RU2687754C1 - Device for femoral neck osteosynthesis - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to medical equipment. Device for femoral neck osteosynthesis consists of three spongioid screws and cerclite wire with diameter of 1–1.5 mm and length of 150–170 mm. Screws are located on vertices of isosceles triangle, wherein two of three screws are located in lower part of femoral neck on one horizontal line, all three screws are not additionally twisted by 5–15 mm, cerclage wire is wound: first, from left to right, bottom-up is thrown on left lower screw, then on right lower screw from above, rounding it clockwise and continuing from bottom to top and from left to right, is thrown on upper screw, enveloping it clockwise, is continued downwards and the first screw is enveloped by the last screw clockwise from bottom to top, both ends of the wire are sipped to the sides and their counterclockwise rotation is performed. After completing the swivel, sufficient for stable tightening of three non-twisted propellers between each other, thereby creating a graduated voltage between them, and ends of corking wire after spinning are bitten, bent and fixed under wire and heads of screwed up screws.EFFECT: invention provides higher effectiveness and reduced length of treatment of patients with femoral neck fractures.1 cl, 5 dwg, 1 ex

Description

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

Fractures of the femoral neck are a pressing medical and social problem, which remains acute due to dissatisfaction with the results of treatment and the continuing increase in the prevalence of osteoporosis throughout the world. The global trend is an increase in the life expectancy of the population and, accordingly, the frequency and severity of age-related changes in bone tissue, while in Russia the rate of population aging is ahead of global trends. The incidence of fractures of the proximal femur, a marker of osteoporosis, is about 60 cases per 100 thousand of the population, and the overall mortality rate for this type of injury exceeds 12%. This is due to the fact that medial fractures of the femoral neck without surgery, as a rule, do not grow together. The risk of hypostatic complications (pressure sores, cardio-respiratory and vascular disorders, decompensation of intercurrent pathology) in case of refusal of surgical intervention is higher than the risk of operative aggression. Therefore, the development of effective and atraumatic methods of osteosynthesis is particularly important in the treatment of femoral neck fractures.

Analogs

Since the introduction of Smith-Peterson (1931) three-blade rod for osteosynthesis of medial fractures of the femoral neck, a number of methods and structures for osteosynthesis have been proposed. These include open and closed methods of femoral neck osteosynthesis: use of a cannulated three-lobed stem with or without a lateral lining, osteosynthesis with several fixatives, transarticular osteosynthesis, osteosynthesis using bone auto-and allograft, hip joint endoprosthesis.

Criticism of analogues

Open methods of osteosynthesis, accompanied by the opening of the hip joint, despite the possibility of accurate reposition and stable fixation of bone fragments, are associated with an aggravation of bone fragments ischemia, which is due to the anatomical features of the blood supply to the femoral neck. Ischemia of bone fragments is often complicated by nonunion of a neck fracture and the development of aseptic necrosis of the femoral head. The latter is also a frequent complication of the use of a cannulated three-blade rod with a side lining and without it, due to the fact that when the hammer strikes during intraosseous hammering of the rod along the axis of the femoral neck, collisions of the femoral head against the bottom of the acetabulum occur. Trans-articular osteosynthesis with penetration of the femoral head and the introduction of a fixator into the bottom of the acetabulum is associated with the inevitable deforming coxarthrosis, that is, the transfer of one pathological condition to another. The use of auto- and allografts is associated with the search for plastic material and the risk of complications from the donor and recipient zones. Endoprosthetics, being a radical high-tech method of treating diseases and injuries of the hip joint, has a high aggression of surgical intervention, many early and late complications, frequent dislocations of the endoprosthesis legs, wear of its components, the frequent need for repeated surgical interventions (revision endoprosthesis) and significant economic costs.

Prototype

As the closest analogue, we present a device and method for closed osteosynthesis of the femoral neck with spongy screws (Traumatology and Orthopedics: A Guide for Doctors / edited by NV Kornilov: in 4 volumes. - SPb .: Hippocrates, 2004 - V. 3: Injuries and diseases of the lower extremity / Under the editorship of NV Kornilov and EG Gryaznukhin. - SPb .: Hippocrates, 2006. - 896 p. - p. 44-70). The use of the device of the prototype is that the femoral neck fracture is repositioned closed on the Hawley table, and osteosynthesis of bone fragments is performed through external access in the region of the greater trochanter without penetrating the hip joint with spongy screws as follows.

On the table, Hawley performs the reposition of bone fragments: bending at right angles in the knee and hip joints, thigh thrust upwards with increasing force, then rotating the thigh medially with its abduction with incessant axial thrust; then the extension of the lower leg and thigh, with the simultaneous burden of the limb along the length and the preservation of internal rotation and abduction of the thigh. The limb is fixed to the foot supports of the Hawley table in moderate tension. Parallel to the pupart ligament on the skin of the abdomen, hem a bar with holes and make needles with the skin, focusing on the neck of the femur. After X-ray control with confirmation of reposition of bone fragments, the optimal needle is left as a guide, all other needles are removed and proceed to the next stage of the operation. A linear longitudinal skin incision is made from the level of the greater skewer down by 7-8 cm. Dissect the subcutaneous tissue, fascia, abductor of the thigh and periosteum exposing the bone area below the base of the greater skewer, through which 3 Kirschner needles are held along the axis of the femoral neck. X-ray control is performed in 2 projections and in the course of the optimal spokes, 2-3 spongy screws are inserted, after which the needle is removed and a control X-ray is performed. The wound is washed with antiseptic solutions and sutured in layers.

Criticism of the prototype

The device prototype and its use in osteosynthesis of the femoral neck have the following disadvantages:

- due to osteoporosis, as a rule, which is an indispensable companion of a medial femoral neck fracture, a bone resorption zone usually occurs between the bone and the metal structure. This reduces the stability of the osteosynthesis and can lead to a secondary displacement of screws, bone fragments and nonunion of the fracture;

- conical shape of the lower part of the cap of the standard spongy screw contributes to the fact that when screwing it, the screw head is wedged into the bone and sinks deeper than the osteoporosis cortical layer of the femur in the region of the greater trochanter. This is the cause of the primary (during the operation of the osteosynthesis) or secondary (developed after the operation due to the lysis of the bone under the cap), the instability of the osteosynthesis. To prevent this complication, washers for caps of screws are often used, however, firstly, it is not always possible to predict in advance the need for their use (and reproducing the screws inevitably weakens their coupling to the bone), and, secondly, bone ischemia is observed under the washers. increases the risk of inflammatory complications and instability of metal structures;

- the need for precision dosing of compression between the bone fragments, because under-tightening (not twisting) the screws does not result in adequate mutual adaptation of the bone fragments, and when overtightening, the threads formed in the bone by the propeller blades (osteoporosis) are broken. This leads to instability and failure of osteosynthesis.

The purpose of the invention is to increase the efficiency of treatment of patients with fractures of the femoral neck.

Summary of Invention

The goal is achieved by using a device consisting of three spongy screws and a cerclage wire, with a diameter of 1-1.5 mm and a length of 150-170 mm.

Apply the device as follows. The femoral neck fracture is retracted closed on an orthopedic table or Hawley table traditionally: bending the patient's lower limb at right angles to the knee and hip joints, thigh thrust upwards with increasing force, thigh rotation inward, with abduction of axial thrust; then the extension of the lower leg and thigh, with the simultaneous burden of the limb along the length and the preservation of internal rotation and abduction of the thigh. Limbs are fixed to the foot supports of the orthopedic table in moderate tension. After radiological confirmation of the reposition of the bone fragments, a linear longitudinal skin incision is made from the level of the base of the greater trochanter down by 7-8 cm. The subcutaneous tissue, fascia, abductor of the thigh muscles and periosteum are dissected below the base of the greater trochanter, through which 3 Kirschner needles are the axis of the neck of the femur. X-ray control is performed in 2 projections, two spokes are removed, and along the optimal spokes, 3 spongy screws are inserted parallel and equidistant from each other, after which the needle is removed. In order to avoid penetration of the femoral head, the length of the screws must be less than the distance from the surface of the base of the greater trochanter to the subchondral zone of the femoral head, which is determined radiographically. For example, if the distance from the base surface of the greater trochanter to the subchondral zone of the femoral head is 110 mm, then the length of the screws should be no more than 100 mm, but not less than 85 mm, since the stability of the osteosynthesis and the possibility of ensuring compression between the bone fragments depend on it. The distance between the screws should be such that, on the one hand, not to go beyond the cross-section of the femoral neck (within 30 mm in both planes), and, secondly, sufficiently far from each other so that the blades of their threads do not enter in conflict with each other and provide sufficient rigidity of fixation of bone fragments - that is, within 20-23 mm from each other. Taking into account the fact that the most stable geometric shape is an isosceles triangle, the screws must be equidistant - on the vertices of the conditional isosceles triangle. Bone density within the perimeter of the femoral neck prevails closer to the Adams arc, in the dorso-caudal direction. Therefore, for greater stability of osteosynthesis, two of the three screws should be held in the lower part of the femoral neck on the same horizontal line. In this case, all three screws do not twist by 5-15 mm (Fig. 1). Then they take the serquel wire, with a diameter of 1-1.5 mm and a length of 150-170 mm, and twist it into three undo-twisted screws as follows (Fig. 2): first, from left to right, bottom-up, they are thrown over the left lower screw (pos. 1), then on the lower right screw from above (pos. 2), bend around it clockwise and, continuing upwards and from left to right (pos. 3), throw it on the upper screw, bend around it clockwise, continue down (pos. 4) and last turn round the first screw upwards clockwise (pos. 5). Both ends of the wire (pos. 1 and pos. 5 of Fig. 2) are gripped by the needle holder or with pliers, pulled to the sides and twisted (Fig. 3, a, b) counterclockwise (Fig. 4, a, b). Performing a twist, sufficient for a stable tightening between the three untwisted screws, thereby creating a metered voltage between them. The tension of the screws near the caps is accompanied by the corresponding tension of their divergence at the other end of the screws - in the threaded part. This uniform tension between the three screws strengthens both their hitch at the metal-bone interface and promotes mutual adaptation between the bone fragments. In addition, all three screws are a single metal structure, which eliminates the secondary migration of each of the screws, and, to an even greater extent, the entire metal structure. After twisting the wire of the cerclage wire, they bite, fold and fix under the wire and screw heads, and screw the screws up to the stop (Fig. 5, a, b), starting with the upper screw, then the lower right screw and ending with the left lower screw. At the same time, on the last turn of each of the screwed screws, the bluetooth wire is even more stretched, and the ends of the wire, distal to the twist, are securely held under the heads of the screws and the hinges of the wire. This eliminates the relaxation and unwinding of the wire due to the plasticity of its metal. In addition, along with the provision of a metered voltage in the metalwork, the cerclage wire prevents the screw heads from wedging into the thinned cortical plate of the greater femur trochanter, that is, performs the function of a cap washer. However, unlike standard washers, bone ischemia does not occur under cerclage wire. After X-ray verification of the viability of the osteosynthesis, the wound is washed with antiseptic solutions and sutured in layers, leaving drainage.

Device Application Example

As an example of the use of the device for compression osteosynthesis of the femoral neck, here is the following observation.

Patient K., 76 years old, was admitted to the Republican Orthopedic and Traumatological Center in Makhachkala on 09/15/17 with a diagnosis: Closed transcervical fracture of the left femur neck with dislocation. Concomitant coronary artery disease, hypertension II degree. From the anamnesis: 2 hours before admission to the hospital, the patient received a household injury when falling to the left side. Radiographically diffuse osteoporosis is noted, type I fracture according to Pauwels (inclination angle not more than 30 °) and type III according to Garden (complete fracture of the femoral neck with partial displacement of bone fragments).

09/19/17, in the planned order, the operation was performed: Closed osteosynthesis of the left femoral neck with spongy screws and x-rayed wire. Under spinal anesthesia on the table, Hawley was performed and in two projections on an electron-optical converter (EOC) the reposition of bone fragments of the femoral neck was verified. Then the provision of Kirchner spokes from the side of the big skewer into the neck of the femur. An optimal knitting needle was left, which was carried out strictly along the center of the femoral neck, which was determined at the tube in both projections, and the other two needles were removed.

A linear longitudinal skin incision, 7 cm long, is made along the outer surface of the hip joint. Subcutaneous tissue and fascia are dissected and along the muscle fibers, the bone area is exposed in a sharp and blunt way below the base of the greater trochanter. In parallel and around the needles, three 6.5-mm spongy screws 90 mm long were made (with a distance of 105 mm from the surface of the greater trochanter to the subchondral part of the femoral head). At the same time, the screws are not twisted with the distance between their caps and the surface of the greater spit of 6-7 mm. Provisional needle removed. The location of the screws was equidistant - at a distance of about 20 mm from each other, within the cross section of the femoral neck and passed along the tops of the conditional isosceles triangle. At the same time, the two lower screws were located on the same horizontal level, while the upper screw was the top of a conditional isosceles triangle. Then the cerclage wire, with a diameter of 1 mm and a length of 150 mm, was screwed onto the screws: first, from left to right, from bottom to top, threw on the bottom left screw from above, then on the bottom right screw from above, bent it in one clockwise direction and, continuing from bottom to top, threw on the top screw, circled it clockwise, continued down and the last turn went around the first screw from bottom to top. Both ends of the wire near the first bottom screw were grabbed with pliers and twisted counterclockwise. Having performed a twist, sufficient for a stable tightening of three loosened screws between them, they created a dosed tension between them, and after the twisting of the cerclage wire they bit off, bent, and fixed under the wire and screw heads. Then the screws are screwed all the way. The image of the EOP confirmed the correct position of the metal structure in the anterior-posterior and axial projections. The wound is sutured in layers, leaving a perforated tubular drainage. Performed a check of movements in the joint - without feeling like an obstacle in the joint. Aseptic wound label applied. The postoperative period was uneventful, the wound healed initially, the sutures were removed on the 8th day. The patient was discharged for outpatient treatment on 09/27/17 with a recommendation to perform physical therapy, breathing exercises and prevention of hypostatic complications, and after a month to perform X-ray control. The result of treatment is regarded as good.

The features of the invention, the distinctive features of the prototype

Design features (distinctive features of the prototype) device for osteosynthesis of the femoral neck are:

- equidistance of the location of the three screws within the cross section of the femoral neck at a distance of 20-23 mm from each other on the tops of the conditional isosceles triangle;

- the two lower screws are located on the same horizontal level;

- the use of cerclage wire, with a diameter of 1-1.5 mm and a length of 150-170 mm, with its holding under the caps of the screws that were not twisted by 5-15 mm in the following sequence (Fig. 2): first, from left to right, bottom-up, wrap the wire on the bottom left screw on top (pos. 1), then on the lower right screw on top (pos. 2), bend around it clockwise and, continuing upwards (pos. 3), throw it on the top screw, bend around it clockwise, continue down ( pos. 4) and the last turn round the first screw upwards (pos. 5);

- both ends of the wire are gripped by the needle holder or pliers and twist them counterclockwise;

- after twisting, the ends of the serclage wire are bitten, bent and fixed under the wire and screw heads, and the screws are screwed all the way.

- screwing screws start with the top screw, then the bottom right and ending with the left bottom screw. At the same time, on the last turn of each of the screwed screws, the bluetooth wire is even more stretched, and the ends of the wire, distal to the twist, are securely held under the heads of the screws and the hinges of the wire.

The technical result (advantages over the prototype) device for osteosynthesis of the femoral neck are:

- a combination of sufficient stability of osteosynthesis with its low trauma;

- the rationality of the arrangement of the three spongy screws within the cross section of the femoral neck with ensuring maximum stability of the structure with minimum material consumption;

- rationality of the location of the wire on the screws with the correct sequence of twisting;

- after twisting, the ends of the serclage wire are bitten off, bent and fixed under the wire and screw heads, and the screws are screwed in as far as they will go;

- the rationality of the screw tightening sequence, starting with the top screw, then the bottom right screw and ending with the left bottom screw. At the same time, at the last turn of each of the screwed screws, the bluetooth wire is even more stretched, and the ends of the wire, distal to the twist, are securely held under the caps of the screws and wire loops, which precludes relaxation and unwinding of the wire due to the plasticity of its metal;

- providing metered voltage between the screws by mutual tightening around the caps and the corresponding voltage divergences at the other end in the threaded part, strengthens both the hitch of the screws at the metal-bone interface and promotes mutual adaptation between the bone fragments;

- all three screws and cordless wire are a single metal structure, which eliminates the secondary migration of each of the screws, and, to an even greater extent, the entire metal structure - even in the presence of pronounced systemic osteoporosis.

- The cerclage wire, in addition to providing a metered voltage in the metalwork, prevents the bottom of the heads of the screws from wedging into the thinned cortical plate of the greater trochanter of the femur, that is, performs the function of a washer under the caps. However, unlike standard washers, bone ischemia does not occur under cerclage wire.

Thus, the device for osteosynthesis of the femoral neck allows us to expect an increase in the effectiveness of treatment of these injuries, a reduction in their terms and an improvement in the quality of life of patients.

Information taken into account

1. Buachidze O.Sh. Surgery of the hip joint / O.Sh. Buachidze, G.A. Onoprienko, V.P. Voloshin, V.S. Zubkov. - M .: Medicine, 2002. - 134 p.

2. Kaplan A.V. Fractures of the femoral neck and their treatment / A.V. Kaplan - M .: Medgiz, 1952. - 172 p.

3. Naumovich S.S. Surgical treatment of hip fractures / S.S. Naumovich. - Minsk: State. publish BSSR, 1963. - 80 p.

4. Gear N.A. Hip fractures: Modern methods of treatment / N.A. Gear wheel, Yu.S. Gamdi, S.V. Ivannikov. - M .: BINOM. Laboratory of knowledge, 2005. - 104 p.

5. Traumatology: national leadership / ed. G.P. Kotelnikova, S.P. Mironov. - M .: GEOTAR-Media, 2008. - 808 p. - (Series “National guidelines”), p. 377-386.

6. Traumatology and orthopedics: A Guide for Doctors / Ed. N.V. Kornilov: in 4 volumes. - SPb .: Hippocrates, 2004 - V.3: Injuries and diseases of the lower limb / Ed. N.V. Kornilov and E.G. Gryaznuhina. - SPb .: Hippocrates, 2006. - 896 p .- P. 44-70 - device prototype.

Claims (1)

A device for osteosynthesis of the femoral neck, characterized in that it consists of three spongy screws and cerclageal wire with a diameter of 1-1.5 mm and a length of 150-170 mm, the screws are located on the tops of an isosceles triangle, while two of the three screws are placed in the lower part neck of the femur on the same horizontal line, all three screws do not twist by 5-15 mm, twist the cervical wire: first, from left to right, bottom-up, throw it on the left lower screw, then on the right lower screw on top, bend around it clockwise and, continuing from bottom to top and from left to right, throw on the top screw, round it clockwise, continue down and round the first screw bottom up clockwise with the last turn, both ends of the wire sip sideways and spin them counterclockwise, doing a twist, sufficient for a stable tightening between the three loose screws, thereby creating a metered voltage between them, and the ends of the cerclage wire after twisting are bitten, bent and fixed under the wire and with the caps screwed all the way into the screws.

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