Method of preparing an acetabulum for receiving a head of a femoral prosthesis

• US 7,104,995 B2
• Filed: 08/09/2004
• Issued: 09/12/2006
• Est. Priority Date: 04/11/2002
• Status: Expired due to Fees

• Current Assignee: Theodore W. Crofford
• Original Assignee: Theodore W. Crofford
• Inventors: Crofford, Theodore W.
• Primary Examiner(s): Robert, Eduardo C.
• Assistant Examiner(s): REIMERS, ANNETTE R
• Application Number:
  US10/914,750
• Publication Number:
  US 20050010230A1
• Time in Patent Office: 764 Days
• Field of Search: 606/72, 606/89, 606/96, 606/99, 606/81, 623 2311- 12, 623/23.14, 623 2326- 27
• US Class Current: 606/81
• CPC Class Codes: A61B 17/175 for preparing the femur for hip prosthesis insertion
• CPC Class Codes: A61B 17/74 Devices for the head or neck or trochanter of the femur trochanteric devices connected to the proximal part of an endoprosthetic femoral shaft A61F2/30739; endoprosthetic internal fixation devices for the head or neck of the femur A61F2/3601
• CPC Class Codes: A61B 17/742 having one or more longitudinal elements oriented along or parallel to the axis of the neck
• CPC Class Codes: A61B 17/8665 Nuts
• CPC Class Codes: A61B 17/8695 Washers surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3601 for replacing only the epiphyseal or metaphyseal parts of the femur, e.g. endoprosthetic femoral heads or necks directly fixed to the natural femur by internal fixation devices non-prosthetic internal fixation devices for the femoral head or neck A61B17/74
• CPC Class Codes: A61F 2/4607 of hip femoral endoprostheses
• CPC Class Codes: A61F 2/4657 Measuring instruments used for implanting artificial joints for surgical instruments A61B90/06
• CPC Class Codes: A61F 2002/30113 circular
• CPC Class Codes: A61F 2002/30156 triangular
• CPC Class Codes: A61F 2002/30224 cylindrical
• CPC Class Codes: A61F 2002/30329 Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2002/30332 Conically- or frustoconically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/30339 Double cones, i.e. connecting element having two conical connections, one at each of its opposite ends
• CPC Class Codes: A61F 2002/30433 using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30535 Special structural features of bone or joint prostheses not otherwise provided for
• CPC Class Codes: A61F 2002/3055 for adjusting length
• CPC Class Codes: A61F 2002/30604 modular
• CPC Class Codes: A61F 2002/30616 Sets comprising a plurality of prosthetic parts of different sizes or orientations
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/3079 : Stepped or enlarged apertures, e.g. having discrete diameter changes
• CPC Class Codes: A61F 2002/30797 : internally-threaded
• CPC Class Codes: A61F 2002/30827 : Plurality of grooves
• CPC Class Codes: A61F 2002/30968 : Sintering
• CPC Class Codes: A61F 2002/3611 : Heads or epiphyseal parts of femur
• CPC Class Codes: A61F 2002/3631 : with an integral complete or partial peripheral collar or bearing shoulder at its base
• CPC Class Codes: A61F 2002/365 : Connections of heads to necks
• CPC Class Codes: A61F 2002/4631 : the prosthesis being specially adapted for being cemented
• CPC Class Codes: A61F 2002/4635 : using minimally invasive surgery
• CPC Class Codes: A61F 2002/4658 : for measuring dimensions, e.g. length
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0006 : circular
• CPC Class Codes: A61F 2230/0023 : triangular
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2250/0058 : Additional features; Implant or prostheses properties not otherwise provided for
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 : Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium

Abstract

A femoral neck fixation prosthesis and method of using same which reduces bone loss and the avoids the other shortcomings of the prior art by allowing the fixation of a stable femoral head replacement while reducing the amount of the femur which must be reamed for the insertion of the prosthesis. The preferred embodiment provides that the femoral head is attached to a fixation prosthesis, which extends coaxially through the canal of the femoral neck, into the femur, and is then attached to the opposite lateral wall of the femur. In this manner, the prosthesis serves to imitate the original structure of the femoral neck. No other support members, either crosspins or arms extending into the length of the femur, are required.

Claims

1. A method of preparing an acetabulum for receiving a head of a femoral prosthesis, the method comprising:

forming a primary passage within the femur that is substantially coaxial to a longitudinal axis of a femoral neck;

forming a secondary passage within the femur that joins and is substantially coaxial to the primary passage;

inserting a femoral neck liner having a liner passage within the primary passage;

inserting a reamer path protector having a reamer passage within the secondary passage;

releasably connecting the reamer path protector to the femoral neck liner such that the reamer passage is substantially aligned with the liner passage;

inserting a reamer shaft through the reamer passage;

attaching a reamer head to the reamer shaft;

reaming the acetabulum by supplying a reaming force to the reamer shaft; and

wherein the reamer shaft is inserted through the reamer passage and the liner passage prior to attaching the reamer head.

2. A method according to claim 1, wherein the reaming force is applied at an end of the reamer shaft opposite that of the reamer head.

3. A method according to claim 1, further comprising the step of placing the femur in a neutral position during the reaming of the acetabulum.

4. A method according to claim 1, further comprising the steps of:

removing the reamer shaft from the reamer passage;

inserting an impactor shaft through the reamer passage;

connecting an impactor head to the impactor shaft;

seating an acetabular portion of the femoral prosthesis in the reamed acetabulum by

supplying an impact force to the impactor shaft to drive the impactor head against the acetabular portion.