WO2004073550A2 - Knee spacer - Google Patents

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
  • A61F2/3872—Meniscus for implantation between the natural bone surfaces
• • 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
  • A61F2/46—Special tools for implanting artificial joints
  • A61F2/4603—Special tools for implanting artificial joints for insertion or extraction of endoprosthetic joints or of accessories thereof
  • A61F2/461—Special tools for implanting artificial joints for insertion or extraction of endoprosthetic joints or of accessories thereof of knees
• • 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
  • A61F2002/30112—Rounded shapes, e.g. with rounded corners
  • A61F2002/30133—Rounded shapes, e.g. with rounded corners kidney-shaped or bean-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
  • A61F2002/30535—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
  • A61F2002/30616—Sets comprising a plurality of prosthetic parts of different sizes or orientations
• • 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
  • 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
  • A61F2230/0004—Rounded shapes, e.g. with rounded corners
  • A61F2230/0015—Kidney-shaped, e.g. bean-shaped

Definitions

• the Unicondulator Interpositional Spacer is intended for use in the Osteoarthritic knee, where substantial amounts of articular cartilage have been lost as a result of the disease.
• the prosfheses will be used in indications for uncemented treatment of the Tibia articulating surfaces (Medial and Lateral) of the following:
• the spacer is intended as an alternative to arthroscopy, high tibial osteotomy (HTO), and knee arthroplasty treatments for those situations where limited degeneration joint destruction exists.
• HTO high tibial osteotomy
• knee arthroplasty treatments for those situations where limited degeneration joint destruction exists.
• a spacer for use in a knee being a kidney-shaped device having a femoral surface which is concave and an opposite tibial surface which is convex.
• the spacer has a uniform thickness between the femoral surface and the tibial surface.
• the femoral surface is the complementary mirror image of the tibial surface.
• the tibial surface has a cusp formed thereon, the cusp being oriented away from the femoral surface.
• FIG. 1 is a top plan view of the lateral spacer.
• FIG. 2 is an end elevation view of the posterior side of the lateral spacer.
• FIG. 3 is a side elevation view of the medial side of the lateral spacer.
• FIG. 4 is a cross-section view taken across the lines 4-4 of FIG. 1.
• FIG. 5 is a partial end elevation view of the anterior side of the lateral spacer showing bores therein.
• FIG. 6 is a top plan view of the medial spacer.
• FIG. 7 is an end elevation view of the posterior side of the medial spacer.
• FIG. 8 is a side elevation view of the medial side of the medial spacer.
• FIG. 9 is a cross section view taken across the lines 9-9 of FIG. 6.
• FIG. 10 is a partial end elevation view of the anterior side of the medial spacer showing bores therein.
• FIG. 11 is a view of the posterior of the right knee showing the lateral spacer and the medial spacer disposed between the femur and the tibia.
• FIG. 12 is a top plan view of the lateral and medial spacers disposed on top of the tibia of the right leg.
• FIG. 13 is a perspective view of the spacer in the knee when the knee is flexed.
• the lateral spacer 10 has an anterior side 12, a posterior side 14, a lateral side 16 and a medial side 18.
• the lateral spacer 10 has a femoral surface 20 which is in contact with the lateral side of the femur 22 of the patient when inserted in the knee.
• the lateral spacer 10 also has a tibial surface 24 which is in contact with the lateral side of the tibia 26 of the patient when inserted in the knee.
• the femoral surface 20 is concave and the tibial surface 24 is convex.
• the lateral spacer 10 has uniform thickness between the femoral surface 20 and the tibial surface 24 such that the femoral surface 20 and the tibial surface 24 are complementary mirror images of each other.
• a pair of spaced-apart bore holes 28 are formed in the anterior side 12 of the lateral spacer 10.
• An instrument (not shown) is received in the two bore holes 24 to hold the lateral spacer 10 when the spacer is being placed in the knee.
• At least one cusp 30 is formed on the lateral spacer 10.
• an anterior cusp 30 and a posterior cusp 30' are formed.
• the cusps 30, 30' are oriented away from the tibial surface 24 forming an arch 32 therebetween. Referring now to FIGS.
• the medial spacer 34 similarly has an anterior side 36, a posterior side 38, a lateral side 40 and a medial side 42.
• the medial spacer 34 has a femoral surface 44 which is in contact with the medial side of the femur 22 when inserted in the knee.
• the medial spacer 34 also has a tibial surface 46 which is in contact with the medial side of the tibia 26 of the patient when inserted in the knee.
• the femoral surface 44 is concave and the tibial surface 46 is convex.
• the medial spacer 34 has uniform thickness between the femoral surface 44 and the tibial surface 46 such that the femoral surface 44 and the tibial surface 48 are complementary mirror images of each other.
• the medial spacer 34 also has a pair of spaced-apart bore holes 24 formed in the anterior side 36 of the medial spacer 34.
• the same instrument (not shown) can be used to hold both the lateral spacer and the medial spacer 34.
• At least one cusp 48 is formed in the medial spacer 34.
• the cusps 48, 48' are oriented away from the tibial surface 46 forming an arch 50.
• FIG. 11 shows the lateral spacer 10 and the medial spacer 34 disposed between the femur
• FIG. 12 is a top plan view of lateral spacer 10 and the medial spacer 34 in the right leg of the patient.
• the thickness of the spacers 10, 34 is uniform in the medial/lateral and anterior/posterior aspects.
• the spacers be formed from an alloy of chromium, cobalt and molybelenum. Implants using this alloy have superior resistance to corrosion, high fatigue strength, and outstanding biocompatibility.
• the tibial surface and the femoral surface of the spacers are highly polished to slide freely against the surfaces of the knee (e.g., the tibia and the femur).
• the spacers 10, 34 are small, metallic kidney-shaped inserts that are intended to restore stability and normal alignment for patients with early arthritis.
• the shape of the implant is similar to the natural anatomy of the tibia and femoral condules of the knee.
• the implant geometry will allow some motion during flexion but will lock in the proper position under load at extension thereby relieving the feeling of "dislocation" caused by other free floating implants on the current orthopedic market.
• the implant conforms to the natural bone structures and stays in place without bone cement or screws. The implantation of the spacer does not require bone cuts.
• the implant design is kidney- shaped to mimic the medial and lateral condules of the femur.
• the tibial surfaces are congruent to the plateau on the tibia.
• the corners of the spacers 10, 34 are smooth and rounded to avoid stress risers and implant malfunction.
• the spacers 10, 34 are not permanent prosthesis but are intended to be used to provide relief for the condition where the cartilege between the femur and tibia has been worn or damaged.
• the use of the spacers 10, 34 will delay the time for a full knee replacement for various times depending upon the age of the patient and the extent of damage in the knee. In most patients, the medial side of the knee wears or is damaged before the lateral side. At the present time, many surgeons repair only the medial side of the knee. This often results in accelerated damage to the lateral side of the knee and the need for full knee replacement at an earlier date.
• the present invention provides a lateral and a medial spacer as a pair to be inserted simultaneously in the knee of the patient.
• the damages are not the same in each patient or even in the legs of the same patient.
• the spacers of uniform thicl ⁇ iess when inserted in the knee(s) of the patient accommodate the irregularities in damage and do not require custom shaping as do the prosthesis of Fell et al (6,206,927) which do not have a uniform thickness.
• the spacers are used by anteriorly making a minimally invasive incision in the knee to provide access to the knee at the interface between the femur and the tibia. The femur and tibia are forced apart extending the ligaments.
• the spacers 10, 34 are slid between the femur and the tibia. Because of the highly polished surfaces of the spacer and the uniform thickness, the spacers are very easily inserted. Similarly, if the spacers are to be removed, they are easily withdrawn. No cement or adhesive is used with the spacers of the present invention.
• the uniformly thick spacers are substantially congruent with the faces of the femur and the tibia (excluding irregular wear portions). Thus, with the tension provided by the ligaments 52, the uniformly thick spacers are not ejected from between the tibia and femur when the knee is flexed (FIG. 13).
• the spacers of the present invention will fit the knee of a larger percentage of the population than can be fitted with spacers custom made and/or having non-uniform thickness.
• the spacers 10, 34 are designed to fill the space between the diseased tibia compartments, medial and/or lateral and intended to:
• the devices may be sold sterile, sterilized by gamma Irradiation at 2.5 MEADS minim.

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• 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)

Abstract

Description

Claims

Applications Claiming Priority (2)

Publications (2)

Family

ID=32908612

Family Applications (1)

Country Status (1)

Cited By (7)

Families Citing this family (10)

Citations (2)

• 2004
  • 2004-02-17 WO PCT/US2004/004596 patent/WO2004073550A2/en active Application Filing

Patent Citations (2)

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