RU216558U1 - DEVICE FOR OSTEOSYNTHESIS OF UNSTABLE FRACTURES OF THE PROXIMAL TIBIRAL METAPHIPHYSIS - Google Patents

Abstract

The utility model relates to medicine, namely to traumatology and orthopedics, and can be used for surgical treatment of unstable fractures of the proximal tibial metaepiphysis. The device for osteosynthesis of fractures of the proximal part of the tibia is made in the form of a T-shaped plate containing the epiphyseal part formed by the transverse plank of the plate, and the metaepiphyseal and diaphyseal parts formed by the longitudinal plank of the plate, while the plate is provided with holes for screws, and the transverse plank of the epiphyseal part plate contains an elongated branch on one side, made with a bend corresponding to the contour of the inner surface of the internal condyle of the tibia. According to the proposed solution, the longitudinal plank of the plate is made with a bend corresponding to the posterior surface of the medial tibia. The epiphyseal part of the plate is provided with two groups of holes for the insertion of screws, while the holes of the first group are located in the transverse bar of the plate and are made with the possibility of fixing the posterior part of the internal condyle when the screws are located in them, and the holes of the second group are located in the elongated branch of the transverse bar of the plate to ensure conduction through them screws in the direction from the inner condyle to the outer. At the same time, the elongated branch of the transverse plank of the epiphyseal part of the plate is made in a configuration that ensures the location of the screws when they are passed through the holes of the second group, above the screws passed through the holes of the first group, in the subchondral layer of the tibial epiphysis. The elongated branch of the plate and the transverse bar of the epiphyseal part of the plate contain additional holes made with the possibility of placing Kirschner wires in them for temporary intraoperative fixation in a predetermined position. The device provides stable fixation of the posterior part of the internal condyle of the tibia and the fracture of the external condyle of the tibia. 4 w.p. f-ly, 37 ill.

Description

Field of technology to which the utility model belongs

The utility model relates to medicine, namely to traumatology and orthopedics, and can be used for surgical treatment of unstable fractures of the proximal tibial metaepiphysis.

State of the art

The prior art device for fixing the internal condyle of the tibia LCP Medial Proximal Tibial Plate 3.5 (DePuy Synthes, Oberdorf, Switzerland), made in the form of a stainless steel or titanium plate with holes of different diameters, consisting of a posterior epiphyseal part for fixing fragments and the diaphyseal part for insertion of locking screws and intended for placement along the inner surface of the tibia.

However, this device is designed to be positioned on the inner surface of the tibia and does not provide adequate support for the posterior internal condyle.

Known plate LCP Posterior Medial Proximal Tibial Plate 3.5 (DePuy Synthes, Oberdorf, Switzerland), designed to fix the posterior internal condyle of the tibia.

This plate provides stable fixation of the fracture, however, it does not allow eliminating the displacement in width and fixing the external condyle, thus does not prevent the development of varus deformity in the postoperative period.

Also known is a fixator for osteosynthesis of fractures of the proximal outer part of the tibia [RF patent No. 161285], made in the form of a plate with convergent holes of different diameters and containing metaepiphyseal and diaphyseal parts for fixing fragments. The metaepiphyseal part of the fixator has a bend and contains an additional epiphyseal branch, and the diaphyseal part contains an additional diaphyseal branch, while both additional branches are removable, with the possibility of rotation around its axis, depending on the type of fracture.

The known solution does not provide stable fixation of the posterior part of the internal condyle of the tibia and fracture of the external condyle of the tibia.

Closest to the claimed is a device for osteosynthesis of the tibial condyles [RF patent №2332185]. The known solution contains a T-shaped plate with holes for cortical and compression screws on the longitudinal and transverse bars, and one of the holes is made elongated for the compression screw, the holes on the transverse bar have a larger diameter for the compression screws. The transverse bar of the T-shaped plate is elongated on one of the sides and arcuately curved, while the radius of curvature of the arcuate bend corresponds to the contours of the posterior part of the tibial condyle, and repairing fixing spikes are made along the inner surface of the elongated part of the transverse bar.

However, this plate also does not provide a support function for the posterior part of the internal condyle of the tibia in combination with stable fixation in the frontal plane.

The technical problem to be solved by the proposed utility model is the creation of a device for simultaneous stable fixation of the posterior part of the internal condyle of the tibia and a fracture of the external condyle of the tibia.

Utility Model Disclosure

The technical result achieved when using the claimed utility model is to ensure stable fixation of the posterior part of the internal condyle of the tibia and fracture of the external condyle of the tibia.

The technical result is achieved by using a device for osteosynthesis of fractures of the proximal part of the tibia, made in the form of a T-shaped plate containing the epiphyseal part formed by the transverse plank of the plate, and the metaepiphyseal and diaphyseal parts formed by the longitudinal plank of the plate, while the plate is provided with holes for screws , and the transverse plank of the epiphyseal part of the plate contains an elongated branch on one side, made with a bend corresponding to the contour of the inner surface of the internal condyle of the tibia. According to the proposed solution, the longitudinal plank of the plate is made with a bend corresponding to the posterior surface of the medial tibia. The epiphyseal part of the plate is provided with two groups of holes for the insertion of screws, while the holes of the first group are located in the transverse bar of the plate and are made with the possibility of fixing the posterior part of the internal condyle when the screws are located in them, and the holes of the second group are located in the elongated branch of the transverse bar of the plate to ensure conduction through them screws in the direction from the inner condyle to the outer. At the same time, the elongated branch of the transverse plank of the epiphyseal part of the plate is configured to ensure the location of the screws when they are passed through the holes of the second group, above the screws passed through the holes of the first group, in the subchondral layer of the tibial epiphysis.

The holes of the first group can be arranged symmetrically with respect to the axis of the plate longitudinal bar and made to ensure parallel arrangement of the screws when they are inserted through these holes. The holes of the second group can also be made so that the screws are parallel when they are inserted through the holes of the second group.

The distal opening of the elongated branch of the plate is made to allow the screw to pass into the articular surface of the posterior lateral condyle of the tibia.

The device preferably contains three holes of the first group and three holes of the second group.

The elongated branch of the plate and the transverse bar of the epiphyseal part of the plate contain two additional holes each, made with the possibility of placing Kirschner wires in them for temporary intraoperative fixation in a preset position.

The proximal opening of the metaepiphyseal part of the plate is made to ensure the passage of the screw at a right angle to the surface of the plate.

The proposed device ensures the achievement of stable fixation in the anterior-posterior and lateral planes, the support function of the posterior part of the internal condyle of the tibia, fixation in the frontal plane in order to reliably prevent varus displacement, reposition and stable fixation of a fracture of the external and internal condyles of the tibia from one access and one plate.

Brief description of the drawings

The utility model is illustrated by drawings, where figure 1 shows a General view of the plate (left); figure 2 is a side view of the plate; figure 3 is a front view of the plate; figure 4 is a section of the plate along the line C-C in figure 3; figure 5, 6 - view of the plate from behind; figure 7 - plate, section along the line B-B in figure 2; figure 8 is a top view of the plate; Fig.9-12 - view of the plate with installed screws (side view, section along the line C-C, rear view, top view, respectively); 13-37 - data of radiographic and CT examination of patients in accordance with clinical examples 1, 2.

The positions in the figures are:

1 - plate;

2 - epiphyseal part of the plate;

3 - metaepiphyseal part of the plate;

4 - diaphyseal part of the plate;

5 - transverse plank of the epiphyseal part of the plate;

6 - an elongated branch of the epiphyseal part of the plate ("shoulder" of the plate);

7 - longitudinal bar of the plate;

8 - hole in the diaphyseal part for the introduction of a bicortical locking screw;

9 - lower hole in the diaphyseal part (positional);

10 - hole in the metaepiphyseal part for insertion of the blocking screw;

11 - hole in the transverse plank of the epiphyseal part of the plate for the introduction of a locking screw that fixes the posterior part of the internal condyle (hole of the first group);

12 - hole in the elongated branch of the transverse bar of the epiphyseal part of the plate for the introduction of a locking screw (hole of the second group);

13 - hole in the epiphyseal part of the plate for the introduction of the Kirchner wire;

14 - distal opening of the elongated branch 6 (one of the openings of the second group) for the introduction of a screw fixing the articular surface of the posterior lateral condyle of the tibia;

15 - recess on the surface of the plate.

Implementation of the utility model

The inventive device is made in the form of a T-shaped metal plate 1, preferably made of titanium alloy, having several anatomical curves that follow the contours of the tibia. The plate 1 consists of epiphyseal 2 parts designed for mounting on the posterior part of the internal condyle of the tibia and the inner surface of the internal condyle of the tibia, as well as metaepiphyseal 3 and diaphyseal 4 parts designed for mounting on the posterior surface of the medial tibia (figure 1) . All parts of the plate correspond to the anatomy of the bone structures of the implantation zone and fit tightly to the surface of the corresponding anatomical structures.

The epiphyseal part 2 of the plate is formed by a transverse bar 5 (with respect to the long axis of the tibia) with an elongated branch 6 having a bend corresponding to the contour of the inner surface of the internal condyle of the tibia. In this case, the elongated branch 6 can be located symmetrically both on the left and on the right side relative to the transverse bar 5 (depending on the limb). Metaepiphyseal 3 and diaphyseal 4 parts of the plate formed by a longitudinal strap 7, designed for attachment to the rear surface of the medial tibia (figure 1-3).

Plate 1 is provided with holes 8, 10, 11, 12 to accommodate blocking screws. At the same time, holes 8 are made in the diaphyseal part 4 of the plate for insertion of cortical locking screws with a diameter, preferably 3.5 mm, which can be inserted at different angles to the surface of the plate. In one embodiment, the distal part of the plate is provided with four eight-shaped combined holes 8, which allow the insertion of screws with a deviation of up to 75 degrees relative to the surface of the plate. The distal edge of the plate (opposite the epiphyseal) has a three-sided conical narrowing for ease of implantation of the plate and may contain an oval-shaped hole 9 (lower positional) to control the correct location of the plate along the axis of the tibia. The metaepiphyseal part 3 of the plate is provided with holes 10 for inserting blocking screws with a diameter, preferably 3.5 mm, while the proximal hole of the metaepiphyseal part (closest to the epiphyseal part) is configured to position the screw at an angle α to the surface of the plate, which is 90°. In a specific example of the implementation of the plate, the metaepiphyseal part 3 of the plate is equipped with two holes 10, one of which (proximal) provides the location of the screw at an angle α=90° to the surface of the plate, and the second (distal) - at an angle β=67° (Fig.9, 10). Holes 8, 10, 11, 12 of the plate can be provided with a conical thread to secure the screw heads.

The epiphyseal part 2 of the plate is provided with two groups of holes: the first group is formed by holes 11 located in the transverse bar 5 of the plate, and the second group is formed by holes 12 located in the elongated branch 6 of the plate. In this case, the transverse bar 5 and its elongated branch 6 have geometric dimensions that make it possible to form on them at least three holes with a diameter, preferably 3.5 mm. Holes 11 of the first group are made with the possibility of passing locking screws through them from back to front (preferably parallel to each other) to fix the posterior part of the internal condyle of the tibia, with the axes of the screws at an angle ((for example, 60°) to the surface of the plate (Fig.10 The holes 12 of the second group are made with the possibility of passing (preferably parallel to each other) locking screws through the inner and outer condyles of the tibia, with the axes of the screws at an angle δ (for example, 76°) with respect to the axes of the screws passed through the holes of the first group (Fig. 12).In this case, the elongated branch 6 of the plate due to its bending (location of the plane of the branch above and with rotation relative to the longitudinal axis of the transverse bar) provides such a configuration of the plate in which the screws inserted through the holes 12 pass in a dense subchondral layer tibial epiphysis above the screws inserted through holes 11 (the direction of the screws, etc. passing through the holes 12 of the plate is organized in such a way that there is no conflict with the screws inserted from back to front through the holes 11), which makes it possible to stably fix the internal condyle to the external condyle in the frontal plane while simultaneously fixing the posterior sections of the internal condyle of the tibia (Fig.9 , eleven). The rear screw, passed through the distal hole 14 of the elongated branch 6 of the plate, provides reliable support for the articular surface of the posterior lateral condyle of the tibia in case of fractures of the posterior lateral condyle or intercondylar zone with the impression of the articular surface.

In the preferred embodiment of the plate, the holes of each group are arranged in a row with the centers of the holes on the corresponding longitudinal axis of the epiphyseal part of the plate, with a distance between adjacent holes of 5-20 mm. In this case, the holes 11 of the first group can be located symmetrically with respect to the axis of the longitudinal bar of the plate and made to ensure a predominantly parallel arrangement of the screws when they are passed through these holes (parallel to the articular surface of the condyle). A similar configuration of the holes 12 of the second group provides a predominantly parallel arrangement of the screws when they are passed through the holes 12.

The transverse bar 5 and the elongated branch 6 of the epiphyseal part of the plate may contain additional holes 13 for the introduction of Kirschner wires for temporary intraoperative fixation in a preset position, located in the upper part of the epiphyseal part of the plate. In one of the embodiments of the plate in the transverse bar 5 and branches 6, two such holes are made, located between the holes 11 and 12, respectively.

The total height H1 of the plate can be from 100 to 180 mm, the height H2 of the longitudinal bar is from 85 to 165 mm (figure 2), the width L1 of the epiphyseal part of the plate in the longitudinal plane can be from 35 to 45 mm, the width L2 in the transverse plane is from 30 to 40 mm, the width L3 of the elongated leg of the plate in the longitudinal plane can be from 15 to 25 mm (Fig.8). The width B1 of the longitudinal strip of the plate can be from 8 to 20 mm, the thickness B2, B3 - from 3 to 6 mm (Fig.7, 8).

The plate from the side of its contact with the tibia contains notches 15 (figure 5, 6) to reduce the surface area of such contact, which reduces trauma to the bone surface. Preferably, the plate is made with a uniform arrangement of such recesses on the edges of the longitudinal strip 7 of the plate, with the exception of the interface with the epiphyseal part of the plate, symmetrically with respect to the longitudinal axis of the strip 7.

During the operation, the plate is placed along the posterior surface of the medial tibia through the posterior medial access to the knee joint with the patient in the prone position, the elongated branch 6 of the plate is placed along the inner surface of the internal condyle of the tibia. Positioning and preliminary fixation of the plate is carried out using Kirschner wires in the proximal part of the plate. The support function of the plate is provided by introducing a cortical screw into the proximal opening of the diaphyseal 4th part of the plate, pressing the bone fragment and the plate itself against the tibial shaft. Next, a screw is inserted into the epiphyseal 2 part of the plate (transverse bar 5) in the direction from the back to the front, and then the screw is inserted through the elongated branch 6 (shoulder) of the plate from the internal condyle to the external condyle of the tibia. The screws are inserted into the metaphyseal part last.

In the process of fracture reposition, first of all, the displacement in the frontal plane is eliminated, the subluxation of the external or internal condyle is eliminated, and the posterior fragment of the internal condyle of the tibia is repositioned. In this case, the reposition of the internal condyle of the tibia is carried out using standard repositioning techniques (bone pins, bone holders, bone stops, joysticks, Hohmann's elevators, collinear bone holders, Matta pelvic instruments, etc.) and preliminary fixation with knitting needles. An obligatory stage of reposition is the installation of a repositioning tightening device with stops in the frontal plane between the internal and external condyles of the tibia, one branch of which is installed along the internal surface of the internal condyle of the tibia (often leaning on the elongated branch of the plate), the second branch is installed through a separate incision (approximately 1 cm) along the outer surface of the lateral condyle of the tibia.

Example of utility model implementation

According to the proposed solution, a plate for fixation of the condyles of the left tibia was made from a titanium alloy with the following dimensions: height H1=124 mm, height H2=103.1 mm, width L1=39.7 mm, width L2=35.7 mm, width L3=17.7. The width B1 of the longitudinal bar of the plate was 11.1 mm, and its thickness B2 was 3.7 mm. The thickness B3 of the epiphyseal part of the plate was 3.9 mm (Fig.7, 8). The number of holes in the diaphyseal part of the plate is five, four of which are eight-shaped, for 3.5 mm screws, one (distal) is oval-shaped (minor axis length r=2 mm). The distance between the edges of the holes in the diaphyseal part is about 5 mm. The number of holes in the metaepiphyseal part is two, for screws 3.5 mm, the distance between the edges of the holes is 15 mm. The diaphyseal part is curved, the radius of curvature R1=4.7 mm (Figure 2). The metaepiphyseal part is bent relative to the diaphyseal part, the radius of curvature R2=33.3 mm, the angle of inclination of the axis of the opening of the diaphyseal part (=101.3° (Figure 4). The number of holes of the first group in the transverse plank of the epiphyseal part of the plate is three, the number of holes there are three groups in the elongated branch of the epiphyseal part of the plate, the holes are made with conical threads for blocking screws with a diameter of 3.5 mm, the number of holes for passing Kirschner wires is four, the radius of curvature of the elongated branch of the plate is R3=0.5 mm (Fig.7).

These specific parameter values demonstrate the possibility of implementing the utility model, while not limiting the possibility of its implementation with other sizes.

Clinical example 1.

Patient A., 30 years old. The injury was received in everyday life as a result of a fall from a scooter on the right leg. Upon admission performed radiography of the knee joint in two projections (Fig.13, 14), computed tomography of the knee joint (Fig.15, 16). The diagnosis was a closed comminuted fracture of the internal condyle of the right tibia with the transition to the intercondylar eminence with displacement of bone fragments (type IV according to the Schatzker classification). Performed the operation of osteosynthesis of the internal condyle with the inventive support-condylar plate from the posterior-internal access (Fig.17, 18). The plate was placed on the posterior surface of the medial tibia and the posterior surface of the internal condyle (Fig.20), providing the support function of the implant and eliminating the displacement of the internal condyle posteriorly. The elongated branch of the plate was placed along the inner surface of the internal condyle of the tibia (Fig.22), thereby providing a more stable fixation of the fracture and the possibility of installing three screws 80 mm long through the holes of the elongated branch of the plate in the direction from the internal condyle to the external condyle (Fig.19) in the posterior part of the plateau (subchondral layer) of the tibia for stable fixation of fragments of the intercondylar eminence and prevention of varus displacement in the postoperative period. Screws inserted through the transverse plate plate were placed in the posterior plateau to fix the fracture of the posterior intercondylar eminence (FIG. 21). The use of three screws for insertion into the transverse bar and three screws for insertion into the extended leg of the plate was optimal for achieving stable fixation and did not complicate the insertion of the plate. The development of movements in the knee joint in the passive mode was started on the 3rd day after the operation. The patient was examined 4 months after the operation. On the control radiographs (figure 23, 24) the axis of the tibia is correct, the position of the implants and bone fragments is correct, the fracture is fully consolidated. The clinical result is satisfactory. Flexion at the knee joint 130 degrees, extension 180 degrees. The patient walks without additional support. The pain syndrome does not bother.

Clinical example 2.

Patient S., 47 years old, suffered an injury to the left knee joint in February 2022. First aid was provided at the site of injury in Makhachkala, the operation of osteosynthesis of the proximal left tibia with two plates of external and internal accesses was performed (Fig.25, 26). In June 2022 (4 months after the operation), against the background of the permitted load on the leg, pain in the knee joint and impaired weight-bearing of the left lower limb began to bother. According to computed tomography of the knee joint, there is a fused fracture of the condyles of the tibia (Fig.27), however, the posterior part of the internal condyle of the tibia is represented by a separate bone fragment, not fixed by the installed implants, there is an intra-articular displacement in the lateral projection (Fig.28, 29, 30) . The plate, installed from the internal access, fixes the anterior part of the internal condyle of the tibia, does not provide a support function and does not fix the posterior part of the internal condyle of the tibia, which caused the remaining displacement of fragments and constant pain. An operation was performed to remove all implants from the external and internal accesses, after which, from the posterior access, a fragment of the internal tibial condyle was repositioned and fixed with the inventive plate due to the supporting function of the implant (Fig.35) and both tibial condyles were fixed with screws installed through the elongated branch of the plate (Fig.31, 32). It should be noted that the removal of both previous implants was only possible due to the shape of the inventive plate and the possibility of fixing the condyles of the tibia in two planes (Fig.37). The patient was examined 3 months after the operation, she walks with a full load on the leg, the pain syndrome is not pronounced, flexion in the knee joint is 110 degrees, extension is 180 degrees. According to the control computed tomography fracture consolidated in the correct position (Fig.36).

Thus, the use of the proposed plate makes it possible to provide a musculoskeletal function due to its location along the posterior surface of the tibia and the anatomical shape of the implant, simultaneously with reliable lateral support due to screws inserted through the elongated branch of the plate through the inner and outer condyles of the tibia.

Claims (9)

1. A device for osteosynthesis of fractures of the proximal part of the tibia, made in the form of a T-shaped plate containing the epiphyseal part formed by the transverse bar of the plate, and the metaepiphyseal and diaphyseal parts formed by the longitudinal bar of the plate, while the plate is provided with holes for screws, and the transverse the plank of the epiphyseal part of the plate contains an elongated branch on one side, made with a bend corresponding to the contour of the inner surface of the internal condyle of the tibia, characterized in that the longitudinal plank of the plate is made with a bend corresponding to the posterior surface of the medial tibia; the epiphyseal part of the plate is provided with two groups of holes for the insertion of screws, while the holes of the first group are located in the transverse bar of the plate and are made with the possibility of fixing the posterior part of the internal condyle when the screws are located in them, and the holes of the second group are located in the elongated branch of the transverse bar of the plate to ensure conduction through them screws in the direction from the inner condyle to the outer; at the same time, the elongated branch of the transverse plank of the epiphyseal part of the plate is configured to provide the location of the screws, when they are passed through the holes of the second group, above the screws, passed through the holes of the first group, in the subchondral layer of the epiphysis of the tibia; moreover, the elongated branch of the plate and the transverse plank of the epiphyseal part of the plate contain additional holes made with the possibility of placing Kirschner wires in them for temporary intraoperative fixation in a preset position. 2. The device according to claim 1, characterized in that the holes of the first group are located symmetrically with respect to the axis of the longitudinal bar of the plate and are made to ensure that the screws are parallel when they are inserted through these holes. 3. The device according to claim 1, characterized in that the holes of the second group are made to ensure the parallel arrangement of the screws when they are inserted through these holes. 4. The device according to claim 1, characterized in that the distal opening of the elongated branch of the plate is made to allow the screw to pass into the articular surface of the posterior lateral condyle of the tibia. 5. The device according to claim 1, characterized in that it contains three holes of the first group and three holes of the second group.

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