Related Experiment Video
Updated: Jun 19, 2026

Minimally Invasive Treatment for Thoracolumbar Burst Fracture Using Sagittal Alignment Screws and A Trauma Reduction Device
Published on: November 8, 2024
The clinical picture of atlantoaxial subluxation changes when atlantoaxial impaction develops
Erja M Lehto1, Sirkka Heikkilä, Hannu Kautiainen
1Department of Rheumatology, Rheumatism Foundation Hospital, Pikijarventie, 18120 Heinola, Finland. erja.lehto@uta.fi
Objectives:
The objective of the study was to evaluate the clinical picture of rheumatoid patients with anterior atlantoaxial subluxation (aAAS), atlantoaxial impaction (AAI) or their combination.
Patients:
There were 156 patients. aAAS was diagnosed from standard lateral-view cervical spine radiographs during flexion. AAI was diagnosed from radiographs by the Sakaguchi-Kauppi method. Cervical range of motion was measured and patients' functional disability evaluated. Intensity of the neck pain was evaluated. Clinical data was collected from patient records.
Results:
aAAS was detected in 138 (88%) of all patients and AAI in 69 (44%), respectively. Forty (48%) patients with severe aAAS had additional AAI, whereas 11 (21%) patients with slight or moderate aAAS had AAI. Range of the neck motion (ROM) was lower in patients with AAI compared with patients with aAAS alone. Rotation (p<0.001) and lateral flexion (p=0.006) were more limited in patients with AAI. Practically normal rotation (> or =120 degrees) was seen in 16 (18%) of patients with aAAS and four (6%) of patients with AAI. Patients with AAI without aAAS had both limited mobility and high intensity of neck pain.
Conclusion:
Patients with atlantoaxial disorders may be painless. Neck pain, which is induced in upright position and relieved during bed rest, is most often due to AAI. ROM may be normal in plain aAAS while rotation is typically reduced when AAI develops.
Related Concept Videos
Articulations of the Vertebral Column
Aneurysm II: Clinical Manifestations and Diagnostic Studies
Herniated Intervertebral Disc l: Introduction
General Case of Eccentric Axial Loading
Consider a member subjected to equal and opposite forces that are applied along a line that does not coincide with the member's neutral axis. In unsymmetrical bending,...
Impact
When particles with different initial velocities collide, they induce deformation by applying equal and opposite impulses. At the point of maximum deformation, the particles move together with...
Secondary Spinal Cord Injury llI: Pathophysiology