アテトーゼ型脳性麻痺における頚髄症の手術的治療―椎弓形成術の適応と限界

Outcome and Limitations of Laminoplasty Surgery Alone for the Treatment of Athetoid Cerebral Palsy Patients

　過去の10年間にアテトーゼ型脳性麻痺（ACP）患者の頚髄症に施行した椎弓形成術16例を対象とした．手術成績はJOAスコア17（－2）点法で評価した．頚椎前弯度，可動域，C2/3～C6/7の不安定性，前屈位での環椎歯突起間距離（ADI）をX線学的に計測した．JOAスコアは約2点改善していたが，手指運動，下肢知覚，膀胱機能では有意な改善はなかった．頚椎前弯度と可動域は術後減少したが，C2/3～C6/7高位での不安定椎間数は術後1/8に減少した．C1/2での不安定性を術前に認めた4例すべてで，術後の前屈位ADIが増加した．本法はACP患者に対しても良好な制動効果を認めるが，術前にC1/2の明らかな不安定性を認める症例では適応にならない．

　The aim of this study was to clarify the surgical outcome of midline laminoplasty without fusion, followed by a 3-month postoperative application of the Halo-vest, for the treatment of cervical myelopathy in athetotic cerebral palsy (ACP9 patients. Sixteen ACP patients (11 men and 5 women；average age, 44.6 years) were included in this study. For clinical evaluation, the Japanese Orthopaedic Association (JOA) score〔full marks, 17 (－2) points〕was used. The cervical lordortic angle and ROM were evaluated using lateral X ray views. The magnitude of the AP translation of the vertebral segments from C2/3 to C6/7 was measured using flexion-extension views to represent the lower cervical stability. The atlantodental interval in the flexion position (ADI flex.) was measured to represent the upper cervical segmental instability. The total JOA scores improved from 8.7±2.5 to 10.8±2.9 after surgery. Each element of the scores improved, but the improvements in finger motor function, lower extremity sensory function, and bladder function were not statistically significant. The cervical lordotic angle and ROM decreased postoperatively. Sixteen lower cervical segments in 10 patients were judged unstable before surgery；this number was reduced to only 2 segments (2 patients) after surgery. In 4 patients whose preoperative ADI flex. was greater than 3mm, the ADI flex. increased postoperatively. Our operative procedure, laminoplasty without fusion, provided the ACP patients with good clinical results and had a stabilizing effect on the cervical spine. For cases with apparent C1/2 instability, this operative procedure may be contraindicated, since the development of instability is a concern.