RU2775212C1 - Radiocarpal endoprosthesis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely, to radiocarpal endoprostheses. The endoprosthesis has a proximal articular cup with a leg, a distal articular head, and three fastening elements. The outer boundary of the proximal articular cup is made oval and consists of an upper and a lower parts, the outer boundary whereof is made oval. The leg of the proximal articular cup is shaped as a cone in the centre, ribs extend from the surface of the cone. The leg is inclined relative to the proximal articular cup in two planes at an angle of 5 to 20 degrees and 2 to 10 degrees, respectively. Each rib of the leg has a protrusion made triangular in the cross section thereof. The centre of the proximal articular cup is offset relative to the centre of the leg by 2.0 to 7.0 mm in two planes. The outer boundary of the distal articular head is made oval, has an upper and a lower parts. The upper part is made flat and has three holes, the outer boundary whereof is made oval. The lower part is made two-part. The holes consist of three parts: two non-closed spheres connected by a cylinder and holes, the outer boundary whereof is made oval. Each fastening element consists of a spherical head and a leg made either in the shape of a four-faced truncated cone, wherein each face has a protrusion made triangular in the cross section thereof along the entire length of the faces, or threaded along the entire length.

EFFECT: terms of post-operative healing are reduced by eliminating inflammatory processes due to the elimination of rigid attachment of the endoprosthesis.

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Description

The invention relates to medicine, specifically to traumatology and orthopedics, and can be used in the treatment of arthrosis, congenital anomalies, complex fractures of the wrist joints.

Known wrist endoprosthesis containing a distal articular head with a stem and a proximal articular cup with a stem, characterized in that the proximal articular cup has a cylindrical shape of round cross section, the working surface of which has a concave spherical shape of a round cross section, and the height of the proximal articular cup is 7-15 mm , and the depth L of its working surface is 3.0-6.0 mm (patent No. 148355, RU) - analogue.

However, the use of this analog does not allow to obtain a stable clinical effect, since it gives a long healing period due to complications in the form of inflammatory processes, because the design of the analog does not provide sufficient initial stability.

Known wrist endoprosthesis having a distal articular head and a proximal articular cup with legs, characterized in that the inner part of the proximal articular cup is made in the form of an oval shape with a large radius R1 and a small radius R2, the centers of which are located on the axis of symmetry, and the large radius R1 is 16.0-20.0 mm, and the small radius R2 is 8.0-10.0 mm, in addition, the proximal articular cup has a flat face on two opposite sides, the stem of the proximal articular cup has a taper of 5-7 degrees and is displaced relative to the center of the proximal articular cup by 1-2 mm towards any flat face, the pedicle of the distal articular head has a taper of 2-4 degrees, the distal articular head is made with the ability to move in the longitudinal direction within a large radius R1 and rotate within a small radius R2 of the proximal articular cups (patent No. 148054, RU) - analogue.

However, the use of this analog does not allow to obtain a stable clinical effect, since it gives a long healing period due to complications in the form of inflammatory processes, because the design of the analog does not provide sufficient initial stability.

Also known is a wrist endoprosthesis having a proximal articular cup with a stem, a distal articular head and three fasteners (patent No. 6869449 B2, 22.03.215.SU) - prototype.

However, the use of the prototype also does not allow to obtain a stable clinical effect, since it gives a long healing period due to complications in the form of inflammatory processes, because its design does not provide sufficient initial stability due to rigid attachment, which does not correspond to the anatomical features of the wrist joint.

The objective of the invention is to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes by eliminating rigid fastening, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint, as it provides the possibility of microdisplacements and microfluctuations.

The problem is solved by the proposed wrist endoprosthesis having a proximal articular cup with a stem, a distal articular head and three fasteners.

The novelty of the proposed radiocarpal endoprosthesis is that the outer border of the proximal articular cup is made in the form of an oval and consists of the upper and lower parts, the outer border of which is made in the form of an oval, the outer border of the distal articular head is made in the form of an oval, the leg of the proximal articular cup is in the form cone in its center, ribs extend from the surface of the cone, the pedicle is inclined with respect to the proximal articular cup in two planes at an angle of 5-20 degrees and 2-10 degrees, respectively, and each rib of the pedicle has a protrusion made in the form of a triangle in its cross section , the center of the proximal articular cup is displaced relative to the center of the stem by 2.0-7.0 mm in two planes; the outer border of the distal articular head is made in the form of an oval, has an upper and lower parts, and the upper part is made flat and has three holes, the outer border of which is made in the form of an oval, the lower part is made of two parts; holes consist of three parts: two open spheres connected by a cylinder and holes, the outer boundary of which is made in the form of an oval; each fastener element consists of a spherical head and a leg made either in the form of a truncated cone having four faces, each face having a protrusion made in the form of a triangle in its cross section along the entire length of the faces, or threaded along the entire length.

The pedicle is inclined relative to the proximal articular cup in two planes at an angle of 5-20 degrees and 2-10 degrees, respectively. The center of the proximal articular cup is displaced relative to the center of the pedicle by 2.0-7.0 mm in two planes.

The diameter of the spherical head is 2.0-7.0 mm.

The protrusion height is 2.0-10.0 mm along the entire length of the stem faces.

The thickness of each leg face is 0.5-2.0 mm.

The length of the distal articular head is 30.0-50.0 mm, its width is 10.0-25.0 mm, and its height is 10.0-20.0 mm.

Each face of the leg, made in the form of a truncated cone, has a height of 0.5-1.0 mm along the entire length of the faces.

The leg, made threaded along the entire length, has a diameter equal to 2.0-7.0 mm and a height equal to 4.0-20.0 mm.

In FIG. 1 shows the claimed wrist endoprosthesis.

In FIG. 2 shows the proximal articular cup 1.

In FIG. 3 shows the distal articular head 3 with holes 13.

In FIG. 4 shows the fastener 4.

In FIG. 5 shows the distal articular head 3 in section.

In FIG. 6 shows the shape of the opening 13 of the distal articular head 3 (side view).

In FIG. 7 shows the shape of the opening 13 of the distal articular head 3 (top view).

In FIG. 8 shows the shape of the opening 13 of the distal articular head 3 (front view).

The radiocarpal endoprosthesis consists of a proximal articular cup 1 with a stem 2, a distal articular head 3, and three fasteners 4.

The outer border of the proximal articular cup 1 is made in the form of an oval and consists of the upper and lower parts, the outer border of which is made in the form of an oval, the length of which A is 20.0-40.0 mm, the width b is 10.0-30.0 mm and consists of an upper part 5 and a lower part 6. The outer border of the upper part 5 of the proximal articular cup 1 has the shape of an oval, consisting of two parts 7, 8. The larger radius R1 of part 7 is 20.0-50.0 mm, the smaller radius R2 part 7 is 10.0-30.0 mm; the larger radius R3 of part 8 is 10.0-30.0 mm, the smaller radius R4 of the second part 8 is 5.0-15.0 mm; the lower part 6 has a convex shape, the larger radius R5 of the lower part 6 is 20.0-35.0 mm, the smaller radius R6 of which is 15.0-25.0 mm.

The leg 2 of the proximal articular cup 1 is made in the form of a cone in its center, ribs extend from the surface of the cone, having four faces 9, and the leg 2 is inclined relative to the proximal articular cup 1 in two planes at an angle of 5-20 degrees and 2-10 degrees respectively. Each face 9 of the stem 2 has a protrusion 10 made in the form of a triangle in its cross section, the height H of the protrusion 10 is 2.0-10.0 mm along the entire length of the faces 9 of the stem 2. The center of the proximal articular cup 1 is displaced relative to the center of the stem 2 by 2.0-7.0 mm in two planes. The thickness S of each face 9 of the leg 2 is 0.5-2.0 mm.

The outer border of the distal articular head 3 is made in the form of an oval, the length A1 of which is 30.0-50.0 mm, the width b1 is 10.0-25.0 mm, the height hi is 10.0-20.0 mm. In addition, the distal articular head 3 has an upper part 11 and a lower part 12. The upper part 11 is made flat and has three holes 13. The lower part 12 is made of two parts 14 and 15. Part 14 has a larger radius R7 and a smaller radius R8, part 15 has a larger radius R9 and a smaller radius R10. The sizes of the radii R7, R8, R9, R10 correspond to the sizes of the radii R1, R2, R3, R4 of part 7 and part 8 of the upper part 5 of the proximal articular cup 1.

Holes 13 consist of three parts: open spheres 16 and 17, connected by a cylinder 18 and holes 19, the outer boundary of which is made in the form of an oval. The diameters d1 of the open spheres 16 and 17 are 3.0-7.0 mm, the diameter d2 of the cylinder 18 is equal to the diameter of the open spheres 16 and 17, and its length L2 is 0.5-2.0 mm.

Each fastener 4 consists of a spherical head 20 and a leg 21. The spherical head 20 has a diameter d3 equal to 2.0-7.0 mm. The leg 21 is made either in the form of a truncated cone, having four faces 22, and each face 22 has a protrusion 23, made in the form of a triangle in its cross section, having a height h3 of 0.5-1.0 mm along the entire length of the faces 22, or threaded along the entire length, having a diameter d4 equal to 2.0-7.0 mm and a height h4 equal to 4.0-20.0 mm.

I offer specific examples of the implementation of a wrist endoprosthesis.

Example 1

The pedicle can be tilted relative to the proximal articular cup in two planes at an angle of at least 5 degrees and at least 2 degrees, respectively.

The center of the proximal articular cup can be displaced relative to the center of the pedicle by at least 2.0 mm in two planes.

This will make it possible to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these sizes a rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The diameter of the spherical head must be at least 2.0 mm. This will make it possible to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these sizes a rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The outer border of the distal articular head 3 is made in the form of an oval, the length A1 of which is less than 20.0 mm, its width less than 10.0 mm will not allow to obtain a stable clinical effect by reducing the postoperative healing time by eliminating inflammatory processes, since only with these data rigid fastening is eliminated in dimensions, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The outer border of the distal articular head 3 is made in the form of an oval, consists of two parts, the larger radius of the first part is less than 20.0 mm, its smaller radius is less than 10.0 mm; its larger radius is less than 10.0 mm, its smaller radius is less than 5.0 mm; the lower part, which has a larger radius of less than 20.0 mm and a smaller radius of less than 15.0 mm, will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these dimensions is rigid fastening eliminated, because the proposed wrist the endoprosthesis corresponds to the anatomical features of the wrist joint.

The protrusion height of less than 2.0 mm along the entire length of the stem faces will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The thickness of each side of the stem less than 0.5 mm will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size a rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint. The length of the distal articular head is less than 30.0 mm, its width is less than 10.0 mm, and its height is less than 10.0 mm, which will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these sizes the rigid fastening, because the proposed wrist endoprosthesis corresponds to the anatomical features of the wrist joint.

The diameter of non-closed spheres less than 3.0 mm will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size a rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The height of each side of the stem, made in the shape of a truncated cone, less than 0.5 mm along the entire length of the sides will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size the rigid fastening is eliminated, because the proposed the radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

A diameter of less than 2.0 mm and a height of less than 4.0 mm of a stem made threaded along the entire length will not allow obtaining a lasting clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these dimensions a rigid fastening is eliminated, because The proposed wrist endoprosthesis corresponds to the anatomical features of the wrist joint.

Example 2

The pedicle can be tilted relative to the proximal articular cup in two planes at an angle of no more than 20 degrees and 10 degrees, respectively.

The center of the proximal articular cup cannot be displaced relative to the center of the pedicle by more than 7.0 mm in two planes.

This will make it possible to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these sizes a rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The diameter of the spherical head of more than 7.0 mm will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size a rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The outer border of the distal articular head 3 is made in the form of an oval, the length A1 of which is more than 40.0 mm, its width is more than 30.0 mm will not allow to obtain a stable clinical effect by reducing the postoperative healing time by eliminating inflammatory processes, since only with these data rigid fastening is eliminated in dimensions, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The outer border of the distal articular head 3 is made in the form of an oval, consists of two parts, the larger radius of the first part is more than 50.0 mm, its smaller radius is more than 30.0 mm; the larger radius of the second part is more than 30.0 mm, the smaller radius of the second part is more than 15.0 mm; the lower part, which has a larger radius of more than 35.0 mm and a smaller radius of more than 25.0 mm, will not allow to obtain a lasting clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these dimensions a rigid fastening is eliminated, because the proposed wrist the endoprosthesis corresponds to the anatomical features of the wrist joint.

The protrusion height of more than 10.0 mm along the entire length of the stem faces will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint. The thickness of each side of the pedicle of more than 2.0 mm will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size rigid fastening is eliminated, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint. The length of the distal articular head is more than 50.0 mm, its width is more than 25.0 mm, and its height is more than 20.0 mm will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these dimensions the rigid fastening, because the proposed wrist endoprosthesis corresponds to the anatomical features of the wrist joint.

The diameter of open spheres of more than 7.0 mm will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size a rigid fastening is eliminated, because the proposed wrist endoprosthesis corresponds to the anatomical features of the radiocarpal joint.

The height of each side of the stem, made in the shape of a cone, more than 1.0 mm along the entire length of the sides will not allow to obtain a lasting clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with this size rigid fastening is eliminated, because the proposed radiocarpal the endoprosthesis corresponds to the anatomical features of the wrist joint.

A diameter of more than 7.0 mm and a height of more than 20.0 mm of a stem made threaded along the entire length will not allow to obtain a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes, since only with these dimensions a rigid fastening is eliminated, because The proposed wrist endoprosthesis corresponds to the anatomical features of the wrist joint.

The proposed wrist endoprosthesis is used as follows:

The operation is performed under regional bleeding using a pneumatic tourniquet. The position of the patient on the back, the hand is placed on the side table. Skin access dorsal longitudinal S-shaped in the area of the wrist joint. The extensor tendon of the first toe is sharply and bluntly exposed. The extensor retinaculum was dissected along the tendon. The tendons are separated in different directions, the capsule of the wrist joint is exposed and cut in a T-shape. The proximal row of carpal bones was removed. Resection of the radius and proximal tuberosity of the capitate was performed at an angle of 90 degrees. With the help of an awl, the formation of the primary canal of the radius was performed, with the help of a compactor, compaction of the cancellous bone was performed. With the help of an awl, the formation of the primary canal of the capitate, stump of the navicular and trihedral bones was performed. Spongy bone compaction was performed using a compactor. The channels are washed and dried. The legs of the endoprosthesis were installed. After installing the legs, the proximal articular cup was inserted into the radius and the distal articular head was put on the legs. The endoprosthesis is assembled in the wound. Performed plastic capsule of the wrist joint. The position of the tendons was restored and their retainer was restored. The wound is sutured in layers, then an aseptic bandage.

Thus, the above-described new features of the proposed wrist joint provide a reduction in postoperative healing time due to the elimination of inflammatory processes, because the proposed wrist endoprosthesis corresponds to the anatomical features of the wrist joint, as it provides the possibility of microdisplacements and microfluctuations.

All of these new features are significant, as they allow to obtain a positive clinical result, expressed in the reduction of postoperative healing time due to the elimination of inflammatory processes.

The proposed wrist endoprosthesis was used in 5 patients. Clinical results have shown a stable clinical effect by reducing the time of postoperative healing by eliminating inflammatory processes by eliminating rigid fastening, because the proposed radiocarpal endoprosthesis corresponds to the anatomical features of the radiocarpal joint, as it provides the possibility of microdisplacements and microoscillations.

Claims (8)

1. A radiocarpal endoprosthesis having a proximal articular cup with a pedicle, a distal articular head and three fasteners, characterized in that the outer border of the proximal articular cup is made in the form of an oval and consists of the upper and lower parts, the outer border of which is made in the form of an oval, the outer the border of the distal articular head is made in the form of an oval, the stem of the proximal articular cup has the shape of a cone in its center, the ribs extend from the surface of the cone, the stem is inclined relative to the proximal articular cup in two planes at an angle of 5-20 degrees and 2-10 degrees, respectively, moreover, each rib of the stem has a protrusion made in the form of a triangle in its cross section, the center of the proximal articular cup is displaced relative to the center of the stem by 2.0-7.0 mm in two planes; the outer border of the distal articular head is made in the form of an oval, has an upper and lower parts, and the upper part is made flat and has three holes, the outer border of which is made in the form of an oval, the lower part is made of two parts; holes consist of three parts: two open spheres connected by a cylinder and holes, the outer boundary of which is made in the form of an oval; each fastener element consists of a spherical head and a leg made either in the form of a truncated cone having four faces, each face having a protrusion made in the form of a triangle in its cross section along the entire length of the faces, or threaded along the entire length. 2. The device according to claim. 1, characterized in that the diameter of the spherical head is 2.0-7.0 mm. 3. The device according to claim 1, characterized in that the height of the protrusion is 2.0-10.0 mm along the entire length of the legs. 4. The device according to claim 1, characterized in that the thickness of each leg face is 0.5-2.0 mm. 5. The device according to claim 1, characterized in that the length of the distal articular head is 30.0-50.0 mm, its width is 10.0-25.0 mm, and its height is 10.0-20.0 mm. 6. The device according to claim 1, characterized in that the diameter of the open spheres is 3.0-7.0 mm, the diameter of the cylinder is equal to the diameter of the open spheres, and its length is 0.5-2.0 mm. 7. The device according to claim. 1, characterized in that each face of the leg, made in the form of a truncated cone, has a height of 0.5-1.0 mm along the entire length of the faces. 8. The device according to claim 1, characterized in that the leg, made threaded along the entire length, has a diameter equal to 2.0-7.0 mm and a height equal to 4.0-20.0 mm.

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