CN215079494U - Anti-bending self-locking pressurizing intramedullary nail - Google Patents

Abstract

The utility model discloses an anti-bending self-locking pressurizing intramedullary nail, which comprises an intramedullary nail body; the method is characterized in that: the outer side surface of the intramedullary nail body is provided with more than two anti-rotation bulges extending from the near end to the far end along the axial direction, the cross sections of the anti-rotation bulges are provided with tip ends, the tip ends of the anti-rotation bulges face outwards, and the cross section area of one anti-rotation bulge is larger than that of the other anti-rotation bulges. Utilize the utility model discloses a structure not only can play the distal end of fracture and prevent the rotation and the pressurization effect in fracture both ends, can improve the bending strength of intramedullary nail moreover.

Description

Anti-bending self-locking pressurizing intramedullary nail

Technical Field

The utility model relates to an intramedullary nail.

Background

Intramedullary nails belong to orthopedic internal fixation instruments in medical instruments. The structure is provided with an intramedullary nail rod, a near-end locking screw hole is arranged at the near end of the intramedullary nail rod, and a pressure reduction plane is arranged on the surface of the intramedullary nail rod. More than one strip-shaped decompression plane is arranged on the surface of the intramedullary nail rod, and the decompression plane can extend from the proximal end of the intramedullary nail rod to the distal end of the intramedullary nail rod. The proximal end of the intramedullary nail rod is provided with a locking screw rod positioning screw hole and a connecting sleeve positioning groove.

The prior intramedullary nails have various structures, and Chinese patent application No. 201410357935.5 discloses a self-locking pressurizing intramedullary nail which can make two ends of a fracture part tightly jointed, comprising an intramedullary nail body; the proximal end of the intramedullary nail body is externally provided with an anti-rotation bulge; a core body is arranged in the intramedullary nail body, an inner locking needle is hinged in the intramedullary nail body on the core body, the intramedullary nail body is provided with an inclined hole for the inner locking needle to pass through, and the inclined hole is inclined upwards from inside to outside; one end of the intramedullary nail body is provided with an axial driving device which is connected with the core body and enables the core body to move axially. The distal end of the intramedullary nail body of the intramedullary nail is round, and after the intramedullary nail is installed in a bone, the bone at two ends of the fracture is easy to rotate and displace, which is not beneficial to the recovery of the fracture.

The patent document with Chinese patent application number 03220675.5 discloses an automatic pressurizing intramedullary nail, which specifically discloses a main nail, wherein two sides of the middle and upper sections of the main nail are respectively provided with a side wing, the side wing can play a role of preventing bones at two ends of a fracture from rotating, and is beneficial to fracture healing, however, if the cross section area of the side wing is too small, although the side wing can be embedded into the bones, the embedding amount is small, the anti-rotation performance is not good, and in the actual use process, the intramedullary nail is often found to be bent due to the weight of a human body or external force, so that the fracture healing is not good, and the smaller side wing is adopted, the anti-bending performance of the intramedullary nail is poor, and the side wing with the larger cross section area is adopted, so that iatrogenic injury is easily caused, and the embedding groove generated on the bones is large, so that the strength of the bones is influenced.

Disclosure of Invention

The utility model aims at providing a prevent crooked auto-lock pressurization intramedullary nail utilizes the utility model discloses a structure not only can play the distal end of fracture and prevent rotatory and fracture both ends pressurization effect, also can improve the anti bending strength of intramedullary nail moreover.

In order to achieve the aim, the anti-bending self-locking pressurizing intramedullary nail comprises an intramedullary nail body; the outer side surface of the intramedullary nail body is provided with more than two anti-rotation bulges extending from the near end to the far end along the axial direction, the cross sections of the anti-rotation bulges are provided with tip ends, the tip ends of the anti-rotation bulges face outwards, and the cross section area of one anti-rotation bulge is larger than that of the other anti-rotation bulges.

The utility model discloses the intramedullary nail near-end to the distal end outside set up more than two axially extended prevent revolving the arch, be equivalent to for the intramedullary nail along the axial direction on installed three strengthening rib, the intramedullary nail radial cross sectional area has been increased, the shape of intramedullary nail radial cross section has been changed, in addition according to the principle of moment of inertia, as the moment of inertia is bigger, the bending resistance can be better, because one of them prevents revolving the bellied sectional area big, therefore, the biggest moment of inertia of preventing revolving the arch is big, the intensity and the rigidity of intramedullary nail have been strengthened, the ability of resisting bending has been increased, prevent bearing a burden too big, cause the bending fracture of intramedullary nail, and other prevent revolving bellied sectional areas are little, therefore the source damage to the bone is little; the tips of the anti-rotation protrusions face outwards, the protrusions adopting the structure can enter bone more conveniently, and simultaneously, after entering a bone cavity, the tips of the anti-rotation protrusions are inserted into the bone to play a role in preventing rotation; therefore, the structure of the utility model not only can play the role of preventing rotation and accelerate the healing of fracture, but also has good bending resistance of the intramedullary nail and little damage to the bone.

Furthermore, the anti-rotation bulge comprises a first anti-rotation bulge, a second anti-rotation bulge and a third anti-rotation bulge, and the sectional area of the first anti-rotation bulge is larger than that of the second or third anti-rotation bulge.

Furthermore, the first anti-rotation bulge, the second anti-rotation bulge and the third anti-rotation bulge are triangular anti-rotation bulges. In this way, the anti-rotation protrusion is easily inserted into the bone.

Furthermore, the center line passing through the vertex of the first anti-rotation bulge is intersected with the center line passing through the vertex of the second anti-rotation bulge at a right angle, and the center line passing through the vertex of the first anti-rotation bulge is intersected with the center line passing through the vertex of the third anti-rotation bulge at a right angle. The three anti-rotation bulges which are vertically crossed are adopted, so that the bending resistance of the intramedullary nail is better.

Furthermore, a core body is movably arranged in the intramedullary nail body, the section of the core body is non-circular, an inner locking needle is hinged on the core body and positioned in the intramedullary nail body, an inclined hole for the inner locking needle to pass through is arranged on the intramedullary nail body, and the inclined hole inclines upwards from inside to outside; the proximal end of the intramedullary nail body is provided with a fixing device connected with the core body. The non-circular core is adopted to prevent the core from rotating in the intramedullary nail body, and the fixing device prevents the core from axially moving towards the far end.

Furthermore, the fixing device comprises an internal thread sleeve and a resisting part connected to the upper end of the internal thread sleeve, an external thread is arranged at the near end of the core body, the internal thread sleeve is meshed with the external thread part of the core body, and the resisting part is resisted on the upper end face of the intramedullary nail body. By adopting the fixing device with the structure, the core body can be prevented from sliding inwards, so that the core body is more firmly and conveniently fixed; meanwhile, the blocking part and the intramedullary nail body interact to play a role in pressurizing, so that two ends of the fracture part can be more closely jointed; the internal thread sleeve is positioned in the intramedullary nail to reduce the length of the fixing device protruding out of the intramedullary nail body.

Furthermore, a longitudinal groove body is arranged on the surface of the far end of the core body, the inner locking needle is hinged in the groove body, and the needle point of the inner locking needle is abutted against the inner wall of the intramedullary nail; a torsion spring is arranged between the core body and the inner locking needle. The torsional spring is arranged between the core body and the inner locking needle, the inner locking needle is in a closed state in the process that the core body enters the intramedullary nail, the inner locking needle is retracted into the groove body, the needle point is abutted against the inner wall of the intramedullary nail, and when the core body moves towards the near end of the intramedullary nail, the inner locking needle can smoothly pass through the inclined hole under the action of the torsional spring.

Further, the inner lock needle is respectively arranged on the front side, the left side and the right side of the distal end part of the core body, and the inner lock needle positioned on the front side can penetrate through the anti-rotation bulge with the largest cross section area.

Furthermore, the inner lock needles are uniformly distributed on the cross section of the core body along the circumference, and the inner lock needles are distributed along the axial direction of the core body in a staggered manner. The inner lock needle adopts the distribution, so that the inner lock needle can have better anti-rotation fixing effect after being opened, and the locking is firmer and more accurate.

Drawings

Fig. 1 is a sectional view of the present invention.

Fig. 2 is a cross-sectional view of another structure of the present invention.

Fig. 3 is a sectional view taken along line a-a of fig. 1 according to the present invention.

Fig. 4 is a schematic view of the bending-proof self-locking compression intramedullary nail of the present invention applied to the fracture between the femoral neck and the tuberosity.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Example 1.

As shown in fig. 1 and 3, the anti-bending self-locking compression intramedullary nail comprises an intramedullary nail body 3, a core 4, an inner locking needle 5 and a fixing device.

The intramedullary nail body 3 penetrates through the fractured bone, and the outer side surface of the intramedullary nail body is provided with anti-rotation protrusions extending from the proximal end to the distal end along the axial direction, wherein the anti-rotation protrusions comprise a first anti-rotation protrusion 31, a second anti-rotation protrusion 32 and a third anti-rotation protrusion 33 in the embodiment.

The three axially extending anti-rotation protrusions arranged from the near end to the far end of the intramedullary nail body 3 are equivalent to three reinforcing ribs arranged on the intramedullary nail body along the axial direction, the shape of the radial section of the intramedullary nail body is changed, the radial section area of the intramedullary nail body is increased, the larger the section area is, the larger the section inertia moment is, the higher the strength and the rigidity of the intramedullary nail body are, the stronger the bending resistance is, and the intramedullary nail body is prevented from being overloaded, so that the bending fracture of the intramedullary nail body is prevented, and the intramedullary nail body is difficult to take out.

The three anti-rotation bulges are triangular wedge-shaped bulges, namely the triangular anti-rotation bulges, and the tips of the anti-rotation bulges face outwards.

The anti-rotation protrusion with the structure can enter a bone more conveniently, and simultaneously, after entering a bone cavity, the protruding triangular tip is inserted into the bone to play a role in preventing rotation.

In the same cross section, the center line passing through the vertex of the first rotation preventing protrusion 31 and the center line passing through the vertex of the second rotation preventing protrusion 32 intersect at right angles, and the center line passing through the vertex of the first rotation preventing protrusion 31 and the center line passing through the vertex of the third rotation preventing protrusion 32 also intersect at right angles.

When the intramedullary nail body is installed in a fractured bone, the first anti-rotation bulge is arranged opposite to the direction with large stress, and the bending resistance is strongest because the cross section area is largest and the inertia moment is larger; therefore, the bending resistance of the intramedullary nail body at the front side and the rear side of the human body can be enhanced, and the intramedullary nail body is prevented from being bent and broken when being impacted by external force or sitting and standing.

The cross-sectional area of the first rotation-preventing protrusion 31 is much larger than that of the second and third rotation-preventing protrusions 32, 33, the cross-sectional areas of the second rotation-preventing protrusion 32 and the third rotation-preventing protrusion 33 are the same, and the second rotation-preventing protrusion 32 and the third rotation-preventing protrusion 33 are oppositely arranged relative to the center of the intramedullary nail body.

In order to improve the anti-rotation and anti-bending effects of the intramedullary nail body, the first anti-rotation bulge is larger, and meanwhile, in order to reduce the damage to the marrow cavity, the second anti-rotation bulge and the third anti-rotation bulge are smaller.

The radius of the circle of the distal anti-rotation convex tip of the intramedullary nail body 3 taking the central axis of the inner cavity of the intramedullary nail body as the center is smaller than the radius of the circumscribed circle of the outer section of the proximal end of the intramedullary nail body.

The highest bulge at the far end of the intramedullary nail body is also arranged in a circumscribed circle of the outer side cross section of the near end of the intramedullary nail body, so that the intramedullary nail body can smoothly pass through other fixing parts.

The outer side of the near end of the intramedullary nail body 3 is provided with a near end anti-rotation bulge 30, and after the intramedullary nail body enters the bone, the near end anti-rotation bulge 30 plays a role in preventing rotation.

The proximal inside of the intramedullary nail body is provided with an internal thread 36.

The internal thread at the inner side of the near end of the intramedullary nail body is used for being matched with the external thread at the tail part of the intramedullary nail body installer to install or take out the intramedullary nail body 3, when the intramedullary nail body 3 is installed, the external thread at the tail part of the intramedullary nail body installer is meshed with the internal thread of the intramedullary nail body to be connected and fixed, the intramedullary nail body is directly inserted into an intramedullary nail body installing pore channel which is formed in the medullary cavity in advance by an electric drill, and the anti-rotation bulge at the near end of the intramedullary nail body is embedded into the bone to play a good anti-rotation role; meanwhile, the anti-rotation protrusion is inserted into the bone, the intramedullary nail body 3 cannot rotate when the core is operated, and when the core is axially moved towards the near end by the external driving instrument, the abutting part of the external driving instrument can press the near end face of the intramedullary nail body to prevent the intramedullary nail body from withdrawing.

The intramedullary nail body 3 is provided with a core 4 axially and movably, and the section of the core 4 is non-circular. The core 4 is of such a non-circular cross-section that rotation of the core 4 relative to the intramedullary nail body 3 is prevented.

The far end of the core body 4 is hinged with more than two inner locking needles 5, in the embodiment, the far end of the core body 4 is hinged with three inner locking needles, the inner locking needles 5 positioned at the far end are uniformly distributed on the cross section of the core body along the circumference, and the three inner locking needles at the far end are distributed along the axial direction of the core body in a staggered way. In this embodiment, at least one distal inside locking pin extends through the first anti-rotation protrusion. More than two inner locking needles 5 are hinged to the core body 4 near the proximal end, in the embodiment, three inner locking needles are hinged to the core body 4 near the proximal end, the inner locking needles 5 near the proximal end are uniformly distributed on the cross section of the core body along the circumference, and the three inner locking needles near the proximal end are distributed along the axial direction of the core body in a staggered manner. In this embodiment, at least one internal locking pin near the proximal end passes through the first anti-rotation protrusion.

The wall body of the intramedullary nail body 3 is provided with an inclined hole 7 which is adapted to the inner locking needle and is used for the inner locking needle to penetrate out, and the inclined hole 7 inclines towards the near end of the intramedullary nail body from inside to outside.

The inclined hole on the intramedullary nail body wall body inclines towards the near end of the intramedullary nail body from inside to outside, so that the penetration of the internal locking needle is facilitated, the internal locking needle is more attached to the inclined hole after penetrating, the shaking of the core body is reduced, and a better anti-rotation fixing effect is achieved. The inner locking needles are respectively arranged at the near end and the far end of the core body, so that the anti-rotation effect of the pressurizing intramedullary nail is better.

The surface of the core body 4 is provided with a longitudinal groove body 6, the inner locking needle 5 is hinged in the groove body 6, and the needle point of the inner locking needle is propped against the inner wall of the intramedullary nail body. The surface of the core body is provided with a longitudinal groove body, so that the inner locking needle is in a closed state in the process that the core body enters the intramedullary nail body, the needle body is retracted into the groove body, and the needle point is abutted against the inner wall of the intramedullary nail body. A torsion spring is arranged between the core body 4 and the inner locking needle 5. When the core body moves, the inner lock needle can pass through the inclined hole more smoothly under the action of the torsion spring.

The core 4 is connected with a fixing device which is resisted on the proximal end face of the intramedullary nail body 3.

The fixing device is an internal thread component 8, the internal thread component 8 comprises an internal thread sleeve 81 and a resisting part 82 connected to the upper end of the internal thread sleeve, an external thread is arranged at the near end of the core body, the internal thread sleeve 81 extends into the intramedullary nail body 3 and is matched with the external thread of the core body 4, and the resisting part 82 is resisted on the near end face of the intramedullary nail body.

By adopting the fixing device with the structure, the core body 4 can be prevented from sliding inwards, so that the core body 4 is more firmly and conveniently fixed; meanwhile, the mutual action of the resisting part 82 and the intramedullary nail body 3 plays a role in pressurizing, so that two ends of the fracture part can be more tightly jointed; the internal threaded sleeve 81 is located inside the intramedullary nail body 3, reducing the protruding length of the fixation device.

The stopper 82 is provided with a hexagonal socket hole 83. Thus, the internal thread component can be rotated more conveniently.

When the intramedullary nail is installed and used, a core 4 hinged with an internal locking needle 5 is firstly installed in an intramedullary nail body 3, the external thread at the tail part of the operation end of an intramedullary nail body installer is firstly meshed with the internal thread 36 of the intramedullary nail body for connection and fixation, the installation direction of the intramedullary nail body 3 is determined, the intramedullary nail body 3 is directly inserted into an intramedullary nail body installation pore canal which is drilled in the intramedullary canal in advance by an electric drill, then, the core 4 in the intramedullary nail body is connected with the external thread of the core through an external driving instrument, the core 4 in the intramedullary nail body moves towards the proximal direction of the intramedullary nail body, the internal locking needle 5 passes through an inclined hole 7 of the intramedullary nail body to be opened and enters the bone at the far end and the proximal end of a fracture part for fixation, and the internal locking needle 5 generates force acting on the bone in the intramedullary canal at the far end of the fracture towards the proximal direction of the intramedullary nail body; after the core 4 reaches a proper position, the external driving instrument is taken out, the fixing device is installed, under the matching action of the hexagonal wrench and the inner hexagonal blind hole 83, the inner thread sleeve 81 extends into the intramedullary nail body and is matched and screwed with the outer thread of the core, the resisting part 82 is resisted on the end surface of the near end of the intramedullary nail body, the core 4 is tensioned by the fixing device, force acting on the near end of the fracture towards the far end direction of the intramedullary nail body 3 is generated, in this way, opposite acting force is generated at the two ends of the fracture simultaneously, the effect of pressurizing the fracture end is achieved, and therefore the two ends of the fracture can be tightly jointed.

When the fracture needs to be healed, the intramedullary nail body 3 is taken out, the fixing device is taken out under the matching action of the hexagonal wrench and the inner hexagonal blind hole 83, the external driving instrument is matched with the external thread of the core body, then the core body 4 is pushed to move towards the far end of the intramedullary nail body 3, the internal locking needle 5 exits from the inclined hole 7 and returns to the nail body of the intramedullary nail body 3, and then the external thread at the tail part of the operation end of the intramedullary nail body installer is matched and connected with the internal thread 36 of the intramedullary nail body for fixing, and then the intramedullary nail body 3 is forcibly pulled out.

The utility model discloses the intramedullary nail near-end to the distal end outside set up more than two axially extended prevent revolving the arch, be equivalent to for the intramedullary nail along the axial direction on installed three strengthening rib, the intramedullary nail radial cross sectional area has been increased, the shape of intramedullary nail radial cross section has been changed, in addition according to the principle of moment of inertia, as the moment of inertia is bigger, the bending resistance can be better, because one of them prevents revolving the bellied sectional area big, therefore, the biggest moment of inertia of preventing revolving the arch is big, the intensity and the rigidity of intramedullary nail have been strengthened, the ability of resisting bending has been increased, prevent bearing a burden too big, cause the bending fracture of intramedullary nail, and other prevent revolving bellied sectional areas are little, therefore the source damage to the bone is little; the tips of the anti-rotation protrusions face outwards, the protrusions adopting the structure can enter bone more conveniently, and simultaneously, after entering a bone cavity, the tips of the anti-rotation protrusions are inserted into the bone to play a role in preventing rotation; therefore, the structure of the utility model not only can play the role of preventing rotation and accelerate the healing of fracture, but also has good bending resistance of the intramedullary nail and little damage to the bone.

As shown in fig. 2, the intramedullary nail body 3 and the core 4 may be curved to meet the requirements of bones with different curvatures, and the bending angle is 3-10 degrees.

Example 2.

Fig. 4 is a schematic view of the bending-proof self-locking compression intramedullary nail of the present invention applied to the fracture between the femoral neck and the tuberosity. The application of the femoral nail is that a main nail 100 is inserted into a femur, and a nail hole 101 is formed on the main nail 100. The lower part of the main nail 100 is provided with at least two lower screw holes 9, the head peripheral surface of a hollow screw 10 arranged at the lower screw hole 9 is provided with external threads, the external threads of the hollow screw 10 can be matched and fixed with the internal diameter threads of the lower screw hole 9, and the tail peripheral surface of the hollow screw 10 is provided with external threads.

After the hollow screw passes through the lower part screw hole and screws into the femur, the external thread of the hollow screw is fixed with the internal diameter thread fit of the lower part screw hole, the thread fit can ensure that the hollow screw and the main nail 100 are fixed firmly and better, the hollow screw is prevented from being pulled out from the main nail 100 and falling off, the external thread is arranged on the circumferential surface of the tail part of the hollow screw, so that the hollow screw can be screwed into the femur, the femur fracture caused by direct insertion is avoided, and meanwhile, the thread structure can prevent the hollow screw from being pulled out from the bone and falling off. Meanwhile, fastening devices are formed at both ends of the hollow screw.

The nail holes are inclined upwards by an angle alpha relative to the vertical side surface of the main nail 100, and the angle alpha is 120-130 degrees.

The included angle of the femoral neck and the femur is called the neck angle, the male neck angle is 132 degrees on average, the female neck angle is 127 degrees on average, so the included angle alpha of the intramedullary nail and the femur is set to 120-130 degrees, the direction of the intramedullary nail can be well controlled, the bone can be prevented from penetrating out, and the femoral neck and the intertrochanteric fracture part can be better inserted.

As shown in fig. 1 and 3, the anti-bending self-locking compression intramedullary nail 200 comprises an intramedullary nail body 3, a core 4, an internal locking needle 5 and a fixing device.

The intramedullary nail body 3 passes through the fractured bone through the nail hole, and the outer side surface of the intramedullary nail body is provided with anti-rotation protrusions extending from the proximal end to the distal end along the axial direction, wherein the anti-rotation protrusions comprise a first anti-rotation protrusion 31, a second anti-rotation protrusion 32 and a third anti-rotation protrusion 33 in the embodiment.

Thighbone supports human trunk, pelvis etc. is the longest of human body, the heaviest bone of bearing a burden, three axial that set up in intramedullary nail distal end nail body outside prevent revolving the arch, be equivalent to for the intramedullary nail along three strengthening rib of axial direction installation, changed the shape of intramedullary nail radial cross section, increased intramedullary nail radial cross sectional area, cross sectional area is big more, cross sectional inertia moment is big more, the intensity and the rigidity of intramedullary nail are big more, it is strong to resist bending ability, prevent that the intramedullary nail bears a burden excessively, cause the bending fracture of intramedullary nail, be difficult to take out.

The three anti-rotation bulges are triangular wedge-shaped bulges, namely the triangular anti-rotation bulges, and the tips of the anti-rotation bulges face outwards.

The anti-rotation protrusion with the structure can enter a bone more conveniently, and simultaneously, after entering a bone cavity, the protruding triangular tip is inserted into the bone to play a role in preventing rotation.

In the same cross section, the center line passing through the vertex of the first rotation preventing protrusion 31 and the center line passing through the vertex of the second rotation preventing protrusion 32 intersect at right angles, and the center line passing through the vertex of the first rotation preventing protrusion 31 and the center line passing through the vertex of the third rotation preventing protrusion 32 also intersect at right angles.

When the intramedullary nail body is installed in a fractured bone, the first anti-rotation bulge is arranged opposite to the direction with large stress, and the bending resistance is strongest because the cross section area is largest and the inertia moment is larger; therefore, the bending resistance of the intramedullary nail body at the front side and the rear side of the human body can be enhanced, and the intramedullary nail body is prevented from being bent and broken when being impacted by external force or sitting and standing.

The cross-sectional area of the first rotation-preventing protrusion 31 is much larger than that of the second and third rotation-preventing protrusions 32, 33, the cross-sectional areas of the second rotation-preventing protrusion 32 and the third rotation-preventing protrusion 33 are the same, and the second rotation-preventing protrusion 32 and the third rotation-preventing protrusion 33 are oppositely arranged relative to the center of the intramedullary nail body.

In order to improve the anti-rotation and anti-bending effects of the intramedullary nail body, the first anti-rotation bulge is larger, and meanwhile, in order to reduce the damage to the marrow cavity, the second anti-rotation bulge and the third anti-rotation bulge are smaller.

The radius of the circle of the distal anti-rotation convex tip of the intramedullary nail body 3 taking the central axis of the inner cavity of the intramedullary nail body as the center is smaller than the radius of the circumscribed circle of the outer section of the proximal end of the intramedullary nail body.

The highest bulge at the far end of the intramedullary nail body is also arranged in a circumscribed circle of the outer side cross section of the near end of the intramedullary nail body, so that the intramedullary nail body can smoothly pass through other fixing parts.

The outer side of the near end of the intramedullary nail body 3 is provided with a near end anti-rotation bulge 30, and after the intramedullary nail body enters the bone, the near end anti-rotation bulge 30 plays a role in preventing rotation.

The proximal inside of the intramedullary nail body is provided with an internal thread 36.

The internal thread at the inner side of the near end of the intramedullary nail body is used for being matched with the external thread at the tail part of the intramedullary nail body installer to install or take out the intramedullary nail body 3, when the intramedullary nail body 3 is installed, the external thread at the tail part of the intramedullary nail body installer is meshed with the internal thread of the intramedullary nail body to be connected and fixed, the intramedullary nail body is directly inserted into an intramedullary nail body installing pore channel which is formed in the medullary cavity in advance by an electric drill, and the anti-rotation bulge at the near end of the intramedullary nail body is embedded into the bone to play a good anti-rotation role; meanwhile, the anti-rotation protrusion is inserted into the bone, the intramedullary nail body 3 cannot rotate when the core is operated, and when the core is axially moved towards the near end by the external driving instrument, the abutting part of the external driving instrument can press the near end face of the intramedullary nail body to prevent the intramedullary nail body from withdrawing.

The intramedullary nail body 3 is provided with a core 4 axially and movably, and the section of the core 4 is non-circular. The core 4 is of such a non-circular cross-section that rotation of the core 4 relative to the intramedullary nail body 3 is prevented.

The far end of the core body 4 is hinged with more than two inner locking needles 5, in the embodiment, the far end of the core body 4 is hinged with three inner locking needles, the inner locking needles 5 positioned at the far end are uniformly distributed on the cross section of the core body along the circumference, and the three inner locking needles at the far end are distributed along the axial direction of the core body in a staggered way. In this embodiment, at least one distal inside locking pin extends through the first anti-rotation protrusion. More than two inner locking needles 5 are hinged to the core body 4 near the proximal end, in the embodiment, three inner locking needles are hinged to the core body 4 near the proximal end, the inner locking needles 5 near the proximal end are uniformly distributed on the cross section of the core body along the circumference, and the three inner locking needles near the proximal end are distributed along the axial direction of the core body in a staggered manner. In this embodiment, at least one internal locking pin near the proximal end passes through the first anti-rotation protrusion.

The wall body of the intramedullary nail body 3 is provided with an inclined hole 7 which is adapted to the inner locking needle and is used for the inner locking needle to penetrate out, and the inclined hole 7 inclines towards the near end of the intramedullary nail body from inside to outside.

The inclined hole on the intramedullary nail body wall body inclines towards the near end of the intramedullary nail body from inside to outside, so that the penetration of the internal locking needle is facilitated, the internal locking needle is more attached to the inclined hole after penetrating, the shaking of the core body is reduced, and a better anti-rotation fixing effect is achieved. The inner locking needles are respectively arranged at the near end and the far end of the core body, so that the anti-rotation effect of the pressurizing intramedullary nail is better.

The surface of the core body 4 is provided with a longitudinal groove body 6, the inner locking needle 5 is hinged in the groove body 6, and the needle point of the inner locking needle is propped against the inner wall of the intramedullary nail body. The surface of the core body is provided with a longitudinal groove body, so that the inner locking needle is in a closed state in the process that the core body enters the intramedullary nail body, the needle body is retracted into the groove body, and the needle point is abutted against the inner wall of the intramedullary nail body. A torsion spring is arranged between the core body 4 and the inner locking needle 5. When the core body moves, the inner lock needle can pass through the inclined hole more smoothly under the action of the torsion spring.

The core 4 is connected with a fixing device which is resisted on the proximal end face of the intramedullary nail body 3.

The fixing device is an internal thread component 8, the internal thread component 8 comprises an internal thread sleeve 81 and a resisting part 82 connected to the upper end of the internal thread sleeve, an external thread is arranged at the near end of the core body, the internal thread sleeve 81 extends into the intramedullary nail body 3 and is matched with the external thread of the core body 4, and the resisting part 82 is resisted on the near end face of the intramedullary nail body.

By adopting the fixing device with the structure, the core body 4 can be prevented from sliding inwards, so that the core body 4 is more firmly and conveniently fixed; meanwhile, the mutual action of the resisting part 82 and the intramedullary nail body 3 plays a role in pressurizing, so that two ends of the fracture part can be more tightly jointed; the internal threaded sleeve 81 is located inside the intramedullary nail body 3, reducing the protruding length of the fixation device.

The stopper 82 is provided with a hexagonal socket hole 83. Thus, the internal thread component can be rotated more conveniently.

When the intramedullary nail is installed and used, a core 4 hinged with an internal locking needle 5 is firstly installed in an intramedullary nail body 3, the external thread at the tail part of the operation end of an intramedullary nail body installer is firstly meshed with the internal thread 36 of the intramedullary nail body for connection and fixation, the installation direction of the intramedullary nail body 3 is determined, the intramedullary nail body 3 is directly inserted into an intramedullary nail body installation pore canal which is drilled in the intramedullary canal in advance by an electric drill, then, the core 4 in the intramedullary nail body is connected with the external thread of the core through an external driving instrument, the core 4 in the intramedullary nail body moves towards the proximal direction of the intramedullary nail body, the internal locking needle 5 passes through an inclined hole 7 of the intramedullary nail body to be opened and enters the bone at the far end and the proximal end of a fracture part for fixation, and the internal locking needle 5 generates force acting on the bone in the intramedullary canal at the far end of the fracture towards the proximal direction of the intramedullary nail body; after the core 4 reaches a proper position, the external driving instrument is taken out, the fixing device is installed, under the matching action of the hexagonal wrench and the inner hexagonal blind hole 83, the inner thread sleeve 81 extends into the intramedullary nail body and is matched and screwed with the outer thread of the core, the resisting part 82 is resisted on the end surface of the near end of the intramedullary nail body, the core 4 is tensioned by the fixing device, force acting on the near end of the fracture towards the far end direction of the intramedullary nail body 3 is generated, in this way, opposite acting force is generated at the two ends of the fracture simultaneously, the effect of pressurizing the fracture end is achieved, and therefore the two ends of the fracture can be tightly jointed.

When the fracture needs to be healed, the intramedullary nail body 3 is taken out, the fixing device is taken out under the matching action of the hexagonal wrench and the inner hexagonal blind hole 83, the external driving instrument is matched with the external thread of the core body, then the core body 4 is pushed to move towards the far end of the intramedullary nail body 3, the internal locking needle 5 exits from the inclined hole 7 and returns to the nail body of the intramedullary nail body 3, and then the external thread at the tail part of the operation end of the intramedullary nail body installer is matched and connected with the internal thread 36 of the intramedullary nail body for fixing, and then the intramedullary nail body 3 is forcibly pulled out.

The utility model discloses the intramedullary nail near-end to the distal end outside set up more than two axially extended prevent revolving the arch, be equivalent to for the intramedullary nail along the axial direction on installed three strengthening rib, the intramedullary nail radial cross sectional area has been increased, the shape of intramedullary nail radial cross section has been changed, in addition according to the principle of moment of inertia, as the moment of inertia is bigger, the bending resistance can be better, because one of them prevents revolving the bellied sectional area big, therefore, the biggest moment of inertia of preventing revolving the arch is big, the intensity and the rigidity of intramedullary nail have been strengthened, the ability of resisting bending has been increased, prevent bearing a burden too big, cause the bending fracture of intramedullary nail, and other prevent revolving bellied sectional areas are little, therefore the source damage to the bone is little; the tips of the anti-rotation protrusions face outwards, the protrusions adopting the structure can enter bone more conveniently, and simultaneously, after entering a bone cavity, the tips of the anti-rotation protrusions are inserted into the bone to play a role in preventing rotation; therefore, the structure of the utility model not only can play the role of preventing rotation and accelerate the healing of fracture, but also has good bending resistance of the intramedullary nail and little damage to the bone.

As shown in fig. 2, the intramedullary nail body 3 and the core 4 may be curved to meet the requirements of bones with different curvatures, and the bending angle is 3-10 degrees.

Claims (9)

1. An anti-bending self-locking pressurizing intramedullary nail comprises an intramedullary nail body; the method is characterized in that: the outer side surface of the intramedullary nail body is provided with more than two anti-rotation bulges extending from the near end to the far end along the axial direction, the cross sections of the anti-rotation bulges are provided with tip ends, the tip ends of the anti-rotation bulges face outwards, and the cross section area of one anti-rotation bulge is larger than that of the other anti-rotation bulges.

2. The anti-bending self-locking compression intramedullary nail of claim 1, wherein: the anti-rotation bulge comprises a first anti-rotation bulge, a second anti-rotation bulge and a third anti-rotation bulge, and the sectional area of the first anti-rotation bulge is larger than that of the second or third anti-rotation bulge.

3. The anti-bending self-locking compression intramedullary nail of claim 2, wherein: the first anti-rotation bulge, the second anti-rotation bulge and the third anti-rotation bulge are triangular anti-rotation bulges.

4. The anti-bending self-locking compression intramedullary nail of claim 2, wherein: the central line passing through the vertex of the first anti-rotation bulge is intersected with the central line passing through the vertex of the second anti-rotation bulge at a right angle, and the central line passing through the vertex of the first anti-rotation bulge is intersected with the central line passing through the vertex of the third anti-rotation bulge at a right angle.

5. The anti-bending self-locking compression intramedullary nail of claim 1, wherein: a core body is movably arranged in the intramedullary nail body, the section of the core body is non-circular, an inner locking needle is hinged in the intramedullary nail body on the core body, an inclined hole for the inner locking needle to pass through is arranged on the intramedullary nail body, and the inclined hole inclines upwards from inside to outside; the proximal end of the intramedullary nail body is provided with a fixing device connected with the core body.

6. The anti-bending self-locking compression intramedullary nail of claim 5, wherein: the fixing device comprises an internal thread sleeve and a resisting part connected to the upper end of the internal thread sleeve, an external thread is arranged at the near end of the core body, the internal thread sleeve is meshed with the external thread part of the core body, and the resisting part is resisted on the upper end face of the intramedullary nail body.

7. The anti-bending self-locking compression intramedullary nail of claim 5, wherein: the surface of the far end of the core body is provided with a longitudinal groove body, the inner locking needle is hinged in the groove body, and the needle point of the inner locking needle is abutted against the inner wall of the intramedullary nail; a torsion spring is arranged between the core body and the inner locking needle.

8. The anti-bending self-locking compression intramedullary nail of claim 5, wherein: the inner lock needle is respectively arranged on the front side, the left side and the right side of the far end part of the core body, and the inner lock needle positioned on the front side can penetrate through the anti-rotation bulge with the largest cross section area.

9. The anti-bending self-locking compression intramedullary nail of claim 1, wherein: the inner lock needles are uniformly distributed on the cross section of the core body along the circumference, and are distributed along the axial direction of the core body in a staggered way.

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