with severe spinal stenosis. There are PEEK disk cages at C3-4, C4-5, C5-6, and C6-7 held in place by anterior interbody screws as well as bony anterior cervical fusion. A feeding tube is also partially visualized. Middle-aged woman with rheumatoid arthritis and unstable atlantoaxial (C1-2) subluxation. Note the wide separation between the odontoid and the anterior ring of C1. The cervical spine was stabilized with an occipital strut held in place by occipital screws and rods extending from the occiput to C2. Lateral mass screws are present connecting to the rods at C2, and there is also posterior spinal wiring. 54 year-old woman with C6-7 zero profile ACDF discovered incidentally on a thoracic spine series after a fall. A PEEK disk cage is at C6-7 held in place by anterior interbody screws.
Posterior cervical spine fusion from occiput with halo brace Posterior cervical wire figure of 8 construction - AP view Posterior cervical wire figure of 8 construction - lateral view Posterior cervical wire figure of 8 construction - sagittal CT reformatted image
Posterior cervical fusion and halo brace Posterior figure of 8 cervical wire Posterior cervical wire fixation figure of 8 Posterior cervical wire fixation figure of 8 CT
53 year-old man with congenital cervical spine fusion and traumatic fracture through fusion mass at C3-7. The spine is stabilized by surgical fusion hardware from the occiput to T2 plus a halo brace. 44 year-old man with C7 vertebral fracture. Posterior figure of 8 wire fixation extends from C4 to C7
Cranial (head) tongs Cranial (head) tongs
Cranial tongs AP view Cranial tongs lateral view Head tongs AP view Head tongs lateral view
Child with severe intracranial and cervical spine injuries with bilateral cranial stabilization tongs, an endotracheal tube, an oroogastric tube, and a feeding tube entering via the nose. From Hunter, 2004 Cranial (head) tongs are used to stabilize the head and neck in a patient with a cervical spine fracture. One or more screws penetrate the outer table of the skull on each side. They are connected to each other by horizontal or vertical bars on each side that are attached to an external traction device. From Hunter, 2004
Posterior cervical spine wiring Halo vest and brace
Posterior spine wiring Posterior cervical spine wiring lateral view Halo vest and brace AP view Halo vest and brace lateral view
Posterior cervical wires from C4 to C7 after laminectomy. The lateral view obtained after cervical myelography. Yoshino, 1994 Yoshino, 1994

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Susceptibility artifact from cervical spine disk prosthesis Metal-on-polyethylene disk at C4-5 and Zero-profile ACDF at C6-7.    
Cervical spinal metallic MRI artifact from disk prosthesis Artificial disk at C4-5 and Zero profile ACDF at C6-7    
43 year-old man with metallic cervical disk prosthesis at C5-6. Metallic susceptibility artifact completely obliterates imaging of the spine and spinal cord at this level. 61 year-old man with past trauma to the cervical spine. A sagittal CT reformatted image shows a metal-on-polyethylene disk at C4-5, bony fusion of C5-6, and a Zero-profile ACDF at C6-7.    

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Thoracic and Lumbar Spine Instrumentation


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Tim Hunter

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