腰椎変性すべり症に対するpedicle screw併用後側方固定術の長期成績

Long-Term Clinical Results of Degenerative Lumbar Spondylolisthesis Treated by Posterolateral Fusion Combined with Pedicle Screw Fixation

　腰椎変性すべり症に対するpedicle screw併用後側方固定術後9年以上経過し，直接検診できた31例（男10例，女21例，平均年齢59.8歳）を対象として長期成績を調査した．骨癒合率は100％であったが，術後得られた矯正位は保持されていなかった．平均改善率は54.1％であった．良好な成績を維持した例以外では成績低下因子として隣接高位問題があり，再手術を要した6例（再手術前平均改善率10.6％）と隣接関与症状あり7例（平均改善率24.2％）がみられ，小さな前弯位や後弯位固定角，既存狭窄状況の関与が示唆された．

　We retrospectively evaluated 31 patients―10 men and 21 women (average age, 59.8 years)―with degenerative lumbar spondylolisthesis treated by posterolateral fusion combined with pedicle screw fixation over a mean follow-up of 10.8 years. Fusion was 100％, but corrected sagittal alignment was not maintained during follow-up. Mean recovery was 54.1％. Patients were divided into 4 groups based on postoperative clinical outcome. Six required more surgery for adjacency problems, with mean recovery before the second surgery 10.6％. Seven had some symptoms related to adjacent levels, with mean recovery of 24.2％. Five had asymptomatic abnormal adjacent level motion (identical rate：64.6％). Thirteen patients had no problem (identical rate：66％). The adjacency problem was thus a factor causing poor long-term surgical results. Hypolordotic alignment of the fused segment and preceding canal stenosis of the adjacent level are considered related to the adjacency problem.