GUIDING APPARATUS FOR X-RAY-FREE SCREW PLACEMENT BY SPINAL POSTERIOR APPROACH

摘要

A guiding apparatus for x-ray-free screw placement by a spinal posterior approach, comprising an interspinous spacer, a slide scale (1), and an angle-changing rod. The apparatus is simple to operate, easy to grasp, and well accepted by physicians. A reliable effect is provided in screw placement. Significantly reduced X-ray exposure is allowed for patients and medical staff. In a small-incision minimally invasive screw placement operation, even without exposing the spinal ligament, a small spike-like protrusion of a base (2) of the interspinous spacer can ensure accurate interspinous positioning across the skin. This is applicable for both minimally invasive and incision surgeries and has a wide range of uses.

主权项

1. A guiding apparatus for x-ray-free pedicle screw placement by spinal posterior approach, comprising an interspinous process retainer, a sliding ruler and an angle change-over lever, wherein:
the interspinous process retainer comprises a platy base, a C-shaped grip, an upper splint and a lower splint; the sides of the upper splint and the lower splint are respectively and fixedly connected to the two end faces of the C-shaped grip; the upper splint and the lower splint are parallel to each other, and the opposite sides of the upper splint and the lower splint are respectively provided with an upper chute and a lower chute along a length direction thereof; the upper side and the lower side of the sliding ruler are respectively disposed in the upper chute and the lower chute and can slide between the upper splint and the lower splint; the bottom end of the lower splint is fixedly connected to the platy base through a connecting column; the external side of the sliding ruler is provided with an angle dial; the center of the angle dial is provided with a round hole; a rotating wheel is disposed in the round hole; a pointer pointing at the angle dial is disposed on the rotating wheel; a through hole having a square section is disposed in the rotating wheel; an axis of the through hole is overlapped with an axis of the round hole; a symmetric axis of the pointer is overlapped with a symmetric axis of the external end face of the through hole and is vertical to one side of the external end face; the angle change-over lever comprises a square metal bar and a tubular member matched with the through hole; one end of the metal bar is in plug-in type connection with the through hole and the other end of the metal bar is connected to the tubular member; the tubular member may rotate around the other end of the metal bar through a connecting piece; an axis of the metal bar penetrates through an axle center of the tubular member; a ruler prompting the distance between the axle center of the tubular member and the sliding ruler is disposed on the metal bar; the internal diameter of the tubular member is equal to the diameter of a pedicle screw placement opening cone.