When should the cervical spine be fused in patients with Rheumatoid Arthritis?
- • Operative stabilization of the rheumatoid cervical spine is indicated in patients with the following structural abnormalities:
- Have atlantoaxial subluxation with a posterior atlantodens interval of ≤14 mm.
- Have atlantoaxial subluxation and at least 5 mm of basilar invagination.
- Have subaxial subluxation and a sagittal diameter of the spinal canal of ≤14 mm.
- • Indications for surgical stabilization based on the presence of neurologic symptoms can be prognostically classified as follows:
- • Ranawat Class I: no neurologic deficits. Neurologic deterioration rarely (10%) occurs. Conservative and surgical outcomes are similar so patients should be treated conservatively with medical treatment of their RA. The 10-year survival rate is 75%.
- • Ranawat Class II: subjective weakness with hyperreflexia and/or dysesthesia. Neurologic deterioration will occur in 67% with conservative therapy. With surgery, 50% improve and 40% stabilize neurologically. The 10-year survival rate is 65%.
- • Ranawat Class IIIA: objective weakness and long tract signs but able to walk. Neurologic deterioration occurs in all with conservative therapy. With surgery, 55% improve and 35% stay the same. The 10-year survival rate is 50%.
- • Ranawat class IIIB: quadriparetic and unable to walk. Neurologic deterioration occurs in all with conservative therapy. With surgery, 60% improve. The 10-year survival rate is 30%.
- • Ranawat Class I: no neurologic deficits. Neurologic deterioration rarely (10%) occurs. Conservative and surgical outcomes are similar so patients should be treated conservatively with medical treatment of their RA. The 10-year survival rate is 75%.
