RU2810413C1 - Device for bone prosthetics when eliminating defects in lower jaw bone - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: device for bone prosthetics when eliminating defects in the lower jaw bone includes an oblong body, one side of which is designed to be connected to the bone. On the oblong body there is a slider designed to be connected to the opposite bone. The slider is equipped with a slider movement screw to ensure reciprocating movement of the slider relative to the elongated body, which is connected to a mechanism for stepwise movement of the slider. The mechanism for stepwise movement of the slider contains a transverse wall on the oblong body on the side opposite to the side of the oblong body intended for connection with the bone, with a through hole, and the end part of the screw passes through the through hole. On the transverse wall on the side that is opposite to the side of the oblong body, intended for connection with the bone, an annular protrusion is formed with a pair of oppositely located additional protrusions with inclined walls, and on the end part of the screw there is an elongated cylindrical part with a smooth surface, a cylindrical widening with longitudinal grooves, ending in an additional cylindrical widening. The end part of the screw is fitted with a bushing with a through longitudinal cavity and protrusions inward on one side, which covers the widening of the cylindrical shape of the screw with longitudinal grooves so that the protrusions of the bushing are placed inside the longitudinal grooves with the possibility of longitudinal movement. The end part without any sleeve protrusions covers the additional cylindrical widening of the screw. A spring is placed in the cavity between the widening of the cylindrical screw with longitudinal grooves and the end part of the bushing without protrusions. The end of the sleeve abuts the transverse wall, and has a pair of oppositely located recesses with inclined walls in size corresponding to additional projections with inclined walls on the annular protrusion of the transverse wall located on the side opposite the bone plate.

EFFECT: invention ensures the development of a technical solution that allows to perform gradual, rather than immediate, expansion of prosthetic elements as conveniently and comfortably as possible for the patient with minimal surgical trauma and expansion of the range of devices intended for performing operations of this type.

4 cl, 42 dwg

Description

The invention relates to medicine and can be used to eliminate defects of the bones and skeleton, in particular, the lower jaw, of a congenital and acquired nature.

A device for bone prosthetics is known, in particular, for eliminating a defect in the lower jaw, which has the ability to lengthen as the healthy half of the lower jaw grows (1, 2). The said device includes an oblong body, one side of which is designed to connect to the bone,

• on the oblong body there is a slider designed to connect to the opposite bone,

• the slider is equipped with a slider movement screw to ensure reciprocating movement of the slider relative to the elongated body,

• which is connected to the mechanism for stepwise movement of the slider,

An individual bone plate, for example, for connecting to the body of the mandible with screws, and a slider connected to the implant of the mandibular ramus, including the articular head, are able to move relative to each other, leading to an increase in the total length of the device in the sagittal direction (1 , 2).

The bone plate and the implant of the mandibular ramus are connected to each other by a screw, when rotated, one part moves along the other (extends). At the same time, the total length of the device increases.

This technical solution was adopted as a prototype of the claimed invention, since it is the closest to it in terms of the totality of common essential features.

Let's take a closer look at the design features of this device.

Its important feature is that the bone plate is rigidly connected, for example, to the healthy part of the lower jaw on one side and to the implant of the lower jaw branch, the end of which is fixed in the glenoid fossa prosthesis, on the other. In plan (in the axial plane), these two parts in the assembly, together with the healthy half of the lower jaw, have a shape resembling the shape of an isosceles triangle, the ends of which are fixed in the articular fossae of the temporal bones. Over time, the healthy half of the lower jaw (one of the sides of the triangle) grows. At the same time, the previously installed structure remains unchanged, which is manifested in the formation and increase of facial asymmetry, bite deformation and the formation of various functional disorders (up to the development of obstructive apnea syndrome due to the distal displacement of half of the lower jaw, and with it the complex of tissues of the floor of the mouth) . To eliminate this pathology, it is necessary to lengthen the installed structure. By rotating the screw, the implant of the mandibular ramus moves relative to the bone plate, which is accompanied by an increase in the length of the entire structure in the sagittal plane.

However, this comes with a number of disadvantages.

As noted above, the bone plate, the implant of the mandibular ramus and the lower jaw itself in plan resemble an isosceles triangle, the ends of which are connected to the articular fossae and the distance between them is constant. Since the bone plate is rigid and solid, when the elements of the device move apart, due to the impossibility of rotating the bone plate and the ramus implant relative to each other, significant stress arises in the bone plate rigidly connected to the body of the lower jaw. This may result in either a fracture of the structure or dislocation of the bone screws holding the bone plate in place.

Another disadvantage of this design is the possibility of lengthening it only in one direction (in the body area), without the possibility of lengthening the branch of the lower jaw.

The next disadvantage is the lack of a mechanism that prevents the elements of the device from twisting under the influence of chewing movements after unscrewing the screw.

For this application, it is especially necessary to note that the design described above does not have the necessary elements that make it convenient and comfortable for the patient to carry out step-by-step extension of the prosthetic elements.

This design provides for only one-stage extension of the structure during surgery. At the same time, strong tissue stretching that occurs when the structure is simultaneously extended over a significant distance (more than 5 mm) leads to the development of ischemic disorders, which is accompanied by pain and can provoke exposure of prosthetic elements.

The purpose of the invention is:

• development of a technical solution that allows for gradual, rather than immediate, expansion of prosthetic elements as convenient and comfortable for the patient as possible with minimal surgical trauma;

• Expansion of the range of devices intended for carrying out operations of this type.

This goal is achieved by the fact that the device for bone prosthetics includes an oblong body, one side of which is intended for connection with the bone, on the elongated body there is a slider intended for connection with the bone located opposite, the slider is equipped with a slider movement screw to ensure reciprocating movement of the slider relative to the oblong body, which is connected to the mechanism for stepwise movement of the slider, and, according to the invention, the mechanism for stepwise movement of the slider contains a transverse wall on the oblong body on the side opposite to the side of the oblong body intended for connection with the bone, with an annular through hole, and the end part of the screw passes through an annular through hole, and on the transverse wall on the side opposite to the side of the oblong body intended for connection with the bone, an annular protrusion with a pair of oppositely located additional protrusions with inclined walls is formed, and on the end part of the screw there is an elongated cylindrical part with a smooth surface, cylindrical widening with longitudinal grooves ending in an additional cylindrical widening, while the end part of the screw is fitted with a bushing with a through longitudinal cavity and protrusions inward on one side, which covers the cylindrical widening of the screw with longitudinal grooves so that the bushing protrusions are placed inside the longitudinal grooves with possibility of longitudinal movement, and the end part without protrusions of the bushing covers the additional cylindrical widening of the screw, and in the cavity between the widening of the cylindrical screw with longitudinal grooves and the end part of the bushing without protrusions, a spring is placed, and the end of the bushing rests against the transverse wall, and there is a pair of opposite located recesses with inclined walls corresponding in size to additional protrusions with inclined walls on the annular protrusion of the transverse wall located on the side opposite to the bone plate.

This set of essential features characterizes the essence of the invention. It is necessary and sufficient for any implementation of the invention.

A device characterized by this set of features allows:

• carry out gradual, rather than immediate, expansion of the prosthetic elements as convenient and comfortable for the patient as possible with minimal surgical trauma;

• Expand the range of devices designed to carry out operations of this type.

This mechanism for gradually moving the slider allows you to obtain a number of other advantages:

• fixing the position of the screw during rotation, which prevents it from being unscrewed back;

• control of the number of screw turns;

• understanding the amount of expansion of prosthetic elements,

• prevention of ischemic disorders in tissues and the development of pain by eliminating the simultaneous expansion of prosthetic elements.

In addition, the applicant considers it necessary to highlight the following developments and/or clarifications of the set of essential features related to special cases of implementation or use.

It is advisable that the mechanism for stepwise movement of the slider would have the following feature: on the elongated cylindrical part of the screw with a smooth surface, inside the annular protrusion on the transverse wall (plug), with an emphasis directly on the transverse wall (plug), a longitudinal ring would be attached, having a longitudinal length along screw, equal to the height of the annular protrusion without taking into account the height of a pair of oppositely located protrusions with inclined walls.

This longitudinal ring is pressed onto the screw when assembling the mechanism for step-by-step movement of the slider, and is a supporting element during distraction. As the screw rotates and the slide moves backward, the longitudinal ring receives force from soft tissue or bone, which resists its stretching. It is also important to take into account that the end part of the screw is very small and is additionally cut with longitudinal grooves, which makes it very unreliable for the perception of force.

There may be several longitudinal grooves on the cylindrical widening with longitudinal grooves of the screw of the stepwise movement mechanism of the slider, but for reliable operation of the mechanism it is most preferable to have four longitudinal grooves.

Numerous modifications of the claimed mechanism are possible, for example, a slider designed to connect to the opposing bone can be connected to it through an implant.

To summarize, we can note the following:

The developed device has the following advantages relative to known analogues:

• the possibility of carrying out a gradual, rather than one-stage, extension of the prosthetic elements as convenient and comfortable for the patient as possible with minimal surgical trauma;

• fixing the position of the screw during rotation, which prevents it from being unscrewed back;

• control of the number of screw turns;

• understanding the amount of expansion of prosthetic elements,

• prevention of ischemic disorders in tissues and the development of pain by eliminating the simultaneous expansion of prosthetic elements;

• expansion of the range of devices of this type.

The advantages described above are achieved due to the design features of the proposed device.

The presence of a slider between the oblong body and, for example, a lower jaw implant, allows you to gradually move (move apart) the elements of the device relative to each other, which leads to the gradual elimination of facial asymmetry and normalization of the position of the lower jaw. The presence at the end of the screw for moving the slider on the side opposite the side of the longitudinal body intended for connection with the bone, for example, the bone plate, of a mechanism for step-by-step movement of the slider allows you to gradually move apart the elements of the device without causing ischemic disorders in the surrounding soft tissues, and also prevents reverse unscrewing of the elements of the device under the influence of chewing movements. This in turn ensures the stability of the treatment results. The presence of a mechanism for step-by-step movement of the slider allows, with minimal trauma to the patient, almost painlessly, to move apart the elements of the device and, thereby, eliminate facial asymmetry. The presence of a removable drive on the opposite side of the bone plate allows the drive to be brought out through the skin in an aesthetically acceptable, inconspicuous (behind the ear) area of the face, which is important for the psychological comfort of the patient. The very possibility of detaching the drive to turn the screw eliminates the need for postoperative care at the site where the drive exits the skin, which also has a beneficial effect on the patient’s quality of life in the postoperative period.

In conclusion of this section of the description, it should be noted that in addition to the advantages noted above, the advantage of the present invention also lies in the fact that the device can be manufactured on technological equipment already used in the medical industry.

The device also allows you to expand the range of devices used for treatment.

The invention is illustrated by its use in a device for mandibular prosthetics and mounted on the lower jaw.

The invention is illustrated by the drawing.

In fig. 1 shows a device for bone prosthetics, in particular prosthetics of the lower jaw, side view, axonometry;

Note 1: in all figures, the device for bone prosthetics is shown using the example of prosthetics of the lower jaw, but it can also be used for prosthetics of other bones;

Note 2: The screws for attaching the bone plate to the mandible are not shown.

In fig. 2 - the same, view from the other side, axonometry;

In fig. 3 - the same, front view, axonometry;

In fig. Figure 4 shows a separate device for mandibular prosthetics, top view, axonometry;

In fig. 5 shows a separate device for prosthetics of the lower jaw at the moment when the slider is in the closest position to the bone plate, side view from above, axonometry;

In fig. 6 - the same, when the slider is in the farthest position from the bone plate, side view from above, axonometry;

In fig. 7 shows an oblong body, end view from the side of the hinges, axonometry;

In fig. 8 - the same; end view without hinges, axonometry;

In fig. 9 - the same, side view, axonometry;

In fig. 10 shows a slider to which the lower jaw implant is attached, view from the side of the slider, axonometry;

In fig. 11 - the same, view from the side to which the slider is not attached, axonometry;

In fig. 12 shows an oblong body, in the oblong groove of which a slider with a lower jaw implant is installed, and the walls of the oblong body are made transparent, axonometry;

In fig. 13 - the same, in which a transverse plug from the side of the bone plate and a transverse plug from the side opposite to the bone plate are schematically shown, axonometry;

In fig. 14 shows the slider moving screw, top view;

In fig. 15 shows an oblong body, in the oblong groove of which, on the transverse plug on the side of the bone plate and the transverse plug on the side opposite to the bone plate, there is a screw installed, previously screwed into the slider, connected to the lower jaw implant, and the walls of the oblong body are made transparent, view of the oblong body from the side of the loops of the oblong body, axonometry;

In fig. 16 - the same, view of the oblong body from the side opposite to the loops of the oblong body, axonometry;

In fig. 17 - the same, vertical section according to AA of Fig. 16;

In fig. 18 shows a cross section BB of FIG. 17;

In fig. 19 shows a transverse plug from the side opposite to the bone plate, a view from the side on which there are no protrusions with inclined walls, axonometry;

In fig. 20 shows a transverse plug from the side opposite to the bone plate, a view from the side on which there are protrusions with inclined walls, axonometry;

In fig. 21 shows a slider moving screw with a cylindrical extension made on the extension of the slider moving screw on the side opposite to the bone plate with longitudinal grooves ending in an end cylindrical widening, and with a sleeve with a through longitudinal cavity mounted on the screw extension on the side opposite to the bone plate and protrusions on one side, as well as a sleeve spring attached to the screw extension, side view, axonometry;

Note: the longitudinal ring is not shown so as not to overload the figure.

In fig. Figure 22 shows the bushing from the side of the protrusions inside the through longitudinal cavity, axonometry,

In fig. 23 shows a separate view of the bushing mounted on the slider displacement screw, axonometry;

Note: the longitudinal ring is not shown so as not to overload the figure.

In fig. 24 - the same, vertical section B-B of Fig. 22 along the longitudinal axis of the slider moving screw;

Note: the longitudinal ring is not shown so as not to overload the figure.

In fig. 25 shows a means for controlling the movement of the slider with the bushing, at a time when a pair of oppositely located protrusions with inclined walls on the transverse plug on the side opposite to the bone plate are located inside a pair of oppositely located recesses with inclined walls at the end of the bushing, side view.

In fig. 26 - the same, at the moment when a pair of oppositely located protrusions with inclined walls on the transverse plug on the side opposite to the bone plate are located outside the pair of oppositely located recesses with inclined walls at the end of the sleeve, side view.

In fig. Figure 27 shows an adapter with a multifaceted longitudinal hole and a transverse through hole in the wall, intended for installing the end multifaceted protrusion of a removable drive with a spring-loaded lock into it, axonometry.

In fig. Figure 28 shows a multifaceted end protrusion of a removable drive with a spring-loaded lock, intended for installation in an adapter with a multifaceted longitudinal hole, axonometry.

In fig. 29 - the same, with the polyhedral end protrusion of the removable drive shown transparent, axonometry.

In fig. 30 shows a cross-section of the end polyhedral projection of the removable actuator passing through the spring-loaded retainer.

In fig. Figure 31 shows an adapter with a multifaceted longitudinal hole and a transverse through hole in the wall, into which the end multifaceted protrusion of a removable drive with a spring-loaded lock is inserted, axonometry.

In fig. 32 - the same, and the adapter with a multifaceted longitudinal hole and a transverse through hole in the wall, as well as the multifaceted end protrusion of a removable drive with a spring-loaded lock inserted into it, are shown transparent, axonometry.

In fig. 33 shows an on-bone plate and an oblong body with a slider and a means for moving the slider along the elongated plate, and the loops of the oblong body and the on-bone plate coincide with the formation of a common through hole, while the loops on the on-bone plate are shown transparent, axonometry.

In fig. Figure 34 shows the bone plate, internal view, axonometry.

In fig. 35 shows a tubular axis, axonometry.

Note: The screw thread (item 74) is not shown to avoid overcrowding the figure.

In fig. 36 shows a tubular axis, longitudinal section.

Note: The screw thread (item 74) is not shown to avoid overcrowding the figure.

In fig. 37 shows a bone plate and an oblong body with a slider and a means for moving the slider along the oblong plate, and the loops of the oblong body and the bone plate coincide with the formation of a common through hole, as well as a tubular axis, before its installation in a common through hole, while the loops of the bone plate are shown transparent, axonometry.

Note: The carvings are not shown to avoid overcrowding the figure.

In fig. 38 - the same, after installing the tubular axis into the common through hole, with all the loops of the oblong body and the bone plate shown transparent, axonometry.

Note: The carvings are not shown to avoid overcrowding the figure.

In fig. Figure 39 shows a screw of a tubular axis, view from the slot side, axonometry.

Note: The screw thread (item 84) is not shown to avoid overcrowding the figure.

In fig. Figure 40 shows a tubular axle screw, side view.

Note: The thread (item 84) is not shown to avoid overcrowding the figure.

In fig. 41 shows a longitudinal section of a screw of a tubular axis.

In fig. 42 shows a bone plate and an oblong body with a slider and a means for moving the slider along the oblong plate, and the loops of the oblong body and the bone plate coincide with the formation of a common through hole, as well as a tubular axis fixed in a common through hole, into the longitudinal through hole of which a tubular screw is screwed axles, partial breakout.

Note: the threads are not shown to avoid overcrowding the figure.

As noted above, the invention is illustrated by its use in a mandibular prosthetic device mounted on the mandible.

Device 1 for prosthetics of the lower jaw includes a bone plate 2 for connection with the body 3 of the lower jaw 4, and an implant 5 of the lower jaw, with the ability to move them relative to each other, and the device contains an oblong body 6, equipped with a slider 7, to which the implant 5 of the lower jaw is attached jaw, with a bone plate 2 attached to the oblong body 6 on one side by means of a rotary axis 8 with the possibility of fixing the angle of rotation, and on the other side a means 9 for moving the slider along the oblong body is attached (Fig. 1 - Fig. 6).

This is the general design of the claimed device.

Let us now consider its individual components and parts.

The oblong body 6 is made with a longitudinal through groove 10 of a T-shape with protrusions 11 directed towards each other on the sides, inside of which a slider 7 is placed with the possibility of reciprocating movement inside the longitudinal through groove 10, and a means 9 for moving the slider 7 along the oblong body 6 contains a screw 12 for moving the slider, installed in a through hole 14 of the slider 7 equipped with a screw thread 13, the end part 15 of which, located on the side of the bone plate, is installed with the possibility of rotation in the through hole 16 in a transverse plug 17 rigidly connected to the elongated body 6, located with sides of the bone plate 2, and the end part 15 of the screw, located on the side of the bone plate, has an external widening 18 at the end with the possibility of support on the transverse plug 17, located on the side of the bone plate 2, and the end part 19 of the screw, located on the side opposite to the bone plate , is installed with the possibility of rotation in the through hole 20 in the transverse wall 21 rigidly connected to the elongated body 6, located on the side opposite the bone plate 2, and has a mechanism 22 for step-by-step movement of the slider, which is designed to fix the position of the screw during rotation, count the turns of the screw and to be able to determine for the doctor a fixed amount of movement of the slider, and, consequently, to determine the amount of distraction.

The applicant draws attention to the fact that the surface of the part of the screw 12 between its end parts 15 and 19 has a thread 23.

Let us consider separately the design of the mechanism 22 for step-by-step movement of the slider.

It contains, on the transverse wall 21, located on the side opposite to the bone plate, an annular protrusion 24 with a pair of oppositely located additional protrusions 25 with inclined walls 26, made on the end part of the screw 12, located on the side opposite to the bone plate 2, an elongated cylindrical part 27 with a smooth surface, a cylindrical widening 28 with longitudinal grooves 29, ending with an additional cylindrical widening 30, mounted on the end part 19 of the screw 12, located on the side opposite the bone plate 2, a sleeve 31 with a through longitudinal cavity 32 and protrusions 33 inward on one side , while the bushing 31 covers the widening 28 of the cylindrical shape of the screw 12 with longitudinal grooves 29 so that the protrusions 33 of the bushing 31 are placed inside the longitudinal grooves 29 with the possibility of longitudinal movement, and the end part 34 without protrusions of the bushing 31 covers the additional cylindrical widening 30 of the screw 12, and in the cavity 35 between the widening 28 of the cylindrical screw 12 with longitudinal grooves 29 and the end part 34 without protrusions of the sleeve 31, a spring 36 is placed, and the end 37 of the sleeve 31 rests against the transverse wall 21, located on the side opposite to the bone plate, and at the end 37 of the sleeve 31 there is a pair of oppositely located recesses 38 with inclined walls 39 corresponding in size to additional protrusions 25 with inclined walls 26 on the annular protrusion 24 of the transverse wall 21 located on the side opposite the bone plate 2, while on the elongated cylindrical part 27 of the screw with a smooth surface , inside the annular protrusion 24 on the transverse wall 21, located on the side opposite the bone plate 2, with an emphasis directly on the transverse wall 21, a longitudinal ring 40 is attached, having a longitudinal length along the screw 12 equal to the height of the annular protrusion 24 without taking into account the height of a pair of oppositely located additional 25 projections with 26 inclined walls.

This longitudinal ring 40 is pressed onto the screw 12 when assembling the mechanism 22 for stepwise movement of the slider, and is a supporting element during distraction. When the screw 12 rotates and the slider 7 moves backward, the longitudinal ring 40 receives force from soft tissues or bones that resist stretching.

The assembly of this part of the device with a means of moving the slide along the oblong body is carried out as follows:

• first of all, take the oblong body 6 and insert the slider 7 into its longitudinal through groove 10, to which the lower jaw implant 5 is already attached;

• then take screw 12 and put spring 36 on it so that it rests against the additional cylindrical widening 30;

• put the sleeve 31 on the screw 12 so that it covers the spring 36 with the end part 34 without protrusions and at the same time the protrusions 33 of the sleeve 31 would be placed inside the longitudinal grooves 29 of the screw 12 with the possibility of longitudinal movement;

• put a longitudinal ring 40 on the elongated cylindrical part 27 of the screw with a smooth surface and secured by tension, thus fixing the sleeve 31 with the spring 36 on the screw 12 with the possibility of limited movement of the sleeve 31 with the spring 36 along the screw 12;

• take the transverse wall 21, located on the side opposite the bone plate, and attach it to the end of the oblong body 6, for example, by microwelding;

• take the transverse plug 17, located on the side of the bone plate, and attach it to the other end of the oblong body 6, for example, by microwelding;

• through the through hole 20 in the transverse wall 21, the end part 15 of the screw, located on the side of the bone plate, is inserted into the oblong body 6 in the direction of the slider 7;

• screw the screw thread 23 of the screw 12 into the screw thread 13 of the through hole 14 of the slider 7 through the holes and continue to do this until the end part 15 of the screw, located on the side of the bone plate, passes through the through hole 16 in a rigidly connected to the elongated body 6 transverse plug 17 from the side of the bone plate;

• create a widening 18 at the end of the end part 15 of the screw, located on the side of the bone plate. In the opinion of the applicant, it is preferable that the extension 18 be made in the form of a washer 41 connected to the end of the screw 12, for example, using microwelding.

The diameter of both end parts 15 and 19 of the screw 12 is slightly smaller than the diameter of the corresponding through holes 16 and 20 of the transverse plug 17 and the transverse wall 21, and the screw 12 can rotate in the through holes, moving the slider 7.

The device operates as follows.

If you grab the protrusion 42 at the end of the screw 12 with a tool (for example, pliers) or your fingers, then when you turn the screw 12, the rotation through the longitudinal grooves 29 on the screw 12 and the protrusions 33 on the sleeve 31 is transmitted to the sleeve 31. The sleeve 31 rotates. It is important that the sleeve 31 is pressed against the transverse wall 21, located on the side opposite the bone plate, using a spring 36. When the sleeve 31 is rotated together with the screw 12, the inclined walls 39 of the recesses (grooves) 38 slide along the inclined walls 26 of the additional protrusions 25 of the transverse wall 21. The protrusions 33 of the bushing 31 move along the axis of the screw 12 in the longitudinal grooves 29. In this case, the spring 36 is slightly compressed.

Thus, when the screw 12 rotates, the sleeve 31 also rotates. In this case, the transverse wall 21, located on the side opposite the bone plate 2, remains motionless, since it is welded to the oblong body 6. The inclined walls 39 of the recesses 38 of the sleeve run over the inclined walls 26 onto the fixed additional projections 25 of the fixed transverse wall 21 located on the side , opposite the bone plate 2. As a result, the sleeve 31 moves back to the height of the recesses (grooves) 38 and slides along additional protrusions 25 until it enters the next recesses (grooves) 38.

The described mechanism 22 for step-by-step movement of the slider is needed for the following purposes:

• fixing the position of screw 12 during rotation,

• counting the number of screw turns 12,

• determining the amount of movement of the slider 7,

• determination by the surgeon at the clinical stage of the amount of distraction and creation of favorable conditions for gradual stretching of the tissues surrounding the prosthesis.

To ensure rotation of the screw 12 to the protrusion 42 at the end of the screw 12, located on the side opposite the bone plate, an adapter 44 with a multifaceted longitudinal hole 45 and a transverse through hole 46 in the wall 47, into which an end polyhedral protrusion is inserted, is microwelded along line 43 48 of the removable drive 49 with a spring-loaded latch 50 containing a rod 51 with a ring-shaped widening 52, placed inside a through transverse hole 53 inside the body 54 of the end polyhedral protrusion 48 of the removable drive 49, and the annular widening 52 of the rod 51 on one side is installed with the possibility of contact with the ledge 55 , made inside the through transverse hole 53 of the end polyhedral protrusion 48 of the removable drive 49, and the other side with the possibility of contact with the surface made with the through hole 56 for the rod 51 by a plug 57 welded to the end polyhedral protrusion 48, and inside the cavity 58 between the annular widening 52 of the rod 51 and a plug 57, a spring 59 is installed to ensure that the annular widening 52 of the rod 51 is pressed to the ledge 55 and, at the same time, when the annular widening 52 of the rod 51 comes into contact with the ledge 55, the end part 60 of the rod 51 protrudes above the surface 61 of the end polyhedral shaped protrusion 48 of the removable drive 4 9 .

For the convenience of explaining the design, the applicant notes that position 53 denotes the entire through transverse hole, position 58 denotes its part, that is, the cavity between the annular widening 52 of the rod 51 and the plug 57, in which the spring 59 is placed (installed).

In this case, the multifaceted longitudinal hole 45 of the adapter 44 is made of a hexagonal shape, and the polygonal end protrusion 48 of the removable drive 49 inserted into it is also made of a hexagonal shape.

When assembling, first the rod 51 is inserted into the through hole 53 until the annular widening 52 stops in the ledge 55. Then, in the through transverse hole 53, a spring 59 is put on the rod 51. After this, a plug 57 is installed on the end part 62 of the rod 51 so that the end part 62 fits into the through hole 56 of the plug 57. The plug 57 is micro-welded to the end polyhedral protrusion 48 of the removable drive 49.

In the initial position, the end part 60 of the rod 51 protrudes above the surface 61 of the end polyhedral protrusion 48 of the removable drive 49 under the influence of the spring 59.

To connect, it is necessary to press the end part 60 of the rod 51 flush with the surface 61 of the end polyhedral protrusion 48 of the removable drive 49 with a finger or a screwdriver, compressing the spring under the influence of the spring 59. Then insert the end polyhedral protrusion 48 into the multifaceted longitudinal hole 45 of the adapter 44 so that after input, the end part 60 of the rod 51 would be opposite the transverse through hole 46 in the wall 47 of the adapter 44. In this case, the end part 60 of the rod 51 under the influence of the spring 59 will extend and fix the connection of the adapter 44 with the end polyhedral protrusion 48 of the removable drive 49.

To disconnect, you must first embed the end part 60 of the rod 51 flush with the surface 61 of the end polyhedral protrusion 48 of the removable drive 49, compressing the spring 59, for example, with a thin rod whose diameter is less than the diameter of the transverse through hole 46 in the wall 47. Then pull out the end polyhedral protrusion 48 of removable drive 49 from adapter 44.

Let us now consider the design of the rotary axis 8 with the possibility of fixing the angle of rotation in more detail.

As noted above, the oblong body 6 is connected to the bone plate 2 by means of a rotary axis 8 with the possibility of fixing the angle of rotation, and the bone plate 2 at the end has a loop 63 with a through hole 64, and the oblong body 6 has a pair of loops, namely, a loop 65 with a through hole 66 and a loop 67 with a through hole 68, in the gap 69 between which a loop 63 of the bone plate 2 is installed, while the through holes of the loops coincide with the formation of a common through hole 70, and the rotary axis 8 is made in the form of a tubular axis 71, rigidly connected to one end 72 to the outer side of the loop 65 of the oblong body 6 and having a longitudinal length corresponding to the total longitudinal length of the loop 65 of the oblong body 6 and the loop 63 of the bone plate 2, and the tubular axis 71 has a longitudinal through hole 73 with a screw thread 74 on part of the length from the side attachment to the outer side of the loop 65 of the oblong body 6, and on the remaining part of the length in its wall there are through longitudinal slots 75, and the thickness of the walls of the tubular axis 71 on the part of the length corresponding to the loop 63 of the bone plate 2 gradually decreases towards the end 76 of the tubular axis 71, forming the surface of a straight circular cone of the walls of the longitudinal through hole 73 of the tubular axis 71, corresponding to the through longitudinal slots 75, while the rod 77 of the screw 78 of the tubular axis is screwed into the screw thread 74 of the tubular axis 71 with a head 80 equipped with a slot 79, and the rod 77 of the screw 78 and the head 80 of the screw 78 are connected by a transition part 81 having a conical shape, forming a surface of a straight circular cone of the transition part 81 of the screw 78 of the tubular axis, located at the place in which the thickness of the walls of the tubular axis 71, corresponding to the longitudinal slots, gradually decreases towards the end 76 tubular axle 71.

Note: by spline we mean a multi-faceted (preferably hexagonal) key socket in the head 80 of screw 78.

When screwing the screw 78 into the screw thread 74, the transition part 81, which has a conical shape, rests from the inside against the tubular axis 71 at the location of the through longitudinal slots 75, where the thickness of the walls of the tubular axis for part of the length of the corresponding loop 63 of the bone plate 2 gradually decreases towards the end 76 of the tubular axis 71. Due to the presence of several through longitudinal slots on the tubular axis 71 with the formation of several strips 82, when screwing the screw 78 into the screw thread 74, the adapter part 81, which has a conical shape, rests from the inside against the tubular axis 71 at the location of the through longitudinal slots 75 and spreads the strips 82 apart. These strips 82 are tightly pressed against the surface of the through hole 64 of the loop 63 and keep the bone plate 2 from rotating. It is important to note that the tubular axis 71 is welded during assembly to the loop 63 of the bone plate 2 from the outside after combining the loops 63, 65, 67 and forming a common through hole 70, into which the tubular axis 71 is inserted, followed by microwelding.

Thus, during assembly, the tubular axle 71 is inserted from above into the common through hole 70 and microwelded around the perimeter of the end 72, and the screw 78 is inserted from below into the tubular axle 71 and screwed into this tubular axle. In this case, the transition part 81 of the screw, which has a conical shape, presses on the strips 82 of the tubular axis 71. As a result, the transition part 81 of the screw, which has a conical shape, expands (spreads apart) the strips 82 and they engage with the walls of the through hole 64 of the loop 63 of the bone plate 2 at with the help of friction, thus fixing the position of the bone plate 2 relative to the oblong body 6.

During surgery, the bone plate 2 is fixed with screws (not shown) through pre-selected holes 83 to the body 3 of the lower jaw 4. The articular head of the prosthesis 5 is installed in the articular fossa.

After a certain time, as the healthy half of the lower jaw grows and functional and aesthetic disorders occur, the need arises to extend the claimed device. To do this, the surgeon creates operational access to the body of the prosthesis, unscrews the screw 78, the screw thread 84 of which on the rod 77 is unscrewed from the screw thread 74 of the tubular axis 71. As a result, the strips 82 of the tubular axis 71 are released and it becomes possible to rotate the bone plate 2 relative to the oblong body 6. This is necessary to compensate for angular changes. To unscrew the screw 78, the head 80 of the screw 78 has a slot 79 (hexagonal socket) for a screwdriver used to turn the screw 78.

Thanks to the design described above, the convenience of the operation is increased

A device for lower jaw prosthetics allows:

• eliminate functional disorders and facial asymmetry that arise as the healthy half of the lower jaw grows due to the expansion of prosthetic elements without causing unwanted stress in the structure and without dislocating the fixing screws;

• carry out, if necessary, lengthening not only in the body area, but also in the branch area;

• prevent reverse twisting of prosthetic elements;

• carry out gradual, rather than immediate, expansion of the prosthetic elements as convenient and comfortable for the patient as possible with minimal surgical trauma;

• carry out surgical access to expand the prosthetic elements in an aesthetically acceptable area.

As a result of the use of the invention, the movement of the slider when extending the prosthesis fixed to the lower jaw occurs along a trajectory that mirrors the contour of the healthy half of the lower jaw, which is an important advantage of the proposed invention.

The essence of the invention is illustrated by a clinical example.

Patient Ya., 7 years old, was admitted to the Department of Maxillofacial Surgery of the Children's City Clinical Hospital of St. Vladimir with a diagnosis of Goldenhar syndrome: underdevelopment of the upper jaw, defect of the lower jaw on the right, underdevelopment of the lower jaw on the left. Obstructive sleep apnea syndrome. It is known from the anamnesis that due to the presence of a dermoid cyst in the area of the right eye, the patient contacted an ophthalmologist with a request to remove the cyst. Due to the presence of severe underdevelopment and distal displacement of the lower jaw, the child was denied general anesthesia and recommended to consult an oral and maxillofacial surgeon in order to normalize the position and movements of the lower jaw.

Upon admission to the department, the patient’s parents complained of the child’s loud snoring during sleep, periodic interruptions of sleep, as well as difficulty chewing due to impaired occlusion of the dentition and facial asymmetry.

In the department of maxillofacial surgery, the patient was examined according to the general rules in surgery. During a clinical examination, facial asymmetry was determined due to a decrease in the volume of tissue in the parotid-masticatory and cheek areas on the right, and a shift in the midline of the chin to the right. The right side of the mouth was located higher than the left. When examining the face in profile, the chin was sloping. When opening the mouth, there was a shift in the midline of the lower dentition to the right, pronounced crowding of the teeth and deformation of the dentition. On the right, closure of the molars was noted according to class II of Engle’s classification, on the left according to class I. There was no contact between the incisors in the anterior region. General blood and urine tests, a biochemical blood test were taken, an ECG and multislice computed tomography of the facial bones (MSCT) were performed. MSCT revealed the absence of the branch, head and distal edge of the body of the lower jaw on the right. The midline of the lower jaw was shifted to the right by 5 mm. It was decided that it was necessary to normalize the position of the lower jaw and eliminate the defect of the lower jaw on the right using an individual titanium prosthesis of the lower jaw with the ability to expand and a prosthesis of the glenoid fossa made of high molecular weight polyethylene. Based on computed tomography data, the CONMET LLC company produced a virtual model of the patient’s skull bones, planned the movement of the lower jaw to the correct anatomical position, modeled an individual titanium mandibular prosthesis with the ability to expand and an individual prosthesis of the articular fossa made of high-molecular polyethylene. After agreeing on the design with the operating surgeons, a solid model of the patient’s skull was made and individual designs were developed. Surgical intervention is planned on the model.

After the specified preoperative preparation, surgical intervention was performed under general anesthesia: after processing the surgical field under inhalation endotracheal anesthesia, an incision was made in the right submandibular region, the edge of the lower jaw on the right in the area of the defect was skeletonized in layers, and the hypoplastic, deformed articular fossa of the temporal bone was skeletonized. In the area of the latter, an individual prosthesis of the glenoid fossa made of high molecular weight polyethylene was installed and fixed using 4 titanium screws with a diameter of 2 mm. An individual sliding titanium prosthesis of the lower jaw is installed on the lower jaw so that its bone plate fits tightly to the edge of the defect of the lower jaw, and the head is located in the prosthesis of the articular fossa. The bone plate is fixed to the lower jaw using 9 titanium screws with a diameter of 2 mm. At the same time, the protrusion of the lower jaw, as planned on the model, occurred. The wound is washed with an antiseptic and sutured with interrupted sutures in layers. Between the seams there is a flat drainage made of glove rubber. Hemostasis was achieved during the operation using an electrocoagulator. An aseptic sling-like dressing was applied.

The postoperative period proceeded smoothly, antibacterial, anti-inflammatory and physical therapy were carried out. The wound healed by primary intention, the drainage was removed on the 3rd day after surgery after the cessation of exudation, the sutures were removed on the 10th postoperative day. The patient was discharged home with improvement. The complaints described above have been completely eliminated.

After 3 years, at the age of 10 years, the patient turned to the St. Children's City Clinical Hospital. Vladimir again with complaints of increasing facial asymmetry, deformation of the dentition and disruption of the process of chewing food. During examination, a displacement of the chin of the lower jaw to the right relative to the midline of the face was determined. When examining the face in profile, the lower lip was located posterior to the upper lip, and the chin was slanted. In the oral cavity, combined deformation of the dentition increased; the midline of the lower dentition was shifted to the right by 4 mm. There was a narrowing of the upper and lower dentition. A multislice computed tomography scan of the bones of the facial skeleton was performed, which revealed that the previously installed structure did not change its linear parameters and its fixation was satisfactory. At the same time, the healthy half of the lower jaw lengthened in the area of the body and branches, relative to the age of seven. It was decided that it was necessary to expand the previously installed individual lower jaw prosthesis.

For this purpose, a surgical intervention was performed under general anesthesia: under endotracheal inhalation anesthesia, after processing the surgical field, an incision was made along the scar in the submandibular region on the right. The distal edge of the lower jaw prosthesis is skeletonized in layers. The plug was removed from the screw connector, and a removable drive was installed to perform distraction of the prosthesis. The wound is washed with an antiseptic and sutured in layers with interrupted sutures around the drive screw. Hemotasis was carried out during the operation using an electrocoagulator. An aseptic dressing is applied. The postoperative period proceeded smoothly, antibacterial and anti-inflammatory therapy was carried out. The sutures were removed on the 10th day after surgery. The sutures were cleaned daily and the aseptic dressing around the removable drive was changed. Distraction of the lower jaw prosthesis began on the first day after surgery, 1 mm per day in 4 doses. The duration of the distraction period was 12 days. Thus, the prosthesis was lengthened by 12 mm. At the same time, the position of the lower jaw was normalized, the relationship of the dentition and the appearance of the child was improved.

After this, under inhalation mask anesthesia, the removable drive is unscrewed from the prosthesis body, the wound is washed with an antiseptic, and a plug is installed in the hole for the drive. The edges of the surgical wound are brought together using one interrupted suture. The postoperative period is smooth, the suture was removed on the 7th day after surgery. A control computed tomography scan of the facial skeleton was performed. According to CT data, the position of the installed prosthesis and fixing screws is satisfactory, the elements of the prosthesis are moved apart by 12 mm.

This observation illustrates the most typical example of a patient with a defect of the lower jaw, for the treatment of which the claimed invention can be used.

The applicant draws attention to the fact that the above design is intended for lower jaw prosthetics.

This is a special case.

The claimed mechanism for step-by-step movement of the slider can be used in devices for prosthetics of other bones.

All its nodes remain unchanged, only the elements to which the slider 7 or oblong body 6 are attached will change. For example, the oblong body 6 can be directly connected to the bone plate without a rotary axis 8. This is selected in each specific case depending on the actual situation.

The following is an explanation of the claimed invention in the general case:

Bone prosthetic device 1 includes

• an oblong body 6, one side of which is intended for connection with the bone, for example, through a rotary axis 8 it is connected to the bone plate 2, which, in turn, is connected by screws 78 to the body 3 of the lower jaw 4. However, the oblong body 6 can be connected differently with bone, for example, directly.

• On the oblong body 6 there is a slider 7, intended for connection with the bone located opposite. In the detailed example described above, the slider 7 is connected to the lower jaw implant 5 with the ability to move them relative to each other. However, the slider 7 may be otherwise connected to another bone, for example directly or through additional structures.

• The slider 7 is equipped with a slider moving screw 12 to ensure reciprocating movement of the slider relative to the elongated body,

• which is connected to the mechanism 22 for stepwise movement of the slider.

• In this case, the mechanism 22 for step-by-step movement of the slider always has the same design, namely, it contains a transverse wall 21 on the oblong body on the side opposite the side of the oblong body intended for connection with the bone, with an annular through hole 20,

• and the end part 19 of the screw 12 passes through the annular through hole 20,

• moreover, on the transverse wall 21 on the side opposite the side of the elongated body intended for connection with the bone, an annular protrusion 24 is formed with a pair of oppositely located additional protrusions 25 with inclined walls 26,

and on the end of the screw are made

• elongated cylindrical part 27 with a smooth surface,

• cylindrical widening 28 with longitudinal grooves 29 ending in an additional cylindrical widening 30,

• in this case, the end part 19 of the screw 12 is fitted with a sleeve 31 with a through longitudinal cavity 32 and protrusions 33 inward on one side,

• which covers the widening 28 of the cylindrical screw 12 with longitudinal grooves 29 so that the protrusions 33 of the sleeve 31 are placed inside the longitudinal grooves 29 with the possibility of longitudinal movement,

• and the end part 34 without protrusions of the sleeve 31 covers the additional cylindrical widening 30 of the screw 12,

• moreover, in the cavity 35 between the widening 28 of the cylindrical screw 12 with longitudinal grooves 29 and the end part 34 of the bushing 31 without protrusions, a spring 36 is placed,

• and the end 37 of the bushing 31 rests against the transverse wall 21,

• and it has a pair of oppositely located recesses 38 with inclined walls 39 corresponding in size to additional projections 25 with inclined walls 26 on the annular projection 24 of the transverse wall 21 located on the side opposite the bone plate.

According to the applicant, it is preferable that a longitudinal ring 40, having a longitudinal length along the screw 12 equal to the height of the annular protrusion 24 without taking into account the height of any of the pair of oppositely located additional protrusions 25 with inclined walls 26. The introduction of a longitudinal ring 40 simplifies assembly and also reduces the load on the end part of the screw, which is significant, which is important to consider to increase reliability, since the end part of the screw has small sizes.

It is advisable that the cylindrical widening 28 with longitudinal grooves 29 of the screw 12 of the stepwise movement mechanism 22 of the slider should have four longitudinal grooves 29. This is preferable from the point of view of optimal redistribution of stresses in the structure.

The slider 7, intended for connection with the bone located opposite, can be connected to it in various ways. According to the applicant, it is most desirable through implant 5.

Thus, when using the present invention, the following occurs:

• elimination of functional disorders and facial asymmetry that arise as the healthy half of the lower jaw grows due to the expansion of prosthetic elements without causing unwanted stress in the structure and without dislocating the fixing screws;

• prevention of reverse twisting of prosthetic elements;

• gradual, rather than immediate, expansion of the prosthetic elements as convenient and comfortable for the patient as possible with minimal surgical trauma;

• the possibility of surgical access to expand the prosthetic elements in an aesthetically acceptable area.

In addition to the above embodiments of the invention, numerous other modifications are possible.

All of them are covered by the following claims.

Sources of information taken into account:

1. Prospect LLC "LOGIX Medical Systems" st. Inzhenernaya, 20, Novosibirsk, Russia, 630090, 09.30.2021, 12:39.

2. Information on the Internet: ED jaw 421054. https://docs.yandex.ru/docs/view?url=ya- mail%3A%2F%2F177047760351058313%2F1.3&name=Oncological ED jaw 421054).pdf&ui ... (prototype ).

Claims (4)

1. A device for bone prosthetics when eliminating defects of the lower jaw bone, including an oblong body, one side of which is intended for connection with the bone, on the oblong body there is a slider intended for connection with the opposite bone, the slider is equipped with a screw for moving the slider to ensure reciprocating movement of the slider relative to the oblong body, which is connected to the mechanism for step-by-step movement of the slider, characterized in that the mechanism for step-by-step movement of the slider contains a transverse wall on the oblong body on the side opposite the side of the oblong body intended for connection with the bone, with a through hole, and the end part of the screw passes through a through hole, and on the transverse wall on the side opposite the side of the oblong body intended for connection with the bone, an annular protrusion is formed with a pair of oppositely located additional protrusions with inclined walls, and on the end part of the screw there is an elongated cylindrical part with a smooth surface, a widening cylindrical in shape with longitudinal grooves ending in an additional cylindrical widening, while the end part of the screw is fitted with a bushing with a through longitudinal cavity and protrusions inward on one side, which covers the widening of the cylindrical shape of the screw with longitudinal grooves so that the protrusions of the bushing are placed inside the longitudinal grooves with the possibility longitudinal movement, and the end part without protrusions of the bushing covers the additional cylindrical widening of the screw, and in the cavity between the widening of the cylindrical screw with longitudinal grooves and the end part of the bushing without protrusions, a spring is placed, and the end of the bushing rests against the transverse wall, and there is a pair of oppositely located recesses with inclined walls corresponding in size to additional projections with inclined walls on the annular projection of the transverse wall located on the side opposite to the bone plate. 2. The device according to claim 1, characterized in that on the elongated cylindrical part of the screw with a smooth surface, inside the annular protrusion on the transverse wall, with an emphasis directly on the transverse wall, a longitudinal ring is attached, having a longitudinal length along the screw equal to the height of the annular protrusion without taking into account the height of any of a pair of oppositely located additional projections with inclined walls. 3. The device according to claim 1, characterized in that there are four longitudinal grooves on the cylindrical widening with longitudinal grooves of the screw of the stepwise movement mechanism of the slider. 4. The device according to claim 1, characterized in that the slider, intended for connection with the opposite bone, is connected to it through an implant.