WO2025109348A1

WO2025109348A1 - Modular bone clamp

Info

Publication number: WO2025109348A1
Application number: PCT/HU2024/050093
Authority: WO
Inventors: János BARTHA
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-11-24
Filing date: 2024-11-12
Publication date: 2025-05-30
Anticipated expiration: 2026-05-24
Also published as: HUP2300406A1

Abstract

Modular clamp (100) having first clamp (1) comprising a head part and a stem, and a stem (2) connected to the stem of the first clamp (1), characterized in that the stem (2) is connected to a rack (3), the rack (3) terminating at the other end in a head.

Description

Modular bone clamp

Field of the invention

The present invention is a modular bone clamp capable of anatomically repositioning fractured bone fragments in the deep after a small skin incision .

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 fracture are bend fractures , spiral fractures , avulsion fractures , compound fractures , segmental fractures , comminuted fractures and defect fractures . Bone fractures may be caused by the direct impact of trauma, when the fracture occurs as the direct result of force and 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) . When internal fixators are used, i f the fractured bone fragments cannot be brought to an anatomical or near anatomical position by external manipulation ( to fix them with intramedullary nails , plate or screws ) , the fracture is very often opened up . Fractured bones that have slipped in three dimensions and are randomly contracted by the muscles are often brought into an anatomical position by the surgeon using various surgical instruments to fix them with a plate or intramedullary nails until the fracture heals .

Bone clamps are most commonly used to anatomically repair broken bone fragments .

Considering the complexity of the problem, i . e . the fact that the muscles remove the fractured bone fragments from their anatomical position and the bones are located under the soft tissues , the type of fracture can be of many types , the approach to the bone fragments is limited too due to the important anatomical formations . The larger the incision to excavate the fracture , the longer the operation time , and as a result , the greater the occurence of wound healing problems and bone infections . The combination of these factors makes it di f ficult to use repositioning devices quickly from small skin incisions .

This is because the clamp should be inserted through a small incision, preferably sparing soft tissue , to the bone fragments , opening under the muscles , so that we can grasp the broken bone ends with both heads of the clamp, and there not j ust press the broken ends together randomly, but bring the bones back into an anatomical position, so that we can fix them until the fracture heals , in order to ensure good fracture healing . Given that bone fragments can move apart randomly at an angle of 360 degrees in a plane perpendicular to the longitudinal axis of the bone , a very large number of shaped clamps are used to bring these bones into anatomical position . The use of such clamps requires a large soft tissue excavation to reach and grasp the bones . The clamp shown here is capable of anatomically positioning pieces of bone that have been randomly displaced in a plane perpendicular to the longitudinal axis of the bone from only one angle . In addition to the bones , the limbs contain important anatomical formations such as nerves , arteries and veins , which must be spared . Therefore , with these clamps we can only partially position the bones anatomically in this plane .

Patent documents CN217390840U, GB2506373A, WO2022096752A1 disclose bone clamps that are suitable for gripping bones and then, after constricting the clamp, for further partial correction of fracture ends by means of a plate that can be pressed perpendicular to the clamping forces in the plane of the clamp . The application of these clamps also requires a large soft tissue opening to access the fracture ends that moved away . As the head grooves of the clamp cannot be shortened or extended along the axis of the clamp shaft , greater soft tissue opening is required to grasp broken, slipped bone fragments .

Patent document CN216652430U discloses a bone clamp capable of approaching and grasping fractured bone fragments through a small soft tissue excavation in deep . The important anatomical formations (nerves , arteries , veins ) delimit the approach to the fractured bone fragment in a plane perpendicular to the longitudinal axis of the bone . Once this clamp has been constricted, it is not suitable for further correction of fractured bone fragments and can therefore only be used success fully for certain fracture types .

Patent documents CN106580421A, CN205569058U, CN205667577U, CN205667578U, CN215384419U, CN217186397U, JP2016067847A describe devices suitable for grasping broken bone fragments in the deep . After inserting the first head, the second head is clamped onto the first head along a threaded shaft . Again, these devices can only be used success fully for certain types of fractures , or require a much greater soft tissue excavation with all its disadvantages , to bring the fractured bone fragments into anatomical position .

Patent documents CN209107498U, CN211094469U, CN212261496U disclose bone clamps suitable for grasping and positioning bones in deep from two small skin incisions . Their applicability is limited because in case of patients with large soft tissues surrounding the bones ( such as the femur ) , the access of bone in the deep is di f ficult and important anatomical structures (nerves , arteries , veins ) may be damaged .

Patent document CN212699047U discloses a clamp that is suitable for inserting the closed clamp under the soft tissue from a small skin incision, where they are first inserted under one of the pieces of bones . Subsequently, the clamp can be opened in the deep and the other fracture end can be grasped by extending the second head part . When the clamps are clamped together, one stem can be shortened or lengthened relative to the other stem . Moving this second stem while the bone fragments are being clamped together is di f ficult and cumbersome because of the muscle forces involved, as the fracture ends are pulled apart by the muscles . With the presented clamp, the set head length cannot be actively locked, which means that the surgeon has to keep the clamp stems in the desired position by hand continuously .

Consequently, there is a need for a device that the surgeon can use for di f ferent bone fractures . In addition, it is important to be able to access bone parts with minimal skin incision . Furthermore , it is important to be able to grasp the spaced fracture ends under the soft tissues and to further adj ust the fracture ends in both directions perpendicular to the clamping forces of the clamps to bring the fracture ends into an anatomical position . It is also important that the application of the device should be simple , quick and ef ficient . Finally, it is necessary that the device is fully sterilisable .

Brief description of the invention

The present invention is based on the recognition that the clamp head of one stem of the clamp can be extended or shortened along the longitudinal axis of the clamp stem at will relative to the first head of the clamp, thereby allowing broken bone fragments to be easily accessed and anatomically positioned .

According to the above , the present invention relates to a modular clamp having a first clamp comprising a head portion and a stem, and a stem connected to the stem of the first clamp, characterised in that the stem is connected to a rack, the rack terminating in a head at the other end .

Some preferred embodiments of the model are defined at the sub-claims . In the figures :

Figure 1 shows a side view of a preferred embodiment of the clamp according to the invention;

Figure 2 shows a perspective view of a preferred embodiment of the clamp according to the invention with the quick fastener disassembled;

Figure 3 shows a perspective side view of a preferred embodiment of the clamp according to the invention;

Figure 4 shows a perspective side view of a screw blocking embodiment of the clamp according to the invention;

Figures 5 and 6 show side and top views of the head parts of the clamp that can be designed in a variety of ways according to the invention .

A detailed description of the invention :

The essence of the modular clamp according to the invention consist of drilling a long bone screw through a protective sleeve next to the first head and thus connecting it to one of the broken bone fragments . Thus , this bone fragment can then be manipulated in three dimensions through the stem of the first head . It is a further advantage of the invention that , relative to the first head of the modular clamp, the second head can be extended or shortened at will from the second receiving stem with or without a gear and can be fixed in the desired position . In this way, the broken piece of bone can be manipulated relative to the other . In other words , once the two bone pieces have been grasped and the modular clamp failed to bring them into an anatomical position, it can be used with this advantageous feature to correct the slippage of the bone pieces perpendicular to the clamping forces of the conventional clamp . In other words , the bone fragments can be approached at any angle in a plane perpendicular to the longitudinal axis of the bone and brought into an anatomical position using this modular clamp .

Figures 1 , 2 , 3 all show the modular clamp marked with a reference symbol 100 , the main parts of which are the first clamp 1 consisting of a stem and a head section connected to a headless stem 2 by a shaft 12 . In the stem of the clamp 1 , a bore is formed along its longitudinal axis up to the head part , which is slotted in the direction of the stem 2 . Into this bore a long protective sleeve 14 may be inserted at will and secured by a thread in the part of the stem of the clamp 1 . The protective sleeve 14 is adapted to receive a long bone screw 15 . The protective sleeve 14 protects the soft tissues up to the bone so that they do not roll up when the bone screw 15 is drilled, and also protects the bone screw so that it does not warp when the stems of the clamp 100 stems are closed .

A rack 3 is connected to the stem 2 , where the other end of the rack 3 terminates in the second head part of the clamp 100 . The stem 2 includes a winding gear 6 that allows the rack 3 to be moved in either direction and can be quickly and easily locked in the desired place with a built-in quick fastener 7 .

The quick fastener 7 shown in Figure 2 comprises a gear 6 , which may end in a butterfly shape , this butterfly part being grippable , windable and slidable along the longitudinal axis of the gear 6 . The butterfly valve of the quick fastener 7 receives a locking shaft 8 on the butterfly side . The gear 6 terminates in a shaft , this shaft containing a slit which is threaded by the shaft 8 . This gear 6 is connected via the shaft 8 to the gear of the quick fastener 7 terminating in a butterfly end . The gear 6 has cylindrical shoulders on each side . Namely, once the rack 3 is inserted into the receiving stem 2 after the gear 6 , the shoulders on each side of the gear 6 locks it against the rack 3 and thus to the stem 2 . The gear 6 can rotate along its axis , thus allowing the rack 3 to be moved and, i f necessary, locked in position . One hal f of the gear 6 ends in a shaft , in this case being cylindrical , but the shaft can be of various shapes . In the centre of this shaft 6 there is a slit perpendicular to the shaft and is threaded by a cylindrical pin 8 . This pin 8 may also be of a di f ferent design, possibly threaded . In the butterfly gear 7 two smaller recesses are formed on the extended part after the split on the shaft of the gear 6 . The butterfly 7 part includes one or more bores perpendicular to the extended axis of the gear 6 . A flexible rod ( or rods ) 9 is fixed in this or these bores . This bore is slotted along its longitudinal axis in the butterfly stem 7 , so that these shafts 9 are movable and these flexible shaft/ shafts 9 can move along the slot . This flexible shaft 9 is stretched out perpendicularly to the part terminating in the shaft portion of the gear 6 and located in one of the two recesses formed in this longitudinal axis 6 . To move the stretched rod 9 out of these recesses , a small force must be exerted . In the slit at the end of the gear 6 shaft , the cylindrical pin 8 prevents the butterfly gear 7 from leaving the shaft of this gear 6 and also controls the sliding of this butterfly gear 7 along the longitudinal axis of the shaft of the gear 6 . But the pin 8 does not allow the butterfly gear 7 to turn along and leave the longitudinal axis of the shaft of the gear 6 . The pin 8 allows the butterfly gear 7 to turn the gear 6 in both directions .

In the section of the stem 2 which is designed to accommodate the gear 6 , the butterfly gear 7 , the pin 8 and the rod 9 parts , a reverse gear is adapted to accommodate the butterfly gear 7 . When the butterfly gear 7 is moved along the shaft of the gear 6 , its distance is controlled by a slit along the longitudinal axis of the gear 6 shaft and by the pin 8 . Thus , the butterfly gear 7 can be pulled out from the stem 2 , i . e . from this negative gear, and can then be turned along the longitudinal axis of the gear 6 . As soon as we want to reattach the gear 6 , we push the butterfly gear 7 along the longitudinal axis of the gear 6 back into the part formed in the stem 2 . To enable the butterfly gear 7 to be easily inserted into the inverted gear of the stem 2 , each tooth of the butterfly gear 7 is laterally sharpened on the side gear 6 . This allows the butterfly gear 7 to fit easily into the bodies 2 from the side . Plate springs 16 are located between the first clamp 1 and the stem 2 , each secured to the stems by a screw, and they continuously tension the head parts of the clamp 100 in a slightly open position relative to each other along a shaft 12 .

According to another embodiment of the invention, the stem 2 ( see in Figure 4 ) comprises a screw 5 blocking the rack 3 , because this embodiment comprises a coilable butterfly gear 4 instead of a quick fastener . The two stems of the modular clamp 100 can be connected together in a compressed position at di f ferent degrees by means of a quick fastener with spring 11 .

Thanks to the preferred design of the modular clamp 100 it is suitable to approach bone fragments perpendicular to the longitudinal axis of the bone through the soft tissues ( skin, fat tissue , muscle sheath, muscles ) and bring them into an anatomical position by grasping them from a small skin incision . That is , the head part at the end of the rack 3 fully bended into the stem 2 is in a shortened position relative to the head of the first clamp 1 . And in this position the head part of the rack 3 of the closed clamp 100 is positioned at the height of the neck part after the head of the first clamp 1 and here it occupies a preferably shaped guide position in the part after the head of the first clamp 1 . When passing through the soft tissue , the head part of the shortened rack 3 of the closed clamp 100 does not get stuck in the soft tissue .

The clamp 100 is inserted in a closed position up to the bone , where the head of the first clamp 1 is inserted under a broken piece of bone . After this , the protective sleeve 14 can then be slid into the slotted hole in the stem of the first clamp 1 and secured by a threaded end in the stem of the first clamp 1 . A long bone screw 15 can be drilled into the protective sleeve 14 , into the bone fragment bypassed by the head of the first clamp 1 . This bone piece is thus fixed to the stem of the first clamp 1 . The stem of the first clamps 1 can be used to correct any twisting or axial slippage of the bone along its longitudinal axis in relation to the other bone fragment . Then, by winding the gear 6 through the butterfly gear 7 , the rack 3 can be moved back and forth along the longitudinal axis of the clamp 100 and the gear on the stem 2 can be fixed in the desired position by means of the quick fastener 7 on the receiving part . According to another embodiment of the clamp 100 ( see in Figure 4 ) , it can be locked by means of a blocking screw 5 , while releasing the quick fastener 11 connecting the two stems .

The quick fastener 11 can be easily released from the stem of the first clamp 1 by means of a boomerang shaped slot 13 , which is fixed to the stem 2 on a shaft . It can be moved backwards and forwards along this shaft , so that you can easily push this boomerang 13 backwards with your wrist or little finger and release a rack 11 from the stem 1 . Once the second piece of bone has been bypassed, the head part of the rack 3 is used to partially close the clamp 100 stem sections together with the quick fastener 11 . When it is observed that the two broken bone pieces are not anatomically aligned, then the butterfly gears of the quick fastener 7 is used to move the head portion of the rack 3 at will through the rack 3 , and with it the partially encircled bone pieces are manipulated relative to one another . The bone pieces thus brought into an anatomical position are fixed in place by means of intramedullary nails or plate and screws . In fact , between the two heads of the clamp 100 , which are preferably designed in such a way that there is also room for a slided plate along the longitudinal axis of the bone once the clamp has set the bones in position .

The shape of the head part of the clamp can vary and is therefore suitable for the fixation of broken bones in di f ferent regions , as can be seen in Figures 5 and 6 . The attachment of the two stems to each other can also be designed in a variety of ways , without the need for the use of the rack 11 , so that in essence the preferred function of the clamp is not af fected .

The advantage of the solution according to the invention is that the advantageously designed collapsible modular clamps can get in through the soft tissue to the broken bones through a small skin incision (minimally invasive ) .

An additional advantage of the solution according to the invention is that a long bone screw can be drilled through a sleeve into one of the stems all the way to the head, so that one of the broken bone fragments is connected to the stem of the clamps and the surgeon can manipulate this bone fragment from the outside in three dimensions relative to the other bone fragment .

A further advantage of the solution according to the invention is that the receiving stem comprises a gear .

A further advantage of the solution according to the invention is that the gear is equipped with a quick fastener, which enables the gear and with it the rack to be moved quickly and easily in either direction along its axis and to be locked in the desired position . This advantageously designed quick fastener suitable to fix the gear and rack and can also be used advantageously for other gear and rack devices .

A further advantage of the solution according to the invention is that the rack and the second head on the rack can be moved by means of the gear, so that the second broken bone fragment can be bypassed more easily and the bone fragments can be moved relative to each other along the longitudinal axis of the clamp .

An additional advantage of the solution according to the invention is that the modular clamps is able to move the broken bone fragments into anatomical position .

An additional advantage of the solution according to the invention is that after a small skin incision, wound healing is faster and less scar tissue and wound infection can be expected . Another advantage of the solution according to the invention is that it is simple and quick to use , without the need for lengthy training of staf f . A further advantage of the solution according to the invention is that due to the varied design of the head parts of the clamps , it can be used in di f ferent anatomical regions to bypass and fix broken, slipped bone fragments . An additional advantage of the solution according to the invention is that the surgeon can easily release the fastener connecting the stems of the clamp with the boomerang-shaped movable handle with one hand without releasing the butterfly with the other hand . This allows the operation to be performed quickly and without any obstruction . At the same time , the surgeon ' s sterile gloves are not damaged during surgery because this boomerang handle protects the stems of the modular clamps from the connecting rack fastener .

Claims

Patent claims

1. Modular clamp (100) having first clamp (1) comprising a head part and a stem, and a stem (2) connected to the stem of the first clamp (1) , characterized in that the stem (2) is connected to a rack (3) , the rack (3) terminating at the other end in a head.

2 The modular clamp (100) according to claim 1, characterized in that the stem (2) receives a gear (6) , said gear (6) being connected on its shaft to a quick fastener (7) .

3 The modular clamp (100) according to claim 2, characterized in that the quick fastener (7) comprises a gear, which has sharpened teeth on the side of the windable gear (6) for connecting to the windable gear (6) .

4 The modular clamp (100) according to claim 1, characterized in that it comprises a blocking screw (5) and a windable integral gear ( 4 ) .

5 The modular clamp (100) according to any one of the proceeding claims, characterized in that it comprises a fastener (11) adapted to clamp the stems together, the fastener (11) being connected to a boomerang shaped slot (13) .

6 The modular clamp (100) according to any one of the preceding claims, characterized in that a slotted hole is formed in the stem of the first clamp (1) for receiving a protective sleeve