RU2020901C1 - Intervertebral disc endoprosthesis - Google Patents

Abstract

FIELD: medical engineering. SUBSTANCE: intervertebral disc endoprosthesis is shaped as clamp made from titanium nickelide having shape memory and V-shaped to make up angle of 30 to 35 deg between its lateral planes. Legs disposed symmetrically in each plate planes are bent off in opposite direction at angle of 15 to 20 deg relative to above-mentioned plate planes. Width of plate legs makes up at least half the total width of plate. EFFECT: more sophisticated design. 2 cl, 4 dwg

Description

 The invention relates to medicine and can be used in neurosurgery, neurotraumatology, neuroorthopedics, traumatology.

 A known design of the intervertebral prosthesis, made in the form of a plate with legs. The prosthesis serves as a retainer, providing stable rigid attachment (arthrodesis) of two vertebrae relative to each other. The legs of the prosthesis, inserted into the holes in the vertebral bodies, provide primary fixation and increase lateral stability.

 However, the aforementioned intervertebral disc prosthesis has a number of significant drawbacks, which does not allow to maintain a limited range of movements in the operated segment, to reduce the load on the underlying discs, in the absence of the need for external immobilization of the spine in patients with discogenic cervical myelopathy, due to the addition of a number of complications or the formation of bone block in the field of surgical intervention.

The essence of the invention lies in the fact that the plate is U-shaped bent to form an angle of 30-36 ^about between its planes, the legs are formed by a U-shaped cut on each plane of the plate, are located symmetrically to each other and form an angle of 15-20 ^about with the corresponding plane of the plate, directed to the side opposite the angle between the planes of the plate, and the endoprosthesis is made of titanium nickelide.

 In FIG. 1 shows a general view of the structure; in FIG. 2 is a side view; in FIG. 3 - view of the structure after its deformation in a cooled state; in FIG. 4 is a design application diagram.

The design is made of a plate of titanium nickelide alloy TEN - 10, 1.8 mm thick with shape memory effect. The design is made in the form of a bracket containing a U-shaped plate 1, with side planes 2, the angle 3 between the side planes 2 is 30-36 ^about symmetrically located legs 4, bent in the opposite direction at an angle 5, which is 15-20 ^about to the side planes 2 of the plate 1.

 The construction is used as follows.

Under general anesthesia in the patient’s position on the back, paratracheal access is made to the right of the anterior surface of the cervical vertebrae. The intervertebral disk (or several disks according to indications) and the posterior bone growths of the vertebral bodies, compressing the spinal cord, are removed. Structure cooled for 3-4 min chloroethyl to -30 ^{° C} and deformed - converging between a side plane 2 of the plate 1 and its legs 4, with reduced corners 3 and 5, respectively, to ^about 10-12 and ^about 5-7. The design in this position is easily placed in the cavity of the remote intervertebral disk 6, so that the legs 4 of the plate 1 are in the rear sections of the disk, and the base of the U-shaped plate 1 is in the front sections of the disk (see Fig. 4). After 30 seconds, in connection with contact heating of titanium nickelide, a shape memory effect is manifested and the design tends to take its original shape. In this case, the ends of the lateral planes 2 of the plate 1 abut against the front sections of the closure plates of adjacent vertebrae 7.8 and 8.9, and the ends of the legs 4 of the plate 1 - in the rear sections, and therefore the structure is reliably fixed in the interbody gap. Since the dimensions of the plate in the vertical plane are greater than the height of the intervertebral disc by 2-3 mm, the structure is constantly in tension, counteracting the axial load of the head and spine, which eliminates the overload of neighboring segments. In this case, inclined movements in the operated segment are saved. When tilted forward, the distance between the planes 2 of the plate 1 and the angle 3 between them decreases. When tilting backward, the distance between legs 4 and angle 5 decreases. When tilting the spine to the side, the distance between the corresponding sections of the structure decreases. Excessive inclined movements in the segment will be limited by the increasing resistance of the side planes 2 and legs 4 of the plate 1. The wound is sutured in layers.

 After the operation, external immobilization of the spine is not required and the patient without neurological deficit can begin work after 1 month. The design can be used at two or more levels of the spine.

 The proposed design for replacing the remote intervertebral disk in patients with discogenic cervical myelopathy operated via the interdiscal method provides reliable fixation of adjacent vertebrae, maintains a limited range of movements in the operated segment, prevents overloading of adjacent disks, does not require external immobilization of the spine, resulting in reduced treatment time for patients and outcomes are improving.

Claims (2)

1. An endoprosthesis of an intervertebral disk, made in the form of a plate with legs, characterized in that the plate is made U-shaped with an angle of 30 - 36 ^o between its planes, the legs are formed by a U-shaped cut on each plane of the plate and are symmetrically one another and form an angle of 15 - 20 ^o with the corresponding plane of the plate, directed to the side opposite to the angle between the planes of the plate, and the endoprosthesis is made of titanium nickelide.  2. The endoprosthesis according to claim 1, characterized in that the width of each leg is at least half the width of the plane of the plate.

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