頚椎症性脊髄症に対する単椎間（2椎弓）の棘突起縦割式脊柱管拡大術の手術成績―単一責任高位のみの後方除圧術

Mono-Segmental Laminoplasty for Cervical Spondylotic Myelopathy : Outcome of the Posterior Decompression for the Single Symptomatic Segment

　抄録：われわれは，1996年から頚椎症性脊髄症に対し適応を厳選して単一責任高位のみの棘突起縦割式脊柱管拡大術を行っている．症例は男性6例，女性4例で，手術時年齢は平均60歳，罹病期間は平均1.8年，術後経過観察期間は平均1.6年である．拡大椎間は，C3/4，4/5，5/6，C6/7がそれぞれ2，2，5，1例である．手術時間は平均1.8（1.2～2.5）時間，術中出血量は平均59（5～200）gであった．JOAスコアは術前11.0±2.1点が，術後14.8±1.6点と有意に改善し，平林らの改善率は65.8±23.1％であった．C2-7間での前弯角は，術前8.1±12.1°が術後14.6±14.3°に，前後屈可動域は，術前37.1±12.6°が，術後平均31.0±12.1°になり，ともに有意差を認めなかった．術後の責任高位での脊髄後方移動距離は，MR画像上で2.39±0.97mmであった．本術式は，頚椎症性脊髄症に対して頚椎の構築性に対する最小限の侵襲で良好な臨床症状の改善が認められた．

　Central splitting laminoplasty in a single symptomatic segment has been performed for cervical spondylotic myelopathy in our institution since 1996. Six men and 4 women were evaluated in the current study. The mean age at surgery, duration of the symptoms and postoperative follow-up period was 60 years, 1.8 years and 1.6 years, respectively. Operation was carried out at C3/4, 4/5, 5/6 and 6/7 in 2, 2, 5 and 1 patients. Operating time ranged from 1.2 to 2.5 hours (average, 1.8). Intraoperative blood loss ranged from 5―200g (average, 59). JOA score has significantly improved from 11.0±2.1 to 14.8±1.6 points, and its recovery rate was 65.8±23.1％. The lordotic angle in C2-7 has changed from 8.1±12.1°to 14.6±14.3°. The range of motion in C2-7 has changed from 37.1±12.6°to 31.0±12.1. But there were no significant differences between the preoperative and postoperative values. The value of posterior shift of the spinal cord at the symptomatic level was 2.39±0.97mm on MRI. An excellent result was obtained with a minimum invasion to the cervinal spine in this procedure.