Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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 or setting implements
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7032—Screws or hooks with U-shaped head or back through which longitudinal rods pass
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B7/00—Connections of rods or tubes, e.g. of non-circular section, mutually, including resilient connections
  • F16B7/04—Clamping or clipping connections
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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 or setting implements
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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 or setting implements
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B17/00—Connecting constructional elements or machine parts by a part of or on one member entering a hole in the other and involving plastic deformation
  • F16B17/004—Connecting constructional elements or machine parts by a part of or on one member entering a hole in the other and involving plastic deformation of rods or tubes mutually
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B2/00—Friction-grip releasable fastenings
  • F16B2/02—Clamps, i.e. with gripping action effected by positive means other than the inherent resistance to deformation of the material of the fastening
  • F16B2/14—Clamps, i.e. with gripping action effected by positive means other than the inherent resistance to deformation of the material of the fastening using wedges
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B3/00—Key-type connections; Keys
  • F16B3/06—Key-type connections; Keys using taper sleeves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B4/00—Shrinkage connections, e.g. assembled with the parts at different temperature; Force fits; Non-releasable friction-grip fastenings
  • F16B4/004—Press fits, force fits, interference fits, i.e. fits without heat or chemical treatment
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16B—DEVICES FOR FASTENING OR SECURING CONSTRUCTIONAL ELEMENTS OR MACHINE PARTS TOGETHER, e.g. NAILS, BOLTS, CIRCLIPS, CLAMPS, CLIPS OR WEDGES; JOINTS OR JOINTING
  • F16B7/00—Connections of rods or tubes, e.g. of non-circular section, mutually, including resilient connections
  • F16B7/04—Clamping or clipping connections
  • F16B7/0406—Clamping or clipping connections for rods or tubes being coaxial
  • F16B7/0426—Clamping or clipping connections for rods or tubes being coaxial for rods or for tubes without using the innerside thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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 or setting implements
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/7004—Longitudinal elements, e.g. rods with a cross-section which varies along its length
  • A61B17/7005—Parts of the longitudinal elements, e.g. their ends, being specially adapted to fit in the screw or hook heads
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • 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 or setting implements
  • A61B17/68—Internal fixation devices, including fasteners and spinal fixators, even if a part thereof projects from the skin
  • A61B17/70—Spinal positioners or stabilisers, e.g. stabilisers comprising fluid filler in an implant
  • A61B17/7001—Screws or hooks combined with longitudinal elements which do not contact vertebrae
  • A61B17/7002—Longitudinal elements, e.g. rods
  • A61B17/701—Longitudinal elements with a non-circular, e.g. rectangular, cross-section
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B2017/00477—Coupling
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B2017/00831—Material properties
  • A61B2017/00867—Material properties shape memory effect

Definitions

• This invention relates to the domain of mechanics, and more precisely methods of making a connection between two or more parts.
• this part may be a screw, a ring, a staple or a wedge, that keeps the parts to be connected in contact with each other.
• this blocking is achieved by friction of the clamping part on the part(s) with which it is in contact.
• Friction between two parts is characterised by a limiting sliding value that depends on the applied clamping force.
• blocking is characterised by a limiting value of resistance that depends on the applied clamping force.
• the value of the clamping force and its precision directly depend on the stiffness of the assembly: if the stiffness decreases, the precision increases but the value of the clamping force also decreases.
• a relatively high force and a relatively low stiffness can sometimes be reconciled using an intermediate part such as a spring with low stiffness. But it is usually difficult to make an assembly with a simple design and a high limiting resistance without using a precisely controlled clamping system.
• the purpose of the invention is to propose a method of connecting two or more parts using a clamping part, to impose a precise value of a clamping force without necessarily needing very precise control over placement of the clamping part. This method could be used particularly, but not exclusively, in an implantable device for medical or veterinary use.
• Said clamping part may display a difference between OM S and ⁇ Af less than or equal to 300 MPa and be set on the unloading plateau when the connection is made.
• the difference between ⁇ Ms and ⁇ Af is preferentially less than or equal to 300 MPa.
• the clamping part may be made from a Ni-Ti alloy containing 55.6% ⁇ 0.4% by weight of nickel having undergone a martensite plates generation heat treatment by maintaining the part between 480 and 520 0 C for 5 to 60 minutes.
• Another object of the invention is a connection system between at least two parts, of the type comprising at least one clamping part applying pressure on at least one of said parts, characterised in that said clamping part is of the type described above.
• One of the parts to be connected may comprise a split cup with a shape corresponding to the shape of one end of the other of the parts to be connected that fits into said cup, and said clamping part is a ring surrounding said split cup.
• Said split cup may be spherical and the end of the other of the parts to be connected that fits into the cup is a ball pivot.
• Said split cup may be cylindrical and the end of the other part to be connected that fits into the cup is cylindrical.
• One of the parts to be connected may comprise at least one tab and at least one ring surrounding said tab and the other of the parts to be connected.
• One of the parts to be connected may comprise a conical perforation with a shape corresponding to the shape of the clamping part, said clamping part being provided with a perforation into which the other part to be connected is inserted.
• Said clamping part may be a wedge inserted between said parts to be connected.
• Said wedge may be tapered.
• Said wedge may be cam-shaped.
• One of the parts to be connected may comprise a fork with two arms between which the other of the parts to be connected fits, and the clamping part applies a force on said arms tending to bring them towards each other.
• Said clamping part may be in the shape of a yoke.
• Said clamping part may also be annular.
• Said clamping part may be a wedge pressed against a first of the parts to be connected by a screw inserted in a threaded hole formed in a second of the parts to be connected, itself comprising an orifice into which said first part is inserted.
• Said clamping part may be a U-shaped staple between the arms of which two tabs each forming part of one of the parts to be connected are clamped in contact with each other.
• Said at least two parts may be part of an implantable device for medical or veterinary use.
• SMA shape memory alloy
• FIG. 3 to 14 diagrammatically show examples of connections in which clamping parts according to the invention can be used.
• test piece is restored to a conventional linear elastic behaviour which is for martensite, the martensitic transformation having been completed in the deformation corresponding to the stress Ow-
• the superelastic SMAs that can be used within the scope of the invention must have:
• the difference EMS between displacements (deformations) corresponding to ⁇ s and OA 5 is often of the order of 5%. This means that for SMAs that can be used within the context of the invention on which a deformation ⁇ corresponding to the plateaus 2, 4 (loading or unloading) is imposed, a difference of a few % in the deformation imposed on the clamping part will only result in a small variation of the clamping stress imposed by said part.
• ⁇ f( ⁇ ) curve, and in particular the presence, stiffness and length of the plateaus, depends not only on the composition of the alloy, but also on the mechanical and crystalline characteristics of the material: small grain size or monocrystalline material, presence of precipitates, hardening rate, heat treatments undergone.
• a material may be suitable either if it is formed from a large number of small grains, or if it is monocrystalline, but intermediate states are not generally desirable.
• EP A 0 864 664 consists of a nickel and titanium alloy comprising 55.6% + 0.4% by weight of nickel having undergone heat or thermomechanical treatments giving it the desired metallurgical structure.
• it underwent a martensite plates generation heat treatment consisting of subjecting the part to a temperature of 480 to 520 0 C for 5 to 60 minutes.
• flash annealing at 600-800 0 C for 10 to 30 seconds, and/or recrystallisation annealing at 700-800 0 C for more than 2 minutes, and/or work hardening between 15 and 18%.
• This document may be referred to in order to obtain more details.
• Iron, copper or vanadium may partially substitute nickel.
• the material that can be used to make the clamping part according to the invention must have a superelastic behaviour as described, at the assembly temperature of the parts to be connected and at their working temperature.
• the material must be biocompatible.
• Figure 3 shows a "blocked ball pivot" system, in which a first part 5 terminates at a ball pivot 6 that fits into a spherical split cut 7 formed at the end of a second part 8 (shown in longitudinal section).
• the split in the cup 7 is not visible in figure 3.
• a ring 9 according to the invention clamps the cup 7 and blocks the ball pivot 6 in it. therefore, the ring 9 is stressed in tension.
• Figure 4 shows a "blocked sliding pivot" system.
• a first part 10 with a circular section is inserted in a cylindrical split cup 11 formed at the end of a second part 12 (shown in longitudinal section).
• a ring 13 according to the invention clamps the cup 11 and blocks the rod 10 in it. Therefore, the ring 13 is stressed in tension.
• a connection can be made between two parts according to the invention by clamping a split cup with an arbitrary shape formed at the end of a part as described, into a ring, the shape of the cup corresponding to the shape of the end of the other part.
• Figure 5 shows a system called a "clamping attachment".
• a first part 14 shown in longitudinal section is provided with two tabs 15, 16 at its end, against which a spindle 17 is to be kept in contact.
• each of two rings 18, 19 according to the invention shown in longitudinal section clamps one of the two tabs 15, 16 and the spindle 17.
• the rings 18, 19 are stressed in tension.
• this type of connection method may be adapted to parts other than a circular spindle 17. It would also be possible to use only one ring 18, 19 and one tab 15, 16.
• Figure 6 shows another attachment system onto a spindle.
• a first part 20 shown in longitudinal section comprises a conical perforation 21 in which a conical clamping part 22 according to the invention is force fitted.
• This clamping part 22 is itself provided with a cylindrical perforation 23 in which a spindle 24 to be blocked is inserted in the first part 20.
• the forces applied by the first part 20 on the clamping part 22 are transmitted by the clamping part to the spindle 24 that is thus blocked.
• the clamping part 22 is stressed in compression.
• this connection mode may be adapted to parts other than a circular spindle 24.
• Figure 7 shows a connection system using a wedge stressed in bending.
• the two parts to be connected are a first part 25 in the shape of a C and a rod 26 placed in a groove 27 of the first part 25, opposite the arms of the C.
• a clamping part in the shape of a grooved wedge 28 according to the invention fills in the available space inside the C between the rod 26 and the arms of the C, such that it is stressed in bending by the arms of the C, the inner faces of the arms being shaped according to the upper face of the clamping part 28.
• Figure 8 shows a connection system using a wedge stressed in compression.
• a first U-shaped part 29 is connected to a second part 30 with a rectangular section.
• the available space inside the U between the two parts 29, 30 is filled by a clamping part 31 according to the invention in the shape of a wedge that pushes the second part 30 into contact with an arm of the first part 29.
• the clamping part 31 is stressed in compression.
• Figure 9 shows a system comparable to that in Figure 8 in which that tapered wedge is replaced by a cam 32 with a partially circular and partially elliptical section. It is fitted into a groove with a section following an arc of a circle 33 formed on a first arm of the U formed by the first part to be connected 34. After inserting the section part to be connected to 35 inside the U, the cam 32 is turned such that its elliptical section part 36 comes into contact with the second part 35 and pushes it into contact with the second arm of the U of the first part 34. The cam 33 is thus stressed in compression.
• Figure 10 shows a "fork clamping" system in which the first part 37 is a fork with two arms between which a rod 38 is placed. Clamping is obtained by a clamping part 39 according to the invention in the form of a yoke, in which the inner space is shaped so as to tend to bring the two arms of the first part 37 together so that they clamp the rod 38.
• the clamping part 39 is stressed in bending.
• Figure 11 shows a variant of the system in Figure 10, in which the clamping part 40 according to the invention is an annular part in which the orifice 41 with a rectangular section in the example shown, is shaped so as to clamp the arms of the first part 42 and to make them clamp the rod 43.
• the annual part 40 is placed above the rod 43 and is stressed in tension.
• Figure 12 shows a variant of the system in figure 11 , in which the clamping part 44 according to the invention, once again in an annular shape with a rectangular orifice, is placed below the rod 45 to be connected to the first part 46 in the shape of a fork, the arms of which are shaped to trap the rod 45 under the effect of the clamping part 44 that is also stressed in tension.
• Figure 13 shows a screw clamping system shows a screw clamping system.
• the first part 47 shown in cross section, includes firstly an orifice 48 in which a rod 49 is blocked using a screw 50 inserted into a threaded hole 51 in the first part 47 opening up into the orifice 48.
• a housing 51 is provided in the first part 47 so that a clamping part 52 according to the invention can be inserted, composed of a wedge that the screw 50 compresses against the rod 49.
• the configuration according to the invention provides a means of more precisely adjusting the force applied to the rod 49, without it being necessary to monitor and very carefully limit the advance of the screw 50 in the threaded hole 51.
• Figure 14 shows a staple clamping system in which two parts 53, 54 each provided with a part 55, 56 are connected by a U-shaped staple stressed in bending, the two tabs 55, 56 being clamped in contact with each other between the arms of the U.
• clamping systems may find applications in various fields, particularly in the field of implantable devices in the human or animal body with the benefits mentioned above.
• those involving a rod or a spindle can be used to hold a rod of an osteosynthesis device for the spinal column inside a bone securing part (screw, hook) implanted on a vertebra.

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Mechanical Engineering (AREA)
• Neurology (AREA)
• Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Molecular Biology (AREA)
• Animal Behavior & Ethology (AREA)
• Heart & Thoracic Surgery (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Biomedical Technology (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Medical Informatics (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Crystallography & Structural Chemistry (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Prostheses (AREA)
• Clamps And Clips (AREA)

Applications Claiming Priority (2)

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• 2006
  • 2006-05-05 FR FR0604063A patent/FR2900694B1/fr not_active Expired - Fee Related
• 2007
  • 2007-04-04 EP EP07734199A patent/EP2016294A1/de not_active Withdrawn
  • 2007-04-04 WO PCT/IB2007/000878 patent/WO2007129154A1/en not_active Ceased
  • 2007-04-04 CN CNA2007800232488A patent/CN101473142A/zh active Pending
  • 2007-04-04 JP JP2009508518A patent/JP2009536305A/ja active Pending
  • 2007-04-04 KR KR1020087029843A patent/KR20090027622A/ko not_active Ceased
  • 2007-04-04 AU AU2007246786A patent/AU2007246786A1/en not_active Abandoned

Non-Patent Citations (1)

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