RU188428U1 - SCREW FOR OSTEOSYNTHESIS OF THE FEMORAL NECK - Google Patents

Abstract

The invention relates to the field of medical technology, in particular to medical devices used in traumatology and orthopedics for osteosynthesis for fractures of the femoral neck.

The screw for osteosynthesis of the femoral neck consists of two parts connected by a telescopic, distal (1) and proximal (2) stem. The proximal rod is made with a through axial channel 3. Each of the rods is provided with a threaded section (4 and 6) to ensure adhesion of the screw to the bone and recesses (5 and 7) under the screwdriver. The distal rod contains a threaded section (for fixing in the neck) at the distal end (8) and a recess for a screwdriver at the proximal end. The proximal rod contains a threaded section (for fixing in the area of the greater trochanter of the femur) and a recess for a screwdriver at the proximal end. The distal end (8) of the distal core self-drilling contains cutting edges and self-tapping screw cutting. The proximal end of the distal rod is installed in the through axial channel of the proximal rod. The distal end of the proximal stem is rolled in such a way that the distal stem equipped with a collar (10) can move along the proximal stem from one extreme position to the other extreme position to a distance in the range from 10 to 20 mm.

The technical result consists in the dynamic fixation of the place of the femoral neck fracture. At the same time, the screw installation is carried out without preliminary reaming of the canal in the bone, and it is possible to adjust the screw length. 3 hp F-ly, 5 ill.

Description

The field of technology.

The invention relates to the field of medical technology, in particular to medical devices used in traumatology and orthopedics for osteosynthesis for fractures of the femoral neck.

Known rod-screw (source [1]: patent RU 14826; Published: 10.09.2000) containing a working part with a screw thread, limited to the thrust pad, and the mounting part. On the mounting part there is a voltage concentrator located in a plane perpendicular to the axis of the rod-screw and located between the support platform and the fixing end.

Known rod-screw to the apparatus for transosseous osteosynthesis (source [2]: patent RU 19638; Published: 20.09.2001). The rod-screw [2] contains a rod that is provided with a tapered pointed working end and a fastening end. The working end has a taper, made at an angle of 30 degrees, and a cone-shaped section, on which a resistant trapezoidal thread (screw thread) is made, in addition, a smooth cylindrical section, and a thread and a section having edges on the fixing end.

Known rod - screw for external fixation device (source [3]: patent RU 143507; Published: 07.27.2014). The rod - the screw [3] cannulated is a rod that consists of a self-tapping and thread-forming part on the one hand, on the other hand a threaded part and a threadless section between them. Inside the core there is a through hole. At the end of the threaded part there is a rubber end cap.

Analogs [1; 2; 3] do not allow dynamic compression at the junction between the bone fragments in the process of walking, since they are made monolithic. The design of the screws does not provide the possibility of changing the length, both during the installation of the screws and in the process of the fracture fusion.

A device for osteosynthesis of the femoral neck is known (source [4]: patent RU 80333; Published: 10.02.2009). The device contains a base in which a rod is fixed, provided with a through axial channel, external threading, at least two sliding blades at the working end and a faceted protrusion in the central part limited by a shoulder. On the ledge mounted swivel key connected by means of a hinge fixed with a bracket on the base of the threaded rod.

Rod [4] involves the use of external fixation on the support (base). External percutaneous fixation is fraught with the penetration of infection through the soft tissue at the site of the passage of the rod. So the rod does not allow dynamic compression at the junction between the bone fragments in the process of walking. The design of the rod does not provide the ability to change its length, both during installation and in the process of fusion of the fracture.

Known screw cannulated telescopic device and method of fixing the femoral neck, disclosed in the patent (source [5]: patent US 2014214034. Published: 01/21/2013). The device is a screw assembly containing two telescopically connected core elements, one of which is made of a larger diameter, the second - the smaller one. The core element of larger diameter is made with an axial through channel and a threaded part at the proximal end. The second core element is made of smaller diameter with the possibility of placement and movement in the through channel of the first core element and also has a longitudinal through channel and a threaded part at the distal end, and is provided with a cap. The shape of the rod of smaller diameter in cross section may differ from cylindrical, while the channel in the rod of larger diameter has a shape that provides a strictly axial movement of the second rod in it (without mutual rotation of the rods relative to each other).

Analogue [5] does not provide an introduction to the bone without prior reaming of the channel in the bone, necessary for its installation. The design of the threaded part of the distal screw stem [5] does not allow it to be screwed into the bone and requires prior reaming of the canal, both in the cortical layer and the spongy layer of the bone. The design of the screw [5] suggests the presence of a longitudinal through channel along the distal and proximal rods for the introduction of drugs, which requires installation of the proximal part of the screw of the plug preventing penetration of infection and outflow of the drug, as well as increasing the diameter of the screw as its distal rod, and the proximal rod. Given that the telescopic design does not allow for the minimum transverse dimensions of the screw body necessary for fixing the place of the femoral neck fracture. The screw [5] is obtained of a larger diameter than in the case when it could be performed without a through longitudinal channel. Therefore, only one such screw [5] can be installed to fix the neck fracture; two or more screws can no longer be placed, since the transverse size of the neck is limited. The analog has not disclosed the optimal geometrical parameters of the screw required for implementation, however, based on the design features, the screw diameter is too large and the bone is significantly weakened before it is installed by drilling a significant part of the bone. In the analogue of [5], the optimal length and the course of dynamization (the course of the distal rod relative to the proximal rod) necessary to use the screw in the treatment of a hip fracture is not determined.

A set of devices for osteosynthesis of bone fractures of the extremities is known (source [6]: patent RU 2621587; Published: 06.06.2017), which includes a fenestrated cannulated compression screw, a screwdriver for the screw and a silicone plug. Fenestrated cannulated compression screw consists of two rods - distal and proximal, made with through axial channels with the possibility of telescopic connection of rods, and holes in the walls of rods. Each of the rods is provided with a threaded section (screw thread) to ensure the adhesion of the screw with the bone material. The distal core of the screw is threaded with a larger diameter compared to the diameter of the thread on the proximal screw stem.

The screw [6] also does not provide an introduction to the bone without preliminary reaming of the canal in the bone, necessary for its installation. The design of the threaded part of the distal rod of the screw [6] does not allow it to be screwed into the bone and requires prior reaming of the canal, both in the cortical layer and the spongy layer of the bone. Before installing the screw [6], the bone is weakened by drilling a significant part of the bone. Screw [6] contains a longitudinal through channel along the distal and proximal rods, as well as transverse holes along the screw body, which are necessary for administering drugs, which requires installation of a plug in the proximal part of the screw to prevent infection and outflow of the drug, as well as increase diameter of the screw, both its distal rod and the proximal rod. The design does not allow for the minimum transverse dimensions of the screw body necessary for fixing the place of the femoral neck fracture. Cross holes and longitudinal through channels weaken the cross section of the screw and reduce its mechanical strength. Therefore, to fix the neck fracture, you can install only one such screw [6], two or more screws can no longer be placed, since they will destroy the neck. In the description, the optimal length and course of dynamization (the course of the distal rod relative to the proximal rod) necessary to use the screw in the treatment of a hip fracture is not determined.

The essence of the technical solution.

The task to be solved by the utility model is to ensure the fixation of the femoral neck fracture with a screw that can be installed into the bone fragments without prior reaming of the bone and will provide dynamic compression at the junction of the fragments during treatment, and also allow changing its length in installation process.

The technical result consists in the dynamic fixation of the place of the femoral neck fracture. At the same time, the screw installation is carried out without preliminary reaming of the canal in the bone, and it is possible to adjust the screw length.

The technical result is achieved by the fact that the screw for osteosynthesis of the femoral neck, consists of two parts connected by a telescopic, distal and proximal stem. Where the proximal rod is made with a through axial channel. Each of the rods is provided with a threaded section to ensure the adhesion of the screw to the bone and the recesses for the screwdriver. The distal rod contains a threaded section (for fixing in the neck) made at the distal end and a screwdriver groove made at the proximal end. The proximal rod contains a threaded section (for fixing in the area of the skew of the thigh) and a screwdriver groove made at the proximal end. The distal end of the distal rod is self-drilling, contains cutting edges and self-tapping screw cutting. The proximal end of the distal rod is installed in the through axial channel of the proximal rod. The distal end of the proximal rod is rolled, so that the distal rod can move, without falling out, along the proximal rod from one extreme position to another extreme position, at a distance in the range from 10 to 20 mm.

The distal core is made, from 35 to 75 mm long, in the form of a metal core with a diameter of 4.75 mm, has a self-cutting screw cut with a pitch of 1 mm at the distal end, and a 3.5 mm hexagonal recess at the proximal end. The proximal rod is made in the form of a cannulated metal rod with an outer diameter of 6.6 mm, at the proximal end containing a screw thread with a pitch of 0.5 mm and a hexagonal recess 5 mm in size, at the proximal end containing a shoulder formed by rolling. A thickening in the form of a collar is also made on the proximal part of the distal rod. The screw threading of the threaded sections is made in steps from 0.5 to 2.5 mm, depth from 0.5 to 1.25 mm. The material for the manufacture of the screw is preferably a titanium alloy or stainless steel, suitable for implantation into the human body.

The technical solution is illustrated with the following graphic materials:

FIG. 1 - screw, general view;

FIG. 2 - screw, general view with separated parts;

FIG. 3 - screw, sectional view;

FIG. 4 - screw (view in section) is shown at the place of installation in the neck of the femur;

FIG. 5 - three screws are shown at the place of installation in the femoral neck.

Implementation of the utility model.

The screw consists of two parts of the distal rod 1 and the proximal rod 2. The total screw length is in the range from 70 to 110 mm, the diameter of the rods 1 and 2 (Fig. 1; 2; 3) does not exceed 8 mm. Parts 1 and 2 are telescopically connected, so that the distal rod 1 can move along the proximal rod 2 from one extreme position to the other extreme position for a distance in the range from 10 to 20 mm, i.e. the course of dynamization up to 20 mm and the possibility of increasing the length up to 10 mm if necessary is provided. The proximal rod 2 is made with a longitudinal through axial channel 3 (Fig. 2; 3), provided with a threaded section 4 (Fig. 1; 2; 3), to ensure adhesion with the bone in the skewer area, and a hexagonal recess 5 (Fig. 3) under the screwdriver. The distal rod 1 is provided with a threaded section 6 (Fig. 1; 2; 3), to ensure adhesion with the bone in the region of the part of the neck with the head, and a hexagonal recess 7 (Fig. 3), under the screwdriver. The threaded section 6 is made at the distal end 8 (Fig. 1; 2; 3) of the distal rod 1. A recess for the screwdriver 7 is made at the proximal end of the distal rod 1. The threaded section 4 and a recess for the screwdriver 6 are made at the proximal end of the proximal rod 2. Distal The end 8 of the distal rod 2 is self-drilling; it contains cutting edges and self-tapping screw cutting on the threaded section 6. The proximal end of the distal rod 1 is installed in the through axial channel 3 of the proximal rod 2. Distal end 9 (Fig. 1; 2; 3) ksimalnogo seamed rod 2 so that the distal rod 1 is allowed to move along the proximal shaft 2 from one extreme position to another extreme position without dropping. The proximal end of the distal rod 1 has a slightly larger diameter than its body, the flange 10 is made (Fig. 2; 3), which ensures its contact with the rolled portion of the proximal rod 2. The distal rod 1 is made from 35 to 75 mm long, in particular, 50 mm of titanium alloy VT6 or stainless steel, in the form of a metal rod with a body diameter of 4 to 5 mm, in particular 4.75 mm. The self-tapping screw thread is made in increments of 0.5 to 2.5 mm, in particular 1 mm. Hex socket for a screwdriver 7 with a size of 3.5 mm (3 and 3.3 mm are allowed). Hex socket for screwdriver 5 5 mm in size (4.5 and 5.5 mm allowed). The proximal rod 2 is made in the form of a cannulated metal rod, with an outer diameter of 6.6 mm body, made of titanium alloy VT6 or stainless steel. The screw threading of the threaded portion 4 is performed in increments of 0.5 to 1.5 mm, in particular 0.5 mm. At the proximal end, the proximal rod 2 contains a shoulder formed by rolling, preventing the free exit of the distal rod 1 from the axial channel 3. Screw threading of threaded sections 4 and 6 is preferably performed in steps of 0.5 to 2.5 mm, depth of 0.5 to 1 , 25 mm. Moving the distal rod 1 in the proximal rod 2 provides the ability to dynamize the fracture site. The distal rod 1 is fixed in the part of the neck with the head 11 (Fig. 4; 5). The proximal shaft 2 is fixed in the region of the greater skewer 12 (Fig. 4; 5) allowing the distal rod 1 to dynamize, move relative to the proximal rod 2. When dynamizing, compression occurs at the junction between the part of the neck and the head 11 and the rest of the femur while the patient is walking, this starts the mechanism of mechanical stimulation of osteogenesis. Screws from 70 to 80 mm long have a stroke of 10 mm. Screws from 80 to 110 mm long have a stroke of 20 mm.

The device allows you to fix the neck with the head relative to the rest of the femur and, when walking, to perform dynamic compression at the junction of bone fragments.

The use of the utility model is shown by the example of osteosynthesis with a screw length of 90 + 10. For the insertion of a screw, a femoral navigator is used (Device for treating patients with injuries and consequences of injuries of the proximal femur, patents RU 148219; RU 2535509; RU 120354.) After positioning the femoral navigator, the cortical is opened through the guide sleeve and the screw is inserted into the fracture area. The screw is fixed on a screwdriver, the working end of which is installed in the recesses 5 and 7. At the same time, the distal rod 1 moves away along the axial channel 3 proximally to the rod 2 at a distance of 10 mm and becomes in the neutral position. In the neutral position, the length of the screw can be increased by 10 mm by twisting the distal rod with a screwdriver. Placing the screw along the longitudinal axis of the femoral neck, using a screwdriver, screw the screw with the threaded section 6 into the part of the neck with the femoral head, with the threaded section 4 in the region of the greater trochanter. The proximal end of the proximal rod 2 is mounted in the area of the greater skewer 12, which allows you to enter the screws with minimal access, without cuts. Moreover, since the transverse size of the screw is small (no more than 8 mm in the proximal part and not more than 6.6 mm in the distal part), one, two or three screws can be inserted into the neck at the same time (Fig. 5). The distal end 8 of the distal rod 2 is self-drilling, contains cutting edges and self-tapping screw cutting, which allows you to insert the screw directly into the bone, and does not require reaming of the channel under the distal rod 1, therefore, the bone mass is maintained and the required rigidity of fixing the screw in the head is provided. To prevent the part of the neck with the head 11 from rotating relative to the part with the large spit 12, two or three screws can be inserted (FIG. 5).

Claims (4)

1. Screw for osteosynthesis of the femoral neck, consisting of two parts, connected telescopically, a rod intended for fixation in the part of the neck with a head, and a rod intended for fixation in the region of the greater trochanter, where the rod intended for fixation in the region of the greater trochanter, made with a through axial channel, each of the rods is provided with threaded sections, designed to ensure the adhesion of the screw with the bone and recesses for a screwdriver, designed to transfer torque, rod, Dedicated for fixing in a part of the neck with a head, contains a threaded section made at the end intended for fastening in the area of the neck with a head, and a recess for a screwdriver made at the end intended for installation in the through axial channel of the rod intended for fixation in the area of the skewer, the rod intended for fixing in the area of the big skewer, contains a threaded section and a recess for the screwdriver, made at its end intended for fastening in the area of the large skewer, different that the opposite end of the rod intended for fixation in the region of the greater skewer is rolled so that the rod intended for fixation in the part of the neck with the head can move without falling out along the rod intended for fixation in the area of the large skewer from one extreme position to another extreme position at a distance in the range from 10 to 20 mm, intended for fastening in the neck area with the head end of the rod, intended for fixing in the part of the neck with the head, self-drilling It contains cutting edges and self-tapping screw-cutting thread. 2. The screw according to claim 1, characterized in that the rod intended for fixing in the part of the neck with the head is made from 35 to 75 mm long, in the form of a metal rod with a body diameter of 4.75 mm, at the end intended for fastening in the area of the neck with a head, contains a self-tapping screw cut with a pitch of 1 mm, at the end intended for installation in the through axial channel of the rod intended for fixation in the area of the greater skewer, contains a hexagonal recess of 3.5 mm 3. The screw according to claim 1, characterized in that the rod intended for fixation in the region of the greater skewer is made in the form of a cannulated metal rod with an outer diameter of 6.6 mm body, at the end intended for fastening in the region of the large skewer containing a screw thread with a pitch of 0.5 mm and a hex socket 5 mm in size, and a shoulder formed by rolling. 4. The screw according to claim 1, characterized in that the screw threading of the threaded sections is made in steps from 0.5 to 2.5 mm, depth from 0.5 to 1.25 mm, the screw material is titanium alloy.

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