# US 10,864,082 B2 · Osteolysis-resistant cementless joint implant with improved stability and seating function

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- Number: US 10,864,082 B2
- Document ID: US10864082B2
- Status: Granted
- Kind: B2
- Application number: 16/165,387
- Filed: 2018-10-19
- Published: 2020-04-23
- Granted: 2020-12-15
- Earliest claimed: 2018-10-19
- Applicants: Roy D. Bloebaum; Efrain Frank Algarin
- Inventors: Roy D. Bloebaum; Efrain Frank Algarin
- Web page: https://patentgrep.com/patent/US10864082B2

## CPC

- A61F 2/30749: {Fixation appliances for connecting prostheses to the body}
- A61F 2/30771: {applied in original prostheses, e.g. holes or grooves}
- A61F 2/3859: {Femoral components}
- A61F 2/389: {Tibial components (A61F2/3868 takes precedence)}
- A61F 2002/30179: {X-shaped}
- A61F 2002/30205: {conical}
- A61F 2002/3021: {frustoconical}
- A61F 2002/30224: {cylindrical}
- A61F 2002/30332: {Conically- or frustoconically-shaped protrusion and recess}
- A61F 2002/3041: {having threaded portions of different pitches}
- A61F 2002/30433: {using additional screws, bolts, dowels, rivets or washers e.g. connecting screws}
- A61F 2002/30841: {Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes}
- 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 improvised anthroplastic prosthetic implant having, in some embodiments, secondary screws with threaded shafts for forming pilot holes into the resected cancellous bone surface, such as the tibia, and primary screws with tapered heads for replacing the secondary screws and forming a Morse friction fit with the implant and seating the implant in close apposition to, and at less than 150 um in, resected bone thereby facilitating implant stability, wherein the heads of the primary screws are recessed into a counterbore in the baseplate to improve axial postoperative stability of the implant.

## Claims

### Claim 1

An osteolysis-resistant, mechanically stable, prosthetic implant for apposition on a resected surface of a bone, the implant comprising:
a baseplate having a substantially planar lower apposition surface and an upwardly rising perimeter edge which forms a tray-like depression for receiving a tibio-femoral insert;
one or more elongate conical anchors protruding inferiorly from the apposition surface, each conical anchor defining a hollow interior through-passage for receiving, mating with, and forming a Morse friction fit with, a tapered screw head received via the through-cavity;
two or more primary socket head shoulder screws comprising a tapered head and threaded shaft adapted to form a Morse friction fit; and
two or more secondary socket head screws comprising a sharpened conical tip and a threaded cylindrical shaft;
wherein the secondary socket head screws are placed into the implant prior to surgical impaction of the implant to form pilot holes and replaced with the primary socket head shoulder screws after surgical impaction of the implant, the primary socket head shoulder screws forming a Morse taper with the through-cavity adapted to seal the through-passage to prevent osteolysis.

### Claim 2 (depends on 1)

The prosthetic implant of claim 1, further comprising an elongate, tapered keel member protruding inferiorly from the apposition surface.

### Claim 3 (depends on 1)

The prosthetic implant of claim 1, further comprising one or more sharpened pegs protruding inferiorly from the apposition surface.

### Claim 4 (depends on 3)

The prosthetic implant of claim 3, wherein each peg comprises a frustoconical tip.

### Claim 5 (depends on 1)

The prosthetic implant of claim 1, wherein the hollow interior through-passage consists of an upper section tapered to form a Morse taper with one or more of the primary socket head shoulder screws.

### Claim 6 (depends on 1)

The prosthetic implant of claim 1, wherein the hollow interior through-passage consists of a lower section threaded to mate with a secondary socket head shoulder screw.

### Claim 7 (depends on 1)

The prosthetic implant of claim 1, wherein each conical anchor comprises a frustoconical tip.

### Claim 8 (depends on 1)

The prosthetic implant of claim 1, further comprising a keel.

### Claim 9

A prosthetic implant for apposition on a resected cancellous surface of a bone, the implant comprising:
a baseplate having a substantially planar lower apposition surface;
an elongate keel member protruding inferiorly from the apposition surface;
one or more sharpened pegs protruding inferiorly from the apposition surface;
one or more elongate protuberating anchors protruding inferiorly from the apposition surface, each protuberating anchor defining a hollow interior through-passage for receiving, mating with, and forming a Morse friction fit with, a tapered screw head received by the through-cavity;
two or more primary screws, each comprising a tapered head and threaded shaft adapted to form a Morse friction fit; and
two or more secondary screws, each comprising a threaded cylindrical shaft and sharpened conical tip;
wherein the secondary screws are placed into the implant prior to surgical impaction of the implant and replaced with the primary screws after surgical impaction of the implant, the primary screws forming a Morse taper with the protuberating anchor adapted to seal the through-passage to prevent osteolysis.

### Claim 10 (depends on 9)

The prosthetic implant of claim 9, wherein the hollow interior through-passage consists of an upper section tapered to form a Morse taper with one of the primary screws.

### Claim 11 (depends on 9)

The prosthetic implant of claim 9, wherein the hollow interior through-passage consists of a lower section threaded to mate with a secondary screw.

### Claim 12 (depends on 9)

The prosthetic implant of claim 9, wherein each conical anchor comprises a frustoconical tip.

### Claim 13 (depends on 9)

The prosthetic implant of claim 9, wherein each peg comprises a frustoconical tip.

### Claim 14 (depends on 9)

The prosthetic implant of claim 9, wherein the keel is X-shaped through a cross-section.