Atlantoaxial subluxation or dislocation/Atlantoaxial instability

Atlantoaxial subluxation or dislocation refers to a loss of stability between the atlas and axis. In simpler words, it is a disorder of C1–C2 that results in loss of normal articulation and causes impairment in neck rotation.

Cause of Atlantoaxial subluxation or dislocation

The atlantoaxial joints can lose stable articulation due to any of the following reasons:  

• Trauma from forced displacement of the neck or head injury
• Inflammatory conditions like chronic rheumatoid arthritis patients, particularly adults
• Upper respiratory tract infection
• Congenital abnormalities like down syndrome, skeletal dysplasia or congenital osseous abnormalities
• Tumor
• Idiopathic   

Symptoms of Atlantoaxial subluxation or dislocation

• Neck pain
• Restricted neck movement
• Weakness and/or numbness
• Sphincter disturbances
• Respiratory distress or failure
• Paralysis
• Death   

Diagnosis of Atlantoaxial subluxation or dislocation

Diagnosis requires thorough evaluation of the symptoms along with physical and neurological examination of the patient. In addition to this, following diagnostic tests may help in confirmation of the diagnosis:  

• X-Ray
• CT scan
• MRI

Treatment of Atlantoaxial subluxation or dislocation  

Treatment depends upon the symptomatic or asymptomatic condition of the patient and may include:  

• Non-operative treatment like
  • Soft collar
  • Cervical halter traction in the supine position
  • Active range-of-motion exercises for 24 to 48 hours
  • Ambulatory orthotic immobilization with active range-of-motion exercises until free motion returns  
  • Halo bracing
• Operative treatment options for fusion of C1 and C2 include:  
  • Trans articular screws (TASs)
  • Screw-rod constructs (SRCs)  
  • Posterior sub laminar wiring  
  • Halifax clamp 

Authored by Dr. Shyam Sundar K