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this delay in diagnosis may affect the treatment because conservative treatment is usually successful , but occasionally may require open reduction if diagnosis is delayed . due to its rarity , the terminology associated with traumatic rotatory injuries at the atlantoaxial level is somewhat confusing , as far as the mechanics of injury .
we report a rare case of acute post - traumatic atlantoaxial rotatory fixation ( aarf ) associated with c2 articular facet fracture in an adult that was treated successfully by conservative means .
a 56-year - old female was involved in a head - on collision between two vehicles .
the patient came back after three days in our emergency with a severe torticollis , with an upper cervical spine pain associated with restricted and painful neck movement . on physical examination , the cervical spine was tender and right sided torticollis was present [ figure 1 ] .
initial examination showing right - sided torticollis without neurological deficit cervical spine radiographs demonstrate straightening and mild scoliotic change of the cervical spine .
a cervical computed tomography ( ct ) scan with 3d reconstructions revealed anterior dislocation of the right lateral mass of c1 and posterior dislocation of the left lateral mass of c1 .
in addition , fracture of the c2 right superior articular facet was noted [ figures 2 and 3 ] .
sagittal reconstruction of cervical computed tomography ( ct ) scan showing fracture of the right superior facet of the axis and posterior atlantoaxial dislocation tridimentional reconstruction showing fielding type 1 atlantoaxial dislocation with right c2 superior facet fracture a manual manipulation was then attempted while patient was awake . at first
, we held the mandible , providing traction in the cephalic direction , confirming that the patient did not develop pain or palsy in the upper extremities , and rotated it slowly to the left to obtain a feeling of reduction . immediately after reduction
post - reductional frontal computed tomography ( ct ) scan reconstruction control showing achieved reduction halo - vest immobilization was applied for 3 months . at 3 months after the halo - vest immobilization , flexion - extension
cervical spine radiographs and ct scans showed healing of the articular facet fracture in an acceptable position with any residual c1-c2 asymmetry [ figure 5 ] .
one year after the injury , she had a good range of neck movements , she was free of pain and torticollis , and returned to her normal daily activities .
third month computed tomography ( ct ) scan control showing optimal stability and healing of the c2 facet fracture
aarf is a rare pathology of the adult upper cervical spine ; it was described for the first time in 1907 by corner , although this pathology is reported to occur frequently in children ; venkatesan , in an english review of the literature , reported only 12 previous cases happened in the adult population of pure aarf .
the prevalence of rotatory dislocation in children may be attributed to specific anatomical features such as a relatively large head , the underdeveloped neck musculature , and the increased laxity of the joint capsule and the horizontal configuration of the c1-c2 articular facets . in children , this is usually seen after infection or inflammation of the surrounding tissues [ grisel 's syndrome ] , and is thought to be secondary to synovial joint effusion and neck muscle spasm .
traumatic adult aarf as in the present case is reported very rarely , and frequently caused by high energy trauma , such as that sustained in traffic accidents or falls and often generated lethal injury .
although the pathophysiology of aarf is not well - defined ; anteroposterior stability of the atlantoaxial joint is primarily maintained by the transverse ligaments , alar ligaments , and the facet joint capsule .
the alar or check ligaments are mostly responsible for rotational stability , as they limit rotation to 50 ; there is evidence from cadaveric dissection and magnetic resonance imaging ( mri ) studies to suggest that the pathologic mechanism by which rotatory dislocation occurs is through disruption of the facet capsule followed by alar ligament disruption .
the lateral mass of the atlas rotating posteriorly locks behind the ipsilateral lateral mass in severe forms of atlantoaxial rotatory instability .
aarf can also be associated with fractures , due to a combination of bone and ligament disruption but this association is very rare ; c2 fractures are relatively the most frequently founded , and only six such cases have been reported in the literature ; but aarf in combination with an articular facet fracture , like in our case , is an extremely rare injury and to the best of our knowledge only seybold described similar case . however , because of the complexity and heterogeneity of these fractures , they are usually lumped under the descriptive category of  miscellaneous c2 fractures  in most published reports . fielding and hawkins described four types of aarf .
this classification , which has been widely accepted , correlates with an increasing risk of spinal instability and potential neurological impairment .
this case was categorized as type i. there is translation of facets without a corresponding increase of the atlantodens interval and the rotation is within the normal range of atlantoaxial rotation .
it is the only type that can occur without the rupture of ligaments , with the dens acting as the pivot .
a type i injury was the most common deformity , and the most difficult to recognise on x - ray . in a typical aarf , the patient presented with torticollis , a painful neck , and without neurologic symptoms after high - energy trauma .
a high index of suspicion , thorough clinical examination and appropriate imaging , are mainstay in obtaining an early diagnosis of this condition .
the plain radiographic findings are non - specific and may sometimes be difficult to demonstrate , due to difficulties in positioning and in radiographic interpretation .
ct scanning is considered the best method to detect this abnormality , and three - dimensional ct reconstruction is an additional aid in demonstrating subluxation .
ct scan also allows an excellent demonstration of abnormal c1-c2 relationships , visualizing the dislocation , determining whether it is unilateral or bilateral , and looking for fractures .
the goals of treatment are to restore the normal pain - free range of motion , prevent or reverse any neurologic compromise , and restore the spinal stability .
the treatment options include conservative care , immobilization , traction , manual reduction , and surgery .
conservative treatment is the first step to treat fixed aarf if the transverse ligament is intact .
therapeutic management of rotatory dislocation with fielding type i involves reduction using the traction method and immobilization with either a halo vest or different types of collars for 6 - 12 weeks has achieved good long - term rotational stability in most cases .
venkatesan et al . , reported two cases of aarf and commented that early recognition of atlantoaxial rotatory subluxation or dislocation is essential to successfully achieve closed reduction .
weikopf et al . , pointed out that the success rate of conservative treatment decreases in proportion to the length of the dislocation treatment interval .
surgical stabilization is advised for cases of aarf showing spinal instability , neurological deficit , delayed diagnosis , failed reduction , ligamentous disruption , and/or recurrent dislocation .
our patient presented with an acute case of fielding type i aarf with no neurological symptoms .
we therefore performed manual reduction with the patient awake , and cervical pain was alleviated after reduction .
have described awake manual reduction without the need for anesthesia , but this kind of manual reduction should be performed as soon as possible by experienced surgeons close to a functional operating theater .
definitive treatment of this injury is still open for discussion . in general , all atlantoaxial dislocations require some form of immobilization , either internal or external .
our patient presented with a rotatory atlantoaxial dislocation accompanied by a superior articular facet fracture of c2 .
one year after the injury , she had a good range of neck movements ; she was free of pain and torticollis , and returned to her normal daily activities .
early diagnosis of aarf improves outcomes with no operative management , but requires a combination of clinical assessment and appropriate radiographic imaging .
to our knowledge , this is the second cases of aarf with c2 lateral articular facet fracture that has successfully treated with conservative means .
traumatic atlantoaxial rotatory fixation is a very rare injury in adults which is often misdiagnosed initially . 
 its combination with c2 fractures is predominated by dens lesions . 
 therapeutic management is challenging because of the difficulty to achieve optimal reduction and permanent stability . 
 we report a rare case of traumatic atlantoaxial rotatory fixation in a 56-year - old women associated with c2 articular facet fracture successfully treated by conservative means after patient - awake manual reduction with optimal functional and radiographic outcome .