# US 5,702,484 A · Endoprosthesis

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- Number: US 5,702,484 A
- Document ID: US5702484A
- Status: Granted
- Kind: A
- Application number: 08/585,388
- Filed: 1996-01-11
- Granted: 1997-12-30
- Earliest claimed: 1995-01-11
- Assignees: Biomet Deutschland GmbH
- Inventors: Volkmar Goymann; Emmanuel Anapliotis; Juergen Darga
- Web page: https://patentgrep.com/patent/US5702484A

## CPC

- A61F 2/30724: {Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity}
- A61F 2/3662: {Femoral shafts}
- A61F 2/30767: {Special external or bone-contacting surface, e.g. coating for improving bone ingrowth}
- A61F 2/367: {Proximal or metaphyseal parts of shafts (trochanteric devices connected to said proximal parts A61F2/30739)}
- A61F 2/3676: {Distal or diaphyseal parts of shafts}
- A61F 2002/30112: {Rounded shapes, e.g. with rounded corners}
- A61F 2002/30156: {triangular}
- A61F 2002/30177: {W-shaped, M-shaped or sigma shaped}
- A61F 2002/30189: {E-shaped or epsilon-shaped}
- A61F 2002/30329: {Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements}
- A61F 2002/30332: {Conically- or frustoconically-shaped protrusion and recess}
- A61F 2002/30571: {Leaf springs}
- A61F 2002/30593: {hollow}
- A61F 2002/30602: {Shaft made of a bundle of anchoring rods or bristles, e.g. fasciculate shaft}
- A61F 2002/30841: {Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes}
- A61F 2002/30845: {with cutting edges}
- A61F 2002/30884: {Fins or wings, e.g. longitudinal wings for preventing rotation within the bone cavity}
- A61F 2002/30906: {shot- sand- or grit-blasted}
- A61F 2002/3625: {Necks}
- A61F 2002/3631: {with an integral complete or partial peripheral collar or bearing shoulder at its base}
- A61F 2002/365: {Connections of heads to necks}
- A61F 2002/368: {with lateral apertures, bores, holes or openings, e.g. for reducing the mass, for receiving fixation screws or for communicating with the inside of a hollow shaft}
- A61F 2220/0025: Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
- A61F 2220/0033: made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
- A61F 2230/0004: Rounded shapes, e.g. with rounded corners
- A61F 2230/0023: triangular
- A61F 2230/0036: E-shaped, e.g. epsilon-shaped
- A61F 2230/0056: W-shaped, e.g. M-shaped, sigma-shaped
- A61F 2310/00023: Titanium or titanium-based alloys, e.g. Ti-Ni alloys
- A61F 2310/00293: containing a phosphorus-containing compound, e.g. apatite
- A61F 2310/00796: Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
- 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 (dental prosthetics A61C)

## Abstract

An endoprosthesis for a cement free anchorage in a bone having a longitudinal direction comprises a prosthetic shank to be secured in the bone in the longitudinal direction of the bone. The prosthetic shank has a proximal end and a distal end and includes three plate-like blades arranged in parallel and presenting a cross-sectional profile that has an open configuration. A first one of the blades constitutes a central web and a second and third ones of the blades constitute side walls which enclose, at least partially, the central web and extend, at least partially, in parallel, in a direction of the central web. The prosthetic shank further includes bridges connecting the side walls with the central web. A region adjacent the distal end of the prosthetic shank is in the shape of a scoop and the blades are joined at least at the distal end to form a common cutting edge. A collar including a pin for receiving a ball joint is attached to the proximal end of the prosthetic shank.

## Claims

### Claim 1

An endoprosthesis for a cement free anchorage in a bone having a longitudinal direction, comprising:
a prosthetic shank to be secured in the bone in the longitudinal direction of the bone and having a proximal end and a distal end, the prosthetic shank comprising three plate-like blades arranged in parallel and presenting a cross-sectional profile that has an open configuration, a first one of the blades constituting a central web and a second and third ones of the blades constituting side walls which enclose, at least partially, the central web and extend, at least partially, in parallel, in a direction of the central web, the prosthetic shank further including bridges connecting the side walls with the central web, wherein a region adjacent the distal end of the prosthetic shank is in the shape of a scoop and the blades are joined at least at the distal end to form a common cutting edge; and
a collar including a pin for receiving a ball joint attached to the proximal end of the prosthetic shank.

### Claim 2 (depends on 1)

The endoprosthesis according to claim 1, wherein the central web has a central plane that is parallel with the side walls and the pin is arranged on the collar to have a central axis that lies in an extension of the central plane of the central web.

### Claim 3 (depends on 1)

The endoprosthesis according to claim 1, wherein the blades are tapered in a streamlined fashion toward the distal end and having a rounded configuration.

### Claim 4 (depends on 3)

The endoprosthesis according to claim 3, wherein the blades each have a medial edge that is substantially S-shaped when viewed from a side of the prosthetic shank.

### Claim 5 (depends on 1)

The endoprosthesis according to claim 1, wherein the cross-sectional profile is substantially m-shaped.

### Claim 6 (depends on 5)

The endoprosthesis according to claim 5, wherein the central web projects medially beyond the side walls.

### Claim 7 (depends on 1)

The endoprosthesis according to claim 1, wherein the bridges are web-like and have distally oriented cutting edges.

### Claim 8 (depends on 1)

The endoprosthesis according to claim 1, wherein each side wall delimits a space between itself and the central web and the prosthetic shank has openings at the proximal end that communicate with a respective one of the spaces between the side walls and the central web.

### Claim 9 (depends on 8)

The endoprosthesis according to claim 8, wherein one of the openings is associated with each one of the spaces.

### Claim 10 (depends on 8)

The endoprosthesis according to claim 8, wherein the openings are in the form of elongated holes that extend from a medial to a lateral direction of the prosthetic shank.

### Claim 11 (depends on 10)

The endoprosthesis according to claim 10, wherein the holes are parallel to one another and are surrounded by rounded-off edges.

### Claim 12 (depends on 1)

The endoprosthesis according to claim 1, wherein each of the side walls has an opening and a recess in a region near the proximal end of the prosthetic shank.

### Claim 13 (depends on 12)

The endoprosthesis according to claim 12, wherein the recess in each side wall has a form of a circular segment which opens laterally and the opening in each side wall has one of a triangular and circular shape.

### Claim 14 (depends on 13)

The endoprosthesis according to claim 13, further including support members mounted in the openings and extending at right angles to the longitudinal direction of the prosthetic shank.

### Claim 15 (depends on 14)

The endoprosthesis according to claim 14, wherein the support members comprise one of spongiosa and bioporous material.

### Claim 16 (depends on 1)

The endoprosthesis according to claim 1, wherein the prosthetic shank has a proximal region that includes a lateral wall that is only partially closed.

### Claim 17 (depends on 16)

The endoprosthesis according to claim 16, wherein the lateral wall has elongated slots that extend parallel to the longitudinal direction of the prosthetic shank.

### Claim 18 (depends on 1)

The endoprosthesis according to claim 1, wherein the endoprosthesis comprises a titanium material and is a vacuum cast product.

### Claim 19 (depends on 1)

The endoprosthesis according to claim 1, wherein the blades of the prosthetic shank have rough surfaces.

### Claim 20 (depends on 19)

The endoprosthesis according to claim 19, wherein the rough surfaces are as a result of sand blasting.

### Claim 21 (depends on 19)

The endoprosthesis according to claim 19, wherein the blades each include a coating of bioporous material which constitutes the rough surfaces.

### Claim 22 (depends on 21)

The endoprosthesis according to claim 21, wherein the coating comprises one of a hydroxyapatite ceramic and a plasma spray with a layer thickness of 50 to 100 micrometers.