関節リウマチ軸椎下病変に対する脊柱管拡大術の治療成績と問題点

Surgical Results and Problems of Laminoplasty for Subaxial Lesion in Rheumatoid Arthritis

　抄録：関節リウマチ軸椎下病変により脊髄症状を呈した19例に対して脊柱管拡大術を行った．術後に頚椎可動域は61.2％に減少し，術後の弯曲異常や不安定性の進行は少なく，おおむね満足すべき結果が得られた．したがって脊柱管拡大術は，その除圧と制動効果によって関節リウマチ軸椎下病変に対する有効な手術方法と考えられた．しかし，術前から後弯のみられた症例ではその進行が認められたことから，本法の適応は少ないと考えられる．また，術後に椎間強直が生じた症例では隣接椎間に不安定性や狭窄が生じる可能性がある．

　Expansive laminoplasty of the cervical spine was performed for 19 patients with subaxial lesion in rheumatoid arthritis. The clinical results were satisfactory, and radiographic evaluation revealed that the range of motion of the cervical spine decreased to 61.2％, spinal alignment was well preserved, and intervertebral slipping advanced only slightly, showing that, expansive laminoplasty is clinically effective for decompressing the subaxial spinal cord without the need for fusion in the region. For the patients with upper cervical instability, laminoplasty with upper cervical fusion appears to be an effective option. In the case in which kyphosis was present preoperatively, the deformity became worse after laminoplasty, and thus, it may be advisable to consider subaxial fusion in such cases. Stenosis or instability of the neighboring intervertebral space can occur if unintended intervertebral ankylosis develops following expansive laminoplasty.