Flexible medullary reaming system
AssigneeHowmedica, Inc.
InventorsGlen A. Kashuba, Antony Koblish, Jay Bichet
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Abstract
An apparatus for reaming a bone canal, such as the medullary canal of a femur, has a flexible shaft (12, 92) with a proximal end (16) for engaging a rotary transmission source. A first reamer (14, 61) is coupled to the distal end of the flexible shaft for rotation therewith to prepare the distal portion of the canal. A second reamer (22, 93) coupled with the proximal portion of the shaft to form the proximal end of the lateral portion of the canal and/or the medial calcar region of the canal. The apparatus further comprises a metaphyseal template (70, 80) having the shape of the prosthesis for guiding the reaming apparatus in forming the calcar region of the canal.
Claims31
An apparatus for reaming a medullary canal in a bone comprising:
- a flexible shaft having a distal end a rigid proximal end for engagement with a rotary power transmission source;
- a head having a distal end comprising a first reamer and a proximal end coupled to said distal end of said flexible shaft for rotation therewith;
- a second reamer having a bore defined therethrough for slideably receiving said flexible shaft, a proximal end, and a distal end;
- a drive coupling at least on said head and said second reamer such that at least said second reamer rotates with said first reamer and said flexible shaft;
- and
- a third reamer positioned on said flexible shaft to ream the proximal portion of a bone;
- wherein:
- when said second reamer is slid onto said flexible shaft, said distal end of said second reamer is adjacent said proximal end of said head and coupled directly by said drive coupling;
- and
- said flexible shaft is flexed from a straight configuration to position said third reamer to ream in an arc in a proximal portion of a bone.
An apparatus for reaming the medial portion of a medullary canal in the calcar region of a long bone having a lateral bore, said reaming apparatus comprising:
- a flexible shaft having distal and proximal ends;
- a first element attached to said distal end of said flexible shaft and having an outer diameter about equal to the inner diameter of the lateral bore of the bone;
- a reamer having a distal end coupled to said proximal end of said flexible shaft, a proximal end, and a concave cutting surface for reaming a convex shape in the calcar portion of the bone;
- and
- a solid shaft having a distal end attached to said proximal end of said reamer and a proximal end;
- and
- a connector at said proximal end of said solid shaft shaped for engagement with a rotary power transmission source.
An apparatus for reaming the medial portion medullary canal in the calcar region of a long bone, containing a lateral bore, said reaming apparatus comprising:
- a metaphyseal template having an elongated member with a distal end, a cannulated cylinder at said distal end of said elongated member, and a hollow member radiating from said elongated member;
- a flexible shaft having a distal end and a proximal end;
- a first element attached to said distal end of said flexible shaft and having an outer diameter equal to the inner diameter of said cannulated cylinder of said template;
- a reamer having a proximal end, a distal end fixedly attached to said proximal end of said flexible shaft, and a cylindrical cutting surface for reaming a convex shape in the calcar portion of the bone;
- and
- a rigid shaft having a distal end fixedly attached to said proximal end of said reamer and a proximal end having a connector shaped for engagement of said rigid shaft with a rotary power transmission source;
- and
- a fluted portion attached to and spaced between said distal and proximal ends of said rigid shaft to guide said flexible shaft within said hollow portion of said template.
A method of preparing a long bone, comprising an opening in the trochanteric fossa, to receive a prosthesis, said method comprising the steps of:
- initially forming a lateral bore by means of a reaming apparatus having at least a proximal reamer and a distal reamer coupled to a flexible shaft;
- and then
- reaming the calcar portion of the bone to complete the shape of the prosthesis by flexing said flexible shaft of said reaming apparatus to position said proximal reamer against the calcar position.
A method of preparing a bone to receive a prosthesis, said method comprising the steps of:
- inserting into the lateral bore of the bone a metaphyseal template comprising an elongated member having a partially circular cavity with a rear wall partially comprising cutting teeth, a cannulated cylinder at a distal end of said elongated member, an elliptical hollow member radiating from said elongated member at an angle to the longitudinal axis of the elongated member, impact receiving means extending laterally at the top of said elongated member and normal thereto, and anteversion control means extending laterally from and normal said elongated member;
- seating said template at the proximal end of the calcar portion of the bone by means of the impact receiving means and the anteversion control means;
- providing a reamer apparatus comprising a first head at a distal end of said reamer apparatus, a flexible shaft, and a reamer at a proximal end of said flexible shaft;
- passing said first head of said reamer apparatus through said hollow portion of said template and into said cannulated cylinder;
- and
- reaming the calcar region of the bone by flexing said flexible shaft of said reamer apparatus and manipulating said reamer in a medial direction in said hollow portions of said hollow member by a series of motions.
An apparatus for reaming a bone canal comprising:
- a flexible shaft having a first end shaped for engagement with a rotary power transmission source, and a second end;
- a first reamer coupled to said second end of said flexible shaft for rotation therewith;
- a second reamer having a bore therethrough for slideably receiving said flexible shaft, said second reamer having a first end which, when said second reamer is slid onto said flexible shaft, is adjacent said first reamer, and a second end;
- and
- a third reamer having a bore therethrough for slideably receiving said flexible shaft, said third reamer having a first end for engaging a second end of said second reamer shaped to permit universal movement between said second and third reamers
- wherein:
- said first and second reamers have a drive coupling therebetween such that said first and second reamers are rotated together with said flexible shaft;
- said third reamer is driven independently from said first and second reamers;
- and
- said flexible shaft is flexed from a straight configuration to position said third reamer to ream in an arc in a proximal portion of a bone.
An apparatus for reaming a femoral medullary canal comprising:
- a flexible drive shaft having a proximal end with a solid shaft portion and a distal portion;
- a first reamer coupled to said distal portion of said flexible shaft and driven by said flexible shaft;
- a second reamer having a concave cutting surface, said second reamer mounted on a proximal portion of said flexible shaft for reaming a convex shape on the proximal portion of said femoral canal;
- and
- means for rotating said first and second reaming elements.
Dependencies are inferred from the claim text.