保存的加療後に外科的治療を要した環椎破裂骨折（Jefferson fracture）の2症例

Atlas Burst Fracture (Jefferson Fracture) Requiring Surgical Treatment after Conservative Treatment—Report of Two Cases

Ⅰ．はじめに

　環椎破裂骨折（Jefferson fracture）は比較的稀な脊椎の骨折で^2），治療法の選択については多様な見解がある．環椎破裂骨折のみの例の大部分は，環軸椎亜脱臼などの不安定性を来すことは少なく，治療はhalo vestなどの外固定が有効で，手術が必要となることは稀であるz^{1,2,4,6,9,11）}．

　今回，保存的加療の後に外科的治療を要した環椎破裂骨折の2症例を経験したので，治療上の問題点と手術のタイミングにつき若干の考察を加え報告する．

Most cases of atlas burst fracture do not require surgical stabilization, because they can be successfully treated with external immobilization. The authors present two cases of atlas burst fracture in which surgical stabilization was required after external immobilization. The first patient was a 50-year-old male and the second patient was a 34-year-old male. Both presented with neck pain without neurological symptoms after a traffic accident. Neuroradiological examinations revealed atlas burst frac-ture in both patients. They were initially treated with conservative treatment; one with a rigid collar and the other with a halo vest.