CHAPTER 17
Atlantoaxial Rotatory Subluxation or Fixation
Introduction/Etiology/Epidemiology
• Atlantoaxial rotatory subluxation, also known as atlantoaxial rotatory fixation, may be a cause of torticollis in older children (acquired torticollis), but it is not common.
• Regional inflammation or trauma can precipitate rotatory subluxation of the C1 facet joints relative to C2, which may become fixed, with an associated torticollis.
— Grisel syndrome, also referred to as viral torticollis, may follow an upper respiratory infection such as otitis media or pharyngitis. It produces inflammation that leads to ligament laxity at the atlantoaxial articulation.
• Atlantoaxial rotatory subluxation should be suspected in any case of new-onset, painful torticollis.
• It can present at any time during childhood, with a peak incidence between 6 and 8 years of age.
Signs and Symptoms
• New-onset, fixed torticollis
• There may be a history of recent upper respiratory infection or recent trauma or surgery, although subluxation can happen spontaneously.
• Pain may be associated, sometimes at rest, but especially while attempting to rotate the head toward the midline.
• A spasm of the sternocleidomastoid muscle may be noted on the side contralateral to the head tilt; this is the opposite of what is seen in congenital muscular torticollis.
Differential Diagnosis
• Less common causes of new-onset, painful torticollis include
— Traumatic injuries, often minor
— Diskitis or osteomyelitis (see Chapter 7, Osteomyelitis)
— Osteoid osteoma or osteoblastoma (see Chapter 58, Common Benign Tumors)
• Eosinophilic granuloma
— Painful torticollis that occasionally presents with neurologic compromise
— Flattened vertebrae (vertebra plana) with bone lysis may be seen on cervical spine radiographs.
— Imaging usually confirms the diagnosis.
— Without neurologic involvement, symptoms typically resolve completely with observation; alternatively, treatment is with a rigid cervical collar to decrease symptoms and maintain alignment.
— Observation, surgery, or medical therapy may be indicated when neurologic compromise is present.
• Cervical and posterior fossa tumors (neurogenic torticollis)
— The torticollis may be acquired or fixed or show rhythmic twisting.
— Photophobia, headache, weakness, and other neurologic signs may be associated (eg, syringomyelia, Arnold-Chiari malformation).
• Juvenile idiopathic arthritis (JIA)
— Neck pain because of cervical spine involvement occurs in about half of patients with polyarticular JIA and frequently in those with systemic onset disease.
— Torticollis is a less common presentation (about 1% of patients with JIA).
— Patients with JIA may be more prone to developing atlantoaxial rotatory subluxation.
— Other radiographic findings can include erosions of the odontoid, ankylosis of vertebrae, and subluxations in the lower cervical spine.
Diagnostic Considerations
• Anteroposterior (AP) and lateral view radiographs of the cervical spine should be ordered first if atlantoaxial rotatory subluxation is suspected.
— Oblique view of C1 and C2 may result; therefore, a lateral view of the skull may be helpful to determine the relationship of C1 and C2.
— Radiography and computed tomography (CT) scan may help differentiate between an atlantoaxial rotatory subluxation and the other conditions noted previously.
• CT scan of C1 and C2 is the definitive imaging study for the diagnosis of atlantoaxial rotatory subluxation.
— It will demonstrate a fixed relationship (with no reducibility) between the facets of C1 and C2, despite rotation in each direction (Figure 17-1).
Treatment
• If symptoms have been present for less than 1 week
— The child may be treated with a soft collar, analgesics, rest, and heat.
— Frequently, spontaneous reduction may occur; however, it should not be assumed, and appropriate follow-up must be facilitated. Delay in treatment can greatly decrease the likelihood of reduction with conservative measures.
• If symptoms have been present for longer than 1 week
— Spontaneous reduction is unlikely to occur.
— A full radiographic evaluation is needed, including AP lateral cervical spine radiographs and, commonly, CT scan.
Figure 17-1. Computed tomography demonstrates a fixed subluxation between the facets of C1 and C2.
©2006 Kaissi AA, Chehida FB, Gharbi H, Ghachem MB, Grill F, Klaushofer K; licensee BioMed Central Ltd Atlanto-axial rotatory fixation in a girl with Spondylo-carpotarsal synostosis syndrome. http://scoliosisjournal. biomedcentral.com/articles/10.1186/1748-7161-1-15. Published October 16, 2006. Accessed September 23, 2020.
— Use inpatient management with cervical halter traction, muscle relaxants, pain management, and close clinical follow-up.
— Reduction is heralded by improved rotational range of motion in the previously restricted direction, and it may be confirmed with a follow-up CT scan.
— Post-reduction management consists of continued nonsteroidal anti-inflammatory drugs and use of a rigid cervical collar for 3 to 6 weeks.
— If halter traction does not yield a reduction, a halo is applied to allow greater traction weight to be applied to facilitate reduction. Reduction is followed by halo vest immobilization for 6 to 12 weeks.
— Finally, if use of halo traction does not facilitate reduction, or if reduction cannot be maintained, atlantoaxial arthrodesis may be performed.
Expected Outcomes/Prognosis
• When reduced promptly, the likelihood of recurrence is low.
• The greater the delay to reduction, the greater the likelihood of requiring more aggressive means to achieve reduction.
When to Refer
• Refer to a pediatric orthopaedic specialist promptly on diagnosis or suspicion of atlantoaxial rotatory subluxation.
Atlantoaxial Instability
INTRODUCTION/ETIOLOGY/EPIDEMIOLOGY
• Atlantoaxial instability (AAI) occurs because of laxity of the transverse and alar ligaments that hold C1 and C2 close together or because of abnormal bony vertebral anatomy.
• Causes of AAI include
— Trauma
—
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
