Mechanism of injury:
Flexion and distraction force with an element of rotational torque.
Classification: Facets can be subluxed, perched or dislocated in uni or bilateral fashion. The most
accepted classification scheme for cervical spine dislocation is:
Allen and Ferguson classification:
Type I: Facet joint Subluxation.
Type II: Unilateral Facet Dislocation.
Type II: Bilateral Facet dislocation with 50% displacement.
Type IV: Complete dislocation.
Some patients may present with mild neck pain and thus can be easily missed.
Unilateral injuries may present with rotational deformity in form of tilting of head opposite to dislocation.
Anteriorly displaced facet may be responsible for radicular symptoms.
Bilateral Facet disloaction can lead to cannal compromise and neuro deficit.
AP, Lateral and open mouth odontoid veiw and if necessary shoulder pull down veiws must be taken in all cases of cervical
Unilateral facet dislocation usually have less than 3-4mm displacement and less than 5-7degrees of angulation.
Forward dislocation of one facet joint over the other in cases of uni lateral dislocation may give rise to ' double sail
Bilateral dislocation have severe degree of displacement and kyphosis.
CT Scan: May show classical empty Facet sign. Axial images are essential to identify presence of pedicle and
laminar farctures. It is also important to recognise presence of a floating lateral mass as they are important in internal
MRI: Evaluates the disk hernaition, posterior ligamnetous injury, degree of canal compromise and state of the
Primary Care: Initial management includes basic ABC and following the ATLS protocol.Patients with neurodeficit
must be administered intravenous methylpredinisolone according to NASCIS protocol (30mg/kg bolus dose and then 5.4 mg/kg/hr
for next 24-48 hr).
Closed reduction: After the initial stabilisation CR is attempted. An awake reduction in a cooperative patient
is preferred as it allows simultaneous evaluation of the neurological status of the patient.
A gardner - wel tongs is applied and weights are added sequentially. Usual protocol is 10-15 lbs for head and an additional
5-10 lb of weight per level of injury. Upto 140 lbs can be added to obtain reduction. During the entire process, neurological
examination and serial radiographs should be taken.
A slight degree of flexion allows the facet joint to disengage, following which head can be manipulated to obtain the
Failed Closed Reduction: In cases where CR has failed, Open reduction (OR) using either an anterior Smith Robinson
approach or a standard dorsal midline posterior approach may be done. Anterior stabilisation involves use of anterior strut
graft and an anaterior plate fixation. If a posterior approach is preffered, various options include interspinous wiring,
oblique wirin ( between the lateral mass and spinous process), lateral mass plating and interlaminar clamps. Lateral mass
screw constructs with rods or plates are considered most stable fixation.
In severe grades of injuries a combined anterior and posterior aproach may be necessary for a rigid stabilisation.