Vertical translocation. Part II. Outcomes after surgical treatment of rheumatoid cervical myelopathy.

This is a prospective observational study in 116 patients with rheumatoid arthritis and vertical translocation who underwent cervical spine surgery after developing symptomatic myelopathy. These patients, whose mean age was 62 years, had suffered from rheumatoid arthritis for almost 25 years. Surgery was performed via a combination of anterior (67 transoral decompressions) and posterior approaches. Surgical morbidity was recorded in 39% of patients, with a 30-day mortality rate of 10.3%, which was largely related to poor preoperative neurological grade. Neurological improvement of at least one Ranawat class was observed in 55 patients. Univariate analysis revealed the following clinical variables to be associated with a good neurological outcome (Ranawat class): younger age and good preoperative muscle power. Significant radiological variables included the degree of vertical translocation as measured by the Redlund-Johnell method and the preoperative spinal cord area. The degree of transgression in the foramen magnum did not significantly affect neurological outcome. Neither the anterior nor the posterior atlantodens interval predicted neurological recovery. Multiple logistic regression models were constructed based on the preliminary evidence of the authors' univariate analysis and these confirmed the importance of preoperative neurological function, spinal cord area, and the degree of vertical translocation in influencing the final neurological grade.