RU153364U1 - LOCKED INTRAMEDULAR DEVICE FOR OSTEOSYNTHESIS OF FRACTURES AND LONG TUBULAR BONES DEFECTS - Google Patents

Abstract

1. An intramedullary device with blocking for osteosynthesis of fractures and defects of long tubular bones, including a tubular rod having sections with axially elongated holes, with the possibility of expanding through them flexible locking elements mounted on the upper and lower bushings and the drive, in the form an elongated element with a thread connecting the upper and lower bushings, characterized in that the flexible elements, made in the form of spokes, are attached to the upper and lower bushings at their ends, and thus way that the drive sleeve and the flexible locking elements together form a locking unit mounted within the tubular shaft for slidable movement within bushing sterzhnya.2. The intramedullary device according to claim 1, characterized in that two or more fixing blocks are installed inside the tubular rod. 3. The intramedullary device according to claim 1, characterized in that the tubular shaft has a round, quadrangular, hexagonal cross section.

Description

INTRAMEDOLLARY DEVICE WITH LOCKING FOR OSTEOSYNTHESIS OF FRACTURES AND LONG DEFECTS

TUBULAR BONES

The utility model relates to medical equipment used in traumatology, namely to orthopedic devices for the surgical treatment of bone fractures and for fixation of implants when replacing bone defects in inflammatory and tumor processes, specifically to expandable intramedullary devices.

The intramedullary fixation method is widely known and used for surgical treatment of long bone fractures, fixing a bone fracture without disturbing the periosteum. The method can be performed without exposing the fracture zone, and a broken bone can be used functionally, withstanding the load, during treatment. The surgical approach for the introduction of intramedullary rods is slightly different for each bone and is well covered in the literature on the treatment of fractures.

Problems associated with traditional intramedullary fixation methods include insufficient synthesized bone stability for rotational displacements and displacements along the longitudinal and transverse axis of the segment when thin rods are used. And also, although the real shape of the bone has some curvature, the intramedullary rods used in the treatment of broken bones are often straight (copyright certificates No. 186082, 09/12/1966, A61B; No. 1695906, 12/07/1991, A61B 17/72 ), therefore, massive rods require the reaming of the bone marrow canal or preliminary bending of the rod with special tools, which on the one hand violates

intraosseous circulation, on the other hand, reduces the mechanical strength of the rod. With intramedullary fixation of fractures by thin rods, blocking screws are usually inserted across the rods, through the walls of the bone and the rods themselves, to enhance the fixing properties, which creates a number of inconveniences. This lengthens the operation time and complicates it and may require additional skin incisions and a longer use of the electron-optical transducer and increase the x-ray load. And also, the resulting design may be too rigid and not have the required elasticity, which at an early load leads to fractures of the locking screws. Complications also include phenomena that develop as a result of influences leading to bone destruction in the area of the metal-bone connection. These effects lead to the development of microcracks in the bone with subsequent resorption of the bone tissue, the appearance of a gap between the bone and the structure and the clinical manifestation of aseptic loosening: instability, pain, violation of the conditions of consolidation.

At the current level of development of traumatology, surgical treatment of fractures should meet the following requirements: the least trauma to the soft tissues surrounding the bone, minimal blood loss, strong fixation of bone fragments with the possibility of leaving patients without external immobilization of the limb, early activation and functional load.

Known intramedullary locking devices, the design of which uses elastic elements in the form of spokes (copyright certificate No. 1072858, 02.15.1984, АВВ 17/18; patent RU 2296525, 04/10/2007, А61В 17/72). However, these devices are difficult to install in the intramedullary canal. Fixation of bone fragments only by filling the internal cavity of the bone with a beam of diverging spokes cannot provide the necessary rigidity

fixation, rotation stability required for proper earlier fusion of bone fragments.

Known expandable orthopedic device (patent RU 2296526, 04/10/2007, A61B 17/72). A device for stabilizing bone includes an elongated body having first and second terminal regions defining a longitudinal axis between them. Many planks come out of the first and second terminal region. Support arms are attached to the brackets, and a drive is attached to the support arms, the drive can be moved in the longitudinal direction relative to the elongated body, forcing the support arms to move the second ends of the brackets from the folded state to the expanded state. The elongated body is a tubular rod, and the actuator includes an elongated element inserted into the rod and connected to the tubular rod with the possibility of sliding movement by means of threaded connecting regions. A sleeve is attached to the elongated element and to the support arms. The elongated element includes a threaded region over which the sleeve is screwed so that the rotation of the elongated element relative to the tubular rod causes the sleeve to move in the axial direction, thereby causing the support arms to move the bars between the folded and extended states. There may be holes in the axial extension through which nails, bolts or other locking elements are inserted to provide additional lateral support.

The disadvantages of this device are the difficulty in manufacturing and installation, as well as limited possibilities for blocking, since with this device it is not possible to fix and block the middle, proximal and distal parts of the bone, create different compressive forces on different parts of the bone, since the cerebral canal of the bone has a different diameter on

its extent. Removing this device is associated with significant technical difficulties.

A device for intramedullary osteosynthesis (RU 2255696, publ. 07/10/2005, A61B 17/72), comprising a hollow cylindrical body with diametrically arranged slots, mounted in the housing, rotatably, a rod connected to two rods, each of which is fixed stops, with the possibility of placing the latter in the slots of the housing. This device is taken as a prototype.

The device has the following disadvantages. The stops are provided with free pointed ends, which has a traumatic effect on the bone tissue. Fixation of the device for intramedullary osteosynthesis is carried out by cutting the stops into the bone tissue, which leads to the appearance of microcracks in the bone with subsequent resorption of the bone tissue, the appearance of a gap between the bone and the structure. The device does not allow for the fixation of several specifically selected sections of the bone. And also the specified device is structurally more difficult.

The technical task of the utility model is to create a technologically advanced and easy to use intramedullary blocking device, as well as expanding its technical capabilities.

The technical result of using the proposed device is the ability to alternately block the distal, intermediate and proximal sections of the bone with varying degrees of fixation (expansion of the spokes) and with the possibility of compression of the fracture zone, reducing the traumatic effect on bone tissue. The device allows for osteosynthesis of diaphyseal fractures of the thigh, lower leg, shoulder, to fix transplants introduced into the area of the defect of the tubular bone, to fix the achieved elongation using a locking device at two or more levels.

An intramedullary device with blocking for osteosynthesis of fractures and defects of long tubular bones, including a tubular shaft, flexible locking elements mounted on the upper and lower bushings, a drive, in the form of an elongated element with a thread connecting the upper and lower bushings. The tubular rod has sections with axially elongated holes. Flexible elements are mounted expandably in axially elongated holes. Moreover, the flexible locking elements are attached at their ends to the upper and lower bushings. The drive, bushings and flexible locking elements together form a locking block mounted in a tubular rod with the possibility of sliding movement of the bushings inside the rod.

Each flexible locking element in the form of a spoke is connected at its ends to the upper and lower bushings, which are also interconnected by means of a drive. The drive can be moved in the longitudinal direction of the relatively flexible elements, causing the flexible elements to move from the folded state to the expanded state. The upper and lower bushings, flexible elements and drive together form a locking block. The locking unit is installed in a spring-loaded state inside the tubular rod with the possibility of sliding movement of the bushings inside the rod. The elongated element has a threaded region that is screwed into the lower sleeve in such a way that the rotation of the elongated element relative to the tubular rod causes the upper sleeve to move in the axial direction, causing the elastic elements in the form of spokes to move between the folded and expanded states. The tubular rod has sections with a solid wall and sections with axially elongated holes made therein to allow the expansion of flexible elements and to provide the required flexibility. In tubular

the rod may also have holes through which nails, bolts or other locking elements are inserted to provide additional lateral fixation. Two and / or more locking blocks may be installed in the tubular rod.

The device can be inserted through an inlet previously made using conventional procedures, for example, into the medullary canal of the femur. Preferably, the guide is first introduced through the inlet into the medullary canal of the bone using conventional methods and is advanced to the distal segment of the bone. Then a tubular rod is inserted along the guide into the medullary canal. After insertion of the rod, the guide can be removed.

After the tubular shaft is fully inserted into the medullary canal, two and / or more locking blocks are introduced into it alternately, as necessary, in a spring-loaded state. Each locking block is installed in a tubular rod in a section where there are elongated holes. The pre-spring-loaded elastic elements are released and partially expand, protruding through these holes, thereby fixing within the shaft.

The drive is actuated using a tool inserted into the tubular bar to bring the elastic elements into an expanded state such that the elastic elements extend significantly through the elongated holes of the tubular bar, protruding beyond it and adhere to the inner surface of the bone or other tissue, thereby reliably fixing the device relative to the bone. Thus, the device can hold the segments of the broken bone inside which it is implanted from longitudinal movement, bending or rotation relative to each other. In the event that additional lateral fixation is required, fixing elements, such as bolts or nails, can be inserted into the bone through openings to further secure the bone segments.

After the fracture is healed, the device can be removed in the reverse order using conventional access procedures.

The use of an intramedullary device according to the present utility model makes it possible to fix broken bone segments relative to rotation, and at the same time provides sufficient stability in other planes without the need for locking rods. This device is minimally invasive and can be implanted through a single incision. The intramedullary device can be configured to various sizes of bone circumference. The use of an intramedullary device at two or more levels allows osteosynthesis of diaphyseal fractures of tubular bones, fixation of transplants and achieved bone elongation. The possibility of sequentially blocking the distal, intermediate and proximal fragments with a different degree of expansion of the spokes allows you to provide a different degree of pressure of the bent spokes on the bone marrow canal, which allows one to exclude perforation of the walls of the bone marrow canal, and on the other to provide the necessary elasticity of design and the possibility of load on the limb. The device of the rod allows you to quickly and easily install and remove it.

An intramedullary device can be inserted using methods commonly used for traditional intramedullary rods for the bones of the thigh, lower leg, and shoulder, which minimizes the dose of x-ray radiation required to control the position of the rod and bone fragments after surgery.

In FIG. 1 shows a general view of the device, FIG. 2 - fixing block in the folded state, FIG. 3 - fixing block in an expanded state, FIG. 4 - installation of the fixing block in the folded state in the tubular rod, FIG. 5 - fixing block in an expanded state, mounted in a tubular rod.

The intermedullary device with blocking includes a tubular shaft 1 in which two and / or more fixing blocks 2 are mounted. The tubular shaft 1 is generally a tubular body, for example having a round, quadrangular, hexagonal cross section. The tubular shaft has sections with a solid wall 3 and sections with axially elongated holes 4 made therein to provide the required flexibility and to allow expansion of the fixing block 2. The locking block 2 includes an upper sleeve 5, a lower sleeve 6, flexible elements 7 and drive 8. Flexible elements 7, made, for example, in the form of spokes, are connected at their ends to the upper 5 and lower 6 bushings, which are also interconnected by means of a drive 8, and the drive 8 is able to move in the longitudinal direction of the relatively flexible elements 7, causing the flexible elements 7 to move from the folded state to the expanded state. The locking unit 2 is installed inside the tubular rod 1 with the possibility of sliding movement of the bushings 5 and 6 inside the rod 1. The drive 8 is made in the form of an elongated element, for example in the form of a screw, and has a head 9 located in the upper sleeve 5 and the region 10 provided with a thread, which can be screwed into the lower sleeve 6 in such a way that the rotation of the elongated element 8 relative to the tubular rod 1 causes the upper sleeve 5 to move in the axial direction, causing, in turn, the elastic elements 7 in the form of spokes to move m I am waiting for the collapsed and expanded states.

The device is used as follows.

The device is inserted through a preformed inlet into the medullary canal of the bone. A guide is inserted into the medullary canal and then a tubular shaft 1 is inserted along it.

After the complete introduction of the tubular rod 1 into the medullary canal, the guide is removed. Then, using a tool, into the tubular

the rod 1 enter the locking block 2. The tool can be any tool that engages with the head 9 of the actuator 8.

In the initial state, the elastic elements 7 are in a spring-loaded state and have a slightly larger size than the cross-section of the tubular rod 1. In the spring state, the elastic elements 7 are driven by a drive 8, screwing it into the lower sleeve 6 so that the upper sleeve 5 moves axially direction, forcing, in turn, the elastic elements 7, in the form of spokes, to move between the folded and extended states.

A spring-loaded locking unit 2 is inserted into the tubular shaft 1 and installed in a selected area 4 with axially elongated holes. Pre-spring-loaded elastic elements 7 are released and partially expand, protruding through these holes, thus being fixed inside the rod 1.

Next, a controlled movement of the upper sleeve 5 is carried out by means of the drive tool and the head 9 of the actuator 8, and the necessary expansion (or folding) of the elastic elements 7. in the axial direction inside the tubular rod 1 until the elastic elements 7 expand, protruding beyond the tubular rod 1 through the holes 4.

In the expanded state, the flexible elements 7 define a diameter that is substantially larger than the diameter of the tubular rod 1. As a result, the flexible elements 7 can reliably engage with the walls of the bone at several points of contact. This allows you to fix the device and, therefore, segments of the broken bone both along the axis and in relation to rotation with respect to each other.

If necessary, two and / or more fixing blocks 2 are introduced into the tubular rod 1 in turn, installing them in the corresponding sections of the rod 1.

After the fracture has been cured, the device can be folded by rotating the drive 8 and the sleeve 5 in the opposite direction to the rotation direction to expand the elements 7. The device can then be removed from the medullary channel.

Claims (3)

1. An intramedullary device with blocking for osteosynthesis of fractures and defects of long tubular bones, including a tubular rod having sections with axially elongated holes, with the possibility of expanding through them flexible locking elements mounted on the upper and lower bushings and the drive, in the form an elongated element with a thread connecting the upper and lower bushings, characterized in that the flexible elements, made in the form of spokes, are attached to the upper and lower bushings at their ends, and thus way that the drive sleeve and the flexible locking elements together form a locking unit mounted within the tubular shaft for slidable movement of the rod within the sleeves. 2. An intramedullary device according to claim 1, characterized in that two or more fixing blocks are installed inside the tubular shaft. 3. The intramedullary device according to claim 1, characterized in that the tubular shaft has a round, quadrangular, hexagonal cross section.

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