CASE REPORT

Delayed diagnosis of atlanto-axial rotatory subluxationwith subsequent occipito-atlantal rotatory subluxation

Anil Singh Dhadwal & Andrew Clarke & Abhinav Singh &

Dan Chan & Mike Hutton

Received: 12 November 2013 /Accepted: 31 March 2014# EFORT 2014

Introduction

Acquired torticollis in the paediatric population has a varietyof aetiologies, yet often causes the same anatomical derange-ment of the atlanto-axial joint. Delayed diagnosis can lead tothe occipito-atlantal joint trying to accommodate the torticol-lis, leading to instability of this joint. We report the case of aboy referred to our Regional Paediatric Spine service.

Case report

A fit and well 13-year-old male developed a right-sided torti-collis 6 months prior to referral to the Peninsula Spine Unit.Both the patient and his family could not remember anypredisposing events such as traumatic injury nor recent upperrespiratory tract infection.

The patient had been reviewed by his local paediatricservice, and a magnetic resonance scan had been performedon both brain and cervical spine. This was reported as normal.Four months later, he was assessed in the paediatric orthopae-dic service at the same institution. His case was then discussedwith our unit and a computerised tomogram (CT) scan wasarranged. This showed an atlanto-axial rotatory dislocationwith subluxation of the occipito-atlantal joint (Fig. 1).Immediate referral was made to the Regional PaediatricSpine Unit.

The patient was admitted the following day for clinicalassessment and application of halo traction. Reviewing thehistory, there were no aetiological clues as to the cause of therare entity. Clinical examination confirmed the rigidtorticollis.

Halo traction was applied under general anaesthesia, alongwith an attempt at a closed reduction with direct digital pres-sure upon the C1 lateral mass in the oropharynx. Over thecourse of 2 weeks, the deformity reduced. A CT scan postreduction showed near anatomical reduction (Fig. 2).Therefore, at 3 weeks, he was placed into a halo jacket.At follow-up 6 weeks later, a repeat CT scan showedsubluxation of the occipito-atlantal joint complex. Afterdiscussion within our unit and the wider global paedi-atric spine community, a decision was taken to place thepatient back on halo traction, followed by operativestabilisation of the occiput to axis.

The patient, under general anaesthesia, was placed proneon a Montreal mattress, with a Doro clamp (Schaerer MedicalAG, Switzerland). The patient was prepped from the skull tothe mid subaxial spine. Atlanto-axial fixation was achievedusing a surgical technique described by Harms in 2001 [1]developed to combat the demands of stabilising atlanto-axialrotatory fixation and possible intraoperative vertebral arterytrauma. The technique used a posterior approach to the cervi-cal spine inserting polyaxial screws into the lateral masses ofC1 and the pars interarticularis of C2. These were thenconnected with rods bilaterally to provide stability oncescrew position and reduction were confirmed with imageintensifier. The equipment used in the procedure wasMountaineer System, provided by DePuy-Synthes™(Raynham, MA), which allowed extension of fixation tothe occiput following reduction of the occipito-atlanto-axial complex (Fig. 3).

At latest follow-up, 7 months after C0–C2 fusion, reduc-tion of the deformity is maintained with no prosthetic

A. S. Dhadwal (*) :A. Clarke :D. Chan :M. HuttonPeninsula Spine Unit, Princess Elizabeth Orthopaedic Centre, RoyalDevon and Exeter Hospital, Barrack Road, Exeter EX2 5DW, UKe-mail: anil.dhadwal@gmail.com

A. SinghThe Peninsula College of Medicine and Dentistry, University ofExeter and University of Plymouth, John Bull Building, ResearchWay, Plymouth, Devon PL6 8BU, UK

Eur Orthop TraumatolDOI 10.1007/s12570-014-0249-z

Fig. 1 Computed tomography:a axial image illustrating atlanto-axial rotation and (b) three-dimensional reconstruction illus-trating compensatory occipito-atlantal subluxation

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complication. The patient has forward gaze, normalswallowing function, a pain free neck and has returned tophysical activity (Fig. 4).

Discussion

Atlanto-axial rotatory fixation (AARF) has been well docu-mented and discussed in the literature since 1830. Occipito-atlantal axial rotatory fixation (OAARF), however, is rare withonly a handful of reports in the world literature since 1959.The joint complexes from the occiput to the axis are the mostintricate of the axial skeleton [2]. Whilst little rotation occursat the occipito-atlantal joint, this increases in chronic cases ofAARF fixation [3].

Fig. 2 Computed tomography: post reduction coronal slice illustratinganatomical reduction

Fig. 3 Intraoperative plain film lateral roentgenograph illustrating thesurgical fixation of the occipito-atlanto-axial complex

Fig. 4 Imaging at 7 months illustrating successful correction of defor-mity and correct alignment of prosthesis. a Weight-bearing plain filmlateral roentgenograph. b Computed tomography: coronal view

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It has been observed that atlanto-axial rotatory deformitiesare usually short lived and correct easily [4]. However, ifallowed to persist, the resultant torticollis can be resistant totreatment. Hence, early diagnosis and treatment are the keys tosuccessful treatment [5]. A persistent torticollis should raisesuspicions in the treating spine surgeon of an occipito-atlantalinstability [5, 6]. A reverse rotation of the occipito-atlantaljoint complex has been reported in chronic cases relative to theatlanto-axial rotation [7].

Chechik et al. [8] have recently proposed an algorithmcentred on conservative treatment for neglected rotatoryatlanto-axial dislocation. They had success in patients withup to 4 months of AARF.

Surgical strategies for the treatment of this delayed presen-tation are debated. However, there is a paucity of publishedliterature on long-term follow-up. Occipito-axial fusion is afunctionally limiting operation. It dramatically reduces cervi-cal spine movements, as the occipito-atlanto-axial arrange-ment is responsible for greater than 50% of flexion, extensionand axial rotation [2].

Conclusion

This case report reinforces the consequences of delayed diag-nosis of atlanto-axial rotatory subluxation and highlights thechallenge that the management of chronic torticollis can pro-vide in the paediatric age group. If early recognition andinvestigation of atlanto-axial subluxation takes place, halotraction can be applied with good reduction. The duration oftraction will be shorter, more successful, and the necessity foropen reduction and internal fixation less, as compensatorymechanisms have not had the opportunity to evolve.

For a persistent AARF with OAARF, we advocate anoccipito-axial fusion as a successful, though movement limit-ing, surgical intervention. More important, however, is theprompt identification and management of an acquired torti-collis thus preventing such a procedure ever having to beperformed and the implications of surgery on a child’s devel-opment and future quality of life.

Conflict of interest The authors declare that they have no conflict ofinterest.

References

1. Harms J, Melcher RP (2001) Posterior C1-C2 fusion with polyaxialscrew and rod fixation. Spine 22:2467–71

2. White AA, Punjabi MM (1990) Clinical biomechanics of the spine.Philadelphia, JB Lippincort Company, Second Edition 92

3. Pang D, Li V (2005) Atlantoaxial rotatory fixation: Part 3—a prospec-tive study of the clinical manifestation, diagnosis, management andoutcome of children with atlantoaxial rotatory fixation. Neurosurgery57:954–972

4. Fielding JW, Hawkings RJ (1977) Atlantoaxial rotatory fixation. JBoint Joint Surg 59(1):37–44

5. Clark CR, Kathol MN, Walsh T et al (1986) Atlanto-axial rotatoryfixation with compensatory counter occipitoatlantal subluxation. Acase report 11(10): 1048–1050

6. Fusco MR, Hankinson TC, Rozelle CJ (2011) Combinedoccipitoatlantoaxial rotatory fixation. Case report. J NeurosurgPaediatrics 8:198–204

7. Ono K, Yonenobu K, Fuji T et al (1985) Atlantoaxial rotatory fixation.Radiographic study of its mechanism. Spine 10(7):602–608

8. Chechik O, Wientroub S, Danino B et al (2013) Successful conserva-tive treatment for neglected rotatory atlantoaxial dislocation. J PaediatrOrthop 33:389–392

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