SU1498480A1 - Washer for a screw for osteosynthesis - Google Patents

Abstract

This invention relates to medical technology and is intended to improve the reliability of osteosynthesis. Plate 1 and legs 5 of the washer are made of a material with a shape memory effect. The washer is installed on the screw in a cooled state, with the plate 1 moving freely along the screw, and the legs 5 straightened. With the introduction of the screw into the fragments of the rib 3, the cutting edges 4 are immersed in the bone. As a result of contact heating, the plate 1 is wedged on the screw, and the legs 5 are bent, resting against the bone. Plate 1 is cooled to remove the screw.

Description

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

The purpose of the invention is to increase the reliability of osteosynthesis by preventing the screw from self-unscrewing.

FIG. 1 shows a washer to an osteosynthesis screw in a working condition, side view; in fig. 2 - the same, view from the ribs; in fig. 3 - washer after deformation in the cooled state, side view; in fig. 4 - the same, view from the edges.

The washer to the screw for osteosynthesis contains a plate 1 with a hole 2 for a screw, diametrically arranged triangular ribs 3 with cutting edges 4 and arcuate legs 5. Plate 1 and legs 5 are made of a material with a shape memory effect, for example, titanium nickelide of the ТН-10 brand that ensures restoration of the initially predetermined shape of the plate 1 and the legs 5 in the working position after the preliminary deformation of the plate 1 to ensure its free movement on the screw jaw and to straighten the legs 5 at a temperature below 10 ° C.

Washer to screw for osteosynthesis works as follows.

Before inserting the screw into the mapped bone fragments, plate 1 and legs 5 are cooled to a temperature below 10 ° C by sprinkling with chloroethyl. In this case, the plate 1 and the legs 5 acquire the shape given to them in a cooled state, the plate 1 is taken out of engagement with the screw neck, and the legs 5 are straightened. During the insertion of the screw into the mapped bone fragments of the rib 3, due to the presence of cutting edges 4, they are immersed in the cortical bone. When contact heating titanium nickelide to 35 ° C, plate 1 and legs 5 acquire a given (i.e.

original) form. In this case, the plate 1 is wedged on the neck of the screw, and when the arcuate bends of the legs 5 are restored, they rest against the bone, providing compression of the bone fragments. Ribs 3, located in the cortical layer,

exclude self-unscrewing of the screw and rotational displacement of bone fragments. After splicing the bone, the screw is removed after pre-cooling the plate 1 to a temperature below 10 ° C to dislodge it from the engagement with the neck of the screw.

Claims (1)

Invention Formula A washer to the screw for osteosynthesis, made in the form of a plate with a hole for the screw and supporting legs, characterized in that, in order to increase the reliability of the osteosynthesis by preventing the screw from self-unscrewing, the plate is provided with pointed ribs perpendicular to the plate, and the plate and legs are made of a material with a shape memory effect, with the possibility of the plate jamming on the screw and bending the legs. ig.2 f 3 and, gz FagL