RU39069U1 - DEVICE FOR LINEAR OSTEOTOMY - Google Patents

Abstract

The proposed utility model relates to medical equipment, namely to instruments used in operative orthopedics and traumatology. Its purpose is to increase the efficiency of surgical treatment of orthopedic patients, namely to improve the quality of linear osteotomy. The goal is realized using a device that is a flat medical chisel, characterized in that its working surface is not perpendicular to the tool length, but beveled at an angle of 60-75 degrees.

Description

The device relates to medical equipment, namely to instruments used in operative orthopedics and traumatology.

Osteotomy (bone intersection) is a typical and widespread orthopedic operation. Its purpose is the correction of axial, rotational, shortening or lengthening bone deformation, the elimination of contracture and ankylosis of the joint in the vicious position of the limb, shape change, trepanation, removal of the destructive focus or bone tumor. An osteotomy is performed, as a rule, in compliance with biomechanical principles, i.e. with preliminary planning and refinement in mathematical and functional terms. To improve the technique of osteotomy and to eliminate the likelihood of its undesirable direction, holes can be made along its proposed line with a perforator. 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 with the whole palm, which is called metacarpal holding of the chisel (Fig. 1, a). If you need a fine design of the bone, obtaining bone chips, etc., the bit should be held with your fingers - digital holding of the bit (Fig. 1, b).

As a prototype, we chose the usual surgical chisel (osteotome), the working surface of which (the tip of the blade) is perpendicular to the instrument dorsum (Ostroverkhoe G.E., Bomash Yu.M., Lubotsky D.N. Surgical surgery and topographic anatomy). The chisel is usually mounted on the bones with the entire plane of its working surface.

(figure 2) and perform osteotomy by hammer blows on 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. Moreover, especially in the initial period of osteotomy, its chopping moment repeatedly prevails over the cutting one, which is fraught with cracking, fragmentation or crushing of the bone. The likelihood of these complications is especially real with a decrease in the mechanical strength of the bone, for example, with its degenerative-dystrophic processes, osteoporosis, osteomalacia of various etiologies, the presence of foci of destruction, with tumors, osteomyelitis, etc. To reduce the cutting and strengthening the cutting moment of osteotomy, it is often necessary to install a chisel blade under angle to the surface of the bone (figure 3). The latter, in turn, is associated with the danger of slipping it off the bone, inconvenience for the operating surgeon, the need for wider surgical access and larger than the traditional position of the bit, the 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:

1) 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 when the mechanical strength of the bone is reduced;

2) Low efficiency of osteotomy;

3) 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 and is associated with the need to increase the operating wound.

To prevent the above drawbacks, a device is proposed, which is a flat bit, different from the traditional one in that its working surface is not perpendicular to the tool length, but

beveled at an angle of 60-75 degrees (figure 4). Due to this slanting of the working surface of the bit during osteotomy, the likelihood of breaking, crushing 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 decrease in the probability of fracture and crushing of the bone is due to an increase in the cutting moment of the osteotomy with the remaining sufficient moment cutting it. 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 60-75 degrees, when the cutting and cutting moments of the osteotomy are in relative equilibrium. To increase the quality of the osteotomy, to facilitate its technical implementation, to prevent its line from exceeding the intended limits and to eliminate the danger of the bit slipping off the smooth bone surface, it is recommended to outline and drill lateral holes at the beginning and at the end of the osteotomy line (Fig. 5).

As an example of the application of the proposed device, the following observation.

Patient B., 57 years old, was admitted to the orthopedic department of the RTC on 02.15.99 in a planned manner with a diagnosis of Hypoplastic false joint of the lower third of the right tibia.

From the anamnesis: on December 31, 1996, as a result of an accident, the patient received a combined injury, which, along with a severe craniocerebral injury and multiple fractures of the ribs of the right half of the chest with small hemopneumothorax, included an open comminuted fracture of both bones of the lower third of the right and middle third left lower leg. By removing the patient from a serious condition and stopping the acute period of the traumatic

illness, 01/12/97 extrafocal osteosynthesis of both legs was performed using Ilizarov apparatus from 4 rings (160 mm). In February 1997, due to the development of suppuration around the knitting needles and the loss of stability of fixation of bone fragments, the Ilizarov apparatus on the right had to be dismantled, and the right lower limb was transferred to a terminal gypsum dressing. Subsequently, the fracture of the right tibia did not grow together and was complicated by post-traumatic osteomyelitis of the tibia (fracture of the left tibia fused without complications and in a timely manner). In May 97, an operation was performed: fistulo-sequestrnecrectomy, establishment of flow drainage of the lower third of the leg. Postoperative wounds healed a second time. Osteomyelitis has been completely cured.

When examining the patient, there was a violation of support ability and a relative shortening of the right lower limb by 1 cm due to the leg segment, the presence of postoperative scars that were not welded with the underlying tissues, pathological mobility in the lower third of the right leg in the range of 25-30 degrees. Neurological and ischemic disorders were noted. Radiologically, the presence of a hypoplastic pseudoarthrosis of the lower third of the tibia with locking plates at the ends of its fragments was noted. The gap of the false joint is clear, with no signs of consolidation.

02.17.99g. the operation was performed: bone grafting of a false joint by a sliding autograft according to Khakhutov with repositional osteosynthesis of fragments of the tibia of the right tibia with knitting needles and a screw. During the operation, the area of the false joint was exposed with skeletalization of the front-inner surface of the ends of the tibia. The ends of the bone fragments are resected by 0.5 cm (“refreshed”) with the removal of the false plates of the false joint and the restoration of patency of the obliterated bone marrow canal. Holes were drilled at the ends of the proposed osteotomy to obtain cortical autografts,

4 mm in diameter, in each of which the tip of the device for linear osteotomy was consistently installed, which is a bit with a working surface beveled at an angle of 65 degrees. In this case, the cutting surface of the bit was set in the direction of the osteotomy performed (to the next hole or to the end of the bone fragment). The surgeon held the chisel's length perpendicular to the bone surface, and placed the tip of the blade toward itself. The slanting of the working surface of the bit made it possible to reduce the fracture or cracking of the bone due to an increase in the cutting moment of the osteotomy with the remaining sufficient cutting moment, and pre-drilled holes were made to increase the quality of the osteotomy, facilitate technical execution and prevent its line from exceeding the intended limits with the exception of the risk of the bit slipping off smooth bone surface. Thus, cortical autografts were obtained, respectively 2.0 x 3.0 x 0.6 and 2, Ox6, OxO, 6 cm. The grafts were removed from their boxes and swapped, and the largest of them blocked the area of the pseudoarthrosis. Bone fragments and autografts were fixed by repositioning osteosynthesis with a Kirschner screw and spokes. A deep plaster cast was applied from the upper third of the thigh to the toes. After healing of the wound and removal of the sutures, Longeta was transferred to a circular plaster cast, in which the patient was discharged and 2.03.99 g for outpatient treatment. Starting from the seventh week after the operation, the patient was ordered to walk on crutches with support on his right leg with a force of 20-3 kg. Recommended x-ray of the lower leg every 1.5 months. On radiographs dated September 5, 1999, adequate dense bone marrow was verified. The patient began to walk without crutches on September 15, 1999. The metalwork (1 cortical screw and 3 fragments of the Kirchner needle) was removed as planned in March 2000. Right lower limb function restored

completely. The result of treatment is regarded by us as good.

Thus, the hallmarks of the prototype and the advantages of the proposed device are the following:

1) The slope of the working surface with respect to the tool length at an angle of 60-75 degrees;

2) The ability to ensure the precision of the osteotomy due to the exclusion of the chisel blade sliding off the bone surface and the osteotomy line going beyond the intended limits;

3) High efficiency of osteotomy, due to the optimal combination of its chopping and cutting moments;

4) No need for an inclined position of the bit if it is necessary to increase the cutting moment of the osteotomy, which makes the surgeon's movements more clear and controlled.

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

Claims (1)

A device for linear osteotomy, which is a flat medical chisel, characterized in that its working surface is not perpendicular to the tool length, but beveled at an angle of 60-75 °.