GB2342582A - Unicompartmental knee prosthesis that limits anterior-posterior, medial-lateral and rotational movement - Google Patents

Unicompartmental knee prosthesis that limits anterior-posterior, medial-lateral and rotational movement Download PDF

Info

Publication number
GB2342582A
GB2342582A GB9822266A GB9822266A GB2342582A GB 2342582 A GB2342582 A GB 2342582A GB 9822266 A GB9822266 A GB 9822266A GB 9822266 A GB9822266 A GB 9822266A GB 2342582 A GB2342582 A GB 2342582A
Authority
GB
United Kingdom
Prior art keywords
tibial
component
meniscal
knee prosthesis
anterior
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
GB9822266A
Other versions
GB9822266D0 (en
GB2342582B (en
Inventor
David Fletcher
George Cremore
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Corin Medical Ltd
Original Assignee
Corin Medical Ltd
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
Application filed by Corin Medical Ltd filed Critical Corin Medical Ltd
Priority to GB9822266A priority Critical patent/GB2342582B/en
Publication of GB9822266D0 publication Critical patent/GB9822266D0/en
Publication of GB2342582A publication Critical patent/GB2342582A/en
Application granted granted Critical
Publication of GB2342582B publication Critical patent/GB2342582B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

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
    • 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
    • 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
    • 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
    • A61F2002/30108—Shapes
    • A61F2002/3011—Cross-sections or two-dimensional shapes
    • A61F2002/30182—Other shapes
    • A61F2002/30187—D-shaped or half-disc-shaped
    • 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
    • A61F2002/30383—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
    • A61F2002/3039—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove with possibility of relative movement of the rib within the groove
    • A61F2002/30392—Rotation
    • A61F2002/30393—Rotation with additional means for limiting said rotation
    • 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
    • A61F2002/30383—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove
    • A61F2002/3039—Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements made by laterally inserting a protrusion, e.g. a rib into a complementarily-shaped groove with possibility of relative movement of the rib within the groove
    • A61F2002/30398—Sliding
    • A61F2002/304—Sliding with additional means for limiting said sliding
    • 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
    • A61F2002/30891—Plurality of protrusions
    • A61F2002/30892—Plurality of protrusions parallel
    • 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
    • A61F2002/3895—Joints for elbows or knees unicompartimental
    • 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
    • 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
    • A61F2230/00—Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2230/0002—Two-dimensional shapes, e.g. cross-sections
    • A61F2230/0028—Shapes in the form of latin or greek characters
    • A61F2230/0034—D-shaped
    • 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
    • A61F2310/00029—Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
    • 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
    • A61F2310/00179—Ceramics or ceramic-like structures
    • A61F2310/00185—Ceramics or ceramic-like structures based on metal oxides
    • A61F2310/00239—Ceramics or ceramic-like structures based on metal oxides containing zirconia or zirconium oxide ZrO2
    • 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
    • A61F2310/00389—The prosthesis being coated or covered with a particular material
    • A61F2310/00592—Coating or prosthesis-covering structure made of ceramics or of ceramic-like compounds
    • A61F2310/00796—Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite

Abstract

A unicompartmental knee prosthesis comprises a femoral component (10), a meniscal component 11 and a tibial component (12). Interengaging means are provided between the meniscal and tibial components such that limited anterior-posterior, medial-lateral and rotational movement of the meniscal component with respect to the tibial component is allowed. The interengaging means comprises anterior and posterior bollards 24 and 25, respectively, on one of the tibial and meniscal components and anterior and posterior recesses 16 and 17, respectively, in the other of the tibial and meniscal components. One of the bollards 24 has an enlarged head 27 and the corresponding recess 16 is undercut. The head 27 is insertable through the mouth of the undercut recess 16. The head and the mouth serve to prevent or discourage axial separation of the meniscal and tibial components, in use.

Description

UNICOMPARTMENTAL KNEE PROSTHESIS This invention relates to a unicompartmental knee prosthesis.
Unicompartmental knee prostheses, which allow replacement of only one side of a knee joint, are known. This type of prosthesis is used when one side of a knee joint is damaged or diseased but the other side is sufficiently healthy to continue to function normally. Unicompartmental replacement of one side or the other of the knee joint avoids unnecessary removal of healthy bone and other tissue, reduces the recovery time of the patient and gives a higher probability of restoration of full function of the knee joint.
Most known unicompartmental knee prostheses consist effectively of two components, the tibial component and the femoral component, although the tibial component may be formed from a metal base and a high-strength, low-friction plastics upper surface fixedly connected to the base. This means that the tibial component must be accurately located with respect to the femoral component, otherwise the knee joint will not manipulate smoothly. Providing accurate location of the tibial component significantly increases the length of the operative procedure because careful and expensive manipulative tests must be carried out before final location of the respective parts can be achieved. Also, the femoral component rotates whilst articulating with the tibial component and, therefore, the knee and tibial component are incongruent for a substantial part of the movement cycle.
This problem has been overcome by providing a mobile meniscal component with a shaped upper side (superior surface) congruent with the femoral component, and a flat underside (inferior surface) to slide on the fixed tibial component.
The present invention seeks to provide an improved unicompartmental three-part knee prosthesis.
According to the present invention, there is provided a unicompartmental knee prosthesis comprising a femoral component, a meniscal component and a tibial component, interengaging means being provided between the meniscal and tibial components such that limited anterior-posterior, medial-lateral and rotational movement of the meniscal component with respect to the tibial component is allowed, wherein the interengaging means comprises anterior and posterior bollards on one of the tibial and meniscal components and anterior and posterior recesses in the other of the tibial and meniscal components, one of the bollards having an enlarged head and the corresponding recess being undercut, the head of said one bollard being insertable through the mouth of the undercut recess, the head and the mouth serving to prevent or discourage axial separation of the meniscal and tibial components, in use.
Preferably, the head will only realign with the mouth of the undercut recess when the meniscal component is in a non-physiological position relative to the tibial component during normal working operation of the knee prosthesis.
Preferably, said one bollard is the anterior bollard and the undercut recess is the anterior recess.
The tibial and femoral components are preferably formed of metal, typically a high carbon cobalt-chromium alloy, or a ceramic material, typically zirconia. The meniscal component may be made from ultra-high molecular weight polyethylene.
The invention will now be more particularly described with reference to the accompanying drawings, in which: Figure 1 is a side view of a tibial component forming part of one embodiment of a unicompartmental knee prosthesis according to the invention, Figure 2 is a front view of the tibial component shown in Figure 1, Figure 3 is a plan view of the tibial component shown in Figure 1, Figure 4 is a side view of a meniscal component forming part of the said one embodiment of the unicompartmental knee prosthesis according to the invention.
Figure 5 is a front view of the meniscal component shown in Figure 4, Figure 6 is a plan view of the meniscal component shown in Figure 4, and Figure 7 is a side view of a femoral component forming part of the said one embodiment of the unicompartmental knee prosthesis according to the invention, on an enlarged scale.
Referring now to the drawings, the individual components of a unicompartmental knee prosthesis are shown. These comprise a femoral component 10, a meniscal component 11 and a tibial component 12. The femoral component is shown in Figure 7 and consists essentially of a unicondylar surface 13. The femoral component 10 is of standard shape and also includes some form of fixing component (not shown), such as a femoral stem. The femoral component 10 can be fixed to the prepared femur of the recipient of the prosthesis assembly by the fixing component.
The fixing component forms no part of the present invention and will not be described in further detail.
The meniscal component 11 is shown in Figures 4 to 6. As shown in Figure 6, the meniscal component 11 is generally D-shaped in plan view. The meniscal component 11 has an upper condylar surface 14 which is shaped to interact with and support the condylar surface 13 of the femoral component 10 such that both components, when in contact through the range of motion, are fully congruent. The meniscal component 11 also incorporates a planar inferior surface 15 in which are provided anterior and posterior recesses 16 and 17, respectively. The anterior recess 16 is undercut so that the dimensions of the mouth of the recess are smaller than the inner part of the recess. The posterior recess 17 is open at its rearmost end, has two side walls 18 and 19 which converge slightly from the open end of the recess towards the forward end of the recess and an arcuate forward end 20.
The tibial component 12 is shown in Figures 1 to 3 and is similar in shape to the meniscal opponent 11 when viewed in plan view. Essentially, the tibial component 12 comprises a plateau 21 having a planar superior surface 22 across which the inferior surface 15 of the meniscal component 11 is intended to glide. The tibial component 12 also incorporates fixing elements 23 which can take the form of pegs as shown or stems. The fixing elements 23 can be varied according to requirements and form no part of the present invention.
The plateau 21 is provided with an anterior bollard 24 and a posterior bollard 25. The anterior bollard 24 comprises a stem 26 and an enlarged head 27 at the free end of the stem 26. The dimensions of the head 27 are such as to enable the head 27 to just pass through the mouth of the anterior recess 16 and into the inner part thereof. However, the position of the anterior bollard 24 on the meniscal component 11 relative to the position of the anterior recess 16 in the tibial component 12 and the dimensions of the head 27 and the mouth of the anterior recess 16 are such that the head 27 will only re-align with the mouth of the undercut recess 16 when the meniscal component is in a non-physiological position relative to the tibial component during normal working operation of the knee prosthesis. This will prevent or discourage axial separation of the meniscal and tibial components, in use.
The posterior bollard 25 extends to the rearmost edge of the plateau 21 and has two side walls 28 and 29 which converge slightly towards an arcuate forward end 30. The relative dimensions of the recesses 16 and 17 and the bollards 24 and 25 are such that limited anterior-posterior, medial-lateral and rotational movement of the meniscal component 11 with respect to the tibial component 12 is allowed.
The femoral component 10 and the tibial component 12 are formed from metal, preferably a high carbon cobalt-chromium alloy, or from ceramics material, typically zirconia. The meniscal component 11 is preferably formed of ultra-high molecular weight polyethylene.
The condylar surface 13 of the femoral component 10 and the superior surface 22 of the plateau 21 are highly polished to give a smooth finish. The fixing components of the femoral and tibial components and/or the other surfaces which are designed to come into contact with bone may be provided with a textured finish designed to encourage bone ingrowth. These surfaces may also be coated with an appropriate porous coating such as Hydroxyapatite.
The fact that the meniscal component 11 can move anteriorally, posteriorally, laterally and medially and can also rotate, all with respect to the tibial component 12, means that the meniscal component 11 can, within certain limits, select its own preferred position with respect to the tibial component 12. This means that the knee prosthesis can tolerate small amounts of misalignment between the femoral and tibial components created during the operative procedure and it also means that the femoral component and meniscal component can remain congruent throughout the range of motion.

Claims (9)

  1. CLAIMS 1. A unicompartmental knee prosthesis comprising a femoral component, a meniscal component and a tibial component, interengaging means being provided between the meniscal and tibial components such that limited anterior-posterior, medial-lateral and rotational movement of the meniscal component with respect to the tibial component is allowed, wherein the interengaging means comprises anterior and posterior bollards on one of the tibial and meniscal components and anterior and posterior recesses in the other of the tibial and meniscal components, one of the bollards having an enlarged head and the corresponding recess being undercut, the head of said one bollard being insertable through the mouth of the undercut recess, the head and the mouth serving to prevent or discourage axial separation of the meniscal and tibial components, in use.
  2. 2. A unicompartmental knee prosthesis as claimed in claim 1, wherein the head will only realign with the mouth of the undercut recess when the meniscal component is in a non-physiological position relative to the tibial component during normal working operation of the knee prosthesis.
  3. 3. A unicompartmental knee prosthesis as claimed in claim 1 or claim 2, wherein said one bollard is the anterior bollard and the undercut recess is the anterior recess.
  4. 4. A unicompartmental knee prosthesis as claimed in any one of claims 1 to 3, wherein the anterior and posterior bollards are on the tibial component and the anterior and posterior recesses are in the meniscal component.
  5. 5. A unicompartmental knee prosthesis as claimed in any one of the preceding claims, wherein the tibial and femoral components are formed of metal.
  6. 6. A unicompartmental knee prosthesis as claimed in claim 5, wherein the tibial and femoral components are formed of a high carbon cobalt-chromium alloy.
  7. 7. A unicompartmental knee prosthesis as claimed in any one of claims 1 to 4, wherein the tibial and femoral components are formed of a ceramic material.
  8. 8. A unicompartmental knee prosthesis as claimed in any one of the preceding claims, wherein the meniscal component is made from ultra-high molecular weight polyethylene.
  9. 9. A unicompartmental knee prosthesis substantially as hereinbefore described with reference to the accompanying drawings.
GB9822266A 1998-10-14 1998-10-14 Unicompartmental knee prosthesis Expired - Fee Related GB2342582B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9822266A GB2342582B (en) 1998-10-14 1998-10-14 Unicompartmental knee prosthesis

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9822266A GB2342582B (en) 1998-10-14 1998-10-14 Unicompartmental knee prosthesis

Publications (3)

Publication Number Publication Date
GB9822266D0 GB9822266D0 (en) 1998-12-09
GB2342582A true GB2342582A (en) 2000-04-19
GB2342582B GB2342582B (en) 2002-10-30

Family

ID=10840443

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9822266A Expired - Fee Related GB2342582B (en) 1998-10-14 1998-10-14 Unicompartmental knee prosthesis

Country Status (1)

Country Link
GB (1) GB2342582B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002009623A1 (en) * 2000-08-01 2002-02-07 Aubaniac Jean Manuel Unicompartmental knee prosthesis

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2302282A (en) * 1995-06-15 1997-01-15 Corin Medical Ltd Knee prosthesis
GB2312167A (en) * 1996-04-17 1997-10-22 Finsbury An endoprosthetic knee

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2302282A (en) * 1995-06-15 1997-01-15 Corin Medical Ltd Knee prosthesis
GB2312167A (en) * 1996-04-17 1997-10-22 Finsbury An endoprosthetic knee

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002009623A1 (en) * 2000-08-01 2002-02-07 Aubaniac Jean Manuel Unicompartmental knee prosthesis
FR2812541A1 (en) * 2000-08-01 2002-02-08 Jean Manuel Aubaniac UNICOMPARTMENTAL KNEE PROSTHESIS

Also Published As

Publication number Publication date
GB9822266D0 (en) 1998-12-09
GB2342582B (en) 2002-10-30

Similar Documents

Publication Publication Date Title
EP0546726B1 (en) Prosthetic knee joint
US6506215B1 (en) Synthetic knee system
US5219362A (en) Knee prosthesis
US7094259B2 (en) Physiological total knee implant
US4353135A (en) Patellar flange and femoral knee-joint prosthesis
US4081866A (en) Total anatomical knee prosthesis
EP1421920B1 (en) Femoral prosthesis
EP2200539B1 (en) Systems for providing deeper knee flexion capabilities for knee prosthesis patients
EP2149354B1 (en) Orthopaedic Prosthesis
EP2275053B1 (en) Orthopaedic knee prosthesis
US20040006394A1 (en) Self-aligning knee prosthesis
US20100100190A1 (en) Tibial tray having a reinforcing member
US20030139817A1 (en) Prosthesis
US9289305B2 (en) Total knee arthroplasty with symmetric femoral implant having double Q-angle trochlear groove
EP0702537A1 (en) Unicompartmental knee prosthesis--------------------------------
US20120209391A1 (en) Modular prosthesis
DE69528655D1 (en) Asymmetrische femorale prothese
GB2355935A (en) Unicompartmental knee prosthesis
GB2342582A (en) Unicompartmental knee prosthesis that limits anterior-posterior, medial-lateral and rotational movement
GB2302282A (en) Knee prosthesis
GB2341803A (en) A knee prosthesis

Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20111014