Technical Field of the Invention

The present invention relates to a cable-supported cannulated screw developed to be used in fracture fixation, fusion, and osteotomy applications of large and small bones.

The present invention particularly relates to a cannulated screw that is developed to be used in orthopedic surgical applications, and that is prevented from being dislocated by means of cables and plates inserted through the head of the screw and fixed to a suitable and desired location on a bone.

State of the Art

Nowadays, cannulated screws are generally used in cases related to pelvic, hip, knee, foot, and ankle regions. Cannulated screws are used in the reunion of bone fragments in femur neck fractures, sacroiliac joint dislocations, tibial plateau and femur condyle fractures, calcaneus and talus fractures, ankle and subtalar arthrodesis, and humerus and olecranon fractures. In general, cannulated screws comprise threads that bring two fragments closer to one another after reaching the outer section of a fragment like a fracture that is desired to be subjected to compression. Nowadays, as there are cannulated screws head portions of which are provided with said threads and that feature a broader structure so as to ensure that the screw remains stable while advancing inside the fragment, there are headless cannulated screws as well. Cannulated screws, which generally comprise a head and a body portion, are manufactured to feature various dimensions based on the size of the bone into which the screw is going to be inserted. Cannulated screws are inserted by using a Kirschner wire as a guide after the fracture line is drilled. After the screw is inserted, the head of the screw is again conveyed over the guidewire and pulled in order to close the gap between fragments. This process is repeated until the fracture line is closed, thereby fixing the bone.

One of the major complications observed in cannulated screw systems used nowadays is that the threads bearing the entire load of the system fail to provide enough compression against traction, thereby causing the screw to dislocate from the bone it was inserted. Particularly in osteoporotic patients who suffer from weakened cancellous tissue, the fact that threads located on the body of the screw do not have enough healthy bone tissue to cling on and advance significantly increases the dislocation risk for the screw. On the other hand, the muscle-tendon that creates traction by pulling the proximal area of the fracture to the opposite direction on the compression axis may also cause the screw to dislocate. In case the screw gets dislocated prior to the union, the integrity of the entire system disrupts, thereby resulting in nonunion/malunion of the bone. If a dislocated screw goes unrecognized, nonunion may occur due to the influence of fragments and the intervention performed on the biological structure of the tissue. In case union cannot be achieved in the first intervention to the fracture region, surgeons are required to adopt more aggressive and functionally adverse treatment approaches and excise the fragment via surgical intervention. Locking plate and screw systems have been developed in order to overcome this particular problem in the state of the art and to ensure that the screw does not get dislocated after the application. However, since locking plate and screw systems fail to apply enough compression to the fracture region, they slow down the bone union process. Recently, several studies have been conducted and novel configurations have been developed in order to increase the success rate of cannulated screw applications and to provide a healthier bone union process by shortening the union period. While these cannulated screws aimed to structurally increase the success rate of the intervention, they were also designed to provide ease of use to the surgeon. One example of such studies is the invention disclosed in the patent document numbered TR201814688. Said invention relates to screws used in the treatment of various types of bone fractures including OTA 33B1-2 Cl-2-3, Schatzker Type 1, 4, and 5, patellar transverse fractures, pubic and sacroiliac separations, characterized in that; it particularly relates to a cannulated telescopic screw that is applied to the gap (tunnel) created in the bone by making small incisions by matching the fracture lines in fractured bones, thereby eliminating the requirement of inflicting redundant wounds during the surgical intervention stage, that comprises of embedded telescopic female screw and male screw, that is attached to the bone by broadening the fastening surface by means of the outer inverse male screw located on the outer surface of the female screw, thus prevents the deformation of the bone during the fixation of the male screw connected to the female screw path located on the female screw such that it positioned opposite to the female screw by means of the male screw path located thereon, and that features an extendable screw length in which the connection distance of male screw to the female screw is shortened as long as the required compression pressure is maintained during the intervention.

Yet another study in the state of the art is the invention disclosed in the utility model application numbered TR201206768. Said invention, a cannulated dynamic traction screw, relates to an implant product used for the union of the epiphysis of a fractured bone to the body portion thereof in open joint fractures in orthopedics. The aforementioned cannulated dynamic traction screw features a dynamic structure that comprises two main components which are the traction head and the screw. Cannulated dynamic traction screw is designed to feature various diameters and lengths in order to accommodate the application field based on the sizes of various bones. Said invention provides ease of use and ensures the fixation of the bone via traction.

Yet another study conducted in the state of the art is the invention disclosed in the patent application numbered TR200808426. The aforementioned invention is designed to ensure a more stable fracture fixation in hip fractures, comprises holes on the threaded portion thereof, and a cannula passing through the midsection of both the head of the screw and the stem of the screw. After the cannulated screw is inserted into the fracture line, the cement used in orthopedics and traumatology surgeries is transferred through the cannula created on the head of the screw and fastened, thereby ensuring that the cement reaches the spongy tissue through the holes located on the threaded portion of the screw. Thus, the screw adheres to the cement, thereby preventing any potential complications such as the slipping of the screw and ensuring a more stable fixation. Screws, which are custom-designed to feature a specific number of holes and a predetermined size based on the shape of the fracture are provided in a screw box and accordingly sterilized. Cannulated hexagonal screwdriver is used since the screw is cannulated.

Yet another study conducted in the state of the art is the invention disclosed in the patent application numbered TR201600962. Said invention relates to a tension band system that consists of a locking screw-washer that not only serves as a tensioning band for the internal fixation of olecranon but also ensures internal fixation in olecranon fractures in upper extremities or after olecranon osteotomy. In general, the tension band technique is implemented through screw or Kirschner wire (k-wire) apart from other fixation methods for the internal fixation in olecranon fracture or subsequent to olecranon osteotomy. However, fixations performed by using screws or k-wire usually result in implant failure (loosening or migration) and stability problems. Said invention differs from the available tension band techniques in terms of both stability and management of implant failure issues. Said invention is a tension band system that consists of a locking screw-washer system that may be used in the fixation of all fractures and osteotomies in which the tension band method is implemented. This particular system prevents screw migration as the fracture or osteotomy region is internally fixed by means of a single screw and due to the fact that the tension band wire (cerclage wire) features screw connection through the holes located on the washer that ensure interlocking between the screw and the washer. The locking olecranon screw- washer system to be used in tension band fixation comprises of two main components. The first component is the locking cannulated screw system, which in turn comprises 3 main sections as the proximal, medial, and distal sections. The proximal section (A) of the screw is capable of interlocking the head of the screw and the screw washer. The medial section (B) of the screw is the cannulated screw body that is positioned inside the bone. And the distal section is the threaded portion of the screw featuring various lengths. The second component is the locking washer system and comprises a single piece. This washer system further comprises two main sections, which are the midsection and the periphery section. While the midsection comprises the threaded portion that allows for locking the screw system to the washer, the periphery section is the part that comprises holes in sufficient number and suitable configuration in order to fasten the cerclage wire, which is used in tension band technique, to the locking washer system. Said invention comprises of a screw system that may be fully or partially threaded and that may feature various lengths and widths based on the fixation of the fracture or osteotomy, and a screw washer system that includes holes with various dimensions and configurations. The locking screw- washer system is required to be provided together with corresponding screwdrivers and other surgical equipment among other surgical sets.

Consequently, the need for a cable-supported cannulated screw that overcomes the disadvantages of the state of the art, and the insufficiency of the available solutions necessitated making an improvement in the relevant technical field.

Brief Description of the Invention

The present invention relates to a cannulated screw that is developed to be used in surgical applications in orthopedics, and that meets the aforementioned requirements, and that eliminates all disadvantages and provides further advantages.

The object of the present invention, based on the state of the art, is to improve the union rate and application success by preventing the system from dislocating after the application by means of the cables inserted into the head of the cannulated screw and plates that allow for fixing said cables to the desired positions on the bone.

The object of the present invention is to render the patient independent of applications like splints earlier, thereby initiating the rehabilitation period at an earlier stage and improving the joint mobility in the postoperative period by preventing the cannulated screw from getting dislocated. Yet another object of the present invention is to promote the surgeon's confidence in fixation through fixing the cannulated screw to the bone by means of cables, thereby allowing the surgeon to recommend postoperative exercises to the patient at an earlier stage.

Structural and characteristic features of the present invention, as well as all advantages thereof, will be understood more clearly by means of the attached figures and the detailed description written by making references to said figures, therefore the respective evaluation should be conducted by taking the detailed description and the figures into consideration.

Brief Description of the Figures

The present invention needs to be evaluated together with the figures described below in order to understand the configuration, additional elements, and advantages of the present invention.

FIGURE 1 illustrates the general schematic view of the inventive cannulated screw. FIGURE 2 illustrates the detailed schematic view of the connector positioned on the body.

FIGURE 3 illustrates the general schematic view of the plate in a disassembled state.

FIGURE 4 illustrates the general schematic view of the inventive cannulated screw fixed onto a fracture in a preferred embodiment of the present invention.

Reference Numerals

100. Cannulated Screw 110. Body

Ill. Thread

120. Screw Head with Screwdriver Insert Hole

130. Connector 131. Cable Socket on the Connector

140. Plate

141. Concave Surface

142. Connector that Fixes the Plate to the Bone

143. Cable End Insertion Hole 144. Cable Side Exit Hole

150. Cable

A. Bone

A1. Fracture Line

Detailed Description of the Invention In the detailed description provided herein, the inventive cannulated screw (100) developed to be used in surgical applications in orthopedics is only described to provide a better understanding of the subject and without constituting any limiting effects thereon. The inventive cannulated screw (100) developed to be used in surgical applications carried out in the field of orthopedics, and comprising a body (110) that is inserted to the region in which the fracture line (Al) is located on the bone and that includes threads (111) thereon, a screw head with screwdriver insert hole (120) that is created so as to stay on the surface of the bone (A) above said body (110), and a connector (130) comprises in the most basic form thereof; cable (150) that prevents the body (110) from coming out of the bone (A); a connector (150) on which the screw head with screwdriver insert hole (120) is located and through which said cables (150) is inserted through; a plate (140) that is applied to a region of the bone (A) other than the fracture line (Al) and that secures the cables (150) by fastening them.

The inventive cannulated screw (100) illustrated in Figure 1 is used in order to properly and stably rejoin the fracture lines (Al) that occur on the bone (A), thereby ensuring a proper union process. The cannulated screw (100) comprises; a body (110) that is inserted into the bone (A), a screw head with a screwdriver insert hole (120) that remains outside of the bone (A), a connector (130) that is attached to the screw head with screwdriver insert hole (120), a plate (140) that is attached to the other side of the fracture line (Al), and a cable (150) that interconnects the plate (140) and the connector (130). After the body (110) is inserted into the bone (A), the threads (111), which are shaped like screw pitches, located on the body not only enable the cannulated screw (100) to advance inside the bone (A) and cling thereon but also ensure union by applying compression to the fracture line (Al). The tip of the body (110) may feature a tapered, blunt, or mixed structure depending on the procedure to be performed and the characteristics of the bone (A). The screw head with screwdriver insert hole (120), which remains outside of the bone (A) into which the cannulated screw (100) is inserted, and that features a structure wider than the body (110) inserted into the bone (A), remains on the outer surface of the bone (A) after the application procedure. The screw head with screwdriver insert hole (120) comprises the connector (130) that is used to stabilize the body's (110) position inside the bone (A). As the connector (130) may be integrated into the screw head with screwdriver insert hole (120), it may also be designed to be independent therefrom. In case the connector (130) is designed to be independent, then it features a cap form, and accordingly, fitted onto the crew head with screwdriver insert hole (120). The connector (130) illustrated in Figure 2 comprises the cable sockets on the connector (131) through which the cable (150) is inserted. The connector (130), which preferably has a rectangular shape, comprises cable socket on the connector (131) on every edge thereof through which the cable (150) is inserted. The cable socket on the connector (131) allows for tensioning the connector (130) from both sides by means of a cable (150) and connected to the plate (140) attached to the other side of the fracture line (Al). Each cannulated screw (100) preferably comprises at least 2 plates (140). The plate (140) illustrated in Figure 3 comprises a cable end insertion hole (143) through which the cable (150) is fastened and secured after the cable is inserted through the connector (130) and tensioned and the connector that fixes the plate to the bone (142). After said cables (150) are run through the cable end insertion hole (143) and the cable side exit hole (144), they are fixed to the concave surface (141) by means of a fastening apparatus. Once the cables (150) are run through the cable end insertion hole (143) and the cable side exit hole (144) and the suitable tension is achieved, they are fastened through the concave surface (141) by means of fastening apparatus. Thus, the cannulated screw (100) is prevented from loosening and getting dislocated due to factors like tendon traction and insufficiency of healthy bone (A) tissue. Said plate (140) is fixed to the bone (A) by means of the connector that fixes the plate to the bone (142). When the cannulated screw (100) illustrated in Figure 4 is applied to the fracture line (Al) on the bone (A), it is set up such that the fracture line initially passes the fracture (Al) fragment, and then applies compression thereto. Subsequently, the plates (140) with an excisable connector that fixes the plate to the bone (142) are applied to a suitable bone (A) region other than the fracture line (Al) by means of a locking screw. Said plates (140) are preferably positioned such that they are 1 or 2 in quantity. Then, the cables (150) are run through any of the two cable sockets on the connector (131) on the connector (130) located on the upper section of the cannulated screw (100) and this operation is repeated for the other surface. After the cables (150) are run through the cable socket on the connector (131), they are first run through the cable end insertion hole (143) on the plate (140), and then through the cable side exit hole (144). Once the cables (150) are run through and the suitable tension is achieved by pulling the cables, the concave surfaces (141) located on both sides of the plate (140) are crushed and fixed by means of a fastening apparatus. The potential risk of dislocation of the cannulated screw (100) is eliminated once said cables (150) are fixed.

In an embodiment of the present invention, a total of 8 cable socket on the connector (131) through which the cables (150) are run through, are positioned such that 2 of each are located on each side of the connector (130) located on the screw head with screwdriver insert hole (120) of the cannulated screw (100).

The inventive cannulated screw (100) may be applied to several different bone (A) fracture lines (Al). However, the main area of use of the inventive cannulated screw (100) is the bone (A) fracture lines (Al) in fractures of the olecranon, trochanter major, tibial tubercle, and medial malleolus in which a tendon or ligament is attached thereto. The reason is that such fractures usually comprise vectorial forces during the movement of tendons or ligaments attached to the aforementioned bones, which makes fixation of the fraction line (Al) difficult. Supporting the inventive cannulated screw (100) with cables (150) improves the durability thereof and reduces the risk of implant failure development. The inventive cannulated screw (100) may be applied to various fracture lines (Al) in a customized manner. In a preferred embodiment of the present invention, the inventive cannulated screw (100) is applied to the olecranon (elbow) bone (A). The inventive cannulated screw (100) was inserted through the proximal and distal (closer and farther to the body) fragments of the fracture line (Al) located on the olecranon bone (A), and cables (150) were run through the connector (130). Said cables (150) were attached to the distal (farther from the body) fragment of the fracture line (Al) in a tensioned manner by preferably 2 plates (140), thereby preventing the cannulated screw (100) from getting dislocated, the triceps tendon that is attached to the proximal (closer to the body) of the bone (A) on which the fracture line (Al) is located, applies traction to the proximal fragment in the opposite direction by pulling it and produces an effect that forces the cannulated screw (100) implanted to the bone. The fact that said cables (150) are parallel to the direction of compression produces a force opposite to the traction applied by the tendon, thereby preventing the cannulated screw (100) from loosening and getting dislocated.

In a further embodiment of the present invention, a plate (140) with an excisable connector that fixes the plate to the bone (142) assumes a role auxiliary to fixation in segmented fracture lines (Al) instead of the connector that fixes the plate to the bone (142) of the cable end insertion hole (143) and the cable side exit hole (144) of the plate (140) through which the cable (150) is run. For example; the plate (140) was provided with six side cable exit holes (144) and said plates (140) were fixed to the bone (A) by means of six connector that fixes the plate to the bone (142) positioned side by side on the same plane in an ulna metaphyso-diaphyseal fracture (Al) accompanied by olecranon fracture (Al).