EP4468977A1

EP4468977A1 - External manipulator for manipulating fractured humerus bones

Info

Publication number: EP4468977A1
Application number: EP23712589.3A
Authority: EP
Inventors: János BARTHA
Original assignee: Individual
Current assignee: BARTHA, JANOS
Priority date: 2022-01-26
Filing date: 2023-01-20
Publication date: 2024-12-04
Also published as: HUP2200022A1; WO2023144571A1

Abstract

An external manipulator (100) having a first head (7) and a second head (9), the first head (7) being connected to a rod (3) and the first head (7) and the second head (9) securing bone screws (8), characterized by that a stem (1) is connected to the rod (3) and is fixed to a ridge shaft (6) via a connection (15), the ridge shaft (6) being fixed to a body (14), which body further fixes the second head (9).

Description

External manipulator for manipulating fractured humerus bones

Field of the invention

The present invention relates to an external manipulator capable of manipulating fractured bones in the event of a fracture of the upper part of the humerus .

State of the art

In the human body, bones form a rigid, solid skeleton . Because of their rigidity, these bones are sensitive to sudden and/or strong mechanical forces that can cause fractures or breaks . In the case of such fractures , it is important to restore the human skeleton as much as possible to its original state before the bones heal , so that the patient does not develop musculoskeletal dys function after healing .

The di f ferent types of fractures are bend fractures , spiral fractures , avulsion fractures , compound fractures , segmental fractures , comminuted fractures , and defect (bone loss ) fractures . Bone fractures may be caused by the direct impact of trauma, when the fracture occurs as the direct result of force at the same position as the force ( defence , compression or penetration fractures ) , or as a result of indirect trauma, when a fracture occurs as a consequence of force exerted at a location further away from the fracture ( tear, bend, twist , compression or combined mechanism fracture ) . A fracture is called a pathological fracture i f the fracture was caused with the involvement of minimal force due to the weakening of the bone . Such fractures are caused by osteoporosis or by certain tumours . Spontaneous fractures are when fractures occur in healthy bones without any external force. Such fractures may be caused by the sudden, intensive contraction of the muscles, or in the case of stress fractures, when the bone fracture is caused as a result of the continuous repetition of a force that would not cause a fracture under normal circumstances.

After the fracture, bone fragments can move relative to each other laterally, longitudinally with shortening or lengthening, axially with misalignment and rotationally with twisting. These displacements are usually combined. Such displacements usually occur because the traction forces exerted by the muscles adhering to the bones are now resisted by the bone fracture in a reduced and/or different direction.

The different types of fractures can be open fractures, where the fracture is visible to the naked eye, and closed fractures, where the outer tissues cover the fracture. Understandably, an open fracture is always associated with soft tissue and external injuries (skin, tendon, muscle, blood vessels and nerves) , but closed fractures can also involve injury to these tissues and are more difficult to identify (Surgery, 10th edition, edited by Csaba Gaal, 10th edition, Medicina Kdnyvkiado, Budapest, 2016, pp . 1094-1099) .

To repair bone fractures, the displaced bone parts are restored to their original position as far as possible and then the bones are fixed in this restored position. During the restoration process, the bone parts are typically moved manually by the doctors, possibly with the aid of mechanical devices. The fixation can be external (plaster cast, external manipulator) or internal (anterior nail, plate) (Surgery, 10th edition, edited by Csaba Gaal, 10th edition, Medicina Kdnyvkiado, Budapest, 2016, pp . 1103-1107) . The humerus is a long tubular bone with a body ( corpus ) and two end parts (proximal and distal epiphyses - the end parts towards the shoulder and elbow, respectively) . The part towards the shoulder ends in a head ( caput humeri ) . The head is separated from the lesser and greater tubercles ( tuberculum maius and tuberculum minus ) by a shallow groove ( collum humeri or collum anatomicum) . The part between the tip and the body, which narrows towards the body, is a common site of fracture of the humerus , known as the surgical neck ( collum chirurgicum) . A crista extends downwards from each of the two tubercles of the shoulder end, forming between them the sulcus intertubercularis , into which the tendon of the long head of the biceps carisma is embedded .

Fractures of the upper part of the humerus ( collum anatomicum, or chirurgicum) are often a challenge for the surgeon . Because getting the fractured bone fragments into an anatomical position and holding them there until the bone fragments are fixed is a maj or task . I f the original anatomical relationships ( length, axial misalignment , rotation) are not restored, the patient ' s shoulder j oint will often be subj ect to a reduction in motion and possibly loosening of the fixation devices after surgery .

Intramedullary nails and plates may be used for the repositioning of fractured bones in those cases when the patient has not suf fered li fe-threatening, severe inj uries ( for example , several bones were fractured at the same time or the nervous system or internal organs were also inj ured when the fracture took place ) , or i f the patient does not take anticoagulant medication, or has not suf fered large-scale soft tissue inj ury . Otherwise , patients may not be primarily treated using intramedullary nails or plates due to the possible complications . External manipulators are typically used to repair open fractures and fractures that have caused more serious soft tissue inj uries . Such an external manipulator is disclosed in patent US2016270830A1 , an external manipulator for fixation of fractured bone fragments of the humerus by attaching two sets of screws to two fragments of bone . The heads holding the screws are connected by a straight rod . Due to its design, this device is not suitable for proper spatial manipulation of broken bone ends . The device is more suitable for temporary fixation of bones or for the treatment of simple fractures where the displacement of the fractured bone fragments is minimal and the bone fragments can be easily repositioned .

Patent document US2021100586B1 discloses an external manipulator that can be used to move fractured humerus bones in space , but requires the attachment of three pairs of screws to the fractured bone fragments for proper spatial manipulation . A maj or disadvantage of the device is that it requires the fixation of screws in three places during the operation . Furthermore , the forces applied after the fracture cause the fractured bone ends to move relative to each other . This displacement is reinforced by the muscles attached to the head and the stem . During resetting the bones , the broken bone ends have to be brought into an anatomical position against these muscle forces , and therefore the great disadvantage of the device is that it does not allow the surgeon to correct the axial length, rotation or the tilting or sliding of the head against the stem separately i f necessary . Conversely, i f the bone parts are not moved accurately into the correct position the first time , the spatial movement of the broken bone parts has to be restarted, which results in loss of time and additional X-ray exposure . The external manipulator according to patent document EP1857063B1 fixes the broken bone fragments by using two pairs of triplet of screws . The bone parts are manipulated and adj usted by means of a shaft consisting of movable parts connecting the heads holding the screws . The disadvantage of the device is that during surgery it is di f ficult to move the screws and the bone parts in which the screws are fixed by adj usting the individual elements of the shaft . Furthermore , moving some parts of the shaft cannot avoid moving the bone parts not only in the desired direction but also in other directions . Furthermore , displacements in the plane perpendicular to the longitudinal axis of the bone are not or only to a limited extent repairable , and the repair of a fractured humeral stem in the - head can only be achieved by pulling the bones apart , which is di f ficult and may cause further soft tissue inj uries .

Consequently, there is a need for a device that can be used to move and rotate the bone fragments in all directions with a minimum number of screws fixed in the bone fragments to restore the displaced bone fragments in the event of humeral fracture . It is also important that the application of the device is quick and ef ficient . Finally, the device must be fully sterili zable and should also be able to be used outside the operating theatre in exceptional situations .

Brief description of the invention

The present invention is based on the recognition that ball j oints and shafts can be used to repair humeral fractures by means of two heads holding bone screws fixed together . According to the above , the present invention relates to an external manipulator having a first head and a second head, the first head being attached to a rod and the first head and the second head securing bone screws , and characterised in that the rod is attached to a stem which is secured to a ridge shaft via a connection, the ridge shaft being secured to a body, the body further securing the second head .

According to a preferred embodiment of the external manipulator according to the invention, the body is provided with ball j oints to which connecting shafts are attached to connect the body to the second head and the ridge shaft .

According to another preferred embodiment of the external manipulator according to the invention, the second head has a slotted ball shape .

According to a more preferred embodiment of the external manipulator according to the invention, the body is provided with ball j oints , wherein one ball j oint is connected to the ridge shaft by a connecting shaft and the second head is connected to the other ball j oint .

According to a preferred embodiment of the external manipulator according to the invention, the stem and the ridge shaft are of slotted plate configuration, which are fixed at right angles to each other by the coupling .

According to an advantageous embodiment of the external manipulator according to the invention, the external manipulator comprises a quick-release fastener for the ridge shaft . According to a preferred embodiment of the external manipulator according to the invention, an upper shaft is connected to the body .

According to a preferred embodiment of the external manipulator according to the invention, the upper shaft connection is provided on at least two sides of the body .

According to a preferred embodiment of the external manipulator according to the invention, the first head and the second head fix at least two or more bone screws each .

In the figures

Figure 1 shows the external manipulator of the invention in perspective view;

Figure 2 shows a perspective bottom view of the cross shaft according to the invention;

Figure 3 shows a perspective front view of a preferred embodiment of an external manipulator according to the invention .

Detailed description of the invention

The essence of the device according to the invention lies in that being able to move the heads that fix the screws in the required directions by placing one head on a rigid rod in a way that allows it to move along the length of the rod, and connecting the other head with a ball j oint and a cross shaft . In this way, the screws fixed by the heads can be drilled into the broken bone fragments and the bone fragments can be moved and rotated in any direction required . Figure 1 shows an external manipulator marked by reference number 100 , the main parts of which are an upper shaft 17 connected to a body 14 . A second head 9 is connected to the body 14 via a connecting shaft 13 , and a ridge shaft 6 is connected via a connecting shaft 2 . The second head 9 fixes some bone screws 8 . The body 14 is further connected to a ridge shaft 6 by means of a connecting shaft 2 terminating in a sphere at its upper end . The ridge shaft 6 is connected to a stem 1 via a connection 15 shown in Figure 2 , forming a cross shaft . The connection 15 is provided with a quick-release fastener 16 . The cross shaft is connected to a rod 3 , which secures the first head 7 supporting the bone screws 8 . Also there is shown in the figure a plier 10 and a broken bone comprising a head portion 11 and a stem portion 12 .

The connecting shaft 13 and the part of the connecting shaft 2 towards the body 14 are spherical , so that the body 14 can rotate along these connecting shafts 2 , 13 .

The role of the 9 second head and 7 first head is to secure the 8 bone screws and hold them in position .

The role of the connection 15 is to prevent the centrally slotted stem 1 and the ridge shaft 6 as a slotted plate perpendicular to the stem 1 from rotating relative to each other . At the same time , it allows the stem 1 and the ridge shaft 6 to move along their slots after the quick-release fastener 16 is released . This is because the locking part of the connection 15 is square , which keeps the stem 1 and the ridge shaft 6 at right angle to each other, but prevents them from rotating . In this way, in a plane perpendicular to the longitudinal axis of the bone , the broken bone parts can be adj usted and locked in their fixed position . The connecting shaft 2 extending from the body 14 j oins to the ridge shaft 6 and a ball j oint , and connecting shaft 13 j oins to a second ball j oint and the second head 9 . This ball j oint , which belongs to the connecting shaft 13 allows that the angle of the bone screws 8 attached to the second head 9 be varied . In this way, the bone screws 8 can be fixed at the correct angle into the fractured bone part . After the bone screws 8 are fixed, the ball j oint that fixes the connecting shaft 13 is fixed at the desired angle in the body 14 . This is achieved by connecting one of the ball j oints of the body 14 to the second head 9 via the connecting shaft 13 and allowing it to rotate directly, so that the angle of the bone screws 8 to the second head 9 can be precisely adj usted in the hori zontal direction . The other ball j oint is connected to the cross shaft via the connecting shaft 2 and can thus rotate the body 14 and the bone part fixed thereto via the bone screws 8 of the second head 9 in the vertical direction relative to the cross shaft . In this way, i f necessary, the broken head portion 11 can be rotated and the head portion which has been bent in a direction relative to the longitudinal axis of the bone can be restored .

The role of the upper shaft 17 is to allow the body 14 to move easily around the ball j oints and the connecting shafts 2 , 13 . The upper shaft 17 can be connected by means of a quickrelease fastener and rotatably fixed in the body 14 . Once properly adj usted, the upper shaft 17 can be detached from the body 14 so that the surgeon is not hindered during surgery .

The role of the rod 3 is to fix the first head 7 longitudinally . In addition, the cross shaft can be moved perpendicularly around the rod 3 through the 1 stem, so that it can be adj usted to the desired angle so as not to hinder the movement of the staf f during surgery . The device 100 according to the invention involves making a small incision in the skin at the level of the fractured bone fragments of the patient who has suf fered a fracture . For the purpose of the present description, a fracture is assumed where the bone is broken in one place , i . e . two bone parts have to be j oined during the operation . After the incision, some bone screws 8 , preferably two bone screws 8 , are fixed to each of the broken bone parts . The bone screws 8 fixed to each bone fragment are fixed in a first head 7 and a second head 9 in such a way that two parallel bone screws 8 are attached to each head . The bone screws 8 in the first head 7 are drilled into the bone after the head 7 has been moved to the correct position in the longitudinal direction of the rod 3 and fixed in place . The angle at which the bone screws 8 in the second head 9 are to be drilled is adj usted by rotating the second head 9 through the shaft 13 relative to the body 14 to any desired angle . Afterwards we fix the ball j oint of the body 14 to the second head 9 .

In case the stem portion 12 of the humerus becomes wedged in the head portion 11 of humerus during the fracture , a 10 plier is used to pry the two broken bone parts apart through the 8 bone screws .

In the next step, the rotational and axial misalignments of the broken bone are corrected by rotating the body 14 around the shaft 2 , and thus the cross shaft , through the second head 9 . This element is then also fixed to the body 14 .

The movement perpendicular to the longitudinal axis of the humerus is achieved by moving the cross shaft , more precisely by moving the ridge shaft 6 after releasing the quick-release fastener 16 . In this way, the ridge shaft 6 , which is connected to the stem 1 through a slot in the ridge shaft 6 , can be moved perpendicular to the stem 1 .

According to the preferred embodiment of the external manipulator 100 according to the invention, one of the ball j oints in the body 14 secures the second head 9 , which is slotted ball shaped . This design is advantageous because , in the case of the second head 9 connected via the connecting shaft 13 , i f the length of the bone screws 8 exceeds the length of the portion of the second body 9 configured to receive the bone screws 8 , the crew will be obstructed by the protruding bone screw 8 . For example , it will cause loss of time to cut the bone screw 8 , and may also destroy the shape of the bone screw 8 , which will not be able to be drilled into the bone .

By omitting the connecting shaft 13 , this problem can be avoided . And to connect the second head 9 directly to the ball j oint of the body 14 , a substantially spherical design is appropriate , with a slot to allow the 8 bone screws to be secured . The ball j oint design may, for example , be clampshaped at the portion of the ball j oint that connects to the second head 9 , to firmly hold the second head 9 after attachment .

In addition, to facilitate the work of the crew, the connection of the upper shaft 17 can be designed so that at least two sides of the body 14 have a suitable connection for the upper shaft 17 . Thus , even in the event of a left or right side fracture , the upper shaft 17 can be easily attached to the body 14 to allow the body 14 to be moved in the desired direction during surgery by means of the upper shaft 17 . The advantage of the invention is that the movement and rotation in each direction can be performed with elements independent from each other, so that the fractured bone parts can be individually adj usted to the correct anatomical position .

An additional advantage of the invention is that bone screws are fixed in the bone in two place , no more incisions are needed .

An additional advantage of the invention is that the external manipulator allows the bone screws to be advantageously drilled into the bone parts , the bone parts to be moved quickly and accurately and leaves room for a possible fixation by means of an intramedullary nail or plate while the bones are fused together .

Another advantage of the invention is that the device can be removed quickly after surgery .

Another advantage of the invention is that it is simple and quick to use , can be used in a variety of conditions and does not require long training procedure of the staf f .

Claims

1. An external manipulator (100) having a first head (7) and a second head (9) , the first head (7) being connected to a rod (3) and the first head (7) and the second head (9) securing bone screws (8) , characterized by that a stem (1) is connected to the rod (3) and is fixed to a ridge shaft (6) via a connection (15) , the ridge shaft (6) being fixed to a body (14) , which body further fixes the second head (9) .

2. The external manipulator (100) according to claim 1, characterized by that the body (14) is provided with ball joints to which connecting shafts (2, 13) are connected connecting the body (14) to the second head (9) and to the ridge shaft ( ) .

3. The external manipulator (100) according to claim 1, characterized by that the second head (9) is in the form of a slotted ball.

4. The external manipulator (100) according to claim 3, characterized by that the body (14) is provided with ball joints, wherein one ball joint is connected to the ridge shaft (6) by a connecting shaft (2) , and the second head (9) is connected to the other ball joint.

5. The external manipulator (100) according to any one of the preceding claims, characterized by that the stem (1) and the ridge shaft (6) are formed as slotted plates, which are fixed at right angles to each other by the connection (15) .

6. The external manipulator (100) according to any one of the preceding claims, characterized by that the ridge shaft (6) is provided with a quick-release fastener (16) .

. The external manipulator (100) according to any one of the preceding claims, characterized by that an upper shaft (17) is connected to the body (14) .

8. The external manipulator (100) according to claim 7, characterized by that the connection of the upper shaft (17) is provided on at least two sides of the body (14) .

9. The external manipulator (100) according to any one of the preceding claims, characterized by that the first head (7) and the second head (9) fix at least two or more bone screws (8) each .