Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/38—Joints for elbows or knees
  • A61F2/3868—Joints for elbows or knees with sliding tibial bearing
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
  • A61B17/16—Bone cutting, breaking or removal means other than saws, e.g. Osteoclasts; Drills or chisels for bones; Trepans
  • A61B17/17—Guides or aligning means for drills, mills, pins or wires
  • A61B17/1739—Guides or aligning means for drills, mills, pins or wires specially adapted for particular parts of the body
  • A61B17/1764—Guides or aligning means for drills, mills, pins or wires specially adapted for particular parts of the body for the knee
• • 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
  • A61B17/88—Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices
• • 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
  • A61B17/88—Osteosynthesis instruments; Methods or means for implanting or extracting internal or external fixation devices
  • A61B17/92—Impactors or extractors, e.g. for removing intramedullary devices
  • A61B2017/922—Devices for impaction, impact element
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
  • A61B90/03—Automatic limiting or abutting means, e.g. for safety
  • A61B2090/033—Abutting means, stops, e.g. abutting on tissue or skin
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
  • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
  • A61F2002/30329—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
  • A61F2002/30433—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
  • A61F2002/30316—The prosthesis having different structural features at different locations within the same prosthesis; Connections between prosthetic parts; Special structural features of bone or joint prostheses not otherwise provided for
  • A61F2002/30535—Special structural features of bone or joint prostheses not otherwise provided for
  • A61F2002/30604—Special structural features of bone or joint prostheses not otherwise provided for modular
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2/30767—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
  • A61F2/30771—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
  • A61F2002/30878—Special external or bone-contacting surface, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves with non-sharp protrusions, for instance contacting the bone for anchoring, e.g. keels, pegs, pins, posts, shanks, stems, struts
  • A61F2002/30884—Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2220/00—Fixations or connections for prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2220/0025—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
  • A61F2220/0041—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements using additional screws, bolts, dowels or rivets, e.g. connecting screws
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2310/00—Prostheses classified in A61F2/28 or A61F2/30 - A61F2/44 being constructed from or coated with a particular material
  • A61F2310/00005—The prosthesis being constructed from a particular material
  • A61F2310/00011—Metals or alloys
  • A61F2310/00023—Titanium or titanium-based alloys, e.g. Ti-Ni alloys

Definitions

• the invention relates to a knee-joint endoprosthesis with a femur part, a tibia part and a plastic bearing body arranged between the femur and tibia part, in particular polyethylene, the bearing body being supported on a spherical-shell-shaped bearing surface of the tibia part facing the femur part.
• Such a knee joint endoprosthesis is known from US-A-4,224,696. This knee joint endoprosthesis allows both a rotary movement and a sliding movement of the
• knee joint endoprostheses that only allow the bearing body to rotate relative to the tibia bearing surface, but no transverse displacement (TACK knee joint prosthesis system from aldemar Link GmbH & Co., Hamburg, prospectus 736 d-en 3.92) .
• This knee joint prosthesis is a relatively uncomplicated one
• the present invention is based on the object of further developing a knee joint endoprosthesis of the type mentioned at the outset in such a way that an exact rotation and longitudinal guidance is guaranteed. Furthermore, a "rocking out" of the bearing body beyond the tibia plate should be avoided.
• the flexion resistance does not increase with increasing flexion or knee flexion.
• the inclination of the tibial bearing surface according to the invention ensures that the flexion resistance remains relatively low even in the final phase of knee flexion or flexion, in particular in connection with a femur part with a radius that becomes increasingly smaller towards the rear.
• Figure 1 is a front view of a knee joint endoprosthesis according to the invention in the inserted state.
• FIG. 2 shows a side view of the knee joint endoprosthesis according to FIG. 1;
• Figure 3 shows the tibia bearing surface in plan view.
• FIG. 4 a top view of a bearing body made of plastic, in particular polyethylene, inserted between the femur part and the tibia part;
• FIG. 5 shows the bearing body according to FIG. 4 in a front view, showing different heights and widths
• FIGS. 4 ' and 5 shows the bearing body according to FIGS. 4 ' and 5 in
• Fig. 7 shows a retaining screw for the bearing body according to FIGS. 4 to 6 on the tibia bearing surface
• Fig. 8 shows an instrument for preparing the tibia for the implantation of the tibia part of the knee joint endoprosthesis according to the invention, in perspective
• FIG. 9 shows a part of the instrument according to FIG. 8 in a perspective view
• Fig. 10 is a side view of a tibial milling machine.
• the knee joint endoprosthesis shown in FIGS. 1 and 2 consists of a femur part 10, tibia part 11, and a bearing body 12 made of plastic, in particular polyethylene, arranged between the femur and tibia part.
• Femur part 10 and Tibia ⁇ part 11 are in a known manner by mandrels 13, 14 and 15 with the thigh or. Shin bone connected.
• the femoral part further comprises a so-called femoral slide 16 with two convexly curved sliding surfaces 17, 18, which, in the implanted state, correspond to complementary concave sliding surfaces on the upper side of the bearing body 12 in such a way that a so-called roll-sliding surface between the bearing body 12 and the Movement takes place.
• a tibia bearing plate 19 is attached to the end of the tibia part 11 facing the femur part 10.
• the tibia bearing surface 20 facing the femur part 10 is spherical-shell-shaped or spherically curved.
• the underside of the bearing body 12 assigned to the bearing surface is designed in a corresponding manner, so that the bearing body 12 is supported both rotatably and displaceably in the knee bend plane without risk of lifting off the tibia bearing surface.
• the bearing body 12 is guided on the tibia bearing surface 20.
• a pin-like stop 21 protrudes from the tibia bearing surface 20 and enters a slot-like opening 22 on the support or sliding surface of the bearing body 12 facing the tibia bearing surface 20, as is shown in FIGS. 1 and 2 is recognizable.
• the pin-like stop 21 is screwed onto the tibia bearing surface 20 (see screw thread 23 in FIGS. 1 and 2).
• the upper side or the side of the pin 21 facing the femur part 10 is hemispherical.
• the cross-section and the inner corners of the slot-like opening or recess 22 in the bearing body 12 are adapted to the contour of the stop pin 21.
• the described shape of the stop pin 21 does not prevent the shin from rotating relative to the thigh.
• the tibia bearing plate 19 is asymmetrical in plan view. 4, in plan view, the bearing body 12 has an approximately kidney-shaped outline. It is made in one piece from plastic, in particular
• the bearing shells assigned to the convex sliding surfaces 17, 18 of the femoral slide 16 are identified in FIG. 4 by the reference number 24.
• the slot-like opening 22 in the bearing body 12 mentioned with reference to FIGS. 1 and 2 is designed as a continuous passage 25 in the embodiment according to FIGS. 4 to 6.
• the threaded and shaft part of a cap screw 26 can be passed through this passage, as is shown, for example, in FIG. 7.
• the cap screw 26 is screwed into the tibia bearing plate 19 or its bearing surface 20.
• the corresponding threaded bore is identified in FIG. 3 with the reference number 27.
• the complementary threaded section of the cap screw 26 is provided with the reference number 28 in FIG. 7. 7 has the shape of a lens. This screw head is in the assembled
• the screw 26 can have an internal thread with which the screw 26 can be screwed onto a threaded pin at the upper end of the tibial dome 15.
• the lines 32 in FIGS. 5 and 6 indicate a differently high bearing body 12, while the lines 33 show the possible widths of the bearing body 12. In this respect, it is a graphical representation of different sizes of the bearing body 12 in height and width.
• the lower boundary surface 34 of the cylindrical section 31 of the cap screw 26 is flat.
• a ring which is convexly curved on one side is interposed.
• bearing body 12 All parts with the exception of the bearing body 12 are preferably made of titanium or a titanium alloy.
• the bearing surfaces can additionally be provided with a ceramic layer.
• the angle of inclination with respect to the horizontal is marked with a.
• the angle ⁇ between the spherical shell-shaped bearing surface 20 and the tibial axis, which coincides with the geometric central longitudinal axis 37 of the tibial dome 15, is smaller than 90 ° by the angle ⁇ .
• the angle of inclination is preferably 5 to 15 °, in particular approximately 10 °. Accordingly, the angle ⁇ is 75 ° to 85 °, in particular approximately 80 °.
• the inclination of the spherical shell-shaped bearing surface 20 is defined by the inclination of the connecting straight line between the two end points of the bearing surface in the knee-bend plane (in FIG. 2, the plane of the drawing).
• the geometric center 36 of the spherical shell-shaped bearing surface 20 of the tibia part 11 is opposite the central longitudinal axis 37 of the tibial dome 15, which coincides with the tibia axis and accordingly with the central longitudinal axis of the extended knee joint endoprosthesis or knee joint endoprosthesis in the extended position. moved backwards.
• the described inclination of the spherical shell-shaped bearing surface 20 of the tibia part 11 towards the back ensures that the resistance to flexion does not increase in the final phase of the knee flexion, as is the case with the natural knee.
• the sphericity of the bearing surface 20 also ensures that there is still sufficient resistance in the end-knee flexion position to prevent the bearing body from sliding off beyond the rear edge of the bearing surface.
• the tibial mandrel 15 is displaced forward relative to the central longitudinal axis of the spherical shell-shaped bearing surface 20 of the tibia part 11 (see also FIG. 2).
• This relative position between the spherical shell-shaped bearing surface 20 and the mandrel 15 also approaches the proximal end of the tibia to the naturally lying knee joint.
• the force application into the tibia is then perpendicular to the implant contact surfaces, so that loosening of the tibia part is unlikely even after prolonged use.
• the force transmission into the tibia is optimal.
• the tibial bearing surface 20 is formed by a plate shaped like a spherical shell, the plate of which Thickness is about 1.0 to 2.0 mm. This measure makes it possible to remove only a minimum of bone material from the proximal end of the tibia. However, it is necessary to make the proximal end of the tibia correspondingly concave.
• an instrument according to FIG. 1 is an instrument according to FIG.
• the tibia shaped part 38 can be plugged onto the proximal end of the impact device 43 in the direction of the arrow 44.
• the striking surface 39 is located exactly above the shaping surface 40, so that the spongiosa on the proximal, initially flat cutting surface of the tibia can be formed in a correspondingly concave manner by one or more strikes on the striking surface 39 with a hammer or the like striking tool so that the tibia bearing plate 19 can be fitted exactly, as indicated in FIG. 2.
• a bore for the tibial mandrel 15 is made through it by means of a bone cutter.
• a bore 41 for guiding the bone cutter 42 according to FIG. 10 is formed in the tibia shaped part 38.
• the bore 41 is placed in such a way that the tibial mandrel bore can be produced in exact association with the bearing surface 20 of the tibia part 11 to be implanted.
• the tibia shaped part 38 has two transverse slots 45, of which only one is visible in FIG. 8.
• Complementary holding forks 46 of the impact device 43 can be inserted into these transverse slots 45.
• Legs 47 of a U-shaped holder 48 which are of correspondingly flat shape, can also be pushed into the transverse slots 45.
• the tibia shaped part 38 can be held in position by means of the holder 48 in order then to be tion 41 through the bone cutter 42 to form the tibial dome bore.
• the distal end of the impact device 43 has a protruding nose 50.
• this nose 50 rests on the upper side thereof. The impact is thus transmitted from the impact surface 39 via the shaft and the mentioned nose 50 of the impact device 42 to the tibia shaped part 38.
• Tibial part is inclined backwards downwards, as shown in FIG. 2.

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• Health & Medical Sciences (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Surgery (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Medical Informatics (AREA)
• Molecular Biology (AREA)
• Transplantation (AREA)
• Dentistry (AREA)
• Vascular Medicine (AREA)
• Cardiology (AREA)
• Physical Education & Sports Medicine (AREA)
• Prostheses (AREA)

Applications Claiming Priority (3)

Publications (1)

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• 1994
  • 1994-12-16 US US08/513,954 patent/US5755802A/en not_active Expired - Fee Related
  • 1994-12-16 JP JP7517753A patent/JPH08507245A/ja active Pending
  • 1994-12-16 WO PCT/EP1994/004194 patent/WO1995017860A1/de not_active Application Discontinuation
  • 1994-12-16 EP EP95904493A patent/EP0689406A1/de not_active Withdrawn

Non-Patent Citations (1)

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