GB2312166A - Tibial plate for an endoprosthetic knee - Google Patents

Tibial plate for an endoprosthetic knee Download PDF

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Publication number
GB2312166A
GB2312166A GB9607922A GB9607922A GB2312166A GB 2312166 A GB2312166 A GB 2312166A GB 9607922 A GB9607922 A GB 9607922A GB 9607922 A GB9607922 A GB 9607922A GB 2312166 A GB2312166 A GB 2312166A
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United Kingdom
Prior art keywords
tibial plate
tibial
plate
face
distal face
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Withdrawn
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GB9607922A
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GB9607922D0 (en
Inventor
Michael Anthony Tuke
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FINSBURY
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FINSBURY
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Priority to GB9607922A priority Critical patent/GB2312166A/en
Publication of GB9607922D0 publication Critical patent/GB9607922D0/en
Publication of GB2312166A publication Critical patent/GB2312166A/en
Application status is Withdrawn legal-status Critical

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2/38Joints for elbows or knees
    • A61F2/389Tibial components
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2/30767Special external or bone-contacting surfaces, e.g. coating for improving bone ingrowth
    • A61F2/30771Special external or bone-contacting surfaces, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2/38Joints for elbows or knees
    • A61F2/3868Joints for elbows or knees with sliding tibial bearing
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2002/30001Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30108Shapes
    • A61F2002/3011Cross-sections or two-dimensional shapes
    • A61F2002/30112Rounded shapes, e.g. with rounded corners
    • A61F2002/30133Rounded shapes, e.g. with rounded corners kidney-shaped or bean-shaped
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2002/30001Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316The 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
    • A61F2002/30535Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30594Special structural features of bone or joint prostheses not otherwise provided for slotted
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2002/30001Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
    • A61F2002/30316The 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
    • A61F2002/30535Special structural features of bone or joint prostheses not otherwise provided for
    • A61F2002/30604Special structural features of bone or joint prostheses not otherwise provided for modular
    • A61F2002/30616Sets comprising a plurality of prosthetic parts of different sizes or orientations
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2/30767Special external or bone-contacting surfaces, e.g. coating for improving bone ingrowth
    • A61F2/30771Special external or bone-contacting surfaces, e.g. coating for improving bone ingrowth applied in original prostheses, e.g. holes or grooves
    • A61F2002/30878Special external or bone-contacting surfaces, 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
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2/00Filters 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
    • A61F2/02Prostheses implantable into the body
    • A61F2/30Joints
    • A61F2/46Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor
    • A61F2002/4631Special tools or methods for implanting or extracting artificial joints, accessories, bone grafts or substitutes, or particular adaptations therefor the prosthesis being specially adapted for being cemented
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2230/00Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
    • A61F2230/0002Two-dimensional shapes, e.g. cross-sections
    • A61F2230/0004Rounded shapes, e.g. with rounded corners
    • A61F2230/0015Kidney-shaped, e.g. bean-shaped
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61FFILTERS 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
    • A61F2310/00Prostheses classified in A61F2/28 or A61F2/30 - A61F2/44 being constructed from or coated with a particular material
    • A61F2310/00005The prosthesis being constructed from a particular material
    • A61F2310/00011Metals or alloys
    • A61F2310/00029Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium

Abstract

The present invention relates to knee prostheses and provides a tibial plate for an endoprosthetic knee, the plate having a smooth proximal face, a distal face, anchoring means on the distal face for anchoring the plate to the proximal end of a resected tibia, and a distal reinforcement portion projecting from an anterior region of the distal face and having an abutment surface bevelled with respect to the distal face of the tibial plate. This reinforcement portion is designed to seat on a resected tibia at an anterior chamfered edge portion thereof. The prosthesis may be a total knee prothesis, a unicompartmental prosthesis or a "bi-unicompartmental" prosthesis.

Description

KNEE PROSTHESIS The present invention relates to knee prostheses and, in particular, to a tibial plate for used in endoprosthetic meniscal knees.

Conventionally, two principal types of endoprosthetic knee are known. The first type, the so-called total knee, comprises a tibial plate and a femoral component with an intervening meniscal component, each component having medial and lateral sides. Typically the tibial plate and femoral compartment are made from a suitable metal or metal alloy, such as an alloy of cobalt and chromium, whereas the meniscal components are made from a synthetic plastics material, for example ultra high molecular weight polyethylene. In most designs the meniscal component is fixed to the tibial plate. In other designs the meniscal component is free to float to a certain extent with respect to the tibial plate in order that the prosthesis shall mimic better the natural movement of the knee. The total knee is designed to replace all of the articulating surfaces of the knee.

The second type of endoprosthetic knee, the so-called unicompartmental knee, also has a tibial plate, a femoral component and an intervening meniscal component. Again it is usual for the meniscal component to be fixed to the tibia but in some designs a certain floating movement of the meniscal component is provided for. However, in this case, only a medial or, alternatively, a lateral femoro-tibial replacement is provided.

A third type of endoprosthetic knee, referred to herein as the "biunicompartmental" type comprises two unicompartmental knee prostheses used, one on each of the lateral and medial sides, to replace all of the articulating surfaces of the femoro-tibial articulation.

In a variation on the total knee prosthesis, it is possible to have a single tibial plate with medial and lateral portions upon which are seated two separate meniscal components, one meniscal component upon each ofthe respective medial and lateral portions of the tibial plate.

The present invention is applicable to all of the above mentioned types of endoprosthetic knee.

Knee arthroplasty requires, inter alia, resection of the proximal tibia. A prosthetic tibial plate is then anchored to the resected surface, generally by means of one or more anchoring pegs, posts or screws which are cemented or simply inserted into one or more longitudinal cavities formed in the shaft of the tibia, from the proximal resected surface thereof.

Resection of the proximal tibia necessarily weakens the load-bearing capacity of the bone since the bone becomes increasingly sponge-like beneath the surface.

To preserve as much as possible of the natural bone, the tibial resection in knee arthroplasty is generally made as a horizontal cut across the tibia, that is to say a cut in a plane which would be horizontal when the patient is standing erect. However, this has the effect of increasing the potential shear load across the anterior portion of the tibia when the prosthesis is fitted because it does not compensate for the natural slope of the proximal tibia, which in the natural knee is angled downwardly from the horizontal towards the posterior of the tibia with a slope of about 5"-10 ".

One conventional endoprosthetic knee addresses this problem to a certain extent by requiring the surgeon to make a tibial resection at an angle of between 5 and 10 to the horizontal, thus mimicking the natural knee in this respect.

Whatever the plane ofthe proximal tibia resection, a flat cut is normally used.

This has the disadvantage of relying on the fixation means for all shear loads in both translation and rotation.

It is therefore an object of the present invention to provide an improved tibial plate for endoprosthetic knees.

Accordingly, the present invention provides a tibial plate for an endoprosthetic knee, the plate having a proximal face, a distal face, anchoring means on the distal face for anchoring the plate to the proximal end of a resected tibia, and a distal reinforcement portion projecting from an anterior region of the distal face and having an abutment face bevelled with respect to the distal surface of the tibial plate.

Thus, the invention provides a tibial plate for an endoprosthetic knee, the plate having a proximal face, a distal face, anchoring means on the distal face for anchoring the plate to the proximal end of a resected tibia, and an anterior projection portion projecting from the distal face and having an abutment face bevelled with respect to the distal face of the tibial plate.

Preferably, the proximal face is smooth to allow glidable movement of a prosthetic meniscal component thereon.

To make use of a tibial plate according to the invention, the surgeon should therefore make two cuts on the proximal tibia. The first cut is at 5-10" to the horizontal, sloping downwardly towards the posterior region ofthe tibia. The second cut is made at an angle to the first cut so as to make a chamfered edge at the anterior region of the resected tibia.

An advantage of endoprosthetic knees utilising tibial plates in accordance with the invention is that the torsional loads and anterior-posterior translational loads on the tibia are supported by the distal reinforcement portion, thus providing a fitting which is more secure and less likely to loosen than conventional tibial plates. The load-bearing capacity of the tibia is increased in relation to conventional endoprostheses. This is particularly the case at the anterior portion of the tibia because of the increased surface area contact between the tibial plate and the resected tibia in this region.

In a preferred embodiment of the invention, the bevel angle formed between the abutment face ofthe reinforcement portion and the distal face ofthe tibial plate is between about 100 and about 1300.

Still more preferably, the tibial plate and the reinforcement portion are of unitary construction.

A tibial plate in accordance with the invention may be designed for use in a unicompartmental endoprosthetic knee. In this case the tibial plate is designed so as to replace the lateral only or alternatively the medial portion only ofthe natural tibial head. Alternatively, a tibial plate according to the invention may be designed to form part of a total endoprosthetic knee in which it is intended to replace both the lateral and medial portions of the natural tibia.

A tibial plate according to the invention for use in a total endoprosthetic knee may be provided with a posterior cut-out portion for accommodating a patient's posterior cruciate ligament. Optionally, the cut-out portion may be extended towards the anterior region of the plate in order that the patient's anterior cruciate ligament may also be accommodated therein. This form of total knee tibial component is made feasible by the invention which provides, by way of the distal reinforcement portion, a strong bridge on the anterior tibia. This embodiment of the invention may be regarded as a total knee tibial plate in which two unicompartmental tibial plates are joined, allowing the anterior cruciate ligament to be preserved.

In order that the invention may be clearly understood and readily carried into effect, a number of specific embodiments thereof will now be described with particular reference to the accompanying drawings in which: Figure l(a) shows a top plan view, partially in outline of a tibial plate in accordance with the invention and a corresponding meniscal component which together form part of a unicompartmental endoprosthetic knee; Figure 1 (b) shows a cross-section on line A-A of Figure 1 (a) together with a side elevational view of an appropriately resected tibia; Figure 2(a) shows a top plan view, partially in outline, of two mirror image tibial plates in accordance with the invention and corresponding meniscal components which together form part of a bi-unicompartmental endoprosthetic knee; Figure 2(b) shows a cross-section on line B-B of Figure 2(a) together with a side elevational view of an appropriately resected tibia; Figure 3(a) shows a top plan view, partially in outline, of a tibial plate in accordance with the invention and a corresponding meniscal component which together form part of a first total endoprosthetic knee; Figure 3(b) shows a cross-section on line C-C of Figure 3(a) together with a side elevational view of an appropriately resected tibia; Figure 4(a) shows a top plan view, partially in outline, of a tibial plate in accordance with the invention and two corresponding mirror-image meniscal components which together form part of a second total endoprosthetic knee; Figure 4(b) shows a cross-section on line D-D of Figure 4(a) together with a side elevational view of an appropriately resected tibia; Figure 5(a) shows a top plan view, partially in outline, of a tibial plate in accordance with the invention and two corresponding mirror-image meniscal components which together form part of a third total endoprosthetic knee.

Figure 5(b) shows a cross-section on line E-E of Figure 5(a) together with a side elevational view of an appropriately resected tibia.

Figures 1 to 5 are not drawn to scale.

Referring to Figure 1 there is shown a tibial plate 1 having a smooth proximal face 2 and a distal face 3. Tibial plate 1 comprises a longitudinal pin 4 extending from the distal face 3 of tibial plate 1, pin 4 being adapted for insertion into a longitudinal cavity (not shown) drilled in the patient's tibia 5 to anchor the tibial plate to the bone. Optionally, ancillary anchoring means may also be used. These may comprise one or more further pegs which may be ribbed for extra surface area contact with bone or cement. In addition, distal face 3 may be dimpled to provide better contact with the bone surface. Such methods and means for anchoring the tibial plate to the bone are known and are well understood by those skilled in the art.

Tibial plate 1 is preferably made from an alloy of cobalt and chromium. The dimensions of tibial plate 1 may vary for different patients and/or for different indications. Particularly, the thickness of tibial plate 1 is normally from about 3mm to about 5mm.

Tibia 5 has an angled and posteriorly sloping resected face 6 and a chamfered anterior edge portion 7 formed by the surgeon cutting an anterior part of the tibia 5 at an angle of approximately 30"-45" to the horizontal.

Tibial plate 1 is further provided with a distal reinforcement portion 8 which projects from an anterior region of distal surface 3. Distal reinforcement portion 8 has an abutment surface 9 bevelled with respect to distal surface 3 of tibial plate 1.

When tibial plate 1 is seated on tibia 5, abutment surface 9 is arranged to seat on the resected tibia at chamfered edge portion 7, thereby providing additional surface area contact between tibial plate 1 and tibia 5 in the anterior region of tibia 5.

Meniscal component 10 is seated on tibial plate 1 and is shown only in outline in Figure l(a). Meniscal component 10 may have a substantially flat distal face 11 for glidable seating on proximal face 2 oftibial plate 1. Meniscal component 10 also has a dished proximal face 12 for receiving a femoral component (not shown).

Meniscal component 10 may be constructed from ultra high molecular weight polyethylene. Alternatively, a metal component 10, for example of cobalt chromium alloy, may be used. The dimensions ofthe meniscal component may vary for different patients and/or indications. In particular, the thickness of the meniscal component is normally between about 6mm and l5mm at the thinnest portion of the meniscal component.

Endoprosthetic knees utilising tibial plates according to the invention may be manufactured to fit various bone sizes. The combined thickness of the tibial plate and meniscal component together with the femoral component for use therewith may be chosen to match a particular flexion/extension gap which the surgeon has cut.

Normally, femoral components which are commercially available are manufactured with a standard thickness of about 9mm. The combined thickness of the tibial plate and meniscal component is preferably between about 7mm and about 17mm.

Referring to Figure 2, there is shown a pair of mirror image tibial plates 1 according to the invention and a corresponding pair of meniscal components 10 for use in a bi-unicompartmental endoprosthetic knee.

Referring to Figure 3, there is shown a tibial plate 1 in accordance with the invention and a corresponding meniscal component 10 for use in a first total, endoprosthetic knee. Cut-out portion 13 is provided to accommodate, in use, the patient's posterior cruciate ligament.

Referring to Figure 4, there is shown a tibial plate 1 in accordance with the invention and two corresponding mirror image meniscal components 10 for use in a second total endoprosthetic knee.

Referring to Figure 5, there is shown a tibial plate 1 in accordance with the invention and two corresponding mirror image meniscal components 10 for use in a third total endoprosthetic knee. Tibial plate 1 is provided with a posterior cut-out portion 13 which extends towards the anterior region of tibial plate 1 to accommodate, in use, the patient's posterior and anterior cruciate ligaments. The additional strength provided to the plate by distal reinforcement portion 8 permits a cut-out portion 13 of this magnitude.

Claims (15)

CLAIMS: 1. A tibial plate for an endoprosthetic knee, the plate having a proximal face, a distal face, anchoring means on the distal face for anchoring the plate to the proximal end of a resected tibia, and a distal reinforcement portion projecting from an anterior region of the distal face and having an abutment face bevelled with respect to the distal face of the tibial plate. 2. A tibial plate for an endoprosthetic knee, the plate having a proximal face, a distal face, anchoring means on the distal face for anchoring the plate to the proximal end of a resected tibia, and an anterior projection portion projecting from the distal face and having an abutment face bevelled with respect to the distal face ofthe tibial plate. 3. A tibial plate according to claim 1 or claim 2, wherein the bevel angle formed between the abutment face of the antieror member and the distal face of the tibial plate is between 100 and 1300. 4. A tibial plate according to any one of claims 1 to 3, wherein the tibial plate and the reinforcement portion are of unitary construction. 5. A tibial plate according to any one of claims 1 to 4 which is adapted for use in a unicompartmental endoprosthetic knee and is shaped to replace the lateral portion only of or alternatively the medial portion of the natural proximal tibia. 6. A tibial plate according to any one of claims 1 to 4 which is adapted for use in a total endoprosthetic knee and is shaped to replace both the lateral and medial portions of the natural proximal tibia. 7. A tibial plate according to claim 6, wherein the plate is provided with a posterior cut-out portion for accommodating, in use, a patient's posterior cruciate ligament. 8. A tibial plate according to claim 7, wherein the cut-out portion extends sufficiently towards the anterior region of the tibial plate such that, in use, the patient's posterior and anterior cruciate ligaments may be accommodated within the cut-out portion. 9. A set of tibial plates according to any one of claims 1 to 4, which is adapted for use in a bi-unicompartmental endoprosthetic knee, which set comprises a first tibial plate shaped to replace the lateral portion of the natural proximal tibia and a second tibial plate shaped to replace the medial portion of the natural proximal tibia head. 10. A tibial plate constructed and arranged substantially as described herein with particular reference to the Figures 1 to 5 of the accompanying drawings. 11. A unicompartmental knee prosthesis comprising a tibial plate according to any one of claims 1 to 5. 12. A bi-unicompartmental knee prosthesis comprising two tibial plates according to claim 9. 13. A total knee prosthesis comprising a tibial plate according to any one of claims 6 to 8. Amendments to the claims have been filed as follows
1. A tibial plate for an endoprosthetic knee, the plate having a proximal face, a distal face, anchoring means on the distal face for anchoring the plate to the proximal end of a resected tibia, and a distal reinforcement portion projecting from an anterior region of the distal face and having an abutment face bevelled with respect to the distal face of the tibial plate.
2. A tibial plate for an endoprosthetic knee, the plate having a proximal face, a distal face, anchoring means on the distal face for anchoring the plate to the proximal end of a resected tibia, and an anterior projection portion projecting from the distal face and having an abutment face bevelled with respect to the distal face ofthe tibial plate.
3. A tibial plate according to claim 1 or claim 2, wherein the bevel angle formed between the abutment face of the anterior member and the distal face of the tibial plate is between 100 and 1300.
4. A tibial plate according to any one of claims 1 to 3, wherein the tibial plate and the reinforcement portion are of unitary construction.
5. A tibial plate according to any one of claims 1 to 4, wherein the abutment face of the projecting portion is the anterior-most distal region of the plate.
6. A tibial plate according to any one of claims 1 to 5, wherein the projecting portion extends along substantially the full width of the plate along its anterior.
7. A tibial plate according to any one of claims 1 to 6 which is adapted for use in a unicompartmental endoprosthetic knee and is shaped to replace the lateral portion only of, or alternatively the medial portion of, the natural proximal tibia.
8. A tibial plate according to any one of claims 1 to 6 which is adapted for use in a total endoprosthetic knee and is shaped to replace both the lateral and medial portions of the natural proximal tibia.
9. A tibial plate according to claim 8, wherein the plate is provided with a posterior cut-out portion for accommodating, in use, a patient's posterior cruciate ligament.
10. A tibial plate according to claim 9, wherein the cut-out portion extends sufficiently towards the anterior region of the tibial plate such that, in use, the patient's posterior and anterior cruciate ligaments may be accommodated within the cut-out portion.
11. A set of tibial plates according to any one of claims 1 to 6, which is adapted for use in a bi-unicompartmental endoprosthetic knee, which set comprises a first tibial plate shaped to replace the lateral portion of the natural proximal tibia and a second tibial plate shaped to replace the medial portion of the natural proximal tibia head.
12. A tibial plate constructed and arranged substantially as described herein with particular reference to the Figures 1 to 5 of the accompanying drawings.
13. A unicompartmental knee prosthesis comprising a tibial plate according to any one of claims 1 to 7.
14. A bi-unicompartmental knee prosthesis comprising two tibial plates according to claim 11.
15. A total knee prosthesis comprising a tibial plate according to any one of claims 8 to 10.
GB9607922A 1996-04-17 1996-04-17 Tibial plate for an endoprosthetic knee Withdrawn GB2312166A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9607922A GB2312166A (en) 1996-04-17 1996-04-17 Tibial plate for an endoprosthetic knee

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9607922A GB2312166A (en) 1996-04-17 1996-04-17 Tibial plate for an endoprosthetic knee

Publications (2)

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GB9607922D0 GB9607922D0 (en) 1996-06-19
GB2312166A true GB2312166A (en) 1997-10-22

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Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0950387A1 (en) * 1998-04-15 1999-10-20 Aesculap Knee prosthesis
US6210445B1 (en) 1999-10-26 2001-04-03 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6210444B1 (en) 1999-10-26 2001-04-03 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6217618B1 (en) 1999-10-26 2001-04-17 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6319283B1 (en) 1999-07-02 2001-11-20 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
GB2381458A (en) * 2001-09-21 2003-05-07 Depuy Int Ltd An osteoprosthesis component
EP1854432A1 (en) * 2006-05-09 2007-11-14 Finsbury (Development) Limited Knee prosthesis
US7297161B2 (en) 1999-05-10 2007-11-20 Fell Barry M Surgically implantable knee prosthesis
EP1874235A2 (en) * 2005-04-29 2008-01-09 FELL, Barry M. Surgically implantable prosthetic system
US7338524B2 (en) 1999-05-10 2008-03-04 Fell Barry M Surgically implantable knee prosthesis
US7341602B2 (en) * 1999-05-10 2008-03-11 Fell Barry M Proportioned surgically implantable knee prosthesis
US7491235B2 (en) 1999-05-10 2009-02-17 Fell Barry M Surgically implantable knee prosthesis
US8900316B2 (en) 2010-01-29 2014-12-02 Smith & Nephew, Inc. Cruciate-retaining knee prosthesis
IT201700091423A1 (en) * 2017-08-07 2019-02-07 Rejoint S R L Prostheses for the knee and a method for its realization

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1410561A (en) * 1972-01-14 1975-10-15 Herbert J J M E Prosthetic devices
US4136405A (en) * 1977-04-29 1979-01-30 Zimmer U.S.A. Rotational offset knee prosthesis

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1410561A (en) * 1972-01-14 1975-10-15 Herbert J J M E Prosthetic devices
US4136405A (en) * 1977-04-29 1979-01-30 Zimmer U.S.A. Rotational offset knee prosthesis

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2777452A1 (en) * 1998-04-15 1999-10-22 Aesculap Sa Knee Prosthesis
US6210443B1 (en) 1998-04-15 2001-04-03 Aesculap Knee prosthetics
EP0950387A1 (en) * 1998-04-15 1999-10-20 Aesculap Knee prosthesis
US8128697B2 (en) 1999-04-02 2012-03-06 Fell Barry M Proportioned surgically implantable knee prosthesis
US7338524B2 (en) 1999-05-10 2008-03-04 Fell Barry M Surgically implantable knee prosthesis
US7297161B2 (en) 1999-05-10 2007-11-20 Fell Barry M Surgically implantable knee prosthesis
US7491235B2 (en) 1999-05-10 2009-02-17 Fell Barry M Surgically implantable knee prosthesis
US7341602B2 (en) * 1999-05-10 2008-03-11 Fell Barry M Proportioned surgically implantable knee prosthesis
US6319283B1 (en) 1999-07-02 2001-11-20 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6217618B1 (en) 1999-10-26 2001-04-17 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6210444B1 (en) 1999-10-26 2001-04-03 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
US6210445B1 (en) 1999-10-26 2001-04-03 Bristol-Myers Squibb Company Tibial knee component with a mobile bearing
GB2381458A (en) * 2001-09-21 2003-05-07 Depuy Int Ltd An osteoprosthesis component
US7641689B2 (en) 2004-04-22 2010-01-05 Fell Barry M Surgically implantable knee prosthesis
US7819919B2 (en) 2004-04-26 2010-10-26 Fell Barry M Surgically implantable knee prosthesis
EP1874235A2 (en) * 2005-04-29 2008-01-09 FELL, Barry M. Surgically implantable prosthetic system
EP1874235A4 (en) * 2005-04-29 2010-01-13 Barry M Fell Surgically implantable prosthetic system
EP1854432A1 (en) * 2006-05-09 2007-11-14 Finsbury (Development) Limited Knee prosthesis
US8900316B2 (en) 2010-01-29 2014-12-02 Smith & Nephew, Inc. Cruciate-retaining knee prosthesis
IT201700091423A1 (en) * 2017-08-07 2019-02-07 Rejoint S R L Prostheses for the knee and a method for its realization

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