Atlantoaxial rotatory subluxation

Shekar RoopanKing Dinuzulu Hospital Complex

Introduction

• One of the commonest causes of torticollis

• Characteristically a paediatric problem

• Refers to a facet joint subluxation between C1-C2

Embryology• Caudal sclerotome half of one segment and

cranial sclerotome half of the succeeding segment

• Undergo ossification and chrondrofication passively

• Cranial half of first cervical sclerotome remains as pro atlas

• Proatlas fuses with primitive centra of the atlas forming the odontoid process

Anatomy

Ligaments

Blood supply

The pharyngovertebral veins: an anatomical rationale for Grisel's syndrome.W W Parke ; R H Rothman ; M D BrownJ Bone Joint Surg Am, 1984 Apr

Sternocleidomastoid muscle

Biomechanics• 50% of rotatory movement occurs at C1/2

• Facets smaller and more steeply inclined in children (Kawabe et al)

• Larger head with weak neck musculature in children

• Lax and elastic ligaments and capsules

• Steeles rule of thirds

Terminology

• Rotatory subluxation - most accepted term

• Other names: rotatory dislocation, rotatory displacement

• Rotatory fixation - long standing cases (>3months)

Aetiology

• Upper respiratory infection(Grisel Syndrome)

• Trivial trauma (clavicle fractures)

• Retropharyngeal abscess

• Tonsillectomy

• Pharyngoplasty

Pathology• Watson Jones:

• hyperaemic decalcification of arch of atlas weakens transverse ligament allowing subluxation

• Coutts:

• inflamed synovial fringes prevents reduction when facet sub-luxes

• Ferrani-Gallotta and Luzatti:

• rupture of alar ligaments

• Kawabe Hiroti and Tanaka:

• meniscus like synovial fold in C1/2 facet joint causes subluxation

• Most authors - inflammation and trauma increase laxity of ligaments and capsule

Classification

Fielding and Hawkings

Clinical Presentation• Acute - neck pain,

headache, cock-robin position

• Fixed - pain reduced, torticollis persists

• Long standing - phagocephaly, flat face, vocal changes, difficulty opening mouth

• Neurology - extremely rare

RadiologyX-rays

Radiology

• Cineradiography - high radiation

• CT scan with 3d reconstructions

• Dynamic CTs

• MRI - soft tissue interposition

Differential diagnosis• Torticollis caused by:

• Opthalmologic problems

• Muscular

• Brain stem or posterior fossa tumours

• Spinal cord tumors

• Congenital vertebral anomalies

• Infections of vertebral column

Treatment

Phillips WA, Hensinger RN. The management of rotatory atlanto-axial subluxation in children. J Bone Joint Surg [Am] 1989

Operative• Indications

• Neurological involvement

• Anterior displacement

• Failure to achieve and maintain correction if the deformity exists for longer than 3 months

• recurrence of the deformity after an adequate trial of conservative management

Fielding JW, Hawkins RJ. Atlanto-axial rotatory fixation. J Bone Joint Surg Am 1977

Technique• Halo traction for several days

• No forceful manipulations or reductions

• C1/2 posterior fusion

• Gaille type

• Brookes type

• Postoperatively in halo cast or vest

Gaille vs Brookes

• Gaille preferred as it doesn't reduce space available for the cord (SAC) at C2

• Lesser risk of neurological injury

• Gaille - good overall results

• No significant saggital abnormalities in long term

Fielding JW, Hawkins RJ, Ratzan SA. Spine fusion for atlanto-axial instability.J Bone Joint Surg Am 1976

Parisine P, Di Silvestre M, Greggi T, et al. C1-C2 posterior fusion in growing patients. Spine 2003

• Indications

• Neurological involvement

• Anterior displacement

• Failure to achieve and maintain correction if the deformity exists for longer than 3 months

• recurrence of the deformity after an adequate trial of conservative management

• Staged surgery

• Trans-oral or lateral retropharyngeal approach with release of the atlantoaxial interval (no reduction of subluxation)

• Gradual reduction in skeletal traction post operatively

• Second stage posterior fusion after reduction

• MRI and MRA clearly defined the soft-tissue pathology

Staged reduction and stabilisation in chronic atlantoaxial rotatory fixation; S. Govender, K. P. S. Kumar;J Bone Joint Surg [Br] 2002

• Indications

• Neurological involvement

• Anterior displacement

• Failure to achieve and maintain correction if the deformity exists for longer than 3 months

• recurrence of the deformity after an adequate trial of conservative management

• Larger difference in the lateral mass-dens interval on the initial anteroposterior radiograph compared to those who do not have recurrence

Mihara H, Onari K, Hachiya M, et al. Follow-up study of conservative treatment for atlantoaxial rotatory displacement. J Spinal Disord 2001

Conclusion

• Early diagnosis is important

• Can be treated non operatively or operatively depending on duration

• Staged procedure produces best results for rotatory fixation

Thank You

References

• Lovell and Winters Paediatric Orthopaedics

• Campbells Operative Orthopaedics

• Rockwood and Wilkins fractures in Children