RU2402294C1 - Synostosis apparatus for forefoot reconstruction - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly to orthopaedics and can be used for surgical treatment of spread forefoot. An apparatus is made of a shape-memory material. The apparatus consists of bound retainers. The first retainer represents an open ring. The second retainer comprises an external branch "П"-bound with an internal branch passing in the intramedullary leg folded from a longitudinal axis of the internal branch in the direction from the external branch. The external and internal branches of the second retainer are arranged in parallel. The bonding consists of straight and arched pieces. The straight piece extends from the open ring of the first retainer and passes into the arched piece folded in the direction of an end of the intramedullary leg in a plane perpendicular to a plane of the ring of the first retainer. The apparatus is made of a round-edged plate of thickness 1.5 mm and width 2 mm.

EFFECT: invention ensures the uniform coaptation of I-II instep bone rays along the full length; forcing of the retainers through bone tissue of instep bones in functional forefoot loads is eliminated; long-term functional prognosis of constriction of the spread forefoot is ensured, the imbalance of tension of flexor and extensor tendons is prevented due to normalised position of all the segments of I-II instep bones; transverse arch of the foot is restored, fan-shaped spread instep bones and vicious position of head of II instep bone is eliminated.

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Description

The invention relates to orthopedics and can be used for surgical treatment of anterior flattening of the foot.

Up to 30% of the adult population has a deformity of the feet associated with the flatness of its anterior section, a decrease in the transverse arch.

As a result of a fan-shaped divergence of the metatarsal bones, the spring and musculoskeletal function of the foot is disrupted, a complex complex of progressive deformations develops, up to the formation of a flat-valgus foot.

Synostosing devices used as a transverse plantar ligament to form the transverse arch and eliminate the front flattening of the foot during walking are subject to significant alternating loads exceeding the weight of the human body. There is a high probability of failure of structures, their deformation with loss of correction of the position of the metatarsal bones, up to damage to bone formations.

Tightening devices do not have sufficient elasticity and strength, the distribution of forces of tension is limited to a small area in one plane of impact.

Known is the formation of a transverse plantar ligament from a dacron mesh tape (Surgical treatment of flat feet, Hallux Valgus // I. S. Istomina, V. I. Kuzmin, A. N. Levin. / Bulletin of Traumatology and Orthopedics named after N. N. Priorov. - 2000. - No. 1. - S.55-60). The lavsan mesh tape up to 10 mm wide in the form of an 8-shaped loop with a fixing coverage around the I metatarsal bone (at the level of the upper third of the diaphysis) and the V metatarsal bone (at the level of the subcapital area) is carried out under the plantar surface of the II, III, IV metatarsal bones. By tensioning the two strips of the 8-shaped loop, the fan-shaped divergence of the metatarsal bones is eliminated, after which the strips of the mylar ribbon are sewn together.

The disadvantage of the 8-shaped lavsan tape is the trauma of the operation, due to the need for incisions in the I and IV intertarsal spaces with a wide detachment of soft tissues to form a transverse plantar tunnel with the aim of conducting a lavsan mesh tape.

Under the influence of constant dynamic loads on the forefoot, the lavsan ribbon loses its elasticity and is overstretched. Correction of the fan-shaped divergence of the metatarsal bones is lost, there is a tendency for the tape to shift from the fixation points on the bones, to twist it, which ultimately leads to a relapse of the deformation.

When the forefoot is pulled together with a lavsan tape passing through the plantar canal of the foot, the extension of the middle fingers with the formation of a hammer-like deformation, contracture of the interphalangeal joints, and callosity on the plantar surface decreases.

A device for the treatment of static flat feet (RF Patent for utility model No. 74565, Bull. No. 19, 07/10/2008, IPC A61H 15/00), consisting of a cylinder in the form of five sections of different diameters with a loading mechanism made in the form of elastic ties, one end of which is attached to the cylinder, and the other to the body in which it rotates. By shortening the linear size of the cylinder due to its sections of different diameters moving into each other, correction of the position of the metatarsal bones is achieved with the elimination of a fan-shaped divergence of the metatarsal bones.

The disadvantage of this device is the inability to achieve correction of the position of the heads of the metatarsal bones and, therefore, excessive tension of the extensor tendons is maintained.

The device is intended for external correction of deformation. It is fundamentally impossible to maintain the corrections of anatomical formations achieved during the achieved process, the spring function of the forefoot after removal of the apparatus.

The closest to the claimed invention can be considered a device for correcting the transverse arch of the foot, described in the "Method for correcting the tarsal angle and correction of the transverse arch of the foot and device for its implementation", RF patent 2056801, Bull. No. 9, 03/27/1996, IPC АВВ 17/56. The device is made in the form of a wire superelastic bracket with a shape memory effect with three counter-curved branches for fixation in transversely formed intraosseous canals of I, II, III metatarsal bones. Between the first and second branches of the bracket there is a wave-like bend, the plane of which is perpendicular to the plane of the hook-shaped end of the first branch.

The disadvantage of this device is the traumatic effect of the jaw of the bracket on the cortical bone with its eruption during dynamic elongation and compression of the bracket under the influence of functional loads. The distribution of the contracting force is concentrated on the distal segment of the metatarsal bones and is linear in nature, which increases the load on the structure when transferring body weight to the forefoot and is fraught with breakage of the structure and damage to the metatarsal bones.

The objective of the invention is to create a synostosing device, taking into account the anatomical and topographic and functional features of the forefoot, which allows you to adapt the device to the place of its installation, restore the spring, support, motor function of the forefoot.

This task is achieved in that the synostosing device is made of material with a shape memory effect. It consists of clamps connected by a jumper. The first latch is made in the form of an open ring, and the second latch is in the form of a osseous branch connected by a U-shaped jumper with an intraosseous branch turning into an intramedullary leg bent from the longitudinal axis of the intraosseous branch in the direction from the osseous branch. Bone and intraosseous branches of the second retainer are parallel to each other. The jumper consists of a straight and arcuate sections, while the straight section departs from the open ring of the first retainer and passes into an arcuate section curved in the direction of the end of the intramedullary leg in a plane perpendicular to the plane of the ring of the first retainer. The device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges.

The novelty of the device.

- The first retainer is made in the form of an open ring, circularly covering the I metatarsal bone in the subcapital region, which excludes the formation of a channel in the bone to stabilize the grip.

- The second latch is made in the form of a osseous branch connected by a U-shaped jumper with an intraosseous branch turning into an intramedullary leg bent from the longitudinal axis of the intraosseous branch in the direction from the osseous plate. Bone and intraosseous branches are parallel to each other. The intraosseous part of the device is installed in the head of the II metatarsal bone and prevents plantar displacement of the head during contraction of the forefoot. The bending of the intramedullary leg together with the bending of the jumper ensures the preservation of the spring function of the transverse arch of the foot.

- The device consists of latches connected by a jumper. The jumper consists of a straight and arched sections, while the straight section departs from the open ring of the first retainer and passes into an arc-shaped portion curved in the direction of the end of the intramedullary leg in a plane perpendicular to the plane of the ring of the first retainer. The jumper is a constricting element and provides the convergence of the metacarpal bones in the horizontal and sagittal planes. The design of the jumper allows you to place the osseous elements of the device in the first interdigital space with anatomically advantageous positioning, eliminating the traumatic effect on the tendons and muscles during functional loads.

- The device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges, which reduces the traumatic effect of the structure on the cortical bone and its eruption.

The set of features of the claimed invention allows to achieve uniform convergence of the rays I-II metatarsal bones along their entire length. Excluding the pushing of the bone tissue of the metatarsal bones with the fixing structural elements with functional loads on the forefoot. A long-term functional prognosis of contraction of the flattened forefoot is achieved, an imbalance in the tension of the flexor and extensor tendons is prevented, due to the normalization of the position of all departments of the I-II metatarsal bones.

The transverse arch of the foot is recreated, the fan-shaped divergence of the metatarsal bones, the vicious position of the metatarsal head P are eliminated.

Description of the device is illustrated by drawings.

Figure 1 shows the proposed device in a perspective view.

Figure 2 is a top view of the device.

Figure 3 is a view of the device from the side of the second latch.

Figure 4 is a side view of the device.

Figure 5 shows the position of the synostosis device when constricting I-II metatarsal bones.

On figa presents the x-ray of the patient with flat valgus foot before treatment.

On figb - x-ray after reconstruction of the forefoot.

A synostating device for reconstruction of the forefoot of a material with a shape memory effect, for example titanium nickelide, consists of clamps connected by a jumper. The first latch is made in the form of an open ring 1, and the second latch is in the form of a osseous branch 2 connected by a U-shaped jumper 3 with an intraosseous branch 4 turning into an intramedullary leg 5, bent from the longitudinal axis of the intraosseous branch 4 in the direction from the osseous branch, Fig .one. Bone 2 and intraosseous 4 branches are parallel to each other, Figure 3. The jumper has a slope from the ring 1 to the osseous branch 2 of the second retainer, Figure 4. The jumper consists of a straight 6 and arcuate 7 sections, Figure 4. In this case, the straight section 6 departs from the ring 1 of the first retainer and passes into an arcuate section 7, curved in the direction of the end of the intramedullary leg 5, Figure 1, in a plane perpendicular to the plane of the ring 1 of the first retainer, Figure 1, 2. The device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges.

Synostating device is installed as follows. The envelope incision begins at the level of the neck along the inner surface of the first metatarsal bone, continues transversely and at the level of the head of the second metatarsal bone, continues proximal to the neck of the corresponding bone. A channel is formed outside the articular surface of the head of the II metatarsal bone. The extensor tendons, without injuring their vagina, lift and move medially. The synostosis device with the shape memory effect is cooled to a temperature of -10 ° C, the first retainer made in the form of a ring is unscrewed with the help of crampon forceps, the bridges of the bridge are straightened, the leg is given a shape convenient for insertion into the intramedullary canal of the II metatarsal bone. The deformed synostosis device is transferred to the wound. An intramedullary leg is installed, hammered to the level of a U-shaped bridge 3 of the transition of the osseous branch 2 into the intraosseous branch 4, which covers the head of the metatarsal bone II from the back surface. The jumper is held under the extensor tendons. Ring 1 of the first retainer is wound around the neck of the first metatarsal bone. Under the influence of body temperature, the synostosis device takes its initial shape with a developed force of 80 N, while the metatarsal bones are brought together, the transverse arch of the foot is remodeled while maintaining the ratios in the position of the heads of the metatarsal bones. The wound is sutured.

Example. Patient K., 48 years old. Diagnosis: static flat valgus deformity of the foot, accompanied by a medial deviation of the metatarsal axis I of the metatarsal bone and a valgus deviation of the toe axis of the toe by 35 °, Fig. 6a.

A two-level reconstructive osteotomy of the I metatarsal bone was performed, the purpose of which is to restore the correct axis of the I metatarsal bone and finger. Corrective subcapital epithelial bone osteotomy I ends with normalization of ratios in the metatarsophalangeal joint, osteosynthesis using an S-shaped bracket with shape memory effect. Transverse osteotomy at the metaphysis level I of the metatarsal bone ends with a deviation of the distal fragment to the anatomically correct position of the metatarsal axis I. An implant with through porosity of titanium nickelide is installed in the wedge-shaped defect, followed by fixation of the bone fragments and the implant with an S-shaped bracket with shape memory. The formation of the transverse arch of the forefoot, the elimination of fan-shaped discrepancies of the metatarsal bones is ensured by the installation of the proposed synostosing device made of titanium nickelide. Moreover, the first retainer is located above the S-shaped bracket in the subcapital region of the I metatarsal bone, Fig.6b. The radiograph shows that the fan-shaped discrepancy of the metatarsal bones is eliminated. Formed transverse arch of the foot. The pain in the foot is gone.

Thus, the proposed device reduces the invasiveness of the operation. The device allows you to restore the spring, support, motor function of the forefoot by reconstructing the transverse arch of the foot, eliminating the fan-shaped discrepancy of the metatarsal bones, the vicious position of the head of the II metatarsal bone, excessive tension of the extensor tendons, which allows to increase the effectiveness of treatment compared to known methods.

Claims (1)

Synostatic device for reconstruction of the forefoot of the material with shape memory, consisting of clamps connected by a jumper, characterized in that the first clamp is made in the form of an open ring, and the second clamp is in the form of a bone branch connected by a U-shaped jumper with an intraosseous branch, passing in the intramedullary leg, bent from the longitudinal axis of the intraosseous branch in the direction from the bone branch, the bone and intraosseous branches of the second retainer are parallel to each other, the jumper consists of pit and arcuate sections, while the straight section departs from the open ring of the first retainer and goes into an arcuate section curved in the direction of the end of the intramedullary leg in a plane perpendicular to the plane of the ring of the first retainer, the device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges.

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