Securable pistoning finger prosthesis

Claim 2

A prosthesis device for phalangeal joint replacement between a proximal phalangeal or metacarpal bone and a distal phalangeal bone comprising: (a) an independent metacarpal body having a first end adapted for operative securement to human bone and a second end defining an axially oriented receiving chamber; (b) an independent phalangeal body having a first end adapted for operative securement to human bone and a second end defining an axially oriented receiving chamber; (c) a hinge means joining said independent phalangeal body to said metacarpal body for twisting, flexing, pistoning, distracting, and laterally rotating said phalangeal body relative to said metacarpal body; wherein said first ends of said independent metacarpal and phalangeal bodies include a self-tapping threaded portion with a plurality of spaced interrupting channels; and wherein said second ends of said independent metacarpal and phalangeal bodies are conical in shape with smooth exterior surfaces.

Claim 3

A prosthesis device for phalangeal joint replacement between a proximal phalangeal or metacarpal bone and a distal phalangeal bone comprising: (a) an independent metacarpal body having a first end adapted for operative securement to human bone and a second end defining an axially oriented receiving chamber; (b) an independent phalangeal body having a first end adapted for operative securement to human bone and a second end defining an axially oriented receiving chamber; (c) a hinge means joining said independent phalangeal body to said metacarpal body for twisting, flexing, pistoning, distracting, and laterally rotating said phalangeal body relative to said metacarpal body; wherein said hinge means includes: (A) a hinge stem having a ball element at one end and an opposite extending end, wherein said extending end operatively engages said receiving chamber of said phalangeal body; (B) a hinge body having a first extending end which operatively engages said receiving chamber of said metacarpal body such that said metacarpal body may be engaged by said extending end, and having a second end defining a curvilinear exterior surface and an interior socket for receiving and holding said ball element of said hinge stem, allowing flexing and lateral rotation; and (C) a hinge retainer intermediate said first extending end and said ball element, said hinge retainer having a substantially concave undersurface dimensioned to extend over a predetermined portion of the exterior surface of said receptacle of said hinge body and wherein the undersurface is complementarily contoured to the exterior surface thereof.

Claim 4

A prosthesis device for phalangeal joint replacement between a proximal phalangeal or metacarpal bone and a distal phalangeal bone comprising: (a) an independent metacarpal body having a first end adapted for operative securement to human bone and a second end defining an axially oriented receiving chamber; (b) an independent phalangeal body having a first end adapted for operative securement to human bone and a second end defining an axially oriented receiving chamber; (c) a hinge means joining said independent phalangeal body to said metacarpal body for twisting, flexing, pistoning, distracting, and laterally rotating said phalangeal body relative to said metacarpal body; wherein said hinge means includes: (A) a hinge stem having a ball element at one end and an opposite extending end, wherein said extending end operatively engages said receiving chamber of said phalangeal body; (B) a hinge body having a first extending end which operatively engages said receiving chamber of said metacarpal body such that said metacarpal body may be engaged by said extending end, and having a second end defining a curvilinear exterior surface and an interior socket for receiving and holding said ball element of said hinge stem, allowing flexing and lateral rotation; and (C) a hinge retainer intermediate said first extending end and said ball element, said hinge retainer having a substantially concave undersurface dimensioned to extend over a predetermined portion of the exterior surface of said receptacle of said hinge body and wherein the undersurface is complementarily contoured to the exterior surface thereof.

Claim 5

A prosthesis device as claimed in claim 2, wherein said socket of said hinge means includes enlarged or recessed portions with respect to said ball element, thereby allowing a predetermined amount of lateral rotational movement of said ball element adjacent said recessed or enlarged portions.

Claim 6

A prosthesis device as claimed in claim 3, wherein said hinge stem further comprising a neck between said ball element and said hinge retainer wherein said socket includes a radially located slot sized and positioned to allow movement of said neck through said slot and prevent said ball element of said hinge stem from moving out of said socket, and thereby allowing flexing.

Claim 7

A prosthesis device as claimed in claim 4, wherein said slot has a radial length sufficient to allow said hinge stem to pivot about a predetermined number of degrees around said hinge body, thereby allowing flexing.

Claim 8

A prosthesis device as claimed in claim 5, wherein said hinge retainer further comprising an opposite extending edge and wherein said phalangeal body further comprising a lip such that said opposite extending edge engages said lip and prevents rotation of said phalangeal body about said hinge body beyond a predetermined point.

Claim 9

A prosthesis device as claimed in claim 6, wherein said hinge body defines a flat surface allowing said metacarpal body to abut against said flat surface, while engaged by said extending end of said hinge body.

Claim 10

A prosthesis device as claimed in claim 7, wherein said phalangeal body and said metacarpal body are made of titanium.

Claim 11

A prosthesis device as claimed in claim 8, wherein said hinge stem is made of an alloy of cobalt and chrome.

Claim 12

A prosthesis device as claimed in claim 9, wherein said phalangeal body and metacarpal body are tapered and have self-tapping threads on their ends, said threading defining uniformly spaced interrupting channels.

Claim 13

A prosthesis device as claimed in claim 10, wherein said metacarpal body further defines a circular rim on its widest end which abuts against said flat surface of said hinge body.

Claim 14

A prosthesis device as claimed in claim 2, wherein said hinge body is made of plastic which may flex when said metacarpal body is distracted away from said extending end of said hinge body, thereby allowing energy absorption which might otherwise be transferred to the bones connected.

Claim 15

A prosthesis device as claimed in claim 1, wherein said hinge means comprising: (a) a hinge stem having a ball element at one end and having a bore transversely therethrough and an opposite extending end, wherein said extending end operatively engages said receiving chamber of said phalangeal body; (b) a hinge body having a first extending end which operatively engages said receiving chamber of said metacarpal body such that said metacarpal body may be engaged on said extending end, and having a second end defining a socket and adjoining a radial slot and a transverse slot of predetermined dimensions transversely defined through said hinge body, said socket sized to captively receive and retain therein said ball element of said hinge stem, allowing limited universal movement; and (c) a hinge pin dimensioned and sized to be received within said bore of said ball element and having a length sufficient to engage interior walls of said transverse slot through said socket when fitted within said bore, wherein said hinge pin securably retains said ball element within said socket and restricts relative movement of said ball element when said hinge pin engages said interior walls of said transverse slot.

Claim 16

A prosthesis device as claimed in claim 13, wherein said socket of said hinge body includes enlarged or recessed portions with respect to said ball element, thereby allowing a predetermined amount of lateral rotational movement of said ball element adjacent said enlarged or recessed portions, and wherein said interior walls of said transverse and radial slots outwardly taper at predetermined locations, thereby allowing said hinge pin and said ball element additional lateral rotational movement where the interior walls of said slots are outwardly tapered.

Claim 17

A prosthesis device as claimed in claim 14, wherein said hinge stem further includes a neck between said ball element and said opposite extending end wherein said socket includes a radially located slot sized and positioned to allow movement of said neck through said slot and prevent said ball element of said hinge stem from moving out of said socket, said radially located slot allowing for flexing movement of the prosthesis, and wherein said hinge stem includes a collar between said neck and said opposite extending end of said hinge stem, wherein said second end of said phalangeal body has at least one extending tab to engage said collar and prevent relative rotational motion between said collar and said phalangeal body.

Claim 18

A prosthesis device as claimed in claim 15, wherein said first extending end of said hinge body is tapered and defines a flat surface allowing said metacarpal body to abut against said flat surface, wherein said receiving chamber of said metacarpal body is dimensioned to receive said extending end of said hinge body so that said metacarpal body can seat or distract and flex when distracted while engaging said extending end of said hinge body.

Claim 19

A prosthesis device as claimed in claim 16, wherein said phalangeal body and said metacarpal body are made of titanium, wherein said hinge stem is made of an alloy of cobalt and chrome, and wherein said phalangeal body and said metacarpal body are tapered and have self-tapping threads on their ends, said threading defining uniformly spaced interrupting channels.

Claim 20

A prosthesis device as claimed in claim 1, wherein said second end of said metacarpal body and said second end of said phalangeal body including slots engagable by a tool for rotatively implanting said bodies in their respective bones.

Claim 21

A prosthesis device as claimed in claim 2, wherein said extending end of said hinge body is axially offset from said hinge stem when said hinge means is in a fully extended position, thereby offering greater mechanical advantage to the prosthesis device.

Claim 22

A prosthesis system for phalangeal joint replacement comprising: (a) a phalangeal body having a first end including a receiving chamber; (b) a metacarpal body having a first end including a receiving chamber; (c) a hinge member having a first stem and a second stem, wherein said metacarpal body operatively associates with said hinge member and said first end is adapted to receive said first stem and having a second extending end adapted to be operatively secured to a metacarpal or proximal phalangeal bone; said second stem of said hinge member being adapted for engagement with said receiving chamber of said phalangeal body, said phalangeal body having a second end for securement to a distal phalangeal bone, said hinge member having an intermediate means for interconnecting said first stem said second stem, said intermediate means allowing flexing, pistoning, and limited universal movement of said first stem and said second stem and limited radial and axial rotational movement relative to each other, wherein said second stem of said hinge member is conical and an end of said metacarpal body nearer said hinge member includes a self-tapping threaded segment on an exterior surface of said metacarpal body with a plurality of spaced interrupting channels oriented transversely to said threads and an opposite end of said metacarpal body being free of threads.

Claim 23

A prosthesis system for phalangeal joint replacement comprising: (a) a phalangeal body having a first end including a receiving chamber; (b) a metacarpal body having a first end including a receiving chamber; (c) a hinge member having a first stem and a second stem, wherein said metacarpal body operatively associates with said hinge member and said first end is adapted to receive said first stem and having a second extending end adapted to be operatively secured to a metacarpal or proximal phalangeal bone; said second stem of said hinge member being adapted for engagement with said receiving chamber of said phalangeal body, said phalangeal body having a second end for securement to a distal phalangeal bone, said hinge member having an intermediate means for interconnecting said first stem said second stem, said intermediate means allowing flexing, pistoning, and limited universal movement of said first stem and said second stem and limited radial and axial rotational movement relative to each other, wherein said second stem of said hinge member is conical and an end of said metacarpal body nearer said hinge member includes a self-tapping threaded segment on an exterior surface of said metacarpal body with a plurality of spaced interrupting channels oriented transversely to said threads and an opposite end of said metacarpal body being free of threads.

Claim 24

The prosthesis system in accordance with claim 20 wherein said intermediate means of said hinge member includes a ball portion loosely and captively received within a ball receptacle portion, whereby said flexing, limited universal movement and limited radial and axial rotational and deflecting movement is obtained.

Claim 25

A prosthesis system for phalangeal joint replacement comprising: (a) a metacarpal member having a first end including a tapered receiving chamber with outwardly tapered interior walls; (b) a hinge body having a first stem and a second stem, wherein said first stem is adapted to be operatively secured to a phalangeal bone or the like; said second stem of said hinge member being adapted for engagement with said receiving chamber of said metacarpal body, said second stem of said hinge member having tapered exterior walls to compliment said interior walls of said tapered receiving chamber of said metacarpal body and allow said second stem to engage said receiving chamber and allow seating and distracting movement between said second stem and said tapered interior walls, thereby allowing an additional degree of flexing when distracted, said metacarpal body having a second end for securement to a proximal phalangeal or metacarpal bone, said hinge member having an intermediate means for interconnecting said first stem and said second extending stem, said intermediate means allowing flexing and limited universal movement of said first stem and said second extending stem and limited axial movement relative to each other; wherein said second stem of said hinge member is conical and an exterior surface of an end of said metacarpal body nearer said hinge member includes a self-tapping threaded portion with a plurality of spaced interrupting channels oriented axially.

Claim 26

A prosthesis system for phalangeal joint replacement comprising: (a) a metacarpal member having a first end including a tapered receiving chamber with outwardly tapered interior walls; (b) a hinge body having a first stem and a second stem, wherein said first stem is adapted to be operatively secured to a phalangeal bone or the like; said second stem of said hinge member being adapted for engagement with said receiving chamber of said metacarpal body, said second stem of said hinge member having tapered exterior walls to compliment said interior walls of said tapered receiving chamber of said metacarpal body and allow said second stem to engage said receiving chamber and allow seating and distracting movement between said second stem and said tapered interior walls, thereby allowing an additional degree of flexing when distracted, said metacarpal body having a second end for securement to a proximal phalangeal or metacarpal bone, said hinge member having an intermediate means for interconnecting said first stem and said second extending stem, said intermediate means allowing flexing and limited universal movement of said first stem and said second extending stem and limited axial movement relative to each other; wherein said second stem of said hinge member is conical and an exterior surface of an end of said metacarpal body nearer said hinge member includes a self-tapping threaded portion with a plurality of spaced interrupting channels oriented axially.

Claim 27

A prosthesis system for phalangeal joint replacement comprising: (a) a metacarpal body having a first end including a tapered receiving chamber with outwardly tapered interior walls; (b) a hinge member having a first stem and a second stem, wherein said first stem is adapted to be operatively secured to a phalangeal bone or the like; said second stem of said hinge member being adapted for engagement with said receiving chamber of said metacarpal body, said second stem of said hinge member having tapered exterior walls to compliment said interior walls of said tapered receiving chamber of said metacarpal body and allow said second stem to engage said receiving chamber and allow seating and distracting movement between said second stem and said tapered interior walls, thereby allowing an additional degree of flexing when distracted, said metacarpal body having a second end for securement to a proximal phalangeal or metacarpal bone, said hinge member having an intermediate means for interconnecting said first stem and said second extending stem, said intermediate means allowing flexing and limited universal movement of said first stem and said second extending stem and limited axial movement relative to each other; wherein said second stem of said hinge member is unitary and formed of flexible plastic, whereby additional flexing movement is obtained.

Claim 28

A prosthesis system for phalangeal joint replacement comprising: (a) a metacarpal body having a first end including a tapered receiving chamber with outwardly tapered interior walls; (b) a hinge member having a first stem and a second stem, wherein said first stem is adapted to be operatively secured to a phalangeal bone or the like; said second stem of said hinge member being adapted for engagement with said receiving chamber of said metacarpal body, said second stem of said hinge member having tapered exterior walls to compliment said interior walls of said tapered receiving chamber of said metacarpal body and allow said second stem to engage said receiving chamber and allow seating and distracting movement between said second stem and said tapered interior walls, thereby allowing an additional degree of flexing when distracted, said metacarpal body having a second end for securement to a proximal phalangeal or metacarpal bone, said hinge member having an intermediate means for interconnecting said first stem and said second extending stem, said intermediate means allowing flexing and limited universal movement of said first stem and said second extending stem and limited axial movement relative to each other; wherein said second stem of said hinge member is unitary and formed of flexible plastic, whereby additional flexing movement is obtained.