腰椎椎間孔狭窄における複数回手術例の検討

The Multiply Operated Back Associated with Lumbar Foraminal Stenosis

　腰椎椎間孔狭窄は診断困難で見逃されることも少なくなく，多数回手術の原因になりうる．そこで腰椎椎間孔狭窄が多数回手術になる原因を検討した．腰椎椎間孔狭窄で手術した21例のうち腰椎手術の既往のある11例を対象とし，各症例で初回手術後の経過・再手術の原因を検討した．初回手術からの症状遺残(見逃し)が5例，脊椎症の進行が4例，初回手術後不安定性の進行が1例，固定隣接椎間障害が1例であった．症状遺残(見逃し)例では同一神経根障害が1例，同一椎間障害が3例，同一椎間の障害の合併が1例であった．

　Entrapment by lumbar foraminal stenosis is difficult to diagnose and may lead to a multiply operated back.　The purpose of this study was to identify the causes of multiply operated back in patients with lumbar foraminal stenosis.

　This was a retrospective study of 21 patients who underwent surgical intervention for lumbar foraminal stenosis, 11 of whom had undergone lumbar surgery before.　The clinical course and reason for reoperation were reviewed in each case.　In 5 cases (45%) in which the symptoms persisted the diagnosis of foraminal stenosis was not made during the first operation (45%).　In the symptoms were caused by the development of spondylosis.　In 1 case it was caused by instability after the initial surgery, and in 1 case it was caused by adjacent segment degeneration after fusion.　Among the 5 cases that were misdiagnosed, in 1 case the sympton was caused by same nerve root entrapment, in 3 cases were it was caused by the same level intracanal or foraminal stenosis, and 1 case it was caused by the same level intracanal and foraminal double lesion.