Bone screw of minimally invasive fixation device for lumbar spine

摘要

A bone screw of minimally invasive fixation device for the lumbar spine, comprising positioning sheath (200), the positioning sheath (200) comprising a rod clamp base (210), an alignment portion (220), and an annular groove (230), in which: the annular groove (230) of the positioning sheath (200) is formed between the rod holding base (210) and the alignment portion 220, the clamping base being configured rod and alignment portion integrally; the lower part of the rod holding base (210) has a spherical depression (211) and a through hole, arranged in the central lower portion of the spherical depression, the upper part of the alignment portion (220) having an opening upper and a passage being formed from the upper opening of the alignment portion (220) to the through hole of the rod holder base (210); the wall of the rod holding base (210) has a pair of U-shaped openings (214) aligned with each other, such that the U-shaped openings 214 define a passage of the holding base that laterally crosses the rod clamp base (210); the wall of the alignment portion (220) has at least one pair of alignment openings (221, 222) aligned with each other, and at least one of the pairs of alignment openings (221, 222) defines a passage of the alignment portion, which allows an alignment accessory (600) to laterally traverse the alignment portion (220); two longitudinal notches (224) extend respectively on the wall of the alignment portion (220), from a point adjacent to the upper opening of the alignment portion (220); and the alignment portion (220) of the positioning sheath (200) can be broken into two pieces and separated from the rod clamp base (210), by applying a force on the wall of the portion (220) of alignment to break the longitudinal notches (224), as well as the annular notch (230), so that the alignment portion (220) can be removed from the positioning sleeve (200); characterized in that the longitudinal notches extend downwards, through the alignment openings located on each side, towards the U-shaped openings (214) located on each side.