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
  • A61F2/389—Tibial components

Definitions

• the invention relates to a component for an endogenous prosthesis ge ass the preamble of claim 1.
• such components consist of a metallic part to be anchored in the bone and a part consisting of plastic and containing a sliding surface of the knee joint prosthesis.
• the requirements for such metal / plastic components are namely: simple and safe handling under sterile conditions in the operating room; the security against disintegration of the assembled component implanted in the body under the operating forces occurring, and above all the freedom from play of the two assembled parts.
• the freedom from play is particularly important because micro movements between the two assembled parts cause the smallest abrasion particles in the plastic part, which strain the patient's tissue and can lead to undesirable biological reactions.
• the change in the mechanical conditions in the assembled component is particularly critical due to the inevitable aging of the plastic to this day. Due to the embrittlement of the plastic, the endo-joint components can lose their function partially or completely.
• the invention seeks to remedy this.
• the invention has for its object to provide a component composed of a metal and plastic part for an endogenous joint prosthesis which also guarantees freedom of play between the two parts in the long term.
• the special positive connection between the metal and plastic part also results in the plastic becoming brittle, i.e. in the event of a partial or complete loss of elastic properties, there is still a strong, firm connection between the two parts.
• the invention achieves the stated object with a component which has the features of claim 1.
• a preferred development is that the pin of the plastic part has radial slots. It has the advantage that the desired joining force can be set by appropriate dimensioning and number of slots.
• the pin has a continuous cavity.
• the elastic properties of the pin which can now accommodate a spreader pin in the cavity, can thus be influenced.
• the first part is provided with a guide comb for the positioning of the second part.
• this guide comb supports the positioning and, on the other hand, prevents the pin from being damaged if the position is insufficient. Therefore, the guide comb is preferably arranged at a distance from the bore such that the pin is centered when it is introduced into the bore.
• This process can be further improved if the guide comb has a wedge surface that is inclined to the longitudinal axis of the bore can be brought into contact with a wedge surface attached to the circumference of the second part.
• the plastic components can slide along the inclined plane of the guide comb into their end position, which is locked without play.
• Fig. 3 is a view of an expansion pin for the second part of Fig. 2;
• FIG. 4 shows a longitudinal section through the second part according to FIG. 2 with the spreading pin according to FIG. 3 preliminarily inserted;
• 5 shows a longitudinal section through the second part placed on the first part shortly before contact with the guide comb and penetration of the pin into the bore
• 6 shows a longitudinal section through the second part placed on the first part after the pin has penetrated the bore and anchored the bead in the undercut
• FIG. 7 shows a longitudinal section through the assembled component according to the invention according to FIG. 6, in which the expansion pin is definitely inserted;
• Fig. 8 is a partial perspective view of the component of Fig. 7;
• FIG. 9 shows a perspective view of the first metallic part of the component according to the invention.
• FIG. 10 is a perspective view of the second part made of plastic according to FIG. 2nd
• the component for an endogenous joint prosthesis shown schematically in FIGS. 1 and 2 essentially consists of a metallic first part 1 to be anchored in the bone and a second part 2 made of plastic and containing a sliding surface 3 of the endogenous joint prosthesis.
• the first part 1 has a plane 11 which, as shown in FIG. 9, is surrounded by a peripheral frame 17, on the inside of which a number of undercuts 18 are made. As shown in FIG. 1, this first part 1 can be anchored in the bone by means of a cone 19.
• the second part 2 shown in FIGS. 2 and 10 has a plane 12 which can be brought into contact with the plane 11 of the first part 1 without play relative to the plane 11.
• a number of ribs 20 are attached to the outer circumference of the second part 2 and can be snapped into the undercuts 18 of the first part 1.
• the second part 2 further has a pin 4 running perpendicular to the plane 12 with a peripheral circumferential bead 9.
• the pin 4 has a continuous cavity 7 and has radial slots 8 so that it can be compressed radially.
• the first part 1 has a bore 5, which is complementary to the pin and runs perpendicular to the plane 11, with an undercut 10, which is also complementary to the bead 9 are compressed and then expands in the undercut 10, so that the pin 4 in the bore 5 - as shown in Fig. 6 - is blocked.
• the bead 9 and the undercut 10 are attached in such a way that after blocking both parts 1; 2 are also perpendicular to the planes 11; 12 (and not only in these levels) are free of play.
• an expansion pin 13 which can be inserted into the cavity 7 of the pin 4 can be provided before or after the assembly of the two parts 1; 2.
• the assembly of the two parts 1, 2 is shown step by step.
• a first step (FIG. 5) the second part 2 is supported with its ribs 20 in the undercuts 18 as a swivel joint and rotated towards the guide comb 6 until the two wedge surfaces 16 and 14 come into contact with one another, and the second part 2 against the first part 1 is correctly positioned.
• the pin 4 is arranged at such a distance from the bore 5 that the pin 4 is exactly centered when inserted into the bore 5. After the bead 9 has snapped into the undercut 10, the pin 4 in the bore 5 - as shown in FIG. 6 - is axially blocked.

Landscapes

• Health & Medical Sciences (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Physical Education & Sports Medicine (AREA)
• Cardiology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Transplantation (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Prostheses (AREA)
• Materials For Medical Uses (AREA)

Priority Applications (6)

Applications Claiming Priority (1)

Publications (1)

Family

ID=4551305

Family Applications (1)

Country Status (6)

Citations (4)

• 1998
  • 1998-01-23 AT AT98900517T patent/ATE274881T1/de not_active IP Right Cessation
  • 1998-01-23 WO PCT/CH1998/000026 patent/WO1999037251A1/de not_active Ceased
  • 1998-01-23 EP EP98900517A patent/EP1056418B1/de not_active Expired - Lifetime
  • 1998-01-23 JP JP2000528240A patent/JP2002500924A/ja active Pending
  • 1998-01-23 DE DE59811908T patent/DE59811908D1/de not_active Expired - Lifetime
  • 1998-01-23 AU AU55472/98A patent/AU727988B2/en not_active Ceased

Patent Citations (4)

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