WO2011013021A1 - Sleeve for an osteosynthesis device and osteosynthesis device comprising such a sleeve - Google Patents

Sleeve for an osteosynthesis device and osteosynthesis device comprising such a sleeve Download PDF

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Publication number
WO2011013021A1
WO2011013021A1 PCT/IB2010/053194 IB2010053194W WO2011013021A1 WO 2011013021 A1 WO2011013021 A1 WO 2011013021A1 IB 2010053194 W IB2010053194 W IB 2010053194W WO 2011013021 A1 WO2011013021 A1 WO 2011013021A1
Authority
WO
WIPO (PCT)
Prior art keywords
frusto
sleeve
conical portion
osteosynthesis device
according
Prior art date
Application number
PCT/IB2010/053194
Other languages
French (fr)
Inventor
Francesco Di Bartolo
Original Assignee
Intrauma S.R.L.
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority to ITTO20090579 priority Critical patent/ITTO20090579A1/en
Priority to ITTO2009A000579 priority
Application filed by Intrauma S.R.L. filed Critical Intrauma S.R.L.
Publication of WO2011013021A1 publication Critical patent/WO2011013021A1/en

Links

Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/56Surgical instruments or methods for treatment of bones or joints; Devices specially adapted therefor
    • A61B17/58Surgical 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
    • A61B17/68Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
    • A61B17/80Cortical plates, i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates
    • A61B17/8033Cortical plates, i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates having indirect contact with screw heads, or having contact with screw heads maintained with the aid of additional components, e.g. nuts, wedges or head covers
    • A61B17/8047Cortical plates, i.e. bone plates; Instruments for holding or positioning cortical plates, or for compressing bones attached to cortical plates having indirect contact with screw heads, or having contact with screw heads maintained with the aid of additional components, e.g. nuts, wedges or head covers wherein the additional element surrounds the screw head in the plate hole

Abstract

The present invention relates to a sleeve for an osteosynthesis device and to an osteosynthesis device incorporating such a sleeve. The present invention allows to easily and safely remove the osteosynthesis device from a patient's body, without the risk of damages or lesions. According to the invention, thanks to the fact that the matching between the screws (30) and the sleeves (10) receiving said screws is based upon the conicity of the head of the screws (30) and of the through-hole of the sleeves (10), a little rotation of the screws (30) in the unscrewing direction immediately releases the screws from the respective sleeves; thanks to the fact that the matching between the sleeves (10) and the osteosynthesis plate (20) is based upon the conicity of the outer surface of said sleeves (10) and of the through-bores of the plate (20) receiving said sleeves, a little rotation of the sleeves (10) in the unscrewing direction immediately releases the sleeves from the plate.

Description

"Sleeve for an osteosynthesis device and osteosynthesis device comprising such a sleeve"

DESCRPTION

Technical field

The present invention relates to a sleeve for an osteosynthesis device.

The present invention further relates to an osteosynthesis device comprising such a sleeve.

Prior art

Osteosynthesis plates for fixing one or more fractures in a long bone, such as a femur or a shinbone, are known in the art.

In general, said plates have an elongated shape and they are available in several models, depending on the shape and size of the bone to which they are to be applied.

For instance, in WO 97/08999 an osteosynthesis device for fixing fractures in the end portion, or head, of a bone is disclosed. Said device comprises a plate having an elongated portion that can be fixed to the bone by means of a plurality of screws and an end portion provided with a sleeve which is inserted inside the bone for receiving a screw that penetrates into the bone head. The sleeve, which is integral to the plate, allows to rigidly connect the plate and the screw, eliminating any clearance that may form therebetween.

In WO 01 /91660 an osteosynthesis device is disclosed which comprises a plate and a plurality of sleeves for the passage of corresponding screws that penetrates into the fractured bone, wherein the sleeves are separate from the plate, so that they can be changed at will, and they can have different lengths and inner diameters, according to the needs of the user and to the type of bones. Moreover, in the osteosynthesis device disclosed in WO 01 /91660, each sleeve has a threaded cylindrical outer surface that matches with the internal thread of the through-bore correspondingly provided in the plate for receiving the sleeve and a through-hole for the passage of the corresponding screw comprising a frusto-conical portion, outwardly diverging, so as to perfectly match with the head of a screw having a frusto-conical shape; thanks to the conicity of the screw head and of the sleeve through-hole, the screw, while being screwed into the bone, gets blocked inside the sleeve, automatically eliminating any clearance that can form between the two components. The provision of sleeves separate from the plate undoubtedly represents an advantage with respect to the versatility of the osteosynthesis device. However, the osteosynthesis devices of the above-disclosed kind, are not free from drawbacks.

More particularly, in a device as disclosed in WO 01 /91660, during the removal step, it is necessary to completely unscrew the sleeve from the threaded through-bore provided in the plate, making the sleeve rotate several times so that its external surface can run along the whole thread of the threaded through-bore and the sleeve can thus be released from the plate.

This operation is complex and difficult and it involves a heavy risk of causing damages and lacerations to the patient.

The main object of the present invention is to provide a sleeve for an osteosynthesis device that overcomes the above-mentioned drawbacks of prior art and allows to easily and safely remove the osteosynthesis device from the patient's body.

Another object of the present invention is to provide an osteosynthesis device arranged for incorporating said sleeve, so as to guarantee an easy and safe removal of the device itself.

These and other objects are achieved thanks to a sleeve for osteosynthesis device as claimed in the appended claims.

Disclosure of the invention

Thanks to the fact that the outer surface of the sleeve according to the invention comprises at least a threaded portion having a frusto-conical shape, outwardly diverging, intended to match with a corresponding internally threaded frusto-conical through-bore of an osteosynthesis plate, on one side it is guaranteed that the sleeve is effectively blocked inside the through-bore of the plate, without any clearance, and on the other side, during the removal, a little rotation of the sleeve is enough for releasing it from the plate. Thanks to the fact that the sleeve according to the invention comprises a through-hole having at least a portion of frusto-conical shape, outwardly diverging, intended to match with a corresponding screw with a frusto- conical head, on one side it is guaranteed that the screw is effectively blocked inside the sleeve through-hole, without any clearance, and on the other side, during the removal, a little rotation of the screw head is enough for releasing it from the sleeve itself.

According to a preferred embodiment of the invention, the through-hole of the sleeve according to the invention comprises a first frusto-conical portion, outwardly diverging, having lesser conicity, and a second frusto- conical portion, also outwardly diverging, having greater conicity; said sleeve is intended to match with a screw with a head also comprising a first frusto-conical portion having lesser conicity and a second frusto- conical portion having greater conicity, said second frusto-conical portion having greater conicity acting as abutment for blocking the insertion of the screw into the sleeve at the desired depth.

Brief description of the drawings

Further advantages and features of the invention will be made clearer by the following detailed description of a preferred embodiment of the invention, given by way of non-limiting example, with reference to the attached drawings, wherein:

- Figure 1 is a perspective view of a sleeve for osteosynthesis device according to the invention;

- Figure 2 is a partial prospective view of an osteosynthesis device incorporating the sleeve of Figure 1 ;

- Figure 3 is a perspective view of the plate of the osteosynthesis device of Figure 2;

- Figure 4 is a perspective view of a screw of the osteosynthesis device of Figure 2.

Detailed description of a preferred embodiment of the invention

With reference to Figure 1, a sleeve 10 for osteosynthesis device according to the invention is shown.

Said sleeve 10 has a frusto-conical, outwardly diverging and externally threaded outer surface 10a. Said sleeve is therefore suitable for coupling by screwing with a frusto-conical, outwardly diverging, internally threaded through-bore, as it will be described in detail in the following. The outer surface 10a of the sleeve 10 could optionally be delimited on its upper side by an abutment ring.

Said sleeve 10 has a central through-hole 12 comprising at least a first portion 12a having a frusto-conical shape, outwardly diverging, suitable for receiving the frusto-conical head of a screw, as it will be described in detail in the following.

Preferably, as shown in Figure 1 , the through-hole 12 of the sleeve 10 comprises a first portion 12a having a frusto-conical shape, outwardly diverging, with lesser conicity and a second portion 12 having a frusto- conical shape, also outwardly diverging, with greater conicity, said second frusto-conical portion 12b merging into said first frusto-conical portion 12a at the maximum diameter of the latter. The second frusto-conical portion 12b can advantageously act as abutment for the head of a screw having a corresponding shape, as it will be described in detail in the following.

Advantageously, the top surface of the sleeve 10 is provided with a pair of diametrically arranged notches 14, forming a pilot for a screwdriver or similar tool during the steps of insertion / removal of the sleeve itself into / from the osteosynthesis plate.

With reference to Figure 2, an osteosynthesis device 100 incorporating one or more sleeves 10 according to the invention is shown. The osteosynthesis device 100 comprises:

- a plate 20 having a thin and elongated shape, provided with a plurality of through-bores for the insertion of screws for fixing said plate to a fractured bone;

- at least one sleeve 10 according to the invention, coupled to said plate at one of said through-bores;

- at least one screw 30 suitable for being inserted into said sleeve 10 and penetrating into the fractured bone.

According to the invention, said plate 20, shown in detail in Figure 3, has a plurality of internally threaded through-bores 22 having a frusto-conical shape, outwardly diverging, with a conicity corresponding to the conicity of the outer surface 10a of the sleeve of Figure 1, so that each through- bore 22 can receive such a sleeve and the thread of the outer surface 10a of said sleeve can match with the thread of the inner surface of said through-bore.

Said at least one screw 30, shown in detail in Figure 4, comprises a stem 32 and a head 34. The stem 32 comprises a non-threaded portion 32a joined to the head 34 and a threaded end portion 32b suitable for being screwed into the fractured bone.

According to the invention, the head 34 of the screw 30 comprise at least a first frusto-conical portion 34a, outwardly diverging, having a conicity corresponding to the conicity of the first frusto-conical portion 12a of the through-hole 12 of the sleeve 10, so that the screw 30, while being screwed into the bone, gets blocked inside the sleeve 10 without clearances.

According to the preferred embodiment shown in the Figures, the head 34 of the screw 30 further comprises a second frusto-conical portion 34b, also outwardly diverging, having a conicity corresponding to the conicity of the second frusto-conical portion 12b of the through-hole 12 of the sleeve 10, said second frusto-conical portion 34b merging into said first frusto-conical portion 34a at the maximum diameter of the latter: when the screw 30 is screwed into the bone and penetrates through the sleeve 10, the second frusto-conical portion 34b of the head 34 of the sleeve 30 abuts against the second frusto-conical portion 12b of the through-hole 12 of the sleeve 10, preventing a further advancing of the screw 30 itself. As it can be seen in Figure 4, the top surface of the head 34 of the screw 30 advantageously comprises a pilot 36 for the insertion of an alien wrench or similar tool for the insertion / removal of the screw 30 into / from the fractured bone.

The application of the osteosynthesis device 100 is carried out according to the following steps:

- the plate 20 is placed on the bone and, using the inner wall of through-bores 22 as a guide, as many through-bores as the through-bores 22 in the plate 20 are made in the bone by a drill or similar tool;

- the sleeves 10 are screwed into the plate 20 thanks to the matching between the threaded, frusto-conical outer surface 10a of the sleeves 10 and the threaded, frusto-conical inner surface of the through-bores 22 of said plate;

- the screws 30 are screwed into the bone, which screws, getting blocked inside the sleeves 10 thanks to the matching between the frusto-conical outer surface 34a of their heads 34 and the frusto- conical inner surface of the through-holes 12 of the sleeves 10, fasten the plate 20 to the bone.

The removal of the osteosynthesis device 100 is extremely easy:

thanks to the fact that the matching between the screws 30 and the sleeves 10 is based upon the conicity of the head of the screws

30 and of the through-hole of the sleeves 10, a little rotation of the screws 30 in the unscrewing direction immediately releases the screw from the respective sleeves;

- thanks to the fact that the matching between the sleeves 10 and the plate 20 is based upon the conicity of the outer surface of the sleeves 10 and of the through-bores of the plate 20, a little rotation of the sleeves 10 in the unscrewing direction immediately releases the sleeves from the plate.

From the above disclosure, it is therefore evident that the sleeve for osteosynthesis device and the osteosynthesis device according to the invention satisfactorily achieve the above set objects.

It is further evident that the above described embodiment has been given by way of non-limiting example and that several modifications and variants are possible without departing from the scope of protection ad defined by the appended claims.

For instance, even if in the illustrated osteosynthesis device the sleeves 10 have the same axial dimension of the plate 20 and their surface is completely frusto-conical, it as also possible to provide for sleeves 10 comprising a non-threaded cylindrical portion, merging into the frusto- conical portion 10a of the sleeve 10 at the minimum diameter of the latter, said cylindrical portion being intended to project from the plate 20 and penetrate into the fractured bone for guiding the screw 30. In this case, at the non-threaded cylindrical portion of the sleeve 10, the through-hole 12 will also comprise a non-threaded portion with uniform cross-section, merging into the first frusto-conical portion 12a of the through-hole 12 at the minimum diameter of the latter.

Claims

1. Sleeve (10) for an osteosynthesis device (100) centrally provided with a through-hole (12), characterized in that the external surface of said sleeve comprises at least a first frusto-conical portion (10a), externally threaded, and in that said through-hole (12) comprises at least a first frusto-conical portion (12a).
2. Sleeve (10) according to claim 1 , wherein said through-hole (12) further comprises a second frusto-conical portion (12b) having a conicity greater than said first frusto-conical portion (12a), said second frusto- conical portion (12b) merging into said first frusto-conical portion (12a) at the maximum diameter of the latter.
3. Sleeve (10) according to claim 1 or 2, wherein the external surface of said sleeve further comprises a non-threaded cylindrical portion, merging into said frusto-conical portion (10a) at the minimum diameter thereof, said through-hole (12) correspondingly comprising a non- threaded portion with uniform cross-section, merging into said first frusto-conical portion (12a) of said through-hole at the minimum diameter thereof.
4. Sleeve (10) according to claim 1 or 2 or 3, wherein the top surface of said sleeve (10) is provided with a pair of diametrically arranged notches
( 14), forming a pilot for a screwdriver or similar tool.
5. Osteosynthesis device (100) comprising:
a plate (20) having a flat and elongated shape, provided with a plurality of through-bores (22) for the insertion of screws for fastening said plate to a fractured bone;
a plurality of sleeves associated to said plate, each at one of said through-bores;
a plurality of screws (30), suitable to be inserted through said sleeves and to penetrate into said fractured bone;
characterized in that it comprises at least one sleeve (10) according to any of the claims 1 to 4.
6. Osteosynthesis device (100) according to claim 5, wherein at least one of said through-bores (22) of said plate (20) is internally threaded and has a frusto-conical shape having a conicity corresponding to the conicity of said first frusto-conical portion (10a) of said sleeve (10).
7. Osteosynthesis device (100) according to claim 5, wherein at least one of said screws (30) comprises a head (34) comprising at least a first frusto-conical portion (34a) having a conicity corresponding to the conicity of said first frusto-conical portion (12a) of said through-hole (12) of said sleeve (10).
8. Osteosynthesis device (100) according to claims 2 and 7, wherein said head (34) of said at least one screw (30) further comprises a second frusto-conical portion (34b), having a conicity corresponding to the conicity of said second frusto-conical portion (12b) of said through-hole (12) of said sleeve (10), said second frusto-conical portion (34b) merging into said first frusto-conical portion (34a) at the maximum diameter of the latter.
9. Osteosynthesis device (100) according to claim 7 or 8, wherein the top surface of said head (34) of said screw (30) comprises a pilot (36) for the insertion of an alien wrench or similar tool.
10. Osteosynthesis device (100) according to any of the claims 5 to 9, comprising as many sleeves (10) according to any of the claims 1 to 4 as said through-bores (22) of said plate (20).
PCT/IB2010/053194 2009-07-29 2010-07-13 Sleeve for an osteosynthesis device and osteosynthesis device comprising such a sleeve WO2011013021A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
ITTO20090579 ITTO20090579A1 (en) 2009-07-29 2009-07-29 Compass for osteosynthesis device and osteosynthesis device comprising such a bushing.
ITTO2009A000579 2009-07-29

Publications (1)

Publication Number Publication Date
WO2011013021A1 true WO2011013021A1 (en) 2011-02-03

Family

ID=41727514

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2010/053194 WO2011013021A1 (en) 2009-07-29 2010-07-13 Sleeve for an osteosynthesis device and osteosynthesis device comprising such a sleeve

Country Status (2)

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IT (1) ITTO20090579A1 (en)
WO (1) WO2011013021A1 (en)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997008999A1 (en) 1995-09-08 1997-03-13 Depuy Ace Medical Company Internal bone fracture fixator
WO2001091660A1 (en) 2000-05-31 2001-12-06 Vese, Silvana Device for fixing a bone plate
EP1364623A1 (en) * 1995-04-13 2003-11-26 Fastenetix, L.L.C. A polyaxial locking screw collar and plate assembly
WO2005060845A1 (en) * 2003-12-09 2005-07-07 Aesculap, Inc. Bone fixation assembly and method of securement
WO2006102110A1 (en) * 2005-03-17 2006-09-28 Smith & Nephew, Inc. Screw head adapter for bone plate
US20070010817A1 (en) * 2005-07-06 2007-01-11 Stryker Spine S.A. Multi-axial bone plate system

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1364623A1 (en) * 1995-04-13 2003-11-26 Fastenetix, L.L.C. A polyaxial locking screw collar and plate assembly
WO1997008999A1 (en) 1995-09-08 1997-03-13 Depuy Ace Medical Company Internal bone fracture fixator
WO2001091660A1 (en) 2000-05-31 2001-12-06 Vese, Silvana Device for fixing a bone plate
WO2005060845A1 (en) * 2003-12-09 2005-07-07 Aesculap, Inc. Bone fixation assembly and method of securement
WO2006102110A1 (en) * 2005-03-17 2006-09-28 Smith & Nephew, Inc. Screw head adapter for bone plate
US20070010817A1 (en) * 2005-07-06 2007-01-11 Stryker Spine S.A. Multi-axial bone plate system

Also Published As

Publication number Publication date
ITTO20090579A1 (en) 2011-01-30

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