腰椎変性すべり症に対する前方固定術後の再手術例の検討

The Reasons for Reoperation Following Anterior Lumbar Interbody Fusion for Degenerative Spondylolisthesis

　腰椎変性すべり症に対し前方固定術を施行した33例を対象とし，術後臨床成績と再手術の原因を調査した．治療成績はJOAスコア（日常生活動作を除いた15点満点）で，術前平均7.2点から術後1年で12.4点と改善した．10年以上の最終調査時では10.8点であり，術後経過は概ね良好であるものの，長期的にはやや低下する傾向が認められた．術後再手術症例を5例（15.2％）に認めた．隣接椎間障害3例，隣接椎間板ヘルニアの遺残1例，有症性偽関節1例が再手術となった．隣接椎間障害は術後1年9カ月から12年で再手術を受けており，全例に後方除圧術を追加施行し，症状は改善した．

　There have been many follow-up studies on anterior lumbar interbody fusion (ALIF) for the spondylolisthesis, and excellent clinical outcomes have been reported. However, some cases have required reoperation during the follow-up period. A total of 33 patients could be followed up for two years or more (average：5.4 years). Eight were male and 25 were female and their average age at operation was 55.1 years (range：47-69 years). The Japanese Orthopaedic Association Low Back Pain Score (JOA score without restriction of ADL, perfect score：15 points) was used to evaluate the outcome. The mean JOA score was 7.2 points before surgery, 12.4 points 1 year after surgery, and 10.8 points at final follow-up. Reoperation was necessary in 5 cases (15.2％). Symptomatic adjacent segment disease developed in 3 cases (13％). Symptomatic delayed union was observed in 1 case, and adjacent remaining disc herniation required repeated surgery in 1 case.