Method and apparatus for aligning a prosthetic element

• US 6,273,891 B1
• Filed: 11/01/1999
• Issued: 08/14/2001
• Est. Priority Date: 02/11/1997
• Status: Expired due to Term

• Current Assignee: MedIdea LLC
• Original Assignee: MedIdea LLC
• Inventors: Masini, Michael A.
• Primary Examiner(s): REIP, DAVID OWEN
• Application Number:
  US09/431,511
• Time in Patent Office: 652 Days
• Field of Search: 606/53, 606/81, 606/86, 606/91, 606/92, 606/99, 623/22-1-
• US Class Current: 606/91
• CPC Class Codes: A61B 17/1746 for the acetabulum
• CPC Class Codes: A61B 17/8808 with sealing collar for bone cavity
• CPC Class Codes: A61B 17/8811 characterised by the introducer tip, i.e. the part inserted into or onto the bone
• CPC Class Codes: A61B 17/8825 characterised by syringe details A61B17/8822, A61B17/8827 take precedence
• CPC Class Codes: A61F 2/30724 Spacers for centering an implant in a bone cavity, e.g. in a cement-receiving cavity
• CPC Class Codes: A61F 2/34 Acetabular cups
• CPC Class Codes: A61F 2/4684 Trial or dummy prostheses
• CPC Class Codes: A61F 2002/3007 Coating or prosthesis-covering structure made of elastic material, e.g. of elastomer
• CPC Class Codes: A61F 2002/30154 square
• CPC Class Codes: A61F 2002/30378 Spherically-shaped protrusion and recess
• CPC Class Codes: A61F 2002/305 Snap connection
• CPC Class Codes: A61F 2002/30507 using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30538 for adjusting angular orientation
• CPC Class Codes: A61F 2002/30672 temporary
• CPC Class Codes: A61F 2002/30785 parallel
• CPC Class Codes: A61F 2002/3403 Polar aperture
• CPC Class Codes: A61F 2002/3429 with an integral peripheral collar or flange, e.g. oriented away from the shell centre line
• CPC Class Codes: A61F 2002/3611 Heads or epiphyseal parts of femur
• 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 2230/0021 : square
• CPC Class Codes: A61F 2250/0006 : for adjusting angular orientation
• CPC Class Codes: A61F 2310/00011 : Metals or alloys

Abstract

Methods and apparatus facilitate the positioning of a prosthetic element relative to a bone so as to achieve a desired orientation. An anchoring unit rigidly attaches to a point of the bone surrounding a region associated with receiving the prosthetic element, and at least one structural member is used to physically couple the prosthetic element to the anchoring unit. The combination of the anchoring unit and structural member includes one or more fasteners which may be loosened to temporarily remove the prosthetic element once a desired orientation is achieved, while facilitating re-installation of the element in accordance with the desired orientation following the temporary removal. In a preferred embodiment, the prosthetic element is an acetabular implant, and the surrounding bone forms part of a human pelvis. Regardless of the application, the element may take the form of a trial or a final implant.

Claims

1. A method of positioning an orthopaedic implant relative to bone so as to achieve a desired orientation, comprising the steps of:

providing an implant having an anchoring unit extending therefrom;

adjusting the orientation of the implant so as to achieve the desired orientation;

stabilinzing the positioning of the implant by fixing at least a portion of the anchoring unit to a point of bone surrounding the implant;

temporarily removing the implant, leaving at least a portion of the anchoring unit fixed to the surrounding bone;

applying cement to fix the implant;

re-installing the implant, with the portion of the anchoring unit fixed to the surrounding bone being used to ensure that the implant is returned to the desired orientation for fixation; and

removing at least the portion of the anchoring unit fixed to the surrounding bone.

2. The method of claim 1, wherein the bone is a pelvis and the implant is an acetabular implant.

3. The method of claim 1, wherein one or both of the steps of adjusting the orientation of the implant so as to achieve the desired orientation and stabilizing the positioning of the implant by fixing at least a portion of the anchoring unit to a point of bone surrounding the implant are performed as part of a joint reduction.