Metacarpal Intramedullary Needle

Abstract

The invention relates to a palmar intramedullary needle, comprising a needle body, an inner cavity is provided near the tip of the needle body, at least one pair of elastic locking barbs arranged oppositely are provided in the inner cavity, one end of the elastic locking barb is fixedly connected to the needle body, the other end of the elastic locking barb is directed toward the tail end of the needle body and is curved along the radial outer side, an opening groove for the curved end of the elastic locking barb to extend out is provided on the inner cavity wall of the needle body, a control sleeve is slidably provided in the inner cavity, the control sleeve comprises an intermediate body, a yielding groove corresponding to the opening groove is provided on the intermediate body for the curved end of the elastic locking barb to extend out of the opening groove, a retaining ring and a retracting ring are respectively provided at both axial ends of the intermediate body for the curved end of the elastic locking barb to be retracted in the opening groove, the retracting ring is located at one end of the control sleeve near the front end of the needle body, the control sleeve is connected to a driving device for driving the control sleeve to slide, and the operating end of the driving device is placed at the tail end of the needle body. With an inner locking structure, the intramedullary needle is reliably fixed and convenient to remove.

Description

Technical Field

[0001] The present invention relates to surgical instruments, more specifically to intramedullary needles for metacarpal bones. Background Art

[0002] Metacarpal fractures can generally be divided into four categories: metacarpal head fracture, metacarpal neck fracture, metacarpal shaft fracture and metacarpal base fracture. Among them, metacarpal neck and metacarpal shaft fractures are more common, and the incidence of fractures in men is more common than in women. The displacement of the fracture is small, and external fixation can be performed. There are generally many fixation methods, and the fixation techniques vary, including traction fixation, plaster splint external fixation, small splint fixation and intramedullary nailing. The above surgical treatment methods have their own advantages and disadvantages, but the general development direction of trauma treatment is

[0003] Small trauma, good prognosis, etc. Therefore, intramedullary nailing technology is currently the first choice for the treatment of long-barreled bone fractures. The existing intramedullary nails used in clinical practice are bare rods, which have the problem of weak holding force on the fracture ends and unreliable fixation of the fracture site due to slippage of the intramedullary nail. Summary of the invention

[0004] Purpose of the invention: To overcome the defects of the prior art, the present invention provides a metacarpal intramedullary needle with an internal locking structure and easy to remove.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A metacarpophalangeal intramedullary needle comprises a needle body, the needle body has a tip and a tail end, characterized in that: an inner cavity is provided at a position near the tip of the needle body, and at least a pair of elastic locking barbs arranged oppositely are provided in the inner cavity, one end of the elastic locking barb is fixedly connected to the needle body, and the other end of the elastic locking barb is bent in an arc shape toward the tail end of the needle body and radially outward, an opening groove for the warped end of the elastic locking barb to extend out is provided on the inner cavity wall of the needle body, and a control sleeve is slidably provided in the inner cavity, the control sleeve comprises an intermediate body, the intermediate body is provided with a yield groove corresponding to the open groove for the warped end of the elastic locking barb to extend out of the open groove, a retaining ring and a retraction ring are respectively provided at two axial ends of the intermediate body, and the retraction ring is located at one end of the control sleeve near the front end of the needle body, the control sleeve is connected to a driving device for driving the control sleeve to slide, and the operating end of the driving device is placed at the tail end of the needle body.

[0007] By adopting the above technical solution, when in use, the retaining ring of the control sleeve clamps the warped end of the elastic locking barb, the warped end of the elastic locking barb is located in the opening groove, the intramedullary needle is placed in the medullary cavity of the fracture, the tail end of the intramedullary needle is exposed, the operating end of the operating drive device is operated to move the control sleeve, the retaining ring of the control sleeve disengages the warped end of the elastic locking barb, the yielding groove of the control sleeve corresponds to the opening groove, the warped end of the elastic locking barb extends out of the opening groove under the action of elastic force, so as to be elastically held on the inner wall of the medullary cavity, playing the role of locking the intramedullary needle, and improving the intramedullary needle fixation effect; after the treatment is completed, the operating end of the operating drive device is operated to drive the control sleeve to continue sliding, the retraction ring compresses the elastic locking barb to retract, thereby releasing the lock on the intramedullary needle, and facilitating the subsequent removal of the intramedullary needle. The control sleeve restricts the warped end of the elastic locking barb with the retaining ring, and then releases the restriction on the warped end of the elastic locking barb, the operation stroke is short, and it has the advantages of sensitive and convenient operation, and shortens the operation time.

[0008] Preferably, the driving device includes a traction rope, a channel connected to the inner cavity is provided in the needle body, the channel passes through the tail end of the needle body, one end of the traction rope is connected to the control sleeve, and the other end of the traction rope is an operating end. The tail end of the needle body is provided with an anti-misoperation mechanism to prevent the traction rope from being mistakenly pulled to drive the control sleeve to the retraction ring to retract the elastic locking barb when the control sleeve is in the corresponding position of the yield groove and the opening groove. Under this structural design, the traction rope is used to drive the control sleeve to slide, the structure is simple, the traction operation method is simpler, and the anti-misoperation mechanism can prevent the elastic locking barb from being retracted due to the traction rope being mistakenly pulled after the elastic locking barb is expanded, thereby affecting the fixing effect of the needle body.

[0009] Preferably, the anti-misoperation mechanism includes a blocking ring fixed on the traction rope, the diameter of the blocking ring is larger than the port of the channel located at the tail end of the needle body, the tail end of the needle body is provided with a receiving cavity, the port of the channel is located in the receiving cavity, the blocking ring is movably arranged in the receiving cavity, a cover is detachably provided on the port of the receiving cavity, the cover is provided with an extension hole for the traction rope to extend out, the blocking ring and the cover are blocked and cooperated, and the operating end of the traction rope includes a primary traction end that extends out of the extension hole when the blocking ring is located at the bottom of the receiving cavity, and an ear hole provided on the blocking ring. Under this structural design, the blocking ring ensures that the operating end of the traction rope is external, and the traction end of the traction rope is placed in the channel. In addition, the cooperation between the blocking ring and the cover can ensure that the traction operation is in place and reliable, and ensure that the operating sleeve moves to the warped end of the elastic locking barb to extend out. After the warped end of the elastic locking barb is opened, the primary traction end of the traction rope can be cut off along the extension hole to avoid the traction rope being exposed and affecting the appearance. When the intramedullary needle needs to be removed at a later stage, the cover is removed to expose the ear hole of the blocking ring, and the traction rope can be pulled again to drive the control sleeve to retract the warped end of the elastic locking barb to release the lock of the intramedullary needle.

[0010] Preferably, a compression spring is provided between the blocking ring and the cover to drive the blocking ring to be placed at the bottom of the receiving chamber. With this structural design, after the primary traction end of the traction rope is cut off, the cut end of the traction rope is retracted into the receiving chamber, thereby preventing the traction rope from being exposed and facilitating the selection of the cutting position.

[0011] Preferably, the cover is screwed into the receiving cavity. This structural design has the advantage of being simple in structure.

[0012] Preferably, the inner wall of the control sleeve is integrally formed with reinforcing ribs, and the reinforcing ribs form a connecting entity for connecting the traction rope at the axial center of the control sleeve. Under this structural design, the strength of the control sleeve is improved, and the fixing of the traction rope is also convenient.

[0013] Preferably, the needle body is made of titanium alloy. Under this structural design, titanium alloy has the advantages of high flexibility, better fatigue resistance than other stainless steel materials, and less influence on the regeneration of bone tissue.

[0014] The present invention will be further described below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a stereoscopic diagram of a specific embodiment of the present invention in which the intramedullary needle of the palm and finger is locked;

[0016] Figure 2 This is a schematic diagram of the structure of a specific embodiment of the present invention when the intramedullary needle of the metacarpal bone is locked;

[0017] Figure 3 This is a schematic diagram of the structure of the metacarpal intramedullary needle in the initial state of a specific embodiment of the present invention;

[0018] Figure 4 It is a schematic diagram of the structure of a control sleeve according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0019] See attached Figures 1 to 4The present invention discloses a metacarpal intramedullary needle, comprising a needle body 1. The material of the needle body 1 is titanium alloy. Titanium alloy has high flexibility, is more fatigue-resistant than other stainless steel materials, and has less effect on the regeneration of bone tissue. The needle body 1 has a tip 11 and a tail 12. The needle body 1 is provided with an inner cavity 13 near the tip 11. The inner cavity 13 is provided with at least one pair of elastic locking barbs 14 arranged opposite to each other. One end of the elastic locking barb 14 is fixedly connected to the needle body 1. The needle body 1 comprises a needle head 1-1 integrally formed with the elastic locking barb 14 and a needle body main body with the inner cavity 13. The needle head is inserted into the inner cavity of the needle body main body and is fixedly connected (such as tight fitting or welding), and the other end of the elastic locking barb 14 faces the needle body. 1 and is curved in an arc shape along the radial outer side. An opening groove 131 is provided on the wall of the inner cavity 13 of the needle body 1 for the warped end 141 of the elastic locking barb 14 to extend out. A control sleeve 2 is slidably arranged in the inner cavity 13. The control sleeve 2 includes an intermediate body 21. The intermediate body 21 is provided with a yielding groove 211 corresponding to the opening groove 131 for the warped end 141 of the elastic locking barb 14 to extend out of the opening groove 131. A retaining ring 22 and a retracting ring 23 are respectively provided at both axial ends of the intermediate body 21 for retracting the warped end 141 of the elastic locking barb 14 in the opening groove 131. The retracting ring 23 is located at one end of the control sleeve 2 close to the front end of the needle body 1. The control sleeve 2 is connected to a driving device for driving the control sleeve 2 to slide. The operating end of the driving device is placed at the tail end 12 of the needle body 1. When in use, the retaining ring of the control sleeve clamps the warped end of the elastic locking barb, the warped end of the elastic locking barb is located in the opening groove, the intramedullary needle is placed in the medullary cavity of the fracture, the tail end of the intramedullary needle is exposed, the operating end of the operating drive device is operated to move the control sleeve, the retaining ring of the control sleeve disengages the warped end of the elastic locking barb, the yielding groove of the control sleeve corresponds to the opening groove, the warped end of the elastic locking barb extends out of the opening groove under the action of elastic force, so as to be elastically held on the inner wall of the medullary cavity, playing the role of locking the intramedullary needle and improving the intramedullary needle fixation effect; after the treatment is completed, the operating end of the operating drive device is operated to drive the control sleeve to continue sliding, the retraction ring compresses the elastic locking barb to retract, thereby releasing the lock on the intramedullary needle, and facilitating the subsequent removal of the intramedullary needle. The control sleeve restricts the warped end of the elastic locking barb with the retaining ring, and then releases the restriction on the warped end of the elastic locking barb, the operation stroke is short, and it has the advantages of sensitive and convenient operation, shortening the operation time.

[0020] In this specific embodiment, the driving device includes a traction rope 3, and a channel 15 connected to the inner cavity 13 is provided in the needle body 1. The channel 15 passes through the tail end of the needle body 1. One end of the traction rope 3 is connected to the control sleeve 2, and the other end of the traction rope 3 is an operating end. The tail end of the needle body 1 is provided with an anti-misoperation mechanism to prevent the traction rope 3 from being mistakenly pulled when the control sleeve 2 is in the corresponding position of the yield groove 211 and the opening groove 131 to drive the control sleeve 2 to the retraction ring 23 to retract the elastic locking barb 14. The traction rope is used to drive the control sleeve to slide, which has a simple structure and a simpler traction operation method. The anti-misoperation mechanism can prevent the elastic locking barb from being retracted due to the traction rope being mistakenly pulled after the elastic locking barb is expanded, thereby affecting the fixing effect of the needle body.

[0021] Furthermore, the anti-misoperation mechanism includes a blocking ring 4 fixed on the traction rope 3, the diameter of the blocking ring 4 is larger than the port of the channel 15 located at the tail end of the needle body 1 to prevent the traction rope from retracting, the tail end of the needle body 1 is provided with a receiving cavity 16, the port of the channel 15 is located in the receiving cavity 16, the blocking ring 4 is movably arranged in the receiving cavity 16, and a cover 5 is detachably arranged on the port of the receiving cavity 16, the cover 5 is threadedly screwed in the receiving cavity 16, the cover 5 is provided with an extension hole for the traction rope 3 to extend out, the blocking ring 4 and the cover 5 are blocked and cooperated, and the operating end of the traction rope 3 includes a primary traction end 31 that extends out of the extension hole when the blocking ring 4 is located at the bottom of the receiving cavity 16, and an ear hole 41 provided on the blocking ring 4. The blocking ring 41 ensures that the operating end of the traction rope 3 is external, and the traction end of the traction rope is placed in the channel. The cooperation between the blocking ring and the cover can ensure that the traction operation is in place and reliable, and ensure that the operating sleeve moves to the warped end of the elastic locking barb to extend. After the warped end of the elastic locking barb is opened, the primary traction end of the traction rope can be cut off along the extension hole to avoid the traction rope being exposed and affecting the appearance. When the intramedullary needle needs to be removed at a later stage, the cover is removed to expose the ear hole of the blocking ring, and the traction rope can be pulled again to drive the control sleeve to retract the warped end of the elastic locking barb to release the lock of the intramedullary needle.

[0022] When the traction rope is cut, its cutting position cannot be completely controlled to be flush with the cover, so a compression spring 6 is provided between the blocking ring 4 and the cover 5 to drive the blocking ring 4 to be placed at the bottom of the receiving chamber 16. In this way, after the primary traction end of the traction rope is cut, the cut end of the traction rope is retracted into the receiving chamber, avoiding the traction rope from being exposed and facilitating the selection of the cutting position. The compression spring can be directly fixedly connected to the blocking ring, and the compression spring serves as an ear hole on the blocking ring for secondary traction.

[0023] In order to improve the strength of the control sleeve, the inner wall of the control sleeve 2 is integrally formed with a reinforcing rib 24, and the reinforcing rib 24 forms a connecting entity 241 for connecting the traction rope 3 at the axial center of the control sleeve, thereby improving the strength of the control sleeve and facilitating the fixing of the traction rope.

Claims

1. A metacarpal intramedullary needle, comprising a needle body, the needle body having a tip and a tail, characterized in that: The needle body is provided with an inner cavity near the tip, and at least one pair of elastic locking barbs arranged oppositely is provided in the inner cavity, one end of the elastic locking barb is fixedly connected to the needle body, and the other end of the elastic locking barb is directed toward the tail end of the needle body and is curved in an arc shape along the radial outer side, and an opening groove for the curved end of the elastic locking barb to extend out is provided on the inner cavity wall of the needle body, and a control sleeve is slidably provided in the inner cavity, and the control sleeve includes an intermediate body, and the intermediate body is provided with a yield groove corresponding to the open groove so that the curved end of the elastic locking barb can extend out of the open groove, and the warped ends of the elastic locking barbs are respectively provided at the axial ends of the intermediate body and are retracted into the open groove The retaining ring and the folding ring are located at one end of the control sleeve close to the front end of the needle body, the control sleeve is connected to a driving device for driving the control sleeve to slide, and the operating end of the driving device is placed at the tail end of the needle body; the driving device includes a traction rope, and the needle body is provided with a channel connected to the inner cavity, the channel passes through the tail end of the needle body, one end of the traction rope is connected to the control sleeve, and the other end of the traction rope is the operating end, and the tail end of the needle body is provided with an anti-misoperation mechanism for preventing the traction rope from being accidentally pulled when the control sleeve is in the corresponding position of the give way groove and the opening groove to drive the control sleeve to the folding ring to fold the elastic locking barb, and the material of the needle body is titanium alloy.

2. The intramedullary needle for metacarpophalangeal fossa according to claim 1, characterized in that: The anti-misoperation mechanism includes a blocking ring fixed on the traction rope, the diameter of the blocking ring is larger than the port of the channel located at the tail end of the needle body, the tail end of the needle body is provided with a receiving cavity, the port of the channel is located in the receiving cavity, the blocking ring is movably arranged in the receiving cavity, a cover is detachably arranged on the port of the receiving cavity, the cover is provided with an extension hole for the traction rope to extend out, the blocking ring and the cover are blocked and cooperated, and the operating end of the traction rope includes a primary traction end that extends out of the extension hole when the blocking ring is located at the bottom of the receiving cavity, and an ear hole arranged on the blocking ring.

3. The intramedullary needle for metacarpophalangeal fossa according to claim 2, characterized in that: A compression spring is arranged between the blocking ring and the cover to drive the blocking ring to be placed at the bottom of the receiving cavity.

4. The intramedullary needle for metacarpophalangeal fossa according to claim 2, characterized in that: The cover thread is screwed into the receiving cavity.

5. The intramedullary needle for metacarpal or finger according to claim 1, 2, 3 or 4, characterized in that: The inner wall of the control sleeve is integrally formed with reinforcing ribs, and the reinforcing ribs form a connecting entity part for connecting the traction rope at the axial center of the control sleeve.

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