経腸骨稜アプローチで対応したhigh iliac crestを伴った左第5腰椎-第1仙椎椎間孔部狭窄症の1例

Trans-iliac Crest Approach by Spinal Microendoscopy to Avoid Destruction of Posterior Bony Elements in Foraminal Stenosis at L5-S1 with a High Iliac Crest. Case Report

　症例は76歳の男性で，左下肢痛と間欠跛行を主訴とする左第5腰椎-第1仙椎(L5-S1)腰椎椎間孔部狭窄の1例である．脊椎内視鏡下後方除圧術を計画したが，high iliac crestの存在により椎間孔外からの円筒レトラクターの適正設置が妨げられ，神経除圧に際して峡部・椎間関節の破壊が懸念された．そのため，われわれは脊椎内視鏡下に腸骨稜を掘削することで円筒レトラクターの通過路を作製し，峡部・椎間関節を温存したまま椎間孔内外の神経除圧を達成することに成功した．本アプローチはhigh iliac crestを伴う症例において医原性不安定症を回避する一手法として推奨できる．

　It is well known that the extraforaminal approach at L5-S1 is challenging because of anatomical limitations, such as the back muscle mass and prominence of the posterior iliac crest.　We report a case of lumbar foraminal stenosis in which it was difficult to position a tubular retractor in the extraforaminal space because of a high iliac crest.　Because of the possibility that nerve decompression at the expense of the posterior bony elements might cause subsequent spinal instability, we created a route by drilling a hole through the iliac crest in order to be able to position the tubular retractor outside the foramen.　As a result we were able to leave the isthmus and facet joint intact and achieve a good postoperative clinical outcome.　The trans-iliac crest approach with a spinal microendoscope that avoids destruction of the posterior bony elements is a good approach for the treatment of foraminal stenosis at L5-S1 in patients with a high iliac crest.