日小整会誌（J Jpn Ped Orthop Ass）23（2）：407 415, 2014.
第 24 回日本小児整形外科学会学術集会 JPOA Asian Fellows

Atlanto-Axial Rotatory Fixation in Children：
Comparison of Clinical Findings and Outcomes by Etiology
Kiyotaka Ohtani,1 Noriko Matsumoto,1 Mayu Fujimoto,1 Hitomi Inagaki,1Kazuteru Kitsuda,1 Miho Kaida,1 Masako Kitsunezaki,1 Yukifumi Yokota2
1

Department of Pediatrics, Sagamihara Kyodo Hospital, Sagamihara, Kanagawa, Japan
2

Yokota Kodomo Clinic, Sagamihara, Kanagawa, Japan

Abstract：Background: Atlantoaxial rotatory ﬁxation（AARF）is an uncommon cause of childhood torticollis and is generally associated with trauma or inﬂammation of the upper respiratory
tract and neck. We aimed to clarify the clinical ﬁndings and outcomes of AARF by etiology toprovide pediatricians with valuable for eﬀective treatment.
Methods: Sixteen patients, admitted to our hospital from 2005 to 2013 with AARF, were assigned to 2 groups according to etiology; traumatic（n = 10, age 6.8 ± 0.6 years）
or atraumatic（n= 6, age 6.3 ± 0.4 years）. Patient backgrounds, treatment, and prognosis were evaluated retrospectively and compared between the two groups.
Results: The median length of persistent torticollis and time from the initiation of treatment toremission were longer（but not signiﬁcant）in the atraumatic group than in the traumatic group（16 days vs. 10.5 days;= 0.07, 7.5 days vs. 5 days;= 0.09）. There was a signiﬁcant correlation

between the time to initiate Glisson traction and length of Glisson traction in only those who underwent Glisson traction（r2 = 0.45,= 0.0001）.

Conclusions: Pediatricians should immediately refer AARF patients to surgeons who specialize
in atlantoaxial junction surgery.

Introduction

Since Bell
（1830）reported the ﬁrst case of rotation deformity of the atlantoaxial joint, pro-

Atlantoaxial rotatory fixation（AARF）is an

duced after pharyngeal ulceration in a patient

uncommon cause of childhood torticollis and iswith torticollis, many cases have been report-

generally associated with trauma or inflamma-

ed1）. The termtion of the upper respiratory tract and neck.

first time by Wortzman et al.
（1968）asChildren with torticollis present with asymmet-

was used for the10）. In addition,rical（ cock-robin”）head position and restricted

this clinical condition has been described using

movement.

multiple terms such as rotatory subluxation, ro-

Key words：atlantoaxial rotatory ﬁxation, childhood torticollis, Fielding classiﬁcation, Glisson traction
Corresponding author：Kiyotaka Ohtani
Department of Pediatrics, Sagamihara Kyodo Hospital, 2‑8‑18 Hashimoto, Midori‑ku, Sagamihara, Kanagawa 252‑5188,
Japan
TEL: +81‑42‑772‑4291 FAX: +81‑42‑771‑6709
e-mail：k‑ootani@sagamiharahp.com
日本小児整形外科学会雑誌 Vol. 23, No. 2, 2014

Atlanto-Axial Rotatory Fixation in Children： Comparison of Clinical Findings and Outcomes by Etiology

tatory dislocation, spontaneous hyperemic dislo-

METHODS

cation, inflammatory torticollis（named after its
etiology）, and Griselís syndrome.3）6） The term

Cases of AARF

AARF, coined by Fielding and Hawkins in 1977,

From January 2005 to December 2013, 16 cas-is preferred because ﬁxation of the axis（C2）may

es of AARF were diagnosed at Sagamihara3）

not occur with subluxation or dislocation . The

Kyodo Hospital, Kanagawa, Japan. Patients were

etiology may be trauma; however, upper respi-

retrospectively divided into traumatic andratory tract infections and cervical lymphadeni-atraumatic groups according to etiology andtis as well as inﬂammatory diseases of the neck,clinical ﬁndings of AARF in the medical records.

including rheumatoid arthritis and cervical

AARF was diagnosed on the basis of painful

lymphadenopathy due to Kawasaki disease, may

torticollis and CT or 3D‑CT scans through C1‑

8）

trigger AARF . Many studies have addressed

C2 in patients with clinically diagnosed AARF

AARF in the field of orthopedics. However, in

who demonstrated rotatory subluxation of C1

pediatrics, only few authors have reported abouton C2. Outpatients and patients with a bone

AARF, and none have compared cases with dif-fracture or congenital deformity were excluded.

ferent etiologies.

Traumatic factors were deﬁned as an external

The diagnosis of AARF is generally based on

injury, for example, sudden rotation or fall.

cervical CT, particularly 3-dimensional
（3D）
‑CT,

Atraumatic factors were deﬁned as medical con-

whereas MRI can identify ligamentous dam-

ditions or diseases such as inﬂammation or cer-8）

age . Repositioning is possible using an elastic

vical lymphadenopathy.

cervical orthosis and Glisson traction. However,in recurrent cases or those in which reposition-

Clinical Assessment and Treatment Parame-

ing may be impossible, operative treatment may

ters

2）

be required . Unfortunately, delayed treatment

Patient backgrounds and clinical symptoms

may lead to neurological complications, requir-（age, gender, history, height and weight on ad-

7）

ing elaborate operative intervention . Subach etmission, torticollis direction, and rotation direc-

al.
（1998）reported a relationship between the ini-tion）
, cervical CT ﬁndings［atlantodental inter-tiation of primary care and treatment success,v a（l A D I ）a n d r o t a t i o n a n g l e ］, F i e l d i n grecurrence, complications, and prognosis. There-classiﬁcation, duration of treatment（time to initi-

fore, early diagnosis and treatment of AARF

ate treatment, persistence of torticollis, and time9）

are essential .

from the initiation of treatment to the remission

While AARF is a childhood disease, pediatri-of torticollis）, therapeutic modality（compliancecians do not have the necessary information andwith and duration of Glisson traction, initiation

educational tools to diagnose the disease. Thisof use of an elastic harness, and operative treat-ability is generally restricted to orthopedic spe-ment）
, and prognosis（recurrence and complica-

cialists. Therefore, the present study aimed totions）
were examined. The outcomes for each

investigate and compare clinical findings andparameter were compared between the groups.

outcomes of AARF patients by etiology to pro-Moreover, the patients were evaluated for dis-vide pediatricians with valuable for effective

ease severity using Fielding classification. The

treatment.

rotation angle was determined to be right or left

日本小児整形外科学会雑誌 Vol. 23, No. 2, 2014

Atlanto-Axial Rotatory Fixation in Children： Comparison of Clinical Findings and Outcomes by Etiology

from the neutral position of the C1‑C2 joint on

ﬁcients. A p value less than 0.05 indicated statis-

cervical CT.

tical signiﬁcance.

The time to initiate treatment was deﬁned as
the time from the onset of torticollis to the ap-

Results

plication of an elastic harness or the initiation of

Sixteen patients were assigned to a traumatic

Glisson traction. The persistence of torticollis（n = 10, age 6.8 ± 0.6 years）
or an atraumatic（n

was defined as the time from the onset to the= 6, age 6.3 ± 0.4 years）group. In the traumatic

remission of torticollis. The time from the initia-

group, AARF was caused by sudden rotation（ntion of treatment to the remission of torticollis= 5）, neck sprain（n = 4）, or fall（n = 1）. In thewas deﬁned as the time from the application of

atraumatic group, torticollis was caused byan elastic harness or the initiation of Glisson

acute upper respiratory infection（n = 2）,

traction to the remission of torticollis.

parapharyngeal abscess（n = 1）, cervical lymph-

We examined the correlation between the

adenitis（n = 1）, or Kawasaki disease（n = 2）andtime to initiate treatment and persistence of tor-

AARF occurred secondarily（Table 1）. In theticollis in all the patients and examined the cor-traumatic and atraumatic groups, 4（40％）and 4

relation between the time to initiate Glisson（67％）patients were males, respectively. All thetraction and duration of Glisson traction in only

patients had no neurological complication during

those who underwent Glisson traction. We de-treatment. The direction of torticollis was to-

fined remission as the time when AARF re-ward the right in 8（80％）and 4（67％）
patients insolved and persistence when there was no re-the traumatic and atraumatic groups, respec-

mission.

tively（Table 2）. There were no significant differences in other aspects of patient profiles orFielding Classiﬁcation

clinical ﬁndings between the groups. Because 1

AARF is classiﬁed into 4 types:（i）type I, rota-

patient had a medical history of attention deﬁ-

tory fixation without anterior displacement of

cit/hyperactivity disorder, this patient could not

the atlas;（ii）type II, rotatory ﬁxation with ante-undergo Grison traction.

rior displacement of 3‑5 mm;（iii）
type III, rotato-

There were no signiﬁcant diﬀerences in ADI

ry fixation with anterior displacement of more（traumatic group, 3.5 ± 0.3 mm; atraumaticthan 5 mm; and（iv）
type IV, rotatory fixationgroup, 2.7 ± 0.2 mm）
or the angle of rotation on

3）

with posterior displacement .

cervical CT（traumatic group, 21.5 ± 3.4°
; atraumatic group, 17.7 ± 43.8°; Table 2）between theStatistical Analysis

groups. Moreover, there were no signiﬁcant dif-

Data were analyzed using graphpad prism 5

ferences in Fielding classiﬁcation（type I, II, III:for windows（GraphPad Software, La Jolla, CA,

2, 7, 1 patients in the traumatic group and 3, 2, 0USA）
. Data are presented as the mean ± stan-patients in the atraumatic group）. There weredard error of mean
（SEM）or as the median andno patients with Fielding type IV, and none re-range. Parameters between the groups werequired operative treatment. The use of 3D‑CT

compared using Fisherís exact test and Mann‑imaging for AARF diagnosis has increased in

Whitney U‑test. Non-continuous variables werethe last few years（Table 1）,and for example wecompared using Spearman rank correlation coef-

present 3D‑CT findings for cases 13（Figure.
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Atlanto-Axial Rotatory Fixation in Children： Comparison of Clinical Findings and Outcomes by Etiology

Table 1．Patient background
Patient
Age
GenderNo. （years）

Etiology

Time toFielding
ADI Rotation initiation of Glisson
3D‑CT
classiﬁcation （mm） angle（°） treatment traction（days）

1

5.4

Male

Kawasakidisease

No

−

−

−

19

No

2

5.7

FemaleSuddenrotation

No

II

3.7

5.4

2

Yes

3

5.2

Male

Fall

No

II

3.2

−

6

Yes

4

4.2

Male

Neck sprain

No

II

3.9

−

9

Yes

5

5

Female

Fall

No

I

2.3

17.7

1

Yes

6

9.8

Male

Neck sprain

No

II

4.5

11.1

3

Yes

7

5

FemaleSuddenrotation

No

I

2.5

21.1

2

Yes

8

6.5

Male

URI

Yes

II

3.6

25.4

10

Yes

9

7.6

Female

URI

No

II

2.8

23

5

Yes

10

6

Male

Parapharyngeal abscess

No

I

2.2

6.64

3

No

11

8.8

FemaleNeck sprain

Yes

II

3.5

32

4

Yes

12

7.2

FemaleSuddenrotation

Yes

I

2.4

24.5

9

Yes

13

6

FemaleKawasakidisease

Yes

I

2.7

28.3

11

Yes

14

8.4

FemaleSuddenrotation

Yes

I

2.3

30.8

12

Yes

15

3.6

Male

Cervicallymphadenitis

No

I

2.3

12.4

3

No

16

6.5

Male

Suddenrotation

Yes

III

5.5

29.5

5

Yes

Traumatic group（n＝10）,atraumatic group（n＝6）
ADI, atlantodental interval； URI, Upper respiratory tract infection1a）and 16（Figure. 1b）.
The median time to initiate treatment wasthan that in the traumatic group（5 days, range
3‑51 days;= 0.09; Figure. 2c）. However, eachgreater in the atraumatic group（7.5 days, range

interval was no signiﬁcant diﬀerences between

3‑19 days）than in the traumatic group（4.5 days,

the groups（Figure. 2）. Furthermore, no signiﬁ-

range 1‑12 days;= 0.09; Figure. 2a）. The me-cant diﬀerences were observed for these inter-dian length of persistence of torticollis was lon-vals between the groups when compared byger in the atraumatic group（16 days, range 7‑47

Fielding classiﬁcation. In case of 14 patients indays）
than in the traumatic group（10.5 days,

whom Fielding classification could be deter-

range 5‑30 days;= 0.07; Figure. 2b）. The me-mined, the median time to initiate treatment

dian time from the initiation of treatment to thewas 3 days in type （I range 1‑11 days）andremission of torticollis in the atraumatic group5 days in type II（range 2‑12 days）. The persis-

was 7.5 days（range 4‑28 days）
and was longer

tence of torticollis was 13 days in both type I

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Atlanto-Axial Rotatory Fixation in Children： Comparison of Clinical Findings and Outcomes by Etiology

Table 2．Comparison of backgrounds, imaging, Fielding classiﬁcation, and therapeuticmodality between traumatic and atraumatic groups.
Traumatic group（n＝10）

Atraumatic group（n＝6）

Age（years）

6.6±0.6

5.9±0.5

ns

Gender: Male; n
（％）

4（40）

（
4 67）

ns＊

Variable
Patient background/clinical symptoms

History; n
（％）

（10）
1

（
0 0）

−

Height（m）

1.2±0.04

1.1±0.03

ns

Body weight（kg）

19.8±2.1

20.0±1.1

nsTorticollis direction（right）; n（％）

6（60）

（
3 50）

ns＊

Persistence of torticollis（days）

13±2.821.2±5.9

0.09

ImagingADI（mm）

3.5±0.3

2.7±0.2

ns

rotation angle（°）

21.5±3.417.7±3.8

ns

type I; n
（％）

（20）
2

（50）
3

ns

type II; n
（％）

7（70）

（33）
2

ns

type III; n
（％）

（10）
1

（
0 0）

−

Glisson traction; n
（％）

10
（100）

（50）
3

0.06＊

Duration of Glisson traction（days）

7.4±1.4

6.7±0.8ns

Elastic harness; n
（％）

10
（100）

（83）
5

ns＊

Surgery; n
（％）

0（0）

（0）
0

−

Complications; n
（％）

（0）
0

（0）
0

−

Fielding classiﬁcation

Therapeutic method

Traumatic group（n＝10）,atraumatic group（n＝6）
Mean±standard error of the mean
（SEM）
Mann‑Whitney U‑test；＊ Fisherʼs exact test; ns, not signiﬁcant
ADI, atlantodental interval（range 7‑28 days）
and type II（range 5‑30 days）.

0.0005）. In addition, there was a signiﬁcant cor-

The median time from the initiation of treat-

relation between the time to initiate Glisson

ment to the remission of torticollis was 6 days

traction and duration of Glisson traction in only

in type （rangeI4‑25 days）
and 4 days in type II

those who underwent Glisson traction（r2 = 0.45,= 0.0001; Figure. 3）.

（range 3‑24 days）.
All the patients had complaints regarding
wearing an elastic harness or regarding Glisson

Discussion

traction. There were no significant differences

We retrospectively performed a medical re-

between the groups when compared for thera-

cord-based study to compare clinical findings

peutic modality（Table 2）.

and outcomes of 16 AARF cases by etiology. To

In all the patients, there was a signiﬁcant cor-

the best of our knowledge, this is the ﬁrst com-relation between the time to initiate treatment

parative study on pediatric AARF cases in Ja-

2

and persistence of torticollis（ r = 0.60,=

pan. We demonstrate that it is important for pe日本小児整形外科学会雑誌 Vol. 23, No. 2, 2014

Atlanto-Axial Rotatory Fixation in Children： Comparison of Clinical Findings and Outcomes by Etiology

Fig. 1．3D-CT images of cases 13 and 16.
Torticollis direction was toward the right on admission in case 13 and can also be observed from the front（a）.
In case 16, torticollis direction was toward the right on admission； however, the neck was in the median position during remission（b； back view）.

diatricians to suspect AARF when a patient

joint in a rotated orientation. Some pediatric dis-presents with painful torticollis so that early di-eases, particularly, those causing swelling of theagnosis can be made and treatment can be initi-

lymph nodes, present with inﬂammation, articu-

ated as soon as possible.

lar capsule development, synovial inﬂammation,

Various conditions may lead to AARF devel-and swelling were developed AARF. It is as-

opment. In the present study, 6 of 16 cases de-sumed that atraumatic AARF is caused by suchveloped AARF caused by cervical inﬂammatory

inﬂammatory conditions in conjunction with sus-

diseases, such as inﬂammation of the upper re-tained movement restriction caused by cervicalspiratory tract or neck and Kawasaki disease.

pain. However, some cases assessed in the pres-Hicazi et al.
（2002）
reported that 6 of 33 AARF

ent study did not present with lymph nodecases were caused by upper respiratory tractswelling, suggesting that AARF was caused byand tonsil inﬂammation and that 18 cases devel-

another type of inﬂammation.

oped from unknown causes and did not present
4）

Patient backgrounds, clinical symptoms, andwith lymph node swelling . Thus, these inde-

diagnostic imaging results were not signiﬁcantly

pendent studies have consistently suggested

diﬀerent between the traumatic and atraumaticthat AARF is caused by atraumatic conditions.

groups. These ﬁndings indicated that the clinicalWhile various conditions may lead to AARF,

state was not aﬀected by etiology.

the mechanisms underlying AARF have not

AARF diagnosis is necessary to evaluate rota-

been clearly identified till date. Fielding andtory subluxation of C1 on C2 by cervical CT, to

Hawkins（1977）
proposed possible clues to solve

assess the direction and range of rotation and3）

this problem . They hypothesized that early ar-

migration of the atlantoaxial joint, as well as toticular capsule injury, sustained muscle spasm,

diagnose severity on the basis of Fielding classi-

and synovial swelling could cause ﬁxation of the

ﬁcation.

日本小児整形外科学会雑誌 Vol. 23, No. 2, 2014

Atlanto-Axial Rotatory Fixation in Children： Comparison of Clinical Findings and Outcomes by Etiology

Fig. 2．Relationship of treatment and torticollis in traumatic（n＝10）
and atraumatic（n＝6）
groups.（a）Initiationof treatment: 3 days（5-11 days）vs. 10 days（3‑19 days; ＝0.09）；（b）Persistence of torticollis: 7.5 days（5‑30days）
vs. 18 days
（13‑47 days; ＝ 0.07）；（c）Time from the initiation of treatment to remission of torticollis: 4.5
days（3‑24 days）vs. 8 days
（4‑28 days; ＝0.09）. Data are presented as median（range）. Mann‑Whitney U‑test,＜0.05.

The mean age of the patients in the present

torsion angle as well as large proportion of soft

study was 6.6 ± 0.6 years in the traumatic

tissue in the atlantoaxial joint and its suscepti-

group and 5.9 ± 0.5 years in the atraumatic

bility to inflammation;（iii）
horizontal articulargroup. This is similar to the median age of 6.5

surfaces of the lower cervical spine;（iv）
invagi-years of patients in the study conducted by Mi-

nated synovial walls with clear crescentic vas-5）

hara et al.（2001） AARF is indeed observed

culature in the occiput, atlantoaxial joint, andmore frequently in infants and school-age chil-outer atlantoaxial joint; and（v）
direct connection

dren; some reasons for this may include featuresof the pharyngeal lymph vessel to the venous

pertaining to physical development and anato-

plexus and the resultant susceptibility to inﬂam-

my in children, such as（i）insuﬃcient bony struc-mation.

tural support;（ii）loose joint capsule and large

Our results revealed that the duration of tor日本小児整形外科学会雑誌 Vol. 23, No. 2, 2014

Atlanto-Axial Rotatory Fixation in Children： Comparison of Clinical Findings and Outcomes by Etiology

Glisson traction and duration of Glisson traction.
Previous and current results consistently suggest the effectiveness of early treatment of
AARF.
Conclusion
Pediatric AARF can be caused by traumatic
as well as atraumatic events. We provide key
diagnostic information to aid pediatricians in an
early diagnosis of AARF in children presenting
Fig. 3．Correlation between the time to initiate Glisson traction and duration of Glisson traction in only
those who underwent Glisson traction（n＝13, r2＝0.45, ＝0.0001）. Spearman rank correlation coefficient, ＜0.05.

with painful torticollis so that treatment can beinitiated as soon as possible. For eﬀective treatment, we propose that pediatricians should immediately refer pediatric AARF patients to surgeons who specialize in atlantoaxial junction

ticollis in the atraumatic group tended to be lon-

surgery.

ger than that in the traumatic group. This could
be caused by delayed treatment in the atraumatic cases, wherein the primary disease ispreferentially treated before treating AARF.

Acknowledgements
We appreciate all of our co-workers in Sagamihara Kyodo Hospital.

Roche et al.
（2001）
demonstrated that the ease oftreatment of AARF depends on the elapsed
7）time from onset to diagnosis . When diagnosis

Conﬂict of Interest
The authors have no conﬂicts of interest.

is made within 1 week of disease onset, the casecan be simply treated with an elastic cervicalorthosis. When diagnosis takes over 1 week,
traction is required, and when diagnosis takes
over 3 months, surgical treatment is required.
We therefore conclude that early diagnosis, including assessment for severity, is important.
Subach et al.
（1998）
reported that longer durations in initiating treatment resulted in lower
rates of treatment success and higher rates ofrecurrence and complication（13.8 ± 12.1 days
9）
. In the present study, we
vs. 69.7 ± 52.4 days）

also observed a signiﬁcant correlation between
the time to initiate Glisson traction and remission of torticollis. In addition, in only those who
underwent Glisson traction, we observed a signiﬁcant correlation between the time to initiate
日本小児整形外科学会雑誌 Vol. 23, No. 2, 2014

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