CA1329081C - Transcutaneous pin for fixation of a bone part or fragment - Google Patents
Transcutaneous pin for fixation of a bone part or fragmentInfo
- Publication number
- CA1329081C CA1329081C CA000523819A CA523819A CA1329081C CA 1329081 C CA1329081 C CA 1329081C CA 000523819 A CA000523819 A CA 000523819A CA 523819 A CA523819 A CA 523819A CA 1329081 C CA1329081 C CA 1329081C
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- CA
- Canada
- Prior art keywords
- pin
- pin according
- thread
- flute
- cone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
- A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
- A61B17/56—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
- A61B17/58—Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor for osteosynthesis, e.g. bone plates, screws, setting implements or the like
- A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
- A61B17/84—Fasteners therefor or fasteners being internal fixation devices
- A61B17/86—Pins or screws or threaded wires; nuts therefor
- A61B17/8625—Shanks, i.e. parts contacting bone tissue
- A61B17/8635—Tips of screws
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- Health & Medical Sciences (AREA)
- Orthopedic Medicine & Surgery (AREA)
- Surgery (AREA)
- Life Sciences & Earth Sciences (AREA)
- Heart & Thoracic Surgery (AREA)
- Animal Behavior & Ethology (AREA)
- Engineering & Computer Science (AREA)
- Biomedical Technology (AREA)
- Neurology (AREA)
- Medical Informatics (AREA)
- Molecular Biology (AREA)
- Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Surgical Instruments (AREA)
- Prostheses (AREA)
- Dental Tools And Instruments Or Auxiliary Dental Instruments (AREA)
Abstract
TRANSCUTANEOUS PIN FOR FIXATION OF A BONE
PART OR FRAGMENT
Abstract A transcutaneous fixation pin includes a threaded portion with flutes evenly spaced over the circum-ference of the pin at the anterior end of the threaded portion so as to perform a tapping operation when the end of the threaded portion penetrates a bone fragment.
The flutes take the form of a notch creating a cutting edge of the tap, with a clearance relief being provided behind the cutting edge of the tap which approaches the centerline of the pin until it reaches the next notch, so as to form a clearance angle. In a modification the flutes are disposed helicoidally in relation to the axis of the thread, with the helix and the thread being pitched in the same direction.
PART OR FRAGMENT
Abstract A transcutaneous fixation pin includes a threaded portion with flutes evenly spaced over the circum-ference of the pin at the anterior end of the threaded portion so as to perform a tapping operation when the end of the threaded portion penetrates a bone fragment.
The flutes take the form of a notch creating a cutting edge of the tap, with a clearance relief being provided behind the cutting edge of the tap which approaches the centerline of the pin until it reaches the next notch, so as to form a clearance angle. In a modification the flutes are disposed helicoidally in relation to the axis of the thread, with the helix and the thread being pitched in the same direction.
Description
;
-1- 1 329~ 1 ,..~
,~ P.C. 7059 ~' `, TRANSCUTANEO~J5 PIN FOR FIXATION OF A
.. BONE PART OR FRAGMENT
, ~ .
i~Transcutaneous pins have been known for many years -~and are used in bone surgery, particularly in external :,. . .
osteosynthesis. Such pins pass through the flesh and bone and, in general, are used with the type of external skeletal fixation appliances developed by Dr.
Hoffmann. These external skeletal fixation appliances comprise swivel joints, connecting bars, sliding bars, articulations, and anchorage clamps intended to hold and position the transcutaneous pins. The ~offmann external fixation devices comprise an assembly framework placed around a part or member of the human body and arranged to hold bones or bone fragments in place ~rom the exterior with the aid of pins or groups of transcutaneous pins.
There are many types of transcutaneous pins on the market today. These pins generally comprise a threaded portion with a tapping portion at the end arranged to cut a thread when it is screwed into a bone part or " .. . -- .. ,.. -- ,.. .... . . .
fragment. Before the pin is installed, the bone or bone fragment is first drilled to the desired diameter, which is substantially equal to or greater than the inner diameter of the thread. The end of the pin is then inserted in the drilled hole and the threaded portion of the pin is screwed into the hole. During this operation, the tap provided at the end of the pin cuts the thread in the previously drilled hole. To screw the pin into the hole, use is commonly made of a chuck engaging a portion of polygonal cross section, for example a square cross section located at one end of the pin. In the pins of the prior art, the end of ,~
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the threaded portion mlght take a form like the point of a drilling bit or take different conflgurations known to those skilled in the art.
There i~ also a type of pin, known as a transfixing pin, in which the threaded portion is preceded hy a rod having a drill ` tip at its free end~ Transfixing pins may be in~talled without !, previously drilling a hole in ~he bone. In the ca~e of a transfixiny pin, the hole is drilled by the extremity of ~he tip and the thread is tapped by a tappiny portion provided at the beginning of the ~hread.
; The transcutaneous pins of the prior art do not afford a ~ drilling or a tapping of very high quality. As in any drilling or `s tapping operation, the te~perature rises at the place of the operation, which can cause necroses and deteriorations in ~he bone tissues. Moreover, the prior art pins do not produce tapped surfaces of good quality. The surfaces are torn out in placeR, thus failing to provide a good quality of anchorage between the bone fragment and the pin when the latter has been installed.
Finally, the prior art pins, by reason of their poor performance in the drilllng or tapping operation, can cause undue stre~ses in the bone when they are in place.
The objeat of the present invention is to propo~e a transcutaneou~ pln assuring a drilllng or a tapplng of good quallty, while ensuring a minimal ~emperature rise during insertion.
According ko the present invention, there is provided a transcutaneous pln having a centerline and a tap, said pin for fixation of a bone part or fragmen~ and said pin havi-ng a tap comprisiny a threaded portion with at least one flute at the ~ 30 anterior end of the threaded portion adapted to perform a tapping :~ operation when said anterlor end of the threaded portion penetrate~ the bona part or fragmentr with the at lea~t one flute each taking the form of a notch creating a cutting edge of the tap across the thread, and a clearance relief being provided behlnd the cutting edge of the tap which approaches the centerllne of the ~ pin until it reaches the following notch, thereby forming a .~ 2 .,, ; ., ij ~,:
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clearance angle, wherein said at least one flute is disposed helicoidally in relation to the axis of the thread, with the helix and the thread beiny pitched in the same direction.
The presence of the clearance relief permits a tapping of good quality and an easier penetration of the pin into the bone. Furthermore, since the chips do not remain inside the bone during the procedure and thus present no obstacle to the following cutting edge, the temperature ri~e is much less than with the pins of the prior art.
The anterior portion of the threading of the pin may take the form of a leading cone, with the fllltes defining the cut~ing edges extending over the leading cone of the threading and over the beginning of the central cylindrical portion of said threading.
Various modificationx may be adopted in producing ~he flutes forming the cutting edges. The flutes may take the form of a notch formed by two suhstantially perpendiculax surfaces, or a notch having a rounded shape in cross ~ection. The fluting is preferably accomplished by grinding, after the threading with its ; 20 leadlng cone have been made.
The invention can be adapted to various types of pins, whether pins requirlng a pre-drilled hole or sel~-drilling pins.
In the latter case, the pin advantageously is provlded with a drill tip at least indirectly adjacent the beginning of the leading cone of the thread.
The invention likewise comprises a transfixing pin in which the leading cone of the thread is preceded by ~ .
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The flat ogive-shaped tip may have two clearance cutouts placed opposite each other on its upper portion.
;~ The flat ogive-shaped tip may have a cross section in the shape of an elongated parallelogram defining two opposed cutting surfaces, each followed by a surface ~ forming a clearance angle, said cutting and clearance r'~'' surfaces forming together a cutting edge, and the cutting surfaces having an elongated spoon-shaped ; depression next to the cutting edge so as to modify the r' cutting angle to bring it to zero or to a positive value.
The accompanying drawings show, by way of example, .r:~ several embodiments of the transcutaneous pin according , .:
to the invention.
In the drawings:
FIG. 1 is a side view showing a first embodiment of a transcutaneous pin;
~` FIG. 2 is a side view showing a second embodiment of a transcutaneous pin, i.e. a transfixing pin;
FIG. 3 is an enlarged view of the end of the pin shown in FIG. 1 as seen at III, in a first embodiment of a pin installed after the bone has been drilled to a $ suitable diameter; such a pin is commonly called a blunt tip half-pin;
FIG. 4 is a view similar to FIG. 3 in a second embodiment of a transfixing pin serving additionally to drill the hole before making the tapping, and referred - to as a self-drilling and self-tapping half-pin;
!~' FIG. 5 is an enlarged view of the anterior end of ~x~i the threading of a transfixing pin, in a first -, - embodiment;
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FIG. 6 is a view similar to FIG. 5, in a second ; embodiment;
FIG. 7 is a section view taken along the line VII-VII in FIG. 5;
FIG. 8 is a section view taken along the line VIII-VIII in FIG. 6;
FIG. 9 is an enlarged detail view of the tip of : the pin of FIG. 2, as indicated by the arrow IX; and FIG. 10 is a section view taken through the tip in .,:. FIG. 9, along the line X-X.
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The transcutaneous pin 1 shown in FIGS. 1 and 3 comprises a threaded portion 2, which is the anterior portion of the pin, and a posterior portion 3 which is -~ referred to as the smooth portion 3. The pin 1 is a ,~ cylindrical pin of small diameter compared to its ,~ length, and the posterior or smooth portion 3 is `'~! provided with a groove 4 and a four-sided terminal portion 5. The terminal portion 5 enables use of a : chuck to drive the pin 1 into a bone part or fragment, ~. while the groove 4 serves fo~. retention of the chuck.
.:";: The anterior portion 2 of the pin 1 (see in particular ~i FIG. 3) comprises a thread 6 whose anterior portion `. takes the form of a truncated leading cone 7 terminated by a substantially planar face 8 perpendicular to the centerline of the pin.
In FIGS. 3, 5 and 6, three flutes 9 are placed :~. 120 apart over the circumference of the anterior end : of the pin, to perform the tapping operation. These ~^'f~'` flutes 9 take the form of two perpendicular surfaces 10 and 11, with surface 10 defining the cutting edge 12 of . the tap at its free end (see also the cross section of FIG. 7). Each of the cutting edges 12 is followed! in .~ the direction of rotation of the pin, by a clearance relief 13 which approaches the centerline of the pin :~ X::
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The flutes 9 are preferably realized by grinding.
The grinding operation is performed with a circular grinder moved tangentially over the end of the thread 6. Grinding of the flutes 9 provides a good surface quality at the cutting edge and obviates a subsequent finishing operation. The clearance relief 13 is made in the same manner by bringing a grinder up to the end of the pin and rotating the latter while bringing the grinder closer to the centerline of the pin.
Although the creation of the flutes 9 and of the clearance relief by grinding has given very good results, it will be apparent to those skilled in the ~.:
`~ art that it may also be done by milling or by any other ~ suitable means.
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~i$ The type of pin shown in FIG. 3 is used more ~ specifically to be placed in bones in such a position `~ that, at the exit rom the second cortex, the point of s:~ the pin does not risk wounding the tissues near the 5~; bone.
In other applications, however, it may be desirable to install a so-called transfixing pin, that is a successively self-drilling and self tapping pin, like those shown in FIGS. 2 and 4.
In FIC.. 4, as in the foregoing description, the pin includes a thread 6 terminating on a truncated :'r.~.~ conical portion 7. It nevertheless differs in that the truncated cone 7 is extended by a cylindrical portion 28, which is terminated in turn by a tip 29 of ;~ generally conical shape. The cylindrical portion 28 permits avoidance of interference between the drilling and tapping operations in cortical bone of ordinary } thickness, which would render difficult the correct . ::
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Y cutting of a thread in the bone. In this embodiment, the pin includes two symmetrical flutes 30.
Alternatively, a transfixing pin such as shown in FIG. 2 may be provided, cornprising, like the pin of FIG. 1, a threaded portion 2, a posterior portion 3 i~ having an annular groove 4 adjacent its end, and a -- four-sided end portion 5 intended to be received by a feed chuck.
~?~ The threaded portion 2 includes a thread 6 with a ' leading cone 7 similar to the one detailed in FIG. 3 Here again, the tapping flutes 9 may be created by means of a circular grinder which is moved tangentially to the centerline of the pin, starting from the rod 16 preceding the truncated cone 7 and entering the . threading 6. The rod 16 terminates anteriorly in a cutting tip 17 adapted to drill a hole, which is shown in more detail in FIG. 9.
The tip 17 at the end of the rod 16 of the transfixing pin shown in FIG. 2 has the shape of an ogive 22, the ogive having two clearance cutouts 23 in its upper portion (FIG. 9). The oyive shaped tip 22 : has some particularly interesting design features which ~ are seen in FIG. 9 and in the cross section of FIG. 10 . .
~D~` showing an elongated parallelogram configuration ;. including two cutting surfaces 24 each defining a ;~ cutting edge 25 followed by a clearance surface 26. If ~`~ the tip is rotated in the directioil of rotation .~
.~: indicated by the arrow F, it will be noted that-the .~ surfaces 26 define a sufficiently large clearance angle }
to allow for the clearing of chips produced during ~; drilling of a bone with the ogive 22. On the other :i:. hand, those skilled in the art will note in FIG. 9 that ~ the plane surfaces 24 define cutting surfaces having a : negative cutting angle alpha. In order to modify this :~. cutting angle alpha and bring it to zero or to a ;
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positive value, two elongated depressions 27 are provided adjacent to the cutting edge 25. Thus the cutting angle alpha may be corrected and selected according to the user's preference by changing the ;~ depth of the depressions 27.
.''J.~ The tip of FIGS. 9 and 10, with its oyive shape, its clearance surfaces 26, and its depressions 27 ; bringing the cutting angle to zero or to a positive value, affords drillings of very good quality compared ~ to prior art drill pins. The ogive-shaped tip is, ;~ moreover, especially suitable because i~ fixes itself s in the bone and serves to drill a hole along an axis ~r~ ~ with no lateral deviation.
The pin just described with reference to FIGS. 1, 3 and 4 can vary between 75 and ZOO mm. in overall 1~ length, with diameters ranging from 3 to 6 mm. The truncated cone typically has an inclination of 12 degrees.
~he pin according to the embodiment of FIG. 2, with a central threaded portion, may be of from 175 to ~;` 350 mm. in overall length, with diameters likewise ran~ing from 3 to 6 mm.. ~he anterior portion of the pin shown in FIG. 2, comprising the rod 16, has a diameter equal to or l~ss than the inner diameter of the thread in the threaded portion 6. For a 3, 4, 5 or 6 mm. pin, the portion 16 may have a 2, 3~ 4 and 5 mm.
diameter, respectively. In the case of the pin of FIG.
-1- 1 329~ 1 ,..~
,~ P.C. 7059 ~' `, TRANSCUTANEO~J5 PIN FOR FIXATION OF A
.. BONE PART OR FRAGMENT
, ~ .
i~Transcutaneous pins have been known for many years -~and are used in bone surgery, particularly in external :,. . .
osteosynthesis. Such pins pass through the flesh and bone and, in general, are used with the type of external skeletal fixation appliances developed by Dr.
Hoffmann. These external skeletal fixation appliances comprise swivel joints, connecting bars, sliding bars, articulations, and anchorage clamps intended to hold and position the transcutaneous pins. The ~offmann external fixation devices comprise an assembly framework placed around a part or member of the human body and arranged to hold bones or bone fragments in place ~rom the exterior with the aid of pins or groups of transcutaneous pins.
There are many types of transcutaneous pins on the market today. These pins generally comprise a threaded portion with a tapping portion at the end arranged to cut a thread when it is screwed into a bone part or " .. . -- .. ,.. -- ,.. .... . . .
fragment. Before the pin is installed, the bone or bone fragment is first drilled to the desired diameter, which is substantially equal to or greater than the inner diameter of the thread. The end of the pin is then inserted in the drilled hole and the threaded portion of the pin is screwed into the hole. During this operation, the tap provided at the end of the pin cuts the thread in the previously drilled hole. To screw the pin into the hole, use is commonly made of a chuck engaging a portion of polygonal cross section, for example a square cross section located at one end of the pin. In the pins of the prior art, the end of ,~
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the threaded portion mlght take a form like the point of a drilling bit or take different conflgurations known to those skilled in the art.
There i~ also a type of pin, known as a transfixing pin, in which the threaded portion is preceded hy a rod having a drill ` tip at its free end~ Transfixing pins may be in~talled without !, previously drilling a hole in ~he bone. In the ca~e of a transfixiny pin, the hole is drilled by the extremity of ~he tip and the thread is tapped by a tappiny portion provided at the beginning of the ~hread.
; The transcutaneous pins of the prior art do not afford a ~ drilling or a tapping of very high quality. As in any drilling or `s tapping operation, the te~perature rises at the place of the operation, which can cause necroses and deteriorations in ~he bone tissues. Moreover, the prior art pins do not produce tapped surfaces of good quality. The surfaces are torn out in placeR, thus failing to provide a good quality of anchorage between the bone fragment and the pin when the latter has been installed.
Finally, the prior art pins, by reason of their poor performance in the drilllng or tapping operation, can cause undue stre~ses in the bone when they are in place.
The objeat of the present invention is to propo~e a transcutaneou~ pln assuring a drilllng or a tapplng of good quallty, while ensuring a minimal ~emperature rise during insertion.
According ko the present invention, there is provided a transcutaneous pln having a centerline and a tap, said pin for fixation of a bone part or fragmen~ and said pin havi-ng a tap comprisiny a threaded portion with at least one flute at the ~ 30 anterior end of the threaded portion adapted to perform a tapping :~ operation when said anterlor end of the threaded portion penetrate~ the bona part or fragmentr with the at lea~t one flute each taking the form of a notch creating a cutting edge of the tap across the thread, and a clearance relief being provided behlnd the cutting edge of the tap which approaches the centerllne of the ~ pin until it reaches the following notch, thereby forming a .~ 2 .,, ; ., ij ~,:
,.
., ~
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. , .
clearance angle, wherein said at least one flute is disposed helicoidally in relation to the axis of the thread, with the helix and the thread beiny pitched in the same direction.
The presence of the clearance relief permits a tapping of good quality and an easier penetration of the pin into the bone. Furthermore, since the chips do not remain inside the bone during the procedure and thus present no obstacle to the following cutting edge, the temperature ri~e is much less than with the pins of the prior art.
The anterior portion of the threading of the pin may take the form of a leading cone, with the fllltes defining the cut~ing edges extending over the leading cone of the threading and over the beginning of the central cylindrical portion of said threading.
Various modificationx may be adopted in producing ~he flutes forming the cutting edges. The flutes may take the form of a notch formed by two suhstantially perpendiculax surfaces, or a notch having a rounded shape in cross ~ection. The fluting is preferably accomplished by grinding, after the threading with its ; 20 leadlng cone have been made.
The invention can be adapted to various types of pins, whether pins requirlng a pre-drilled hole or sel~-drilling pins.
In the latter case, the pin advantageously is provlded with a drill tip at least indirectly adjacent the beginning of the leading cone of the thread.
The invention likewise comprises a transfixing pin in which the leading cone of the thread is preceded by ~ .
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.
, .
_4_ 1 3290~ 1 , r a rod of a diameter equal to or less than the inner diameter of the thread of the threaded portion, with said rod terminating in a flat ogive-shaped drill tip.
The flat ogive-shaped tip may have two clearance cutouts placed opposite each other on its upper portion.
;~ The flat ogive-shaped tip may have a cross section in the shape of an elongated parallelogram defining two opposed cutting surfaces, each followed by a surface ~ forming a clearance angle, said cutting and clearance r'~'' surfaces forming together a cutting edge, and the cutting surfaces having an elongated spoon-shaped ; depression next to the cutting edge so as to modify the r' cutting angle to bring it to zero or to a positive value.
The accompanying drawings show, by way of example, .r:~ several embodiments of the transcutaneous pin according , .:
to the invention.
In the drawings:
FIG. 1 is a side view showing a first embodiment of a transcutaneous pin;
~` FIG. 2 is a side view showing a second embodiment of a transcutaneous pin, i.e. a transfixing pin;
FIG. 3 is an enlarged view of the end of the pin shown in FIG. 1 as seen at III, in a first embodiment of a pin installed after the bone has been drilled to a $ suitable diameter; such a pin is commonly called a blunt tip half-pin;
FIG. 4 is a view similar to FIG. 3 in a second embodiment of a transfixing pin serving additionally to drill the hole before making the tapping, and referred - to as a self-drilling and self-tapping half-pin;
!~' FIG. 5 is an enlarged view of the anterior end of ~x~i the threading of a transfixing pin, in a first -, - embodiment;
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FIG. 6 is a view similar to FIG. 5, in a second ; embodiment;
FIG. 7 is a section view taken along the line VII-VII in FIG. 5;
FIG. 8 is a section view taken along the line VIII-VIII in FIG. 6;
FIG. 9 is an enlarged detail view of the tip of : the pin of FIG. 2, as indicated by the arrow IX; and FIG. 10 is a section view taken through the tip in .,:. FIG. 9, along the line X-X.
,~ .
The transcutaneous pin 1 shown in FIGS. 1 and 3 comprises a threaded portion 2, which is the anterior portion of the pin, and a posterior portion 3 which is -~ referred to as the smooth portion 3. The pin 1 is a ,~ cylindrical pin of small diameter compared to its ,~ length, and the posterior or smooth portion 3 is `'~! provided with a groove 4 and a four-sided terminal portion 5. The terminal portion 5 enables use of a : chuck to drive the pin 1 into a bone part or fragment, ~. while the groove 4 serves fo~. retention of the chuck.
.:";: The anterior portion 2 of the pin 1 (see in particular ~i FIG. 3) comprises a thread 6 whose anterior portion `. takes the form of a truncated leading cone 7 terminated by a substantially planar face 8 perpendicular to the centerline of the pin.
In FIGS. 3, 5 and 6, three flutes 9 are placed :~. 120 apart over the circumference of the anterior end : of the pin, to perform the tapping operation. These ~^'f~'` flutes 9 take the form of two perpendicular surfaces 10 and 11, with surface 10 defining the cutting edge 12 of . the tap at its free end (see also the cross section of FIG. 7). Each of the cutting edges 12 is followed! in .~ the direction of rotation of the pin, by a clearance relief 13 which approaches the centerline of the pin :~ X::
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~ -6- l 329~ 1 until it intersects the surface 11 of the following flute 9.
The flutes 9 are preferably realized by grinding.
The grinding operation is performed with a circular grinder moved tangentially over the end of the thread 6. Grinding of the flutes 9 provides a good surface quality at the cutting edge and obviates a subsequent finishing operation. The clearance relief 13 is made in the same manner by bringing a grinder up to the end of the pin and rotating the latter while bringing the grinder closer to the centerline of the pin.
Although the creation of the flutes 9 and of the clearance relief by grinding has given very good results, it will be apparent to those skilled in the ~.:
`~ art that it may also be done by milling or by any other ~ suitable means.
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~i$ The type of pin shown in FIG. 3 is used more ~ specifically to be placed in bones in such a position `~ that, at the exit rom the second cortex, the point of s:~ the pin does not risk wounding the tissues near the 5~; bone.
In other applications, however, it may be desirable to install a so-called transfixing pin, that is a successively self-drilling and self tapping pin, like those shown in FIGS. 2 and 4.
In FIC.. 4, as in the foregoing description, the pin includes a thread 6 terminating on a truncated :'r.~.~ conical portion 7. It nevertheless differs in that the truncated cone 7 is extended by a cylindrical portion 28, which is terminated in turn by a tip 29 of ;~ generally conical shape. The cylindrical portion 28 permits avoidance of interference between the drilling and tapping operations in cortical bone of ordinary } thickness, which would render difficult the correct . ::
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Y cutting of a thread in the bone. In this embodiment, the pin includes two symmetrical flutes 30.
Alternatively, a transfixing pin such as shown in FIG. 2 may be provided, cornprising, like the pin of FIG. 1, a threaded portion 2, a posterior portion 3 i~ having an annular groove 4 adjacent its end, and a -- four-sided end portion 5 intended to be received by a feed chuck.
~?~ The threaded portion 2 includes a thread 6 with a ' leading cone 7 similar to the one detailed in FIG. 3 Here again, the tapping flutes 9 may be created by means of a circular grinder which is moved tangentially to the centerline of the pin, starting from the rod 16 preceding the truncated cone 7 and entering the . threading 6. The rod 16 terminates anteriorly in a cutting tip 17 adapted to drill a hole, which is shown in more detail in FIG. 9.
The tip 17 at the end of the rod 16 of the transfixing pin shown in FIG. 2 has the shape of an ogive 22, the ogive having two clearance cutouts 23 in its upper portion (FIG. 9). The oyive shaped tip 22 : has some particularly interesting design features which ~ are seen in FIG. 9 and in the cross section of FIG. 10 . .
~D~` showing an elongated parallelogram configuration ;. including two cutting surfaces 24 each defining a ;~ cutting edge 25 followed by a clearance surface 26. If ~`~ the tip is rotated in the directioil of rotation .~
.~: indicated by the arrow F, it will be noted that-the .~ surfaces 26 define a sufficiently large clearance angle }
to allow for the clearing of chips produced during ~; drilling of a bone with the ogive 22. On the other :i:. hand, those skilled in the art will note in FIG. 9 that ~ the plane surfaces 24 define cutting surfaces having a : negative cutting angle alpha. In order to modify this :~. cutting angle alpha and bring it to zero or to a ;
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positive value, two elongated depressions 27 are provided adjacent to the cutting edge 25. Thus the cutting angle alpha may be corrected and selected according to the user's preference by changing the ;~ depth of the depressions 27.
.''J.~ The tip of FIGS. 9 and 10, with its oyive shape, its clearance surfaces 26, and its depressions 27 ; bringing the cutting angle to zero or to a positive value, affords drillings of very good quality compared ~ to prior art drill pins. The ogive-shaped tip is, ;~ moreover, especially suitable because i~ fixes itself s in the bone and serves to drill a hole along an axis ~r~ ~ with no lateral deviation.
The pin just described with reference to FIGS. 1, 3 and 4 can vary between 75 and ZOO mm. in overall 1~ length, with diameters ranging from 3 to 6 mm. The truncated cone typically has an inclination of 12 degrees.
~he pin according to the embodiment of FIG. 2, with a central threaded portion, may be of from 175 to ~;` 350 mm. in overall length, with diameters likewise ran~ing from 3 to 6 mm.. ~he anterior portion of the pin shown in FIG. 2, comprising the rod 16, has a diameter equal to or l~ss than the inner diameter of the thread in the threaded portion 6. For a 3, 4, 5 or 6 mm. pin, the portion 16 may have a 2, 3~ 4 and 5 mm.
diameter, respectively. In the case of the pin of FIG.
2, it is advantageous to provide a 6 truncated leading cone.
In the several examples given, the threading is a single thread, but it is of course possible to ~'r alternatively provide multiple threads, the taps ~` passing successively in the same tapping flute several times.
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In the several examples given, the threading is a single thread, but it is of course possible to ~'r alternatively provide multiple threads, the taps ~` passing successively in the same tapping flute several times.
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Claims (13)
1. A transcutaneous pin having a centerline and a tap, said pin for fixation of a bone part or fragment and said pin having a tap comprising a threaded portion with at least one flute at the anterior end of the threaded portion adapted to perform a tapping operation when said anterior end of the threaded portion penetrates the bone part or fragment, with the at least one flute each taking the form of a notch creating a cutting edge of the tap across the thread, and a clearance relief being provided behind the cutting edge of the tap which approached the centerline of the pin until it reaches the following notch, thereby forming a clearance angle, wherein said at least one flute is disposed helicoidally in relation to the axis of the thread, with the helix and the thread being pitched in the same direction.
2. A pin according to claim 1 including at least two flutes regularly spaced over the circumference of the pin.
3. A pin according to claim 1 wherein the anterior portion of the threading takes the form of a truncated leading cone, with the flute defining the cutting edge extending over the leading cone of the threading and over the beginning of the central cylindrical portion of said threading.
4. A pin according to claim 1 wherein the flute takes the form of a notch formed by two substantially perpendicular surfaces.
5. A pin according to claim 1 wherein the flute takes the form of a notch having a generally rounded shape in cross section.
6. A pin according to claim 1 wherein the flute has been created by grinding after the thread with its leading cone has been made.
7. A pin according to claim 3 wherein the anterior portion of said truncated cone is terminated by a face perpendicular to the axis of the pin and intended to fit into a hole previously drilled in the bone part.
8. A pin according to claim 3 wherein the leading code of the threading is preceded by a rod of diameter equal to or smaller than the inner thread diameter of the threaded portion, said rod terminating in a flat drill tip having the shape of an ogive.
9. A pin according to claim 8 wherein the flat ogive-shaped tip has two clearance cutouts placed opposite each other on its posterior portion.
10. A pin according to claim 8 wherein the flat ogive-shaped tip has a cross section in the shape of an elongated parallelogram defining two opposed cutting surfaces, each followed by a surface forming a clearance angle, said cutting and clearance surfaces forming together a cutting edge, and the cutting surfaces having an elongated spoon-shaped depression placed next to the cutting edge so as to modify the cutting angle to bring it to zero or to a positive value.
11. A pin according to claim 3 wherein the anterior portion of said truncated cone is preceded, at least indirectly, by a cone including said flute or flutes so as to form a drill tip.
12. A pin according to claim 11 wherein said leading cone is preceded by a portion of generally cylindrical shape located between the truncated leading cone and said drill cone.
13. A pin according to claim 12 wherein the diameter of the cylindrical drilling portion is larger than the inner diameter of the thread.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH5070/85A CH666398A5 (en) | 1985-11-28 | 1985-11-28 | Transcutaneous pin for fixation of bone part or fragment |
| CH5070/85-9 | 1985-11-28 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1329081C true CA1329081C (en) | 1994-05-03 |
Family
ID=4287439
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000523819A Expired - Fee Related CA1329081C (en) | 1985-11-28 | 1986-11-26 | Transcutaneous pin for fixation of a bone part or fragment |
Country Status (7)
| Country | Link |
|---|---|
| JP (2) | JPS62243551A (en) |
| CN (1) | CN1011191B (en) |
| AU (1) | AU589235B2 (en) |
| CA (1) | CA1329081C (en) |
| CH (1) | CH666398A5 (en) |
| IL (1) | IL80747A0 (en) |
| ZA (1) | ZA868982B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5129901A (en) * | 1991-06-10 | 1992-07-14 | Decoste Vern X | Cannulated orthopedic screw |
| DE4136178A1 (en) * | 1991-11-02 | 1993-05-06 | Deutsche Thomson-Brandt Gmbh, 7730 Villingen-Schwenningen, De | CIRCUIT FOR CONTINUOUS ZOOM ADJUSTMENT OF PICTURE WIDTH IN A TELEVISION RECEIVER |
| JP2563333Y2 (en) * | 1992-01-17 | 1998-02-18 | 長野計器株式会社 | Screw pin |
| JP3323747B2 (en) * | 1996-08-07 | 2002-09-09 | グンゼ株式会社 | Orthopedic tap |
| KR20030028685A (en) * | 2001-09-25 | 2003-04-10 | 주식회사 제일메디칼코퍼레이션 | A screw for medical care |
| CN102210602B (en) * | 2010-04-12 | 2013-09-18 | 上海微创骨科医疗科技有限公司 | Reamer |
| US9782209B2 (en) * | 2012-10-03 | 2017-10-10 | Rtg Scientific | Medical fastener |
| CN103815959A (en) * | 2012-11-16 | 2014-05-28 | 上海底特精密紧固件股份有限公司 | Bone screw |
| CN103876817A (en) * | 2012-12-21 | 2014-06-25 | 江苏安格尔医疗器械有限公司 | Multi-start thread U-shaped nail |
| CN108186103B (en) * | 2018-02-28 | 2021-03-09 | 中国人民解放军陆军军医大学第一附属医院 | Joint fusion fixing nail |
| CN109567917A (en) * | 2018-12-28 | 2019-04-05 | 浙江康慈医疗科技有限公司 | A kind of blunt nosed metal bone needle |
| CN109567915A (en) * | 2018-12-28 | 2019-04-05 | 浙江康慈医疗科技有限公司 | A kind of metal bone needle with drill bit function |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2388482A (en) * | 1943-01-16 | 1945-11-06 | Herbert H Haynes | Surgical screw |
| US2393982A (en) * | 1945-01-06 | 1946-02-05 | Josef H Glesen | Fracture reducer |
| JPS51141953A (en) * | 1975-05-31 | 1976-12-07 | Yoshio Murata | Bolt |
| JPS5249109A (en) * | 1975-10-13 | 1977-04-19 | Hitachi Seiko Kk | Ink feeder for printing press |
| FR2357022A1 (en) * | 1976-07-02 | 1978-01-27 | Thomson Csf | DEVICE FOR COMBINED VISUALIZATION OF A MOBILE MAP AND NAVIGATION INFORMATION AND ELECTRONIC NAVIGATION INDICATOR SYSTEM INCLUDING SUCH A DEVICE |
| JPS6119365Y2 (en) * | 1979-08-20 | 1986-06-11 | ||
| US4414966A (en) * | 1981-04-09 | 1983-11-15 | Ace Orthopedic Manufacturing, Inc. | Fixation pin |
| ES8302449A2 (en) * | 1981-12-09 | 1983-01-16 | Lazo De Zbikowski Juan | Functional attachment system for osteosynthesis |
| US4537185A (en) * | 1983-06-10 | 1985-08-27 | Denis P. Stednitz | Cannulated fixation screw |
-
1985
- 1985-11-28 CH CH5070/85A patent/CH666398A5/en not_active IP Right Cessation
-
1986
- 1986-11-24 IL IL80747A patent/IL80747A0/en not_active IP Right Cessation
- 1986-11-26 CA CA000523819A patent/CA1329081C/en not_active Expired - Fee Related
- 1986-11-27 JP JP61283034A patent/JPS62243551A/en active Pending
- 1986-11-27 AU AU65752/86A patent/AU589235B2/en not_active Ceased
- 1986-11-27 CN CN86108709A patent/CN1011191B/en not_active Expired
- 1986-11-27 ZA ZA868982A patent/ZA868982B/en unknown
-
1992
- 1992-10-19 JP JP1992072700U patent/JP2520199Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| AU6575286A (en) | 1987-06-04 |
| CN86108709A (en) | 1987-06-17 |
| AU589235B2 (en) | 1989-10-05 |
| JP2520199Y2 (en) | 1996-12-11 |
| ZA868982B (en) | 1987-07-29 |
| IL80747A0 (en) | 1987-02-27 |
| JPH0743070U (en) | 1995-08-18 |
| CN1011191B (en) | 1991-01-16 |
| JPS62243551A (en) | 1987-10-24 |
| CH666398A5 (en) | 1988-07-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |