PROBLEM TO BE SOLVED: To provide a vertebral arch spacer which is capable of reliably holding the position of a spinous process cut away from a vertebral arch.SOLUTION: The spacer 1 is used to expand a vertebral canal 140 by inserting the spacer 1 into a gap 150 formed by cutting the vertebral arch 120 after cutting the spinous process 130 away from the vertebral arch 120 and cutting the vertebral arch 120 at the part where the spinous process 130 is cut away. The spacer 1 includes two side surfaces (vertebral arch abutment surfaces) 12 on which cutting end parts (both end parts) 120a, 120b at the site of cutting the vertebral arch 120 abut respectively, a rear surface (a spinous process attachment surface) 13 where the spinous process 130 is attached, and a first through-hole 51 and a second through-hole 52 which respectively penetrate through two side surfaces 12. The spinous process 130 is fixed on the side surfaces 12 by inserting a thread (a first fixing member) 301 into the first through-hole 51, and the spacer 1 is fixed inside the gap 150, with the spacer 1 abutting on the side surfaces 12, by inserting a thread (a second fixing member) 302 into the second through-hole 52.COPYRIGHT: (C)2010,JPO&INPIT【課題】椎弓から切離した棘突起の位置を確実に保持することができる椎弓スペーサを提供すること。【解決手段】本発明のスペーサ１は、椎弓１２０から棘突起１３０を切離するとともに、椎弓１２０を棘突起１３０を切離した部分で切断し、椎弓１２０の切断により形成された間隙１５０に挿入して、脊柱管１４０を拡大するのに使用されるものであり、椎弓１２０を切断した部位の切断端部（両端部）１２０ａ、１２０ｂがそれぞれ当接する２つの側面（椎弓当接面）１２と、棘突起１３０を取り付ける後面（棘突起取付面）１３と、２つの側面１２をそれぞれ貫通する第１の貫通孔５１および第２の貫通孔５２とを有し、第１の貫通孔５１に糸（第１の固定部材）３０１を挿通して、棘突起１３０を側面１２に固定するとともに、第２の貫通孔５２に糸（第２の固定部材）３０２を挿通して、スペーサ１を側面１２に当接した状態で間隙１５０内に固定するよう構成した。【選択図】図１
