RU2584654C1 - Device for osteotomy - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: invention relates to medical equipment, specifically to devices applicable in traumatology and orthopaedics. Device for osteotomy is a flat medical bit with shaped cutting edge. 3/4 of cutting edge is S-shaped to form greater spike and remaining 1/4 is linearly tapered at an angle of 45 degrees to side edge to form a smaller spike.

EFFECT: higher quality of osteotomy, and therefore and efficiency of surgical treatment of orthopaedic patients.

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Description

The invention relates to medical equipment, namely to devices used in traumatology and orthopedics.

Osteotomy is a widely used orthopedic operation. Its purpose may be the correction of axial, rotational or shortening deformities of limb segments, resection of false joints, tumors or foci of destruction, elimination of ankylosis of joints in a vicious position, trepanation, reshaping and modeling of tubular or flat bones, etc. Perform osteotomy with saws or medical chisels - shock devices with a sharp cutting edge. Medical chisel - a tool having a blade with one or two-sided sharpening, perpendicular to the axis of the tool, designed for dissection of bone tissue with a hammer. Chisels are certainly included in the surgical tool kits used in traumatology and orthopedics. To use them, you need a special surgical hammer with metal pads. The surgical hammer is made of stainless steel and consists of a hammer and handle. One side of the striker is smooth, and on the other side a hard rubber cap is worn. The cutting edge of the bit under shock should be sufficiently viscous so that there are no cracks and chips.

An osteotomy is performed, as a rule, in compliance with biomechanical principles, i.e. with preliminary planning and refinement in anatomical and functional respects. An important point in bone operations is the chisel technique. When it is required to apply strong blows to the bone, it is necessary to hold the chisel tightly with the whole palm, which is called metacarpal chisel holding. If you need a fine design of the bone, performing a figured osteotomy, obtaining bone chips, etc., the bit should be held with your fingers - digital holding of the bit. To improve the technique of osteotomy and to eliminate the likelihood of the chisel blade slipping off from the rounded and smooth surface of the bone, holes can be made along the supposed line of the osteotomy with drills of various diameters.

Analogs

According to the shape of the working part, medical chisels are divided into flat, grooved, spoon-shaped and neurosurgical (shorter and with a rounded blade shape). For osteotomy of tubular and flat bones, medical bits of various sizes are usually used, including a device for linear osteotomy proposed earlier by one of the authors.

Criticism of analogues.

Common disadvantages of analogues are the following: the multiple prevalence of the chopping moment of the osteotomy over the cutting, which can cause crushing or cracking of the bone; often the forced position of the bit at an angle to the bone, which is inconvenient for the surgeon and is fraught with slipping the blade of the bit from the inclined plane of the bone; the danger of an uncontrolled “failure” of the bit of the bit with a high risk of damage to underlying tissues, which is also characteristic of a medical bit with a slanting edge, previously proposed by one of the authors of the proposed device.

Prototype.

As a prototype, a conventional flat surgical chisel (osteotome) was chosen, the cutting edge of which is perpendicular to the tool length (Boychev B., Conforti B., Chokanov K. Operative orthopedics and traumatology. - 2nd ed., Revised and additional - DI "Medicine and physical education", - Sofia, 1958, - 832. - S. 76-92). Typically, the bit is mounted on the bone with the entire plane of its working surface and an osteotomy is performed by hammer blows to the end of the instrument. Hammer strokes are transmitted through the working part of the bit to the entire bone surface area in contact with it.

Criticism of the prototype.

Along with the possibility of osteotomy, the prototype device has significant drawbacks, which include, in particular, the fact that in the initial period of osteotomy, its chopping moment often prevails over the cutting one, which is fraught with cracking, fragmentation or crushing of the bone. The likelihood of this complication is especially real with a decrease in the mechanical strength of the bone, for example, with osteoporosis, osteomalacia of various etiologies, the presence of foci of destruction, with tumors, osteomyelitis, etc. To reduce the chopping and enhance the cutting moment of an osteotomy, it is often necessary to install a chisel blade at an angle to the bone surface. This technique, in turn, is associated with the danger of the bit slipping off the bone, inconvenience for the operating surgeon, the need for wider surgical access and larger than the traditional position of the bit, size of the wound, a decrease in the coefficient of performance (COP) and the inefficiency of osteotomy. Therefore, the prototype device has the following disadvantages:

- the perpendicular position of the working surface of the bit to its length causes a multiple prevalence of the chopping moment of the osteotomy over the cutting, which can cause crushing or cracking of the bone, especially with a decrease in the mechanical strength of the latter;

- low efficiency of osteotomy;

- Often the forced location of the bit is not perpendicular, but at an angle to the bone, which is irrational, inconvenient for the operating surgeon, is accompanied by frequent sliding off the inclined plane of the bone and is associated with the need to increase the surgical wound;

- a high probability of an uncontrolled "failure" of the bit of the bit beyond the limits of the target with a high risk of damage to the underlying tissue.

The purpose of the invention is improving the quality of osteotomy.

SUMMARY OF THE INVENTION

To improve the quality of the osteotomy and prevent the disadvantages inherent in the prototype, a device is proposed (Fig. 1), which is a flat bit that differs from the prototype device in the shape of the blade (Fig. 2) (1), namely the shape of its cutting edge (2), ¾ which is S-shaped curved and beveled at an angle of 85-50 degrees relative to the longitudinal axis of the tool with the formation of a larger tenon (3), and the remaining ¼ is linearly beveled in the opposite direction at an angle of 45 degrees to the longitudinal axis of the bit and at right angles to S -shaped edge - with formed smaller spike (4) it. The shape of the cutting edge (2) of the blade (1) is dictated by the fact that due to the S-shape and sloping of the larger tenon (3) of the working surface of the bit during osteotomy, the tool blade does not slide off the round smooth surface of the bone and the likelihood of breaking, creasing or cracking of the bone is reduced, which is especially important when reducing its mechanical strength (osteoporosis, osteomalacia, degenerative-dystrophic processes, the presence of foci of bone destruction, etc.). The exclusion of slipping the blade (1) of the chisel from the bone is due to the fact that the larger tenon (3) of it at the very first blows of the hammer is “cut” into the bone, and the decrease in the likelihood of breaking and crushing of the bone is caused by an increase in the cutting moment of osteotomy with the remaining sufficient chopping moment. Moreover, the degree of increase in the osteotomy cutting moment is proportional to the decrease in the slope of the working surface of the bit. The latter can vary in the range from 45 to 85 degrees, however, the optimum angle of the bit blade is an angle of 55-75 degrees, when the cutting and chopping moments of the osteotomy are in relative equilibrium. A smaller tenon (4) of the curved edge (2) of the bit, which is ¼ of the width of the tool blade (1), is designed to eliminate the danger of its uncontrolled “failure” beyond the limits of the damage to the underlying tissues, which is outlined with a high risk, as well as for better visual control of the depth of immersion in the bone larger spike (3). Consequently, a larger tenon facilitates the osteotomy and eliminates the possibility of the bit slipping off the smooth surface of the osteotomized bone, while a smaller tenon enhances control of the depth of the osteotomy and acts as a stopper. In addition, the area of the bone between the two spikes, which are at right angles to each other and, as it were, covering it on both sides along the larger perimeter, is easier to intersect, which is especially important for osteotomy of the cortical plate of the tubular bone or its sclerosed areas.

An example application of the invention.

As an example of the application of the proposed device, the following observation. Patient M., born in 1991, was admitted to the Republican Orthopedic and Traumatology Center in Makhachkala on 07/11/2014 with a diagnosis of Osteoid-osteoma of the internal condyle of the left tibia (Fig. 3, a, b). From the anamnesis: pain and swelling on the inner side of the upper third of the left tibia in the region of the inner condyle of the tibia appeared for no apparent reason six months ago, since February of this year, and have a tendency to progression.

07/15/2014, the operation was performed: Removing the focus of osteoid-osteoma of the internal condyle of the left tibia. In the patient’s position on the back with a roller under the left knee joint, a linear longitudinal skin incision was made along the front-inner side of the region of the upper third of the leg just below the knee joint in the projection of the inner condyle of the tibia, 5 cm long. The fascia was dissected, muscles were bluntly divided and the periosteum was dissected. which is economically separated in the parties by a raspator. Over the site of greatest bulging of a somewhat rough cortical plate, a terminal osteotomy was performed using our device, which differs from the usual medical chisel in the form of a blade. The cutting edge of the latter is distinguished by its figure: ¾ it is S-shaped and beveled at an angle of 85-50 degrees relative to the longitudinal axis of the blade with the formation of a larger spike, and the remaining ¼ is linearly beveled in the opposite direction at an angle of 45 degrees to the longitudinal axis of the tool and at a straight angle to the S-shaped edge with the formation of a smaller spike. Due to this shape of the cutting edge of the instrument during osteotomy, its slipping off the surface of the bone and the likelihood of crushing or cracking were excluded. This was due to the fact that a larger tenon of the instrument, even at the first tapping of the hammer, entered the bone to a controlled (including visually) depth. In this case, the degree of increase in the cutting moment of the osteotomy was proportional to the chopper, being with him in approximate equilibrium. Thus, a larger tenon of the bit facilitated the osteotomy and excluded the possibility of the bit slipping off the surface of the bone, while a smaller tenon strengthened control of the depth of the osteotomy. The diameter of the osteotomized “window” was about 1.5 cm. Bone spoons and a spherical cutter within a healthy spongy bone scooped out the inhomogeneous contents of coarse bone and cartilage tissue with the formation of a small bone cavity, 1.5 × 1.5 cm in size (Fig. 4 , a, b), moderately bleeding like "blood dew". The osteotomized surface of the bone bed is dried with gauze swabs and treated with an alcoholic solution of iodine. The wound is sutured in layers with interrupted sutures with an aseptic dressing. After wound healing, the patient was discharged for outpatient treatment. At the control examination after 2 weeks, the complete restoration of the musculoskeletal function of the left lower limb was verified.

Signs of the invention, distinctive from the prototype.

Design features (hallmarks of the prototype) devices for osteotomy are:

- the shape of the cutting edge of the blade, ¾ of which is S-shaped and beveled at an angle of 85-50 degrees with respect to the longitudinal axis of the tool, and the remaining ¼ is linearly beveled in the opposite direction at an angle of 45 degrees to the longitudinal axis of the bit;

- the presence of two unequal spikes of the cutting edge of the blade: a larger tenon, S-shaped and beveled at an angle of 85-50 degrees with respect to the longitudinal axis of the tool, and a smaller tenon linearly beveled in the opposite direction at an angle of 45 degrees to the longitudinal axis of the bit;

- a right angle between both spikes, cutting edges being to each other.

The technical result (advantages over the prototype) of the device for osteotomy:

- eliminates the likelihood of the tool blade slipping off from the round smooth surface of the bone, which is due to the fact that a larger spike of the curved edge of the blade is immersed in the bone at the first blow of the hammer;

- the absence of the need to drill holes along the line of the alleged osteotomy with drills of various diameters;

- minimizing the likelihood of fracture, crushing or cracking of the bone, which is especially important when reducing its mechanical strength (osteoporosis, osteomalacia, degenerative-dystrophic processes, the presence of foci of bone destruction, etc.), due to an increase in the cutting moment of osteotomy with the remaining sufficient cutting her moment;

- minimizing the risk of an uncontrolled “failure” of the bit of the bit beyond the intended and the risk of damage to underlying tissues, due to the fact that the smaller spike of the cutting edge of the bit serves, firstly, as a stopper, and, secondly, as an additional factor in visual control of the depth of immersion into the bone of a larger thorn;

- the area of the bone between the two spikes, which are at right angles to each other, intersects more easily, due to the fact that they seem to cover the bone on both sides along the larger perimeter. This is especially important with osteotomy of the cortical plate of the tubular bone or its sclerotic areas;

- high efficiency of osteotomy with the provision of its precision accuracy, due to the optimal combination of chopping and cutting moments;

- the absence of the need for an inclined position of the bit when it is necessary to increase the cutting moment of the osteotomy, which makes the movements of the surgeon more clear and controlled.

Thus, the proposed device can improve the quality of osteotomy, and hence the effectiveness of surgical treatment of orthopedic patients.

Information taken into account

1) Movshovich I.A. Operative orthopedics: (Manual for doctors). - 2nd ed., Revised. and add. - M .: Medicine, 1994 .-- 448 p. - S. 28-35.

2) Ostroverkhoe G.E., Bomash Yu.M., Lubotsky D.N. Operative surgery and topographic anatomy. - Kursk; Moscow: CJSC Litera, 1996 - 720 p. - S. 207-225.

3) Orthopedics: national leadership / ed. S.P. Mironova, G.P. Kotelnikova - Moscow: GEOTAR-Media, 2008 .-- 832 p. - (Series "National Guides"), p. 66-70.

4) Huseynov A.G. Device for linear osteotomy. RF patent for utility model No. 39,069 of 10/22/2003

5) Boychev B., Conforti B., Chokanov K. Operative orthopedics and traumatology. - 2nd ed., Revised. and add. - DI "Medicine and physical education", - Sofia, 1958, - 832. - S. 76-92. - prototype device.

Claims (1)

A device for osteotomy, which is a flat medical chisel, characterized by the shape of its cutting edge, 3/4 of which is S-shaped to form a larger tenon, and the remaining 1/4 is linearly beveled at an angle of 45 degrees to the side edge to form a smaller tenon.

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