Vertical mobile and reducible atlantoaxial dislocation. Clinical article

Area of Science:

• Neurosurgery
• Orthopedics
• Spinal Surgery

Background:

• Atlantoaxial dislocation (AAD) is a complex spinal condition.
• Vertical mobile and reducible AAD presents unique challenges in diagnosis and management.
• Understanding the pathogenesis is crucial for effective treatment strategies.

Purpose of the Study:

• To review the authors' experience with 8 patients treated for vertical mobile and reducible atlantoaxial dislocation.
• To discuss the probable pathogenesis, radiological and clinical features, and management of this condition.
• To evaluate the efficacy of posterior fixation in the reduced dislocation position.

Main Methods:

• Retrospective review of 8 patients treated between January 2006 and March 2008.
• Grading of dislocation (mild, moderate, severe) based on odontoid process migration and instability index.
• Surgical treatment using C-1 lateral mass and C-2 pars plate and screw fixation.

Main Results:

• The study included 5 males and 3 females (mean age 24 years).
• Common symptoms included short neck, torticollis, neck pain, and quadriparesis; 6 patients had a history of trauma.
• All patients showed clinical neurological improvement following posterior fixation surgery, with follow-up ranging from 4 to 30 months.

Conclusions:

• Vertical mobile and reducible atlantoaxial dislocation is a distinct clinical entity.
• Abnormal facet joint inclination and incompetence are likely primary causative factors.
• Posterior fixation in the reduced dislocation position is the cornerstone of successful treatment.