s \ —
`Eur°Pean Patent Office
`OJII
`< * S
`Office europeen des brevets
`
`i i i i i m i i i i i i i i i i i i i i i i i i i i i i i
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`(11)
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`E P 0 8 3 8 1 9 9 A 1
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`(12)
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`EUROPEAN PATENT APPLICATION
`
`(43) Date of publication:
`29.04.1998 Bulletin 1998/18
`
`(21) Application number: 97117950.2
`
`(22) Date of filing: 16.10.1997
`
`(51 ) |nt. CI.6: A61 B 1 7/74, A61 B 1 7/72
`
`(84) Designated Contracting States:
`AT BE CH DE DK ES Fl FR GB GR IE IT LI LU MC
`NL PT SE
`Designated Extension States:
`AL LT LV RO SI
`
`(30) Priority: 24.10.1996 IT BO9601 46 U
`
`(71) Applicant: Hit Medica S.r.l.
`47037 Rimini (IT)
`
`(72) Inventor: laia, Ciro Rosario
`47037 Rimini (IT)
`
`(74) Representative:
`Modiano, Guido, Dr.-lng. et al
`Modiano & Associati S.r.l.
`Via Meravigli, 16
`20123 Milano(IT)
`
`(54)
`
`Nail for reducing fractures of the trochanter and of the neck of the femur
`
`A nail for reducing fractures of the trochanter
`(57)
`and of the neck of the femur, comprising an elongated
`and angled shank (2) in which, proximate to the upper
`end, a head screw (5) can be inserted downward from
`above and can be locked to the nail by a screw (8) which
`is screwed into a threaded axial hole (9) of the top of the
`shank (2); the shank has, in order to facilitate insertion
`in the medullary canal and reduce and better distribute
`the mechanical stresses affecting the bone, a lower end
`(3) which is cut along an inclined plane like a flute
`mouthpiece and has, proximate to a hole (4) for the
`insertion of the head screw (5), a through hole (11)
`which has a reduced diameter and is substantially par-
`allel to the hole of the head screw (5), for the passage of
`a wire (12) which is threaded at its top end (13) for tem-
`porary screwing in the head of the femur (F) and is
`adapted to avoid rotations of the head of the femur dur-
`ing the screwing of the head screw (5).
`
`<7>
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`Printed by Xerox (UK) Business Services
`2.16.1/3.4
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`ZIMMER 1009
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`EP 0 838 199 A1
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`2
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`Description
`
`flute mouthpiece and has, proximate to a hole for the
`insertion of said head screw, a through hole which has
`a reduced diameter and is substantially parallel to said
`hole of the head screw, for the passage of a wire which
`is threaded at its top end for temporary screwing in the
`head of the femur and is adapted to avoid rotations of
`the head of the femur during the screwing of the head
`screw.
`Further characteristics and advantages of the
`present invention will become apparent from the follow-
`ing detailed description of a preferred but not exclusive
`embodiment of a nail for reducing fractures of the tro-
`chanter and of the neck of the femur according to the
`present invention, illustrated only by way of non-limita-
`tive example in the accompanying drawings, wherein:
`
`the only figure is a partially cutout side view of a nail
`for reducing fractures of the trochanter and of the
`neck of the femur according to the present inven-
`tion.
`
`With particular reference to the above figure, the
`reference numeral 1 generally designates a nail for
`reducing fractures f of the trochanter and of the neck of
`the femur F according to the present invention.
`The nail 1 is of the kind constituted by an elongated
`shank 2 which has a cylindrical cross-section and is
`constituted by an upper part 2a and by a lower part 2b
`which has a slightly reduced diameter; these parts form,
`with respect to each other, an angle of six degrees so as
`to reduce the bone drilling diameter for its insertion.
`The lower end 3 of the shank is cut along an
`inclined plane, i.e., like a flute mouthpiece, in order to
`facilitate insertion in the medullary canal and better dis-
`tribute the mechanical stresses affecting the bone.
`Proximate to its upper end, the shank 2a is crossed
`by an oblique hole 4 in which it is possible to insert
`upward, from below, a head screw 5 which has, in its
`lower region, eight rotation-preventing
`longitudinal
`grooves 6 for the selective insertion of the tip 7 of a lock-
`ing screw 8 which is screwed into a threaded axial hole
`9 of the top of the shank.
`A closure plug 10 is screwed into the upper end of
`the axial hole 9 of the shank and is used to prevent, dur-
`ing the healing process, any accumulation of blood
`and/or bone calcification, which should be removed for
`shank extraction.
`Proximate to the hole 4 for the insertion of the head
`screw 5, the shank 2 is crossed by a small through hole
`1 1 which has a reduced diameter and is substantially
`parallel to the hole 4: a steel wire 12, threaded at a top
`end 13 (known in the field as a Kirschner's wire), can be
`inserted in the hole 1 1 for temporary screwing in the
`head of the femur F during the screwing of the head
`screw 5; this wire 12 is adapted to prevent rotations of
`the head of the femur during the screwing of the head
`screw 5 and is removed once fixing has occurred.
`Two diametrical holes 14a, 14b are provided in the
`
`s
`
`is
`
`20
`
`The present invention relates to a nail for reducing
`fractures of the trochanter and of the neck of the femur,
`particularly pertrochanteric, subtrochanteric, intertro-
`chanteric fractures and fractures of the neck of the
`femur.
`Fractures of the trochanter and of the neck of the
`femur are reduced by using steel nails constituted by an
`elongated and angled shank which has, proximate to its 10
`upper end, a slanted inclined through hole in which a
`so-called head screw can be inserted downward from
`above; the top of the head screw is meant to be screwed
`into the head of the femur, and the head screw can be
`locked onto the nail by a screw which is screwed into a
`threaded axial hole of the top of the shank; in the lower
`region of the shank there are provided two diametrical
`holes wherein respective so-called distal screws can be
`screwed in order to fix the base of the shank to the base
`of the femur.
`Those nails entail some drawbacks in relation to the
`angled arrangement of the shank, which forces to drill
`the femur with bores which have an excessive diameter
`with respect to the diameter of the shank, and to the
`stubby shape of the lower end of the shank, which forms 25
`a rather sudden truncation which can produce a prefer-
`torsional
`ential bone breakage region; moreover,
`stresses often affect the head of the femur during the
`tightening of the head screw and there are problems in
`relation to the material that is normally used, usually 30
`highly rigid stainless steel, which generates sometimes
`traumatic stresses in the bone of the femur.
`The aim of the present invention is to obviate the
`cited drawbacks of conventional devices, i.e., to provide
`a nail for reducing fractures of the trochanter and of the 35
`neck of the femur the installation whereof entails drilling
`holes whose diameter is only slightly greater than the
`diameter of the shank, does not entail a preferential
`bone breakage region, does not generate torsional
`stresses in the femur during the tightening of the head 40
`screw and is made of a material whose elasticity is com-
`parable to that of a bone.
`Within the scope of this aim, another object of the
`present invention is to provide a structure which is sim-
`ple, relatively easy to provide in practice, safe in use, 45
`effective in operation and relatively modest in cost.
`This aim, these objects and others which will
`become apparent hereinafter are achieved by a nail for
`reducing fractures of the trochanter and of the neck of
`the femur, of the kind constituted by an elongated and
`angled shank in which, proximate to the upper end, a
`head screw can be inserted downward from above and
`can be locked to the nail by a screw which is screwed
`into a threaded axial hole of the top of the shank, char-
`acterized in that the shank has, in order to facilitate 55
`insertion in the medullary canal and reduce and better
`distribute the mechanical stresses affecting the bone, a
`lower end which is cut along an inclined plane like a
`
`so
`
`2
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`ZIMMER 1009
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`3
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`EP 0 838 199 A1
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`4
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`3. A nail according to claim 1 , characterized in that the
`components are made of titanium alloy, which is
`biocompatible, allows to perform magnetic reso-
`nance and is adapted to make the implant more
`elastic than steel in order to reduce the possibility of
`bone damage.
`
`4. A nail according to claim 2, characterized in that
`said head screw (5) has, in the lower region, eight
`longitudinal rotation-preventing grooves (6) for the
`selective insertion of a tip (7) of said screw (8)
`screwed into the axial hole (9) of said shank (2).
`
`lower region 2b of the shank 2, and two conventional
`screws 15a, 15b can be inserted in said holes and allow
`to fix the lower part 2b of the shank 2 to the bone of the
`femur F.
`Advantageously, all the components of the nail 1
`are made of titanium alloy, which has never been used
`for the specific kind of nail, is biocompatible, allows to
`perform magnetic resonance and has an elasticity mod-
`ulus which is close to that of a bone, so as to make the
`implant more elastic than steel in order to reduce the
`possibility of bone damage.
`It is thus evident that the present invention achieves
`the intended aim and object.
`The invention thus conceived is susceptible of
`numerous modifications and variations, all of which are
`within the scope of the inventive concept.
`All the details may also be replaced with other tech-
`nically equivalent ones.
`In practice, the materials employed, as well as the
`shapes and the dimensions, may be any according to
`the requirements without thereby abandoning the scope
`of the protection of the appended claims.
`Where technical features mentioned in any claim
`are followed by reference signs, those reference signs
`have been included for the sole purpose of increasing
`the intelligibility of the claims and accordingly such ref-
`erence signs do not have any limiting effect on the inter-
`pretation of each element identified by way of example
`by such reference signs.
`
`Claims
`
`5
`
`10
`
`15
`
`20
`
`25
`
`30
`
`1 . A nail for reducing fractures (f) of the trochanter and
`of the neck of the femur (F), comprising an elon-
`gated and angled shank (2) in which, proximate to 35
`the upper end, a head screw (5) can be inserted
`downward from above and can be locked to the nail
`by means of a screw (8) which is screwed into a
`threaded axial hole (9) of the top of the shank, char-
`acterized in that the shank (2) has, in order to facil- 40
`itate insertion in the medullary canal and reduce
`and better distribute the mechanical stresses
`affecting the bone, a lower end (3) which is cut
`along an inclined plane like a flute mouthpiece and
`has, proximate to a hole (4) for the insertion of said 45
`head screw, a through hole (11) which has a
`reduced diameter and is substantially parallel to
`said hole of the head screw (5), for the passage of
`a wire (12) which is threaded at its top end (13) for
`temporary screwing in the head of the femur (F)
`and is adapted to avoid rotations of the head of the
`femur during the screwing of the head screw (5).
`
`so
`
`2. A nail according to claim 1, characterized in that
`said shank (2) is constituted by an upper part (2a) 55
`and by a lower part (2b) which form, between them,
`an angle of six degrees which is adapted to reduce
`the bone drilling diameter.
`
`3
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`ZIMMER 1009
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`EP 0 838 199 A1
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`EP 0 838 199 A1
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` European Patent
`Office
`
`EUROPEAN SEARCH REPORT
`
`AppMca,i°n ^
`EP 97 11 7950
`
`
`
`DOCUMENTS CONSIDERED TO BE RELEVANT
`Citation of document with indication, where appropriate,
`Category
`of relevant passages
`JS 5 562 666 A (BRUMFI ELD DAVID L)
`* column 4,
`line 21 - line 54; figures 1,2
`
`Relevant
`to claim
`1,3
`2,4
`
`CLASSIFICATION Or THE
`APPLICATION (lnt.CI.6)
`A61B17/74
`A61B17/72
`
`Y
`A
`
`Y
`
`A
`
`A
`
`EP G 586 824 A (BATTAGLIA LUIGI)
`line 30 - line 40; figure 1 *
`* column 2,
`
`EP 0 321 170 A (H0WMEDICA INTERNATIONAL
`INC)
`line 38 - line 47; figure 1 *
`* column 4,
`
`DE 32 44 243 A (ENDER HANS GE0RG)
`line 33 - line 37; figure 1 *
`* page 11,
`US 5 364 398 A (CHAPMAN MICHAEL W ET AL)
`* column 4,
`line 22 - line 39; figures
`19,20 *
`
`EP 0 355 411 A (ACE ORTHOPEDIC MFG)
`* abstract; figure 1 *
`EP 0 640 318 A (SYN0S MEDICAL SPA)
`* abstract; figure 1 *
`
`2
`1
`
`4
`
`1
`
`1,3
`
`1,3
`
`1
`
`1
`
`TECHNICAL FIELDS
`SEARCHED
`(lnt.CI.6)
`A61B
`
`The present search report has been drawn up for all claims
`Date of completion of the search
`Place of search
`Hansen, S
`11 December 1997
`BERLIN
`T : theory or principle underlying the invention
`CATEGORY OF CITED DOCUMENTS
`E : earlier patent document, but published on, or
`after the filing date
`X ; particularly relevant if taken alone
`D : document crted in the application
`Y : particularly relevant if combined with another
`L : document cited for other reasons
`document of the same category
`A : technological background
`& : member of the same patent family, corresponding
`O : non-written disclosure
`document
`P : intermediate document
`
`5
`
`ZIMMER 1009
`Page 5