Subaxial lesions in rheumatoid arthritis. Radiographic factors suggestive of lower cervical myelopathy.

STUDY DESIGN

The present study focused on the radiographic and clinical parameters that suggest lower cervical lesions directly or indirectly related to lower cervical myelopathy in rheumatoid arthritis.

OBJECTIVES

The results provided the risk factor for predicting compressive myelopathy due to lower cervical spine lesions in patients with rheumatoid arthritis.

SUMMARY OF BACKGROUND DATA

The clinical pathology and radiographic risk factor for upper cervical myelopathy in rheumatoid arthritis has been well documented, but the compressive factors for lower cervical myelopathy due to subaxial lesions remain unclear.

METHODS

Radiographic analysis on the lateral radiographs (neutral, flexion, and extension) of the cervical spine and neurologic evaluation were carried out in 100 patients with rheumatoid arthritis. Fifty-eight of these patients were followed-up for 5 to 10 years (mean, 5.4 years) radiographically and clinically. A comparative study on the incidence of radiographic abnormalities also was performed in 100 patients with rheumatoid arthritis and in age- and sex-matched patients with cervical spondylosis.

CONCLUSIONS

Among the radiographic parameters of the lesions related to lower cervical myelopathy, marked destruction of spinous processes, axial shortening, and narrow spinal canal may be important factors that suggest myelopathy. Time-related deterioration of lower cervical myelopathy can be predicted by progressions of anterior slip, axial shortening, spinous process erosion, apophysial joint erosion, and intervertebral disc collapse. Younger patient age, longer duration of disease, higher dose of corticosteroid administration, and higher stage or class of rheumatoid arthritis also are thought to be significant general factors for myelopathy.