非骨傷性頚髄損傷に対する頚椎椎弓形成術の術後成績

Surgical Results of Open-Door Laminoplasty for Cervical Cord Injury without Fracture or Dislocation

　抄録：X線上明らかな骨傷のない頚髄不全損傷手術例で，術後1年以上追跡可能であった29例を対象とし，受傷後3カ月未満に手術を施行した群（17例）と受傷後3カ月以降に手術を施行した群（12例）に分け術後成績を比較検討した．後者の群では全例，受傷後にみられていた脊髄麻痺の自然回復は停止していたが，手術により麻痺の改善が得られた（改善率34.0％）．前者での改善率は46.9％で，両群間に有意差はなかった．MRIで髄内輝度変化領域として脊髄損傷高位が確認された症例は16例であった．脊髄損傷高位と頚髄に圧迫を認める高位が一致した7例での平均改善率は57.3％，一致しない9例での改善率は31.1％で，前者が高い傾向にあったが有意差はなかった．本症に対する頚椎椎弓形成術は，慢性期においても，また，MRIでの髄内輝度変化高位と頚髄圧迫高位が異なる症例においても有効であった．

　The purpose of this study is to evaluate the efficacy of spinal cord decompression surgery for cervical spinal cord injury without fracture or dislocation of the spinal column. 29 patients treated by expansive open-door laminoplasty are the subjects to this study. Severity of neurological deficit was assessed by the Japanese Orthopaedic Association (JOA) scoring system. Therapeutic outcome was evaluated by the recovery rate of JOA score. 17 patients were treated by surgically during the acute phase (within three months after injury), and the remaining 12 were in chronic phase (after 3months). The recovery rate showed no significant difference between the two groups (46.9％ vs. 34.0％). In 16 patients, the lesion responsible for spinal cord damage was recognized as a change of the intramedullary signal intensity on MRI, which was most frequently located at C3/4 level. In 7 out of the 16 patients, the most stenotic level agreed with recognized cord injury on MRI, and in the remaining 9 patients, it did not. The recovery rate showed no significant difference between the two groups (57.3％ vs. 31.1％). Even if the neurological dysfunction has been present more than 3months and spontaneous improvement reaches plateau, or spinal cord injury level recognized as a signal intensity change on MRI is not stenotic, there is still some possibility for improving the neurological function through surgery.