RU2778670C1 - Method for triple pelvic osteotomy in mammals and apparatus for osteosynthesis of the musculoskeletal system - Google Patents

Abstract

FIELD: veterinary medicine.

SUBSTANCE: group of inventions relates to veterinary medicine, namely, to traumatology and orthopaedics, and can be used for surgical treatment of post-traumatic and congenital defects of the pelvic bones and pelvic limbs applying an external fixation apparatus. Skin is incised in the area of the pubis, and a fragment of a branch of the pubis is excised, followed by suturing the wound. Osteotomy of the ischium is then performed in a similar way. Then the skin and gluteal muscles are incised to the bone base of the sacroiliac joint. Osteotomy of the sacroiliac joint is performed until full interruption of contact between the bones. The resected half of the pelvis is turned by the required angle in the lateral direction, and the detached half of the pelvis is stabilised towards the sacrum by the external fixation apparatus installed on the iliac bones and the sacrum. An external fixation apparatus is applied in order to fix the osteotomised bone fragments, said apparatus consisting of bars with mounting holes, cylindrical supports, and transosseous rods, transosseous wire fixators, and fastening and connecting elements. Type A and type B polyfunctional monoblocks are used as connecting elements and supplemented with bars with through holes, braces, a hinged fixator, and a modified bracket.

EFFECT: claimed group of inventions provides a possibility of increasing the effectiveness of surgical treatment of pathologies of hip joints by triple pelvic osteotomy by improving the technique of implementation thereof and by providing secure fixation by means of universal external fixation assemblies during postoperative uncontrolled loads characteristic of veterinary practice.

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Description

The invention relates to medicine and veterinary medicine and can be used in the surgical treatment of post-traumatic and congenital defects of the pelvic bones and pelvic limbs using an external fixation device.

The search for effective methods for the treatment of pathologies of the musculoskeletal system, the development and improvement of new fixation devices for osteotomy of the bones of the leg and pelvis, which would ensure the achievement of positive clinical results, are an urgent task. Common pathologies of the musculoskeletal system are hip dysplasia and rupture of the anterior cruciate ligament in dogs, which is treated with double tibial osteotomy. Triple pelvic osteotomy is one of the methods of surgical treatment of hip dysplasia.

A known method of triple pelvic osteotomy in dogs (Yagnikov SA, 2006), which is based on the original method Slocum (1986), and includes the following four stages: segmental osteotomy of the pubic bone; osteotomy of the ischium; transverse or oblique osteotomy of the iliac body, followed by rotation of the osteotomized pelvic segment and fixation of the iliac bone fragments with a specially shaped plate. In the postoperative period, animals are limited in movement for 6-8 weeks, walking on a short leash until the bone tissue is consolidated at the level of osteotomies. Dogs for 2-3 days after surgery with support under the abdomen can get up, stand and walk on their own. Full recovery of limb function should be expected by 12-16 weeks. Plates used for osteosynthesis are not removed. The disadvantages of the operation include the fact that the operation is not simple, requiring special equipment and skills, making the highest demands on the sterility of the operation. In addition, in the early postoperative period, constant monitoring of the animal is necessary to prevent the creation of an uncontrolled increased load on the pelvic bones. And the high cost of bone plates limits the large-scale use of surgical intervention in dogs.

In traumatology and orthopedics, external fixation devices are known, for example, a device for repositioning and fixing pelvic fractures with rupture of the anterior and posterior half rings (Pat. 2309693, IPC A61B 17/66, 2005). The device comprises a pelvic support consisting of semi-arcs connected with the possibility of movement relative to each other, a reposition unit mounted on the semi-arcs of the pelvic support, and threaded rods mounted on it for insertion into the pelvic bones. The repositioning unit consists of two transverse bars with holes, longitudinal and transverse threaded rods, an axial longitudinal threaded rod, fixing and adjusting nuts, brackets and connecting elements made with mutually perpendicular holes. The transverse threaded rods are fixed by means of brackets to the semi-arcs and are installed in the holes of the connecting elements placed on the longitudinal threaded rods, and the latter are rigidly fixed in two transverse strips with holes. At the free ends of the transverse threaded rods there are connecting elements, in mutually perpendicular holes of which a longitudinal axial rod is placed. The fastening of the threaded rods for the pelvic bones on the half-arches was carried out using conical and spherical washers and fixing nuts. In the device, reposition is carried out by ensuring the elimination of horizontal and vertical displacements of fragments of the pelvic bones. However, in this device, the angular stability of the nodes is not sufficient and there is a risk of instability of the external fixator. In addition, the bulky design of the external fixator can cause discomfort. The known design, as well as arcuate-ring hardware designs, do not take into account the anatomy of the animal's pelvis. For such anatomically complex parts of the skeleton, structures assembled on the basis of corner joints are more acceptable.

The objective of the invention is to develop a method that makes it possible to increase the effectiveness of surgical treatment of hip joint pathology using triple pelvic osteotomy by improving the technique for its implementation, and the development of external fixation device nodes that allow forming corner joints.

The technical result of solving the problem is to expand the existing arsenal of methods for treating pathologies of the musculoskeletal system in mammals; in ensuring reliable fixation with the help of universal external fixation units during postoperative uncontrolled loads, typical for veterinary practice; in the possibility of forming angle joints in external fixation devices, taking into account the anatomical structure of the osteotomy area. In addition, the versatility and availability of external fixation units, low cost, make it possible to use them not only for the pelvic bones, but also for fixing the bones of the pelvic limbs.

The claimed technical result is achieved by a group of inventions. A method for triple pelvic osteotomy in mammals includes breaking the integrity of the pelvic bone, repositioning and fixing the pelvis. After preparing the surgical fields, the animal is placed on its back and a skin incision is made in the area of the pubic bone and a fragment of the branch of the pubic bone is excised, followed by suturing the wound. Then an incision is made in the area of the ischium and an osteotomy of the ischium, the wound is sutured. After that, the animal is placed on the stomach and an incision is made in the skin and gluteal muscles up to the bone base of the sacroiliac joint. An osteotomy of the sacroiliac joint is performed until the contact between the bones is completely interrupted. The cut off half of the pelvis is turned to the required angle in the lateral direction in order to change the position of the acetabulum, then the cut off half of the pelvis is stabilized towards the sacrum with an external fixation device installed on the ilium and sacrum.

To fix osteotomized bone fragments, an external fixation device is used, consisting of radius plates, strips with fixing holes, cylindrical supports and transosseous rods, spoke fixators, as well as fastening and connecting elements. As connecting elements, polyfunctional monoblocks of type A and type B are used, and they are supplemented with strips with through holes, brackets, a hinged lock and a modified bracket. Polyfunctional monoblock type A is made in the form of a tetrahedral elongated prism with an axial threaded hole and smooth holes located on the sides, having a figured shape. Polyfunctional monoblock type B is made in the form of a tetrahedral elongated prism with an axial non-through threaded hole in the end, as well as with a figured through hole and a through threaded hole located on adjacent side walls with an offset. The hinged retainer contains two brackets mated together end-to-end along the entire plane of contact with the possibility of rotation relative to each other, connected by a fixing screw, and at the distal ends of both brackets, having the shape of a tetrahedral prism, mutually perpendicular smooth holes of a figured shape are made, and from the ends of both brackets make threaded holes. In addition, the spoke fixator has a figured through hole. The figured shape of through holes can be drop-shaped, U-shaped, semicircular. Finally, the modified bracket threaded hole located at the rounded end of the bracket is provided with radial grooves.

The essential distinguishing features of the claimed invention are as follows

- the proposed technique of surgical intervention makes it possible to perform a multidirectional rotation of the acetabulum, providing a predictable coverage of the femoral head with the arch of the acetabulum for the stability of the hip joint and ensuring its high-quality work with elements of prevention of coxarthrosis in the long-term period;

- the probability of instability and rejection of bone implants is eliminated due to their non-use in the proposed method, in contrast to previously known methods, where implants in the form of bone plates with fastening screw elements are always used;

- the method of performing surgery for hip dysplasia using an external fixation device makes the proposed surgery widely available;

- earlier fusion of the osteotomized area of the iliac sacral joint is provided due to the large area of contact of the osteotomized surface;

- simpler technical implementation of surgical intervention;

- polyfunctional monoblocks of two types, performing connecting and fixing functions, allow to increase the functionality and versatility of the nodes, because the ability to include in various connection schemes allows you to model external fixation structures that correspond to the anatomical structure of the osteotomy area;

- a bar with holes allows you to expand the functionality. For example, the combination of a bar with two type B monoblocks creates a rigid and stable corner joint, and, if necessary, the angle can be changed;

- the addition of a bracket makes it possible to securely fix the corner joint formed, for example, by two smooth supports;

- hinged fixator provides dosed controlled position of bone fragments by means of angular displacement and linear displacement;

- combinations of hinged clamps with strips and polyfunctional monoblocks allow you to implement any corner connections;

- making holes of figured shape (teardrop-shaped, U-shaped, semicircular) in polyfunctional monoblocks, a hinged fixator, an arm and a spoke fixator, makes it possible to eliminate the rotation of smooth transosseous rods and supports of various diameters fixed in them, to increase the stability of the nodes, to ensure rigid fixation of transosseous rods, to prevent development postoperative complications with maximum and uncontrolled loads.

The conducted patent research on the subclasses of the IPC А61В 17/56, 17/62, 17/74 did not reveal technical solutions that have all the features of the invention expressed by the formula, and this allows us to conclude that it is new. The features by which the claimed invention is characterized in two independent claims differ from the closest analogues, which indicates the inventive step of the invention. The inventive method and external fixation nodes can be reproduced repeatedly and do not require the use of exclusive means for implementation.

The invention is illustrated by the description and illustrative material:

Fig. 1 - polyfunctional monoblock type A;

Fig. 2 - polyfunctional monoblock type B;

Fig. 3 - bar;

Fig. 4 - bracket;

Fig. 5 - hinged latch;

Fig. 6 - bracket;

Fig. 7 - corner connection of two type B monoblocks and straps;

Fig. 8 - corner connection of two type B monoblocks, fixed with a bracket;

Fig. 9 - corner joint stabilized by two hinged clamps;

Fig. 10 - corner connection using a bracket;

Fig. 11 - photo of a clinical case of triple pelvic osteotomy using an external fixation device.

The method of triple pelvic osteotomy includes the following steps of the operation. After preparing the operating fields, the animal is placed on its back and a skin incision is made in the area of the pubic bone. A fragment of the pubic bone branch is excised, then the wound is sutured. An incision is made in the area of the ischium and an osteotomy of the ischium, the wound is sutured. Next, the animal is placed on the stomach and an incision is made in the skin and gluteal muscles up to the bone base of the sacroiliac joint. An osteotomy of the sacroiliac joint is performed until the contact between the bones is completely interrupted. The cut off half of the pelvis is turned to the required angle in the lateral direction in order to change the position of the acetabulum. An external fixation apparatus is applied to the ilium and sacrum in order to stabilize the severed half of the pelvis towards the sacrum. In this case, the pins are passed through the wing of the osteotomized ilium, then through the body of the sacral bone, then through the adjacent wing of the ilium and are fixed on the arched frame of the external fixation apparatus. Then, cylindrical supports are attached to the frame formed on both sides parallel to the spinal column and sacrum, on which hinged devices mounted from the claimed parts are further installed. Hinged devices provide a swivel assembly to which a platform in the form of a radius plate is attached, on which transosseous elements of small diameter are installed using spoke fixators, or a polyfunctional monoblock is attached separately to the hinge, which holds a large diameter transosseous element. Transosseous elements are introduced into the area of the tubercle of the ischium for additional fixation of the apparatus.

The external fixation device is made up of external fixation units, for which half rings, strips with mounting holes, cylindrical supports and transosseous rods, as well as fasteners and connecting elements are used. In the invention, spoke fixators (according to Pat. 2657203, 2017, RU) are used as connecting elements, in which the holes for transosseous rods have a figured shape (teardrop-shaped, U-shaped or semicircular), and polyfunctional monoblocks (according to Pat. 2739266, 2020, RU ), the design of which has also been modified.

The polyfunctional monoblock (Fig. 1) 1 of type A is made in the form of a tetrahedral elongated prism with three holes: axial through threaded 2 for installing mounting studs, bolts, and smooth through holes 3, 4 placed on adjacent side faces of the monoblock 1 perpendicular to the axis of the monoblock 1 and with offset. Holes 3, 4 are shaped to eliminate rotation and loosening of the fixed elements. The shape of holes 3, 4 can be drop-shaped, U-shaped, semicircular. Smooth transosseous wires or supports are inserted into holes 3, 4, which are fixed with pins/bolts inserted from the ends of monoblock 1.

Polyfunctional monoblock 5 (Fig. 2) type B is made in the form of a tetrahedral elongated prism with three holes. On adjacent side faces, a through hole 6 of a figured shape (teardrop-shaped, U-shaped, or semicircular) is made with an offset for installing transosseous rods or supports, and a through threaded hole 7 for mounting studs. From the end of the monoblock 5, an axial non-through threaded hole 8 is made, designed to strengthen, for example, a transosseous pin or a support installed in the hole 6.

The strap 9 (Fig. 3) has two through holes 10, 11 located at opposite ends of the strap.

Bracket 12 (Fig. 4), made of a bent metal bar, is designed to achieve stability and rigid fixation of the corner joints. The bracket 12 is inserted into the holes 3, 4 of the polyfunctional monoblock 1 or into the hole 6 of the polyfunctional monoblock 5. For convenience and versatility, a set of brackets with different lengths of the bracket body can be made.

Hinged latch (Fig. 5) consists of two brackets 13 and 14, pivotally connected to each other end-to-end along the plane of contact of the elements with the possibility of rotation relative to each other. To do this, each bracket has one rounded end in plan, and the distal end has the shape of a tetrahedral prism. To connect the brackets to each other, a fixing screw 15 is used, which is inserted into the connecting holes located on the rounded part of the brackets: a smooth hole 16 and a threaded hole 17 on the brackets 13 and 14, respectively. The screw 15 fixes the swivel joint and controls the possibility of making a selective turn. At the distal ends of both hinged brackets 13 and 14, mutually perpendicular smooth holes 18, 19 of figured shape (teardrop-shaped, U-shaped, semicircular) are made for the installation of smooth transosseous elements, cylindrical supports 21, 22. Threaded holes are made from the ends of both brackets 13, 14 20 to install mounting screws. Hinged lock (Fig. 5) allows you to change the angular position of the elements fixed in it. The hinged fixator is used for repositioning and dosed controlled change in the position of bone fragments.

The modified bracket (FIG. 6), the modification of which is that the hole 17 on the outside is provided with radial grooves 23, allows the formation of mutually perpendicular connections between the transosseous elements and cylindrical smooth supports.

To form the nodes of the external fixation apparatus, the connections are performed as follows.

By connecting the bar 9 (Fig. 7) with two monoblocks 5 and strengthening with fixing bolts, an angular connection is made that allows you to adjust the distance between the transosseous elements installed in the polyfunctional monoblocks 1 and the osteotomy area, and achieve the most rigid fixation; angular displacement of transosseous elements in different planes.

By connecting the bar 9 (Fig. 8) with two polyfunctional monoblocks 5, the necessary corner connection is made between two cylindrical supports 21 and 22. The bracket 12, inserted into the polyfunctional monoblocks 1, mounted on cylindrical supports 21,22, prevents loosening of the corner joint, achieves a stable and rigid fixation of the completed corner connection.

An angular connection of two supports 21, 22 (Fig. 9) is performed using a bar 9 and polyfunctional monoblocks 5. Each support 21, 22 is mounted on a hinged lock using the holes 18, 19 of the brackets. For structural rigidity, a beam 24 is inserted into the hinged brackets and the stability of the gusset between the supports 21, 22 is increased. This variant of the gusset is the most reliable and is characterized by versatility.

To form a mutually perpendicular connection (Fig. 10) between the cylindrical support 22 and the transosseous rod 25, a modified bracket is used (Fig. 6), which is mounted on the support 22. are placed along the grooves 23 (not shown in Fig. 10) of the modified bracket and tightened with a fixing nut 27 from the opposite side.

The proposed connection nodes for the formation of an external fixation device make it possible to insert the rods into the bone at different angles, place them at different widths from the support, create a diverse arrangement of external supports in the form of a single support, frame, etc., which increase the rigidity of fixation. The proposed technical solutions provide an opportunity to adapt to the variations that may be encountered during the surgical intervention and achieve improved functional and anatomical conditions for the patient while increasing the reliability and stability of osteosynthesis.

Example 1

An example of a clinical operation. Dog outbred, age 11 months, weight 16 kg. She was admitted to the veterinary clinic with signs of intermittent claudication of the pelvic limbs, observed by the owners for more than 3 months. Clinical examination revealed instability of the right hip joint. The Ortolani test of the right hip joint is strongly positive. Left - negative. X-ray examination revealed bilateral hip dysplasia. At the same time, dysplasia of the left joint was assessed as 1st degree, of the right joint - as 3rd degree. Proposed surgical intervention on the right hip joint to change the position of the acetabulum and adequate coverage of the femoral head with the arch of the acetabulum. Anesthesia was performed according to the traditional technique. After preparation of the surgical fields, the animal was placed with its back on the operating table, and with the limbs apart, a skin incision was made in the region of the right pubic bone. After preparation of the underlying tissues, a fragment of the pubic bone branch was excised, then the wound was sutured. Next, the incision was made in the area of the ischium and osteotomy of the ischium was performed in a similar way, the wound was sutured, then a metal rod 4 mm in diameter was inserted into the ischial tubercle 4 cm deep into the bone. The animal was then turned over and placed on its stomach. The skin in the region of the sacroiliac joint was treated with antiseptic solutions. Next, an incision was made in the skin and gluteal muscles to the bone base of the sacroiliac joint. Using a bone chisel, an osteotomy of the sacroiliac joint was performed until the contact between the bones was completely interrupted. Next, the cut-off half of the pelvis was turned to the required angle and, using a drill, was initially fixed with two short wires along the sacroiliac joint. After that, an X-ray examination was performed in a direct projection. After obtaining a satisfactory result, the final fixation of the pelvic bones was performed. To do this, the animal was repeatedly placed on the operating table with its stomach down. The needles intended for research were removed. At the same time, two long wires prepared in advance parallel to each other were inserted with a drill through the right wing of the ilium into the articulation area of the sacral bone, passing through its thickness, then the wires were passed through the left wing of the ilium and the percutaneous one was removed. Then one long wire was inserted from the lower corner of the right wing of the ilium, through the thickness of the muscles into the upper corner of the wing of the left ilium, and passing through it, was removed percutaneously. Similarly, a long needle was inserted on the left side. From the lower angle of the wing of the left ilium to the upper angle of the wing of the right ilium. Then, the removed transdermal wires were attached to a pre-mounted radius frame with the help of finger-type spoke fixators. Then, to the frame on the right side, a bearing cylindrical support was fixed with a length equal to the length of the pelvis. After that, a hinged fixator was installed on the support, to which a polyfunctional monoblock was attached. Next, the transosseous rod, previously introduced into the thickness of the ischium, was fixed in this monoblock (Fig. 11). After suturing the muscles and skin over the sacroiliac joint, the animal was taken out of anesthesia. The postoperative period included the use of antibiotics, a sparing diet, and movement control. During 14 days the animal cautiously dragged the right pelvic limb. Then there was an increase in the intensity of movements. The hardware structure was removed on the 42nd day with signs of complete stabilization of the osteotomized area in the area of the sacroiliac joint. The lameness finally disappeared on the 56th day. Repeated X-ray examination showed significant coverage of the femoral head by the acetabular arch. Ortolani's test is negative.

The versatility of the claimed fixation units is confirmed by the possibility of their use in the treatment of anterior cruciate ligament rupture in dogs.

Example 2. Dog breed "Cane Corso", age 3 years, weight - 52 kg. There was a rupture of the anterior cruciate ligament of the left pelvic limb. Within 3 weeks, the animal had lameness of support up to a complete loss of support on the diseased limb and a crunch in the joint was noted, the "drawer" test was positive. The animal is offered a double osteotomy of the tibia, followed by linear hardware fixation using the inventive fixation nodes. During surgery, an arthrotomy of the knee joint was performed with its subsequent revision. A hematoma was removed from the joint cavity, a degenerate fatty body was removed, and the remnants of the anterior cruciate ligament of the knee joint were removed. After revision and suturing of the knee joint capsule, a double osteotomy of the tibia was performed with fixation of the proximal and distal sections of the osteotomized bone using thin anti-rotation pins and subsequent application of a linear external fixation apparatus consisting of a cylindrical horizontal support on which type B monoblocks were attached. relation to the horizontal support was 90°. After coming out of anesthesia, the animal rose uncontrollably and, after a few steps, stumbled and fell on the operated limb. The subsequent assessment of the integrity of the apparatus construction and the area of the osteotomy showed the viability of the construction. After the operation, the animal was kept for 5 days in an aviary with limited range. At the same time, the evaluation of the nodal connections of the hardware design after 5 days showed the presence of stable fixation. Further, the content of the animal was not limited to the aviary. The animal was free-range for most of the daylight hours. Assessment of the condition of the nodal connections of the hardware design after 3 weeks also showed the presence of stability. Further, the conditions of keeping provided by the owner were such that the walking was carried out over rough terrain in a mountainous region, the animal climbed the mountain up to 2 kilometers and then went down, sometimes the animal fell with a load on the operated limb. Control of the state of the hardware structure and nodal connections 6 weeks after the operation made it possible to note their stability. Also, after 6 weeks, the hardware structure was dismantled from the animal and the anti-rotation pins were removed.

Thus, the proposed external fixation nodes are stable with significant unregulated and unprevented loads on the osteotomy area, which increase in the postoperative period and until the moment of consolidation of the osteotomy bone planes. The structures are easy to use and versatile for use in anatomically complex areas, for example, in the area of fixation of the lower leg and pelvis, where it is difficult to fully install arcuate ring hardware structures. The device is applicable in the field of practical medicine and veterinary medicine.

Scientific literature sources taken into account:

1. Yagnikov S.A. Treatment of hip dysplasia in dogs (guidelines for a lecture course on veterinary surgery) / Yagnikov S.A. -M., 2006. - 41 p.

Claims (6)

1. A method of triple pelvic osteotomy in dogs, including violation of the integrity of the pelvic bone, reposition and fixation of the pelvis, characterized in that after the preparation of the surgical fields, the animal is placed on its back and a skin incision is made in the area of the pubic bone and a fragment of the branch of the pubic bone is excised, followed by suturing the wound , then an incision is made in the area of the ischium and an osteotomy of the ischium, the wound is sutured, after that the animal is placed on the stomach and the skin and gluteal muscles are incised to the bone base of the sacroiliac joint and the osteotomy of the sacroiliac joint is performed until the contact between the bones is completely interrupted, and the cut-off half of the pelvis is turned to the required angle in the lateral direction, then the cut-off half of the pelvis is stabilized towards the sacrum with an external fixation device installed on the ilium and sacrum, while the spokes are passed through the wing of the osteotomized ilium, then through the body of the sacral bone, then through the contiguous the leg wing of the ilium and are attached to the arc-shaped frame of the external fixation apparatus, then cylindrical supports are attached to the formed frame parallel to the spinal column and sacrum on both sides, on which hinged devices mounted from the parts of the external fixation apparatus according to item 2 are then installed. 2. An external fixation device for fixing osteotomized bone fragments, containing straps with mounting holes, cylindrical supports and transosseous rods, fixators of transosseous rods, as well as fastening and connecting elements, characterized in that polyfunctional monoblocks of type A and type B are used as connecting elements and supplemented with strips with through holes, brackets, a hinged latch and a modified bracket, while the polyfunctional monoblock type A is made in the form of a tetrahedral elongated prism with an axial threaded hole and smooth holes located on the sides, having a figured shape, and the polyfunctional monoblock type B is made in in the form of a tetrahedral elongated prism with an axial non-through threaded hole in the end, as well as with a figured through hole and a through threaded hole located on adjacent side walls with an offset; the hinged latch contains two brackets mated to each other end-to-end along the plane of contact with the possibility of rotation relative to each other, connected by a fixing screw, which is inserted into the connecting holes located on the rounded part of the brackets, the first bracket is made with a smooth hole, and the second one - with a threaded hole , moreover, at the distal ends of both brackets, having the shape of a tetrahedral prism, mutually perpendicular smooth holes of a figured shape are made, and threaded holes are made from the ends of both brackets for installing fixing screws; the modified bracket is a bracket whose threaded hole located at the rounded end of the bracket is provided with radial grooves. 3. The device according to claim 2, characterized in that the transosseous rod fixator has a figured through hole. 4. The device according to claim. 2, characterized in that the figured shape of the holes can be drop-shaped. 5. The device according to claim. 2, characterized in that the figured shape of the holes can be U-shaped. 6. The device according to claim 2, characterized in that the figured shape of the holes can be semicircular.

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