The invention discloses a semi-opened and semi-closed spine ilium bolt, and relates to one of
internal fixation implants which are used in spine-
pelvis stable reconstruction for treating spine malformations, lumbosacral portion traumas, inflammations and tumor diseases. The semi-opened and semi-closed spine ilium bolt is characterized in that the bolt comprises a bolt cap, an intermediate body, a
retainer ring and a bolt body, the interior of the bolt cap is hollow, an internal threaded hole is formed in the upper portion of the interior of the bolt cap, two
waist-shaped holes are formed in the circumferential direction of the bolt cap, one
waist-shaped hole is closed and is the closed
waist-shaped hole of the bolt cap, and the other waist-shaped hole is opened and is the opened waist-shaped hole of the bolt cap, so that placing of a lateral connection rod is convenient; the intermediate body is provided with a hemispherical inner cavity, and the top end of the intermediate body is provided with a through hole; the head of the bolt body is of a spherical structure, the top end of the spherical structure is provided with steps, the upper end of the head is provided with a bolt internal hexagon hole, and the head of the bolt body is clamped in the bolt cap by being screwed in the
retainer ring; the head of the bolt body is clamped in the bolt cap through the
retainer ring so that disengagement of the bolt body cannot be achieved.