RU2271768C1 - Device for curing complicated of thigh-bone fractures - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: device can be used for close intramedulary osteosynthesis at complicated fractures of long tubular bones. Device has two-step cylindrical intramedulary pin provided with step of bigger diameter where four blocking holes, crossing axis, are made for blocking screws to block fragments of proximal department. Pin also has step of smaller diameter provided with tip for blocking fragments of distal department. Threaded hole is made at the end of pin. Guide is made with straight and bent ends and it has slanted holes for trocar at its end. The holes correspond to blocking holes in the pin. There is centering hole at bent end; connecting bushing is aligned inside the hole. Edge of pin is conjugated with edge of connecting bushing and it is fitted with it by means of screw-tie which goes through connecting bushing and is screwed into coaxial threaded hole of the pin. Lengths of pin and step of bigger diameter are constant, and diameter of step with smaller diameter corresponds to diameter of bone-cerebral channel. Two blocking holes, made in pin of bigger diameter, are disposed at angle of 130° to axis of the step. Two other blocking units of the same step are disposed at angle of 90° to axis of the step. Axis of part of smaller sized step disposed at disposed at distance from edge of pin being equal to 1,27 length of bigger sized step is bent relatively axis of bigger diameter step for angle being equal to 6° at the plane of disposition of axes of blocking holes of bigger diameter step. It has shape of arc with radius being 100 times bigger than diameter of step of bigger diameter pin. Center of arc of the part is disposed onto perpendicular line to axis of step of bigger diameter. Round-shaped hole and through elongated rounded groove are made in step of smaller diameter at the side of tip. Length of groove is 8,6 times shorter than length of bigger diameter step and its width is 2 times shorter than length of groove. Axes of the hole and axes of elongated groove are turned to the right and to the left correspondingly to left and right extremities for angle of 15° relatively axis of part of step of smaller diameter pin which is bent by angle of 6°. Straight and bent ends of guide are made as a unit.

EFFECT: widened capabilities of curing thigh-bone fractures; simplified design; improved comfort at application during operation; reduced time for operation; reduced bone defects; improved efficiency of cure.

2 cl, 7 dwg

Description

The invention relates to medical equipment and can be used for closed intramedullary osteosynthesis in complex fractures of long tubular bones.

Known devices for intraosseous osteosynthesis of the femur contain an intramedullary pin with threaded holes located across the axis of the pin and designed to block the proximal and distal bone fragments by introducing transverse blocking hairpins into them through the cortical layers of the bone fragments. In such devices there is a compression nut coaxially screwed onto the pin from the side of the greater trochanter of the femur, and a guide plate with holes (see AS SU No. 1616639, 1990 [1] or Pat. RU No. 2111134, 1998 [ 2]).

However, in devices [1, 2], the pin has a straight shape and is made without taking into account the anatomical shape of the thigh in various planes, which complicates the installation of the pin during surgery and increases the time of the operation.

In addition, these devices do not provide tools to facilitate the insertion of locking screws through the bone into the threaded hole of the pin, and when searching for a locking hole, it is necessary to make a hole for the locking screw in the nearest bone layer more than the hole in the pin. In this case, a weakened fixation and loose connection of the threaded rod with the external nut lead to the mobility of the locking screw in the pin hole and to a reduced rigidity of the connection.

Known devices with a curved pin that takes into account the anatomical bending of the thigh (see US Pat. No. 5352228, EP No. 1233712, 2004, WO 02/085228, 2002).

However, in all of the aforementioned analogs, the locking holes for distal locking are located on the pin section that does not take into account the bends of the anti-thigh version in the distal region, which complicates the installation of the pin and increases the operation time.

The closest analogue is a device for the treatment of complex fractures of the femur, containing a two-stage cylindrical intramedullary pin with a step of a larger diameter, in which there are four locking holes crossing the axis for locking screws to block fragments of the proximal part, with a step of a smaller diameter with a tip to block fragments of the distal section and at the end of the pin there is a coaxial threaded hole, a guide made with straight and bent ends and having at the straight end there are inclined holes for the trocar corresponding to the locking holes in the pin, and in the bent end there is a centering hole with a connecting sleeve coaxially mounted in it, and the end face of the pin is mated to the end of the connecting sleeve and fastened with a tie screw passed through the connecting sleeve and screwed into the coaxial threaded hole of the pin (see US Pat. EP No. 0715832, publ. 2002).

However, this device contains a straight cylindrical pin, having the shape and location of the locking holes, which do not fully take into account the anatomical bends of the thigh in various planes, including, as in all of these analogues, there is no section with a bend that takes into account the anti-version of the thigh in the distal region, which complicates the installation of pins and increases the operation time. The diameter of the step of a larger diameter in these devices is not less than 17 mm, which leads to the formation of large bone defects that require filling with bone tissue and an increase in recovery time.

In addition to this, the device does not provide opportunities for dynamic axial compression of fracture fragments during treatment, which reduces the effect of treatment and increases the healing time.

The guide in this device is made integral, contains a bent end and interchangeable straight ends, in each of which holes are made for a trocar located at different angles to the axis of the pin. To install the locking screws in the locking holes of the pin at different angles to the anatomical axis, it takes time to reinstall the straight end, which complicates the operation and increases the time it takes.

The objective of the proposed technical solution is to expand the capabilities, simplify and increase the convenience of installing the device during surgery while reducing the time of the operation, reducing bone defects and shortening the recovery time.

To solve the problem in the proposed device for the treatment of complex fractures of the femur, containing a two-stage cylindrical intramedullary pin with a step of a larger diameter, in which there are four blocking holes intersecting the axis for locking screws to block fragments of the proximal section, with a step of a smaller diameter with a tip to block fragments distal section, and at the end of the pin there is a coaxial threaded hole, a guide made with a straight and bent to cores and having at the straight end inclined holes for the trocar corresponding to the locking holes in the pin, and in the bent end - a centering hole with a connecting sleeve coaxially mounted in it, and the end face of the pin is mated to the end of the connecting sleeve and fastened with a tie-screw through it the connecting sleeve and screwed into the coaxial threaded hole of the pin, according to the invention, the pin has a constant length and diameter of the step of a larger diameter, and the diameter of the step of a smaller diameter corresponding to the diameter of the marrow the channel, while two locking holes in the pin step of a larger diameter are located at an angle of 130 ° to the axis of this stage, and two other locking holes in this pin are located at an angle of 90 ° to the axis of this stage, the axis of the portion of the pin step of a smaller diameter located with the distance from the end of the pin, equal to 1, 27 of the length of the step of a larger diameter, is bent relative to the axis of the step of a larger diameter by an angle equal to 6 °, in the plane of the axes of the locking holes of the step of a larger diameter and has the shape of an arc, the radius of which is 100 times larger than the diameter of the step of the pin of a larger diameter, with the center of the arc of this section located perpendicular to the axis of the step of the larger diameter of the pin, while in the step of the smaller diameter of the pin on the tip side, a round hole and a through elongated rounded groove are made for locking screws, length which is 8.6 times less than the length of the step of a larger diameter, and the width is 2 times less than the length of the groove, and the axis of this hole and the elongated groove are turned left and right, respectively, for the left and right limbs 15 ° angle relative to the axis stage portion of smaller diameter of the pin, rotated by an angle of 6 °, wherein the straight line and the folded ends of the guide are made integrally.

In addition, according to the invention, the solution of the tasks can be achieved by the fact that the locking holes made in the pin, inclined at an angle of 130 ° to the axis of the step of a larger diameter, are located between the locking holes, inclined at an angle of 90 ° to this axis.

The technical result of the proposed device is to simplify and increase the convenience of installing the device during the operation, to reduce the operation time by 10% while reducing the recovery time.

Figure 1 shows the proposed device assembly.

Figure 2, 3 shows the pin and the locking holes made therein are visible.

Figure 4 shows a cross section of a circular hole made from the side of the pin tip.

Figure 5 shows a cross section of a through elongated groove.

Figure 6 shows the shape of the through groove (view A).

7 shows a plug designed to prevent the locking screw from being unscrewed.

The device contains a two-stage intramedullary pin 1, which is made with a step 2 of a larger diameter and with a step 3 of a smaller diameter. The guide 4 serves to secure the pin 1 and is designed to guide the locking screw 5 into the corresponding locking hole. In the step 2 of the larger pin, four locking holes 6, 7, 8, 9 are made.

Two of these locking holes 6, 7 are located at an angle of 130 ° to the axis of the step of a larger diameter, and two other locking holes 8, 9, having a diameter 1.6 times smaller, are located at an angle of 90 ° to this axis. The locking holes 6, 7, inclined at an angle of 130 °, can be located in the pin between the locking holes, inclined at an angle of 90 ° to the axis of the step of a larger diameter.

The axis of the portion 11 of the step of the pin of smaller diameter, spaced from the end of the pin 1, equal to 1.27 the length of the step of the larger diameter (L), is bent outward relative to the axis of the step 2 of the larger diameter by an angle equal to 6 ° in the plane of the axes of the locking holes 6 , 7, 8, 9 steps of larger diameter. The axis of this portion of the pin has the shape of an arc 12, the radius of which (R) is 100 times larger than the diameter of the step 2 of the larger pin, and the center of the arc 12 is located with the same indent (1.27 L) on the perpendicular to the axis of the step 2 of the larger diameter of the pin.

A round hole 14 and a through elongated rounded groove 15 are made in the pin on the side of the tip 13 of the step 3 of smaller diameter. The axis of the hole 14 and the groove 15 are rotated left and right for the left and right limbs by an angle of 15 ° relative to the axis of the section 11 of the step 3 of the smaller diameter, rotated 6 ° relative to the step of a larger diameter.

The bent end 16 of the guide 6 is integral with the straight end 17. At the straight end 17 of the guide, holes 18 are made for a trocar (not shown) in accordance with the location of the locking holes in the pin. In the bent end 16, a centering hole 19 is made with the connecting sleeve coaxially mounted in it 20. The end face of the pin 1 is paired with the end face of the sleeve 20 and fastened with a tie screw 21, passed through the connecting sleeve 20 and screwed into the threaded hole 22 made in the pin from the end side . The coupling of the ends of the pin and the sleeve is performed through the reciprocal grooves and protrusions 23 made therein.

In the straight end 17 of the guide 6 at the level of coupling of the ends of the pin with the connecting sleeve 20, a hole 24 is made for the spoke.

The device provides for preventing the unscrewing of the locking screw 5. For this, a threaded plug 25 is used, which is made with a stop nose 26, and the locking screw 5 is made with a stop collar 27. Four equal conical recesses 28 are made in the lock screw 5, which are equidistant from the stop collar, evenly spaced around the axis of the locking screw 5 and have the largest diameter towards the shoulder 27. The threaded holes 22 made in the pin 1 are made with a section without thread 22 ′, which is in communication with the upper block full-time opening 6 pin, tilted at an angle of 130 ° to the axis of stage 2 of larger diameter.

To perform distal locking of the pin 240 mm long, additional holes 29 for the trocar can be made in the guide.

The device is used as follows.

After access (3 cm long), a spoke (3.2 mm in diameter) is inserted into the bone marrow canal over the top of the greater trochanter. A cannula with a cannula drill (15 mm in diameter) is used to make a canal, which provides an opening of the marrow canal.

The fastening of the pin 1 on the guide 4 is performed by pairing the ends of the pin 1 and the connecting sleeve 20 through the reciprocal grooves and protrusions 23 made therein, followed by screwing the tie screw 21 through the connecting sleeve 20 into the threaded hole 22 of the pin 1.

Straight 17 and bent 16 ends of the guide 4 are integral at the same time, which eliminates the time spent on permutation and reduces the time of the operation. The guide 4 is located outside the femur.

The pin is selected according to the size of the patient's bone marrow canal, which must correspond to the diameter of the step 3 of the smaller diameter of the pin 1. There are three diameters in the step of the smaller diameter: 9 mm, 10 mm, 11 mm, which expands the possibilities of using the pin. A pin is inserted into the bone marrow canal through a cannula-made canal, and a step of a larger diameter is placed along the anatomical axis of the femur. The guide is positioned outside the femur.

The choice of the pin with the appropriate location of the locking holes 6, 7 or 8, 9 in it determines the nature of the fracture. In the case of a fracture of the proximal bone using blocking holes 6, 7, providing for the installation of blocking screws at an angle of 130 ° to the anatomical axis of the thigh. In case of fractures of the upper, middle and lower third of the diaphysis of the thigh, locking holes 8, 9 are used, providing for the location of the locking screws at an angle of 90 ° to the anatomical axis of the thigh. The pin is designed for all types of specified fractures.

When blocked, a trocar (not shown) is inserted into the corresponding hole in the holes 18 of the guide 4 and spokes are inserted through the trocar, the direction of which determines the location of the holes made in the guide and the locking holes in the step 2 of the larger diameter pin. After controlling the location of the spokes, which is performed by the image intensifier tube, and removing the spokes one by one through the trocar installed in the guide, holes are formed in the near and far layers of the bone into which the self-tapping locking screws 5 are inserted. Similarly, through the round hole 14 and the through elongated groove 15, located in step 3 of a smaller pin diameter, distal blocking is performed.

The pin is made taking into account the anatomical shape of the femur and the angle of inclination of the axis of the step of a smaller diameter to the axis of the step of a larger diameter in the plane of the axes of the locking holes of the steps of a larger diameter is 6 ° in the plane of the axes of the locking holes of the step of a larger diameter, and the axis of this section of the pins of the kit has the shape arc 12, the radius of which is 100 times larger than the diameter of the larger step of the pin, and the center of the arc is located with the same indentation (1.27 L) from the end of the pin on the perpendicular to the axis of the stage 2 of the larger m. This facilitates the insertion of a pin into the bone marrow canal.

The axis of the round hole 14 and the through elongated rounded groove 15 are rotated left and right for the left and right limbs by an angle of 15 ° relative to the axis of the curved section 11 of a smaller diameter rotated by 6 °, which allows for anti-thigh version and facilitates distal blocking.

The axis of the round hole 14 and the point of the rounded groove closest to the tip 13 of the step 3 of the pin 1 of smaller diameter are located at distances from the extreme point of the tip, respectively 50 mm and 14.8 mm. The length of the groove is 8.6 times less than the length of the step of a larger diameter, and the width is 2 times less than the length of the groove, which allows 1-2 months after surgery to perform osteosynthesis dynamization, which is performed by removing the screw from the round hole, which creates opportunities for axial compression fragments of a fracture during a load on a limb.

The pin has a constant diameter in steps 2 of a larger diameter, which does not exceed 15 mm, which allows to reduce bone defects and helps to reduce the healing time.

In the particular case, when the length of the step 3 is larger than the diameter of the pin, equal to 90 mm, the length of the pin can be 340 mm, 360 mm, 380 mm, 400 mm, 440 mm.

However, this does not limit the capabilities of the proposed device and the guide can be used, for example, with a pin 240 mm long.

After removing the guide 4, to prevent the locking screw 5 from being unscrewed, a plug 25 with a nose 26 is screwed into the threaded hole 22 of the pin 1, which, passing through the section without threads 22 ', abuts against the upper conical recess 28 made in the locking screw 5, which will securely hold the screw 5 from unscrewing. This allows you to increase the effectiveness of treatment and reduces the recovery time of patients.

The technical and economic effect of the proposed technical solution consists in expanding opportunities in the treatment of complex fractures of the femur, in simplifying and increasing the convenience of installing the device during surgery, while reducing the time of the operation, reducing bone defects, increasing the effectiveness of treatment and shortening the healing time.

Claims (2)

1. A device for the treatment of complex fractures of the femur, containing a two-stage cylindrical intramedullary pin with a step of a larger diameter, in which there are four blocking holes intersecting the axis for the locking screws to block proximal fragments, with a step of a smaller diameter with a tip to block the distal fragments, and a coaxial threaded hole is made in the end of the pin, a guide made with straight and bent ends and having inclined holes in the straight end under the trocar, corresponding to the locking holes in the pin, and in the bent end, a centering hole with a connecting sleeve coaxially mounted in it, and the end face of the pin is mated to the end of the connecting sleeve and fastened with a tie screw through the connecting sleeve and screwed into the coaxial threaded a pin hole, characterized in that the pin has a constant length and diameter of the step of a larger diameter, and the diameter of the step of a smaller diameter corresponds to the diameter of the marrow canal, with two blocking holes I in the step of a pin of a larger diameter are located at an angle of 130 ° to the axis of this step, and the other two locking holes of this step are located at an angle of 90 ° to the axis of this step, with the axis of the section of the step of the pin of a smaller diameter indented from the end of the pin equal to 1 , 27 the length of the step of a larger diameter, bent relative to the axis of the step of a larger diameter by an angle equal to 6 °, in the plane of the axes of the locking holes of the step of a larger diameter and has the shape of an arc whose radius is 100 times the diameter of the step of the pin b of a larger diameter, with the center of the arc of this section located perpendicular to the axis of the step of larger diameter, while in the step of smaller diameter, a round hole and a through elongated rounded groove are made for locking screws, the length of which is 8.6 times less than the length of the larger step diameter, and the width is 2 times less than the length of the groove, and the axis of this hole and the elongated groove are turned left and right, respectively, for the left and right limbs by an angle of 15 ° relative to the axis of the section of the step of smaller diameter Tift rotated by an angle of 6 °, wherein the straight line and the folded ends of the guide are formed integrally. 2. The device according to claim 1, characterized in that the locking holes made in the pin, inclined at an angle of 130 ° to the axis of the step of a larger diameter, are located between the locking holes, inclined at an angle of 90 ° to this axis.

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