RU2402295C1 - Synostosis apparatus for three instep bones - 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. An apparatus consists of three joined curved retainers. The second retainer comprises an external branch, an internal branch passing in the intramedullary leg and a "П"-bridge connecting the external and internal branches. The intramedullary leg is folded in its centre from a longitudinal axis of the internal in the direction from the first retainer. The external and internal branches are arranged in parallel. The first and third retainers represent open with a gap from the side directed to the internal branch of the second retainer and bound together. The "П"-bridge lies in a plane perpendicular to the ring plane of the first and third retainers. The internal branch of the second retainer extends from the middle of the first and third retainers. The apparatus is made of a round-edged plate of thickness 1.5 mm and width 2 mm.

EFFECT: apparatus allows repairing spring, support, motor functions of forefoot by reconstruction of transverse arch of foot, eliminated fan-shaped spread instep bones, vicious position of head of the II and III instep bones, excess tension of extensor tendons.

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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 the mylar mesh tape (Surgical treatment of flat feet, Hallux Valgus // I.S. Istomina, V.I. Kuzmin, A.N. Levin / 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 ribbon passing through the sole of the foot, the extension of the middle fingers with the formation of a hammer like deformation, contracture of the interflank 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 correlation of anatomical formations of the spring function of the forefoot achieved in the process of achieved corrections after removal of the apparatus.

The closest to the claimed 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 a 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 uniformly approximate the rays of the I-III metatarsal bones along their entire length, to exclude the pushing of the metatarsal bone tissue by the fixing structural elements with functional loads on the forefoot, the long-term functional prognosis of retraction of the flattened forefoot, and prevention of tension imbalance of the flexor and extensor tendons due to the normalization of the position of all departments of I-III metatarsal bones.

The problem is solved by a synostosis device for three metatarsal bones of the forefoot of a material with a shape memory effect consisting of three curved clamps interconnected. The second retainer is made in the form of a osseous branch, an intraosseous branch that passes into the intramedullary leg, and a U-shaped bridge connecting the osseous and intraosseous branches. The intramedullary leg is bent in the middle part from the longitudinal axis of the intraosseous branch to the side opposite to the location of the first retainer. Bone and intraosseous branches are parallel to each other. The first and third retainers are made in the form of open rings having a gap from the side directed to the intraosseous branch of the second retainer and interconnected by a jumper. The U-shaped jumper lies in a plane perpendicular to the plane of the rings of the first and third retainers. From the middle of the first and third retainers departs the osseous branch of the second retainer. The device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges.

The jumper is made straight or has straight sections extending from the rings of the first and third clamps connected by an S-shaped curved section.

The novelty of the device.

- The first third retainers are made in the form of open rings having a gap from the side directed to the inner branch of the second retainer, covering circularly I and III metatarsal bones in the subcapital region, which excludes the formation of a channel in the bone to stabilize the grip.

- The first and third clamps are connected by a jumper. The jumper is a constricting element and ensures the convergence of the metacarpal bones in the horizontal plane. The jumper allows you to place the osseous elements of the device in the first and second interdigital spaces with anatomically advantageous positioning, eliminating the traumatic effect on the tendons and muscles during functional loads.

- The second retainer is made in the form of a osseous branch, an intraosseous branch that passes into the intramedullary leg, and a U-shaped bridge connecting the osseous and intraosseous branches. The intramedullary leg is bent in the middle part from the longitudinal axis of the intraosseous branch to the side opposite to the location of the first retainer. Bone and intraosseous branches are parallel to each other. The U-shaped jumper lies in a plane perpendicular to the plane of the rings of the first and third retainers. 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 ensures the preservation of the spring function of the transverse arch of the foot.

- 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 jumper is made straight or has straight sections extending from the rings of the first and third clamps connected by an S-shaped curved section. 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. This design allows you to increase the force of convergence of the metatarsal bones.

The implementation of the synostosing device, taking into account the anatomical and topographic and functional features of the forefoot allows you to maximize the adaptation of the device at the place of installation. 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 divergence of the metatarsal bones, the vicious position of the heads of the II and III metatarsal bones, excessive tension of the extensor tendons.

Description of the device is illustrated by drawings (Fig.1-6).

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 third latch.

Figure 4 is a view of the device from the side of the jumper with an S-shaped curved section.

Figure 5 is a view of the device from the side of the jumper made straight.

Figure 6 shows the position of the synostosing device when constricting I-III metatarsal bones.

A synostosis device for three metatarsal bones of the forefoot made of a material with a shape memory effect, such as titanium nickelide, consists of three curved clamps interconnected. The first 1 and third 2 retainers are made in the form of open rings having a gap from the side directed to the intraosseous branch 3 of the second retainer (Figure 1-2).

The first 1 and third 2 retainers are interconnected by a jumper 4 (Figure 5), from the middle of which there is a osseous branch 5 of the second retainer connected by a U-shaped jumper 6 lying in a plane perpendicular to the plane of the rings with the intraosseous branch 3 of the second retainer (Fig .one). Bony 5 and intraosseous 3 branches of the second retainer are parallel. The intraosseous branch 3 of the second retainer passes into the intramedullary leg 7, bent in the middle part from the longitudinal axis of the intraosseous branch 3 to the side opposite to the location of the first retainer 1 (Figure 3). The device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges.

The jumper 4 is made straight (Figure 5) or has straight sections 8 extending from the rings of the first 1 and third 2 clamps connected by an S-shaped curved section 9 (Figs. 2, 4). The layout of the synostosing device on the foot is shown in (Fig.6).

The device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges.

Synostating device set as follows. The envelope incision begins at the level of the neck along the inner surface of the I metatarsal bone, continues transversely at the level of the heads of the II and III metatarsal bones and proximal to the neck of the III metatarsal 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 1 and third 2 clamps made in the form of a ring are unbent with crampon forceps, straighten the bends, if the jumper 9 has an S-shaped section, the leg 7 is shaped in a convenient shape introductions into the intramedullary canal of the II metatarsal bone. The deformed synostosis device is transferred to the wound. Install the intramedullary leg 7 of the second latch, driving it to the level of the U-shaped jumper 6 of the transition of the osseous branch 5 into the intraosseous branch 3. The jumper 9 is held under the extensor tendons. Ring 1 of the first retainer is wound around the neck of the first metatarsal bone. Ring 2 of the third retainer winds around the neck of the III metatarsal bone. Under the influence of body temperature, the synostosing 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 (Figure 6). The wound is sutured.

Example. Patient S., 28 years old, diagnosis: static flat feet, anterior flattening of the right foot of the third degree.

The operation was performed under conduction anesthesia. The skin incision from the outer surface of the I metatarsal bone with a transition to the dorsal surface at the level of the heads of the II-III metatarsal bones, the incision is continued proximal to the III intertarsal space. I-II-III metatarsals are brought together. A milling hole was made in the head of the II metatarsal bone. A synostating device with a shape memory effect is cooled to a temperature of -10 ° C and deformed by unbending ring grips and an S-shaped curved section of the jumper. The deformed structure is transferred to the wound. Install the intramedullary leg by hammering it into the milling hole to the level of the bend of the U-shaped jumper. Then, on the III and I metatarsal bones, ring-shaped grips are placed in the subcapital segments. The design after form restoration firmly holds the forefoot. Primary healing.

Foot function restored after 3 weeks. After 1 year, the patient has no complaints. There is no tension of the plantar, calf muscles, the formed transverse arch of the foot retains its height.

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 (2)

1. Synostatic device for three metatarsal bones of the forefoot of a material with a shape memory effect, consisting of three interconnected curved fixators, characterized in that the second fixer is made in the form of a osseous branch, an intraosseous branch that passes into the intramedullary leg, and P- shaped bridge connecting the osseous and intraosseous branches, the intramedullary leg is bent in the middle part from the longitudinal axis of the intraosseous branch to the side opposite to the location of the first fixator, the osseous and internal the tricuspid branches are parallel to each other, the first and third retainers are made in the form of open rings having a gap from the side directed to the intraosseous branch of the second retainer, and connected by a jumper, the U-shaped jumper lies in a plane perpendicular to the plane of the rings of the first and third retainers, from the middle of the first and third retainers departs the osseous branch of the second retainer, the device is made of a plate 1.5 mm thick, 2 mm wide with rounded edges. 2. Synostosing device according to claim 1, characterized in that the jumper is straight or has straight sections extending from the rings of the first and third clamps connected by an S-shaped curved section.

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