腰椎後弯変形に対する脊椎短縮骨切り術の検討―最近4年間に行われた46例の術後調査から

Clinical Outcomes after Pedicle Subtraction Osteotomy for Fixed Sagittal Imbalance

　腰椎短縮骨切り術を行った46例を調査した．平均年齢は71歳，平均手術時間は190分，平均出血量は883mlであった．骨切り角は平均33°，腰椎前弯は平均21°矯正された．平均26カ月間の観察期間中で続発性骨折が11例，インプラント折損が3例，深部感染が2例発生し，再手術は4例行われた．手術で腰椎アライメントは改善されたが，手術部位以外での後弯進行のため，脊椎全体のアライメント改善は不十分であった．日本整形外科学会腰痛治療成績判定基準(JOAスコア)の改善率は44％であった．種々の問題を有してはいるが，本法は腰痛やADL障害の改善が得られる患者満足度の高い方法である．

　The purpose of this study was to evaluate the surgical outcomes of patients who underwent pedicle subtraction osteotomy (PSO) for lumbar kyphosis.　Between July 2006 and January 2010, 46 PSO procedures were performed in our hospital.　The mean age of the patients at the time of surgery was 71 years, and the average follow-up period was 26 months.　The mean number of fixed segments was 5.6.　Mean operation time was 190 min, and mean intraoperative blood loss was 883ml.　The mean osteotomy angle was 33 degrees, and the mean improvement in lumbar lordosis was 21 degrees.　A secondary compression fracture developed in 11 cases.　Implant breakage occurred in 3 cases, and deep infection in 2 cases.　Patient satisfaction with the operation was obtained in 81% of the cases.　Although lumbar lordosis was effectively improved by PSO, it was difficult to maintain the C7 plumb line in an position because of progression of the kyphosis in other parts of the spine.　Nevertheless, PSO was a very effective procedure that relieved back pain and improved ADL impairments.