RU2352283C2 - Solomin-utekhin-vilensky apparatus for perosseous osteosynthesis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention concerns medicine, namely, traumatology and orthopedy. The apparatus contains two rings and six telescopic bars, the latter connect the mentioned rings. Each telescopic bar consists of a cardan joint, a carving hinge, a nut, a bush and an axis. One carving hinge end is connected to the cardan joint, other carving hinge end passes through the bush and is conneded to it by the nut rotating on it. Each leg has three telescopic bars the mounted by the ends which have the cardan joint. By means of a bond of the bush with the cardan joint the next telescopic bar the telescopic bars going from opposite rings are connected in pairs. The bush is connected to the cardan joint the next telescopic bar by means of the axis to forming of the two-axial hinge.

EFFECT: invention provides simplification of installation of the apparatus, rising of the efficiency of reposition and augmentation of rigidity of osteosynthesis.

1 ex, 7 dwg

Description

The invention relates to medicine, namely to traumatology and orthopedics, and can be used to treat fractures, multiplanar deformities, false joints of bones.

The well-known Ilizarov apparatus (O. Kaplunov "Transosseous osteosynthesis according to Ilizarov in traumatology and orthopedics", "GEOTAR-MED", M., - 2002, S.13-31), which consists of several stainless steel rings, to which transosseous elements (knitting needles, screw rods) are attached with special clamps. The rings of the Ilizarov apparatus are interconnected by connecting rods or hinges.

The disadvantages of this device

1. The need for partial remounting of the apparatus when eliminating multi-plane deformations.

2. When eliminating each component of the deformation, x-ray control is necessary, which increases the radiation dose to the patient and medical personnel.

3. When using replacement knitting needles, the layout of the apparatus should include two base and two reposition-fixation supports. This increases the bulkiness of the structure.

Closest to the proposed is the apparatus of C. Taylor-Taylor Spatial Frame (C. Radler, Limb lengthening and deformity correction using the Taylor Spatial Frame: A retrospective review of 48 cases / C. Radler, R. Ganer, M. Manner, HG Petje , F. Grill // Journal of Bone and Joint Surgery, Jan. 2003), which is an external fixation apparatus based on two rings interconnected by six telescopic rods (striations). The apparatus is based on a hexapod system equipped with computer navigation, which provides accurate mathematical calculation for reposition of fragments.

The disadvantages of this device

1. The supports of the apparatus should be located perpendicular to the anatomical axis of the bone fragments. Otherwise, the probability of error in the calculations of reposition is quite high.

2. Strata (telescopic rods of the original design) connecting the supports of the apparatus have six fixation points on each support, which limits the number of possible fixation points of transosseous elements.

3. Strata according to the technique should be located strictly in certain places on the rings ("tabs"). This complicates the installation of the apparatus, can lead to a decrease in the rigidity of fixation of bone fragments due to the inability to conduct a transosseous element in the projection of the “taba”.

4. "Tabs" are located at the same distance on the ring, forming the figure of an equilateral triangle. This leads to the fact that the possibility of using supports constituting geometrically less than 2/3 of the ring, for example half rings, is excluded.

5. When eliminating gross deformation, there is a high probability of replacing a stratum of one size with another, which can lead to secondary displacement of fragments in the apparatus.

6. The length of the stratum of the minimum size (91 mm) for cases of eliminating gross angular deformation of the bones may be too large, i.e. It will not be possible to assemble the device. The length of the stratum of the maximum size included in the apparatus (311 mm) may not be sufficient for the final correction of deformation.

7. The presence of significant play in all planes due to the articulated joints of the striations and the external supports of the apparatus significantly reduces the rigidity of osteosynthesis, causing a painful reaction in patients.

These disadvantages are deprived of the proposed device.

The technical result of the invention is to simplify the installation of the apparatus, increase the efficiency of reposition and increase the rigidity of osteosynthesis.

Simplification of the apparatus installation is ensured by the fact that there is no need to install the apparatus supports strictly perpendicular to the anatomical axes of the bone fragments. Non-perpendicular installation of supports does not affect the quality of the reposition. There are only three points of fixation of the telescopic rods to each support. The fixation points of the telescopic rods to each support can be arbitrarily selected; there is no need to choose them so that they "form" an equilateral triangle. All this not only simplifies the installation of the apparatus, but also increases the number of options for the introduction and fixation to the supports of transosseous elements. In the proposed apparatus, half rings can be used as supports. The design features of the telescopic rods do not need to be changed during the reposition period (deformation correction).

Improving the efficiency of reposition is ensured by the fact that:

- design features of telescopic rods exclude the need for their replacement in the correction of deformation of any type;

- non-perpendicular arrangement of the supports of the apparatus to the anatomical axis of the segment does not affect the accuracy of the reposition.

An increase in the rigidity of osteosynthesis is ensured by the fact that:

- there is the possibility of arbitrary location of the fixation points of telescopic rods to external supports, which allows for transosseous elements, so that this provides the maximum possible rigidity of fixation of bone fragments;

- halving in comparison with the prototype cardan joints allows to reduce the backlash.

The proposed apparatus (Fig. 1) consists of two external supports (1, 2), which can be either closed (ring support) or open (2/3 rings, half ring), which are interconnected by a system of six telescopic rods ( 3). At the same time, the fastening of this system is carried out at three points to each support, which do not have a strictly defined position and can be moved if necessary.

Each telescopic rod (figure 2) of the apparatus consists of a cardan (4), a threaded rod (5), a nut (6), a sleeve (7), an axis (8) and a clip (9). In this case, one end of the threaded rod is fixedly connected to the cardan, the other end of the threaded rod passes through the sleeve and is connected to it by means of a nut that rotates freely on it. The sleeve is connected via an axis to the cardan of an adjacent telescopic rod. The connection of the threaded rod with the sleeve using a nut that rotates freely on it and the connection of the sleeve with the cardan of the adjacent telescopic rod with the help of the axis form a biaxial joint.

A cardan, a two-axis hinge, a connection of a threaded rod to a bushing with a nut allow you to connect a telescopic rod with the same rod fixed in an arbitrary chosen location on the opposite ring. The connection of adjacent telescopic rods using a two-axis hinge makes it possible to simultaneously correct all components of multi-plane deformation.

The clip is mounted on the groove of the sleeve so that the thread on the clip is aligned with the thread on the threaded rod. Due to this connection, the clip remains stationary relative to the threaded rod. Therefore, when changing the length of the telescopic rod, the clip moves along with the threaded rod along the sleeve. Using the mark on the clip and the scale applied on the sleeve, the magnitude of the change in the length of the telescopic rod is determined.

The figures depict:

Figure 1. Diagram of the apparatus for transosseous osteosynthesis of Solomin-Utekhin-Vilensky, where

1 - the upper support of the external fixation apparatus;

2 - lower support of the external fixation apparatus;

3 - telescopic rods;

Figure 2. Scheme of a telescopic rod, where:

4 - cardan;

5 - threaded rod;

6 - nut connected to the sleeve and freely rotating on it;

7 - a sleeve connected via an axis to an adjacent telescopic rod;

8 - axis connecting the sleeve with a cardan joint of an adjacent telescopic rod;

9 - clip;

Figure 3. Photos and X-ray diffraction patterns of patient C. before surgery;

Figure 4. Photos and X-ray diffraction patterns of patient C. after surgery;

Figure 5. Photographs and X-ray diffraction patterns of patient Sh. After elimination of deformation,

6. Photographs and X-ray diffraction patterns of patient Sh. Before removal of the AFF;

7. Photograph of a patient after removing the AFF.

The device is used as follows. In preoperative planning using x-ray images made in two standard projections, the angular deformation, the displacement of fragments along the length and width, and the torsion displacement are determined. Based on these values, such a length of the threaded rod (Fig. 2.5) is determined that will allow the final reposition of fragments without replacing the telescopic rod.

The operation begins with transosseous elements (knitting needles, screw rods) through the proximal and distal bone fragments. Transosseous fragments are fixed in external supports. After that, three telescopic rods are attached to each support. Telescopic rods are attached to the support with ends that have cardans.

If necessary, for example, to increase the rigidity of fixation of bone fragments during osteoporosis, two supports can be mounted on each bone fragment. In this case, telescopic rods are installed between the "internal" supports of the apparatus.

Then, by connecting the sleeve with the cardan joint of the adjacent telescopic rod, the telescopic rods coming from opposite rings are connected in pairs.

Reposition, elimination of deformation are achieved by changing the lengths of telescopic rods. When the nut rotates, the threaded rod moves along the sleeve, and the length of the telescopic rod changes. The change in the length of the telescopic rods during the reposition is controlled using the mark on the clip and the scale printed on the sleeve. The magnitude of the change in the lengths of telescopic rods is calculated using a computer program.

Clinical example.

Patient Sh., 52 years old, was admitted to 2 departments. RNIITO 05/18/2006 with a diagnosis of False joint of the middle third of the left tibia. X-ray observed antecurvation deformation with an angle of 24 degrees. and varus deformation with an angle of 27 degrees. (Figure 3). May 24, 2006 the operation was performed: Osteotomy of the left fibula in n / 3, application of the Solomin-Utekhin-Vilensky apparatus (Figure 4). Since May 29, 2006, the elimination of deformation has begun. The deformation is eliminated in 12 days (Figure 5). After the deformation is eliminated, a system of 6 telescopic rods is replaced by rods from the Ilizarov apparatus set. The fracture is fused (Fig.6). The fixation period was 130 days; the device is dismantled (Fig.7).

Claims (1)

An apparatus for transosseous osteosynthesis, containing two rings and six telescopic rods, the latter connect the aforementioned rings, characterized in that each telescopic rod consists of a cardan, a threaded rod, a nut, a sleeve and an axis, while one end of the threaded rod is connected to the cardan, the other end of the threaded rod passes through the sleeve and is connected to it by means of a nut rotating on it; three telescopic rods are attached to each support with ends that have a cardan, by connecting the sleeve cardan adjacent telescopic boom telescopic rods are connected in pairs extending from opposite rings, wherein the sleeve is connected to the universal joint adjacent the telescopic arm by means of an axis to form a two-axis hinge.

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