自然経過の観点からみた関節リウマチ―上位頚椎病変に対する手術の影響

Surgical Treatment of Upper Cervical Lesions in Patients with Rheumatoid Arthritis and Effect on the Natural Course of the Disease

　上位頚椎病変により脊髄症状を呈した関節リウマチ患者に対する後頭頚椎固定術が患者の自然経過に及ぼす影響を検討した．対象は後頭頚椎固定術46例と非手術例25例の計71例であり，ムチランス型の症例が手術例で11例，非手術例で8例あった．術後のX線変化としてムチランス型の症例では術後の軸椎下脱臼の出現が明らかに多く，手術による脊髄症状の改善についても非ムチランス型に比べ有意に不良であった．患者の生命予後は非ムチランス型の症例では手術を行うことにより明らかに改善していたが，ムチランス型の症例の生命予後を改善させるまでの効果はなかった．この手術は非ムチランス型の症例については自然経過に良い影響を与えたといえるが，ムチランス型の症例については限界があった．

　The long-term outcome of rheumatoid arthritis patients with upper cervical lesion treated by occipitocervical fusion and nonsurgically was compared to evaluate the significance of this operative procedure. The subjects were 46 patients with rheumatoid arthritis who exhibited myelopathy caused by atlantoaxial dislocation that was treated by occipitocervical fusion and 25 rheumatoid arthritis patients who exhibited myelopathy caused by atlantoaxial dislocation that was not treated surgically as control. There were 11 cases mutilans type rheumatoid arthritis in the operated group and 8 cases in the non-operated group. The patients were followed up until their death. The incidence of postoperative subaxial subluxation was significantly higher in the mutilans group than in the non-mutilans group. In the non-mutilans group, spinal cord symptoms were alleviated in 25 of the 35 cases (71％). In the mutilans group, they were alleviated in only 4 cases, remained unchanged in 3 cases, and were exacerbated in 4. The postoperative survival time of the patients with mutilans type rheumatoid arthritis was markedly shorter than in the non-mutilans group. Occipitocervical fusion is effective treatment for patients with non-mutilans type rheumatoid arthritis, but the results among patients with mutilans type rheumatoid arthritis became poorer over time.