SU1584926A1 - Washer for srcew used in osteosynthesis - Google Patents

Abstract

This invention relates to medical technology and is intended to facilitate the insertion of an osteosynthesis screw while reducing trauma. The washer is made of a material having a shape memory effect and is mounted on the screw in a cooled state. After inserting the screw into the bone, the outboard plate 1 is wedged on the screw 3 by reducing the diameter of the inner hole. The support legs 4 and 5, heating up, are bent in the direction of the screw 3, with the pointed ends 6 and 7 entering the bone. The support legs can be either arcuately curved or straight, with the pointed ends perpendicular to the support plate. 2 hp f-ly, 6 ill.

Description

fie. one

The invention relates to medical technology, namely to traumatological instruments for osteosynthesis.

The purpose of the invention is to facilitate the insertion of the screw while reducing the morbidity.

FIG. 1 shows the variants of the washer to the screw for osteosynthesis, a view in the working position; in fig. 2 - washer, view from the ends of the plates; in fig. 3 - the same, side view; in fig. 4 - the same view from the side of the plate ends, after deformation in the cooled state; in fig. 5 is the same side view in a chilled state.

A washer to an osteosynthesis screw, made of a material with a memory effect, contains an outboard plate 1 with a hole 2 in the center of the screw stem 3, and the diameter of the hole 2 is smaller than the diameter of the rod 3 to ensure that the plate 1 is fixed diametrically opposed, arcuately curved rectangular support plates 4 and 5 with pointed ends 6 and 7 lying outside the plane of the outer surface of plate 1. According to another embodiment (Fig. 6), pointed gical 6 and 7 are disposed perpendicularly to the supporting plates 4 and 5.

The implementation of the outboard plate 1 and the supporting plates 4 and 5 from a material with a memory effect, such as titanium nickelide, ensures that the plate 1 is wedged on the rod 3 of the screw and restores the arcuate bends of the supporting plates 4 and 5 (Fig. 1-6) after preliminary opening 2 and the deformations of the support plates 4 and 5 to the location of the tapered ends 6 and 7 in the plane of the outboard surface of the plate 1 in the cooled state.

The washer to the screw for osteosynthesis is used as follows.

The outboard plate 1 is cooled, for example, by spraying with chloroethyl, the opening 2 of the plate 1 is enlarged in diameter and it is freely mounted on the rod 3 near the screw head 8. Then, most of the screw is inserted into the bone fragments 9 and 10 and cooled on the back plate 1 with support plates 4 and 5, for example, by spraying with chloroethyl, the opening 2 of the plate 1 increasing in diameter and plate 1 can move freely on the rod 3 of the screw, and the pointed ends 6 and 7 of the supporting plates 4 and 5 are located in the plane of the outboard plate 1 (Fig. 4 and 5) and do not prevent further insertion of the screw into the bone fragments 9 and 10. When the screw is inserted until the plate 1 is in firm contact with the bone fragment 9 and head 8 screws, bearing plates s 4 and 5 are preferably oriented in a plane perpendicular to the axis of the bone. When heated, the overlay plate 1 and the support plates 4 and 5 show the effect

a shape memory and an outer plate 1 with supporting plates 4 and 5 restores the given shape (i.e., initial) shape (Fig. 2 and 3) - the diameter of the aperture 2 of the plate 1 decreases and its closure on the rod 3 near the screw head 8 , and when restoring the arcuate bends of the supporting plates 4 and 5, the pointed ends 6 and 7 are inserted into the cortical layer of the bone fragment 9 (Fig. 1), ensuring compression of the bone fragments 9 and 10.

When the pointed ends 6 and 7, which are perpendicular to the supporting plates 4 and 5, are immersed, the plates limit the depth of the ends 6 and 7 to the cortical layer of the bone fragment 9 (Fig. 6).

Q Due to the reliable fixation of the bone plate 1 on the screw core 3 and the insertion of the tapered ends 6 and 7 of the support plates 4 and 5 into the cortical bone layer, a reliable compression osteosynthesis with the exception of self-unscrewing is provided

5 screws.

After splicing the fracture, the support plates 4 and 5 bite or saw off, remove the pointed ends 6 and 7 from the bone and then remove the screw with the outer plate 1 from the bone,

0 The washer to the screw for osteosynthesis has a simple design, low material consumption, is easy to manufacture, eliminates screw self-unscrewing, provides constant dynamic compression of bone fragments, which increases the stability of the osteosynthesis using bone screws.

Claims (3)

Invention Formula 0 1. A washer to an osteosynthesis screw, containing an overlay plate with a screw hole, made of a material with shape memory, with diametrically arranged support plates, characterized in that, in order to facilitate 5 insertion of the screw while reducing the morbidity, the support plates are made with pointed ends and are made of a material with a shape memory, with the possibility of bending in the direction of the screw. 2. A washer according to claim 1, characterized in that the supporting plates are made straight and the pointed ends are perpendicular to the plate. 3. Washer according to claim 1, characterized in that the support plates are arcuate-curved. 0 Fiel FIG. five FIG. b