頚椎症性脊髄症に対する椎弓形成術の脊髄除圧効果についての検討

Spinal Cord Decompression Effect Following Laminoplasty for Cervical Spondylotic Myelopathy

　抄録：頚椎症性脊髄症に対して頚椎椎弓形成術を受けた104例について，術前後の各高位における脊髄横断面積や前方くも膜下腔の変化を調査し，神経症状改善との関連を検討した．術前の脊髄横断面積が著しく小さい症例の症状改善は不良であったが，術後の脊髄面積や拡大率は臨床成績と相関しなかった．一方，脊髄前方のくも膜下腔が術後も増大しない症例の成績は劣っており，脊髄前方の血流や髄液流の改善が脊髄機能回復にとって重要と推察された．本術式においては，頚椎や頚髄のアライメントのほか，それらの相互位置関係の変化に注意する必要がある．

　Morphological and clinical evaluations were performed in 104 cases of cervical spondylotic myelopathy treated by expansive laminoplasty. Patients with much smaller spinal cord dimension preoperatively had significantly poorer neurological recovery, however, neither the postoperative spinal cord dimension nor its expansion rate was significantly correlated with neurological recovery rated by the Japanese Orthopaedic Association scoring system (JOA score). Increased anterior subarachnoid space was instead found to be significantly correlated with neurological recovery after the laminoplasty. These findings support our hypothesis that increased blood supply to the anterior aspect of the spinal cord and better cerebrospinal fluid circulation are responsible for improving the condition of the spinal cord after laminoplasty. Thus, greater attention should be paid not only to cervical alignment but to spinal cord alignment and to spatial relationships between the spinal column and the spinal cord.