Modular hip prosthesis

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising a body member having an upwardly and inwardly directed portion including a planar surface defining a plane generally coincident with said neck basal plane, the planar surface having an opening, the body member also having a tapered longitudinal bore generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, a head member sized to replace the head of the femur and means for coupling said head member with the opening in the planar surface of the upwardly and inwardly directed portion of the body member, and an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore and a cylindrical portion near to the upper portion whereby the lower cylindrical portion is received in a lower extremity of the longitudinal tapered bore and has a diameter which is less than that of the tapered bore at said lower extremity so that stress concentration at the lower extremity of the bore is avoided.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising:

• a body member having an upwardly and inwardly directed portion including a planar surface defining a plane generally coincident with said neck basal plane, the planar surface having an opening including a threaded portion and a tapered portion, the body member also having a tapered longitudinal bore generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, and a top surface at the uppermost end of the body member, perpendicular to said first axis, and intersecting the neck basal plane coincident surface, an upper end of the longitudinal cavity emerging through the top surface,
• a head member sized to replace the head of the femur including a tapered hole,
• a neck member including a first end formed to include a tapered projection that is sized to be received into the a tapered hole in said head member to secure said head member to said neck member and a second end including a threaded portion for engaging said opening threaded portion and a tapered portion between the threaded portion and the first end portion for engaging the opening in the upwardly and inwardly directed portion of the body member,
• an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore and a cylindrical portion near to the upper portion where the lower cylindrical portion is received in a lower extremity of the longitudinal tapered bore and has a diameter which is less than that of the tapered bore at said lower extremity so that stress concentration at the lower extremity of the bore is avoided, and
• fastener means situated above said top surface of the body member, coupled to an upper end of the elongated stem member, and having a lower surface confronting the top surface.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising a body member formed to include an upwardly and inwardly directed portion and a tapered longitudinal bore that is generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, a head member sized to replace the head of the femur including means for engaging said head member with the upwardly and inwardly directed portion of the body member, and an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore,

• wherein the upwardly and inwardly directed portion of the body member includes a planar surface defining a plane generally coincident with said neck basal plane, said planar surface formed to include an opening receiving said means for engaging said head member.
• wherein said means for engaging said head member with the upwardly and inwardly directed portion of the body member further comprises:
• a neck member including a first end formed to include a tapered projection that is sized to be received into a tapered hole in said head member to secure said head member to said neck member, and a second end for engaging said body member.
• wherein said opening in said planar surface includes a threaded portion and said neck member second end includes a threaded portion for engaging said opening threaded portion, and wherein said first end further includes a frangible torque control means for controlling the torque applied to the neck member when engaging said opening.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising a body member formed to include an upwardly and inwardly directed portion and a tapered longitudinal bore that is generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, a head member sized to replace the head of the femur including means for engaging said head member with the upwardly and inwardly directed portion of the body member, and an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore,

• wherein the upwardly and inwardly directed portion of the body member includes a planar surface defining a plane generally coincident with said neck basal plane, said planar surface formed to include an opening receiving said means for engaging said head member.
• wherein said means for engaging said head member with the upwardly and inwardly directed portion of the body member further comprises:
• a neck member including a first end formed to include a tapered projection that is sized to be received into a tapered hole in said head member to secure said head member to said neck member, and a second end for engaging said body member.
• wherein said opening in said planar surface includes a threaded portion and said neck member second end includes a threaded portion for engaging said opening threaded portion,
• wherein said opening in said planar surface includes a tapered portion and said neck member second end further includes a tapered portion between the threaded portion and the first end for engaging said body member.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising a body member formed to include an upwardly and inwardly directed portion and a tapered longitudinal bore that is generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, a head member sized to replace the head of the femur including means for engaging said head member with the upwardly and inwardly directed portion of the body member, and an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore,

• wherein the upwardly and inwardly directed portion of the body member includes a planar surface defining a plane generally coincident with said neck basal plane, said planar surface formed to include an opening receiving said means for engaging said head member;
• wherein said body member further comprises:
• a locking finger, and wherein said stem member further comprises a locking groove, said locking finger and said locking groove adapted to mate to orient the stem member with respect to the body member.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising a body member formed to include an upwardly and inwardly directed portion and a tapered longitudinal bore that is generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, a head member sized to replace the head of the femur including means for engaging said head member with the upwardly and inwardly directed portion of the body member, and an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore,

• wherein the upwardly and inwardly directed portion of the body member includes a planar surface defining a plane generally coincident with said neck basal plane, said planar surface formed to include an opening receiving said means for engaging said head member;
• the implant system further comprising:
• a collar member adapted to be disposed between said neck member and said body member in a plane generally coincident with said neck basal plane;
• wherein said collar member, adapted to be disposed between said neck member and said body member, further comprises:
• an extension over the top surface at the uppermost end of the body member and the upper portion of said stem, the collar member including two openings, the first opening configured to receive said upper portion of the stem member and the second opening configured to receive a portion of said neck member.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising a body member formed to include an upwardly and inwardly directed portion and a tapered longitudinal bore that is generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, a head member sized to replace the head of the femur including means for engaging said head member with the upwardly and inwardly directed portion of the body member, and an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member. including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore,

• wherein the upwardly and inwardly directed portion of the body member includes a planar surface defining a plane generally coincident with said neck basal plane, said planar surface formed to include an opening receiving said means for engaging said head member;
• the implant system further comprising:
• a collar member adapted to be disposed between said neck member and said body member in a plane generally coincident with said neck basal plane;
• wherein said collar member adapted to be disposed between said neck member and said body member further comprises a generally trapezoid-shaped portion, and said body member includes a generally wedge-shaped slot, said trapezoid-shaped portion configured to be received in said wedge-shaped slot to attach said collar member to said body member.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising a body member having an upwardly and inwardly directed portion including a planar surface defining a plane generally coincident with said neck basal plane, the planar surface having an opening, the body member also having a tapered longitudinal bore generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, a head member sized to replace the head of the femur and means for coupling said head member with the opening in the planar surface of the upwardly and inwardly directed portion of the body member, and an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore and a lower portion near to the upper portion whereby the lower portion is received in a lower extremity of the longitudinal tapered bore and has a cross-sectional area which is less than that of the tapered bore at said lower extremity so that stress concentration at the lower extremity of the bore is avoided.

An implant system for replacing a portion of a femur, said femur having a neck with a base defining a neck basal plane and having a longitudinal cavity defining a first axis, the implant system comprising:

• a body member having an upwardly and inwardly directed portion including a planar surface defining a plane generally coincident with said neck basal plane, the planar surface having an opening including a threaded portion and a tapered portion, the body member also having a tapered longitudinal bore generally aligned with said first axis, said tapered bore extending from a lower region to an upper region of the body member, and a top surface at the uppermost end of the body member, perpendicular to said first axis, and intersecting the neck basal plane coincident surface, an upper end of the longitudinal cavity emerging through the top surface,
• a head member sized to replace the head of the femur including a tapered hole,
• a neck member including a first end formed to include a tapered projection that is sized to be received into the a tapered hole in said head member to secure said head member to said neck member and a second end including a threaded portion for engaging said opening threaded portion and a tapered portion between the threaded portion and the first end portion for engaging the opening in the upwardly and inwardly directed portion of the body member,
• an elongated stem member having a proximal portion received and secured in the tapered longitudinal bore of the body member and a distal portion received in the longitudinal cavity of the femur, the proximal portion of the elongated stem member including an upper tapered portion adapted to be snugly received in the tapered longitudinal bore and a lower portion near to the upper portion where the lower portion is received in a lower extremity of the longitudinal tapered bore and has a cross-sectional area which is less than that of the tapered bore at said lower extremity so that stress concentration at the lower extremity of the bore is avoided, and
• fastener means situated above said top surface of the body member, coupled to an upper end of the elongated stem member, and having a lower surface confronting the top surface.