骨粗鬆症性脊椎椎体骨折後に生じた遅発性神経根症

Delayed Onset Lumbar Radiculopathy after Osteoporotic Spinal Fracture

　骨粗鬆症性脊椎椎体骨折後に生じた腰神経根症の4例を経験した．いずれも骨折部痛が軽快した後で椎間孔部狭窄症が発生していた．一般に同部の診断は難しく，本症例においても高度な下肢痛の原因を特定できなかった．この臨床上の問題点の解決策としてわれわれが着目したのが以下の3つの共通のエピソードである．1．骨粗鬆症性脊椎椎体骨折として保存的治療を受けた．2．骨折部痛が軽快後に歩行時の腰下肢痛が出現する．3．MRIや脊髄造影では明らかな病変を認めない．今回われわれは臨床の現場における注意を喚起する目的で骨粗鬆症性脊椎椎体骨折後の遅発性神経根症という新しい疾患概念を提唱したい．

　We report four cases of delayed-onset lumbar radiculopathy secondary to an osteoporotic spinal fracture.　In all four patients, foraminal and/or extraforaminal stenosis developed after resolution of low back pain caused by the fracture.　However, the lesions that caused the severe radiculopathy in any of our cases could not be recognized in several medical institutes.　The long duration of doctor's delay was recognized as a clinical problem.　The authors realized that the doctor's delay was mainly attributable to the difficulty in identifying this type of stenosis with routine imaging studies, so that it appears important to recommend to all doctors to pay attention to the patients' unique history in our cases.　It consists of three episodes, which are osteoporotic spinal fracture, delayed-onset lumbar radiculopathy, and no apparent lesions in imaging studies.　These are the key to success to identify foraminal and/or extraforaminal lesions in this disease condition.