Methods of Preparing a Femur for Insertion of a Prosthetic Femoral Stem Component
AssigneeMidland Medical Technology Ltd
InventorDerek James Wallace McMinn
Life of this patent
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Abstract
The disclosure relates to methods of preparing a femur for hemi arthroplasty or total hip replacement. An aim is to create a channel through the femur, for receipt of a vent tube, which can be attached to a surgical suction device to lower the pressure on the mid and distal femur and thereby prevent or at least reduce a risk of embolisation. The channel may be created from (and accessed via) a proximal end of the femur or a distal end of the femur. Furthermore, the methods disclosed herein may be selectively used with cemented or uncemented components and with flat (blade-shaped) or rounded (conical) femoral stem components.
Claims21
A method of preparing a femur for insertion of a prosthetic femoral stem component, the femur comprising a femoral head, a femoral neck, a trochanteric fossa, a greater trochanter and a femoral canal, the method comprising:
- amputating the femoral head and a portion of the femoral neck;
- excavating the trochanteric fossa;
- preparing the femoral canal for insertion of the prosthetic femoral stem component such that a proximal end of the prosthetic femoral stem component is adjacent to a posterior cortical wall of the femoral canal, antero-medially of the excavated trochanteric fossa;
- preparing the femoral canal for insertion of a vent tube in a vent path through an anterior portion of the femur, into the femoral canal and along an anterior cortical wall of the femoral canal to a position distal of a distal end of the prosthetic femoral stem component, when inserted in the femoral canal;
- and
- inserting a vent tube into the vent path such that a tip of the vent tube is located in soft cancellous bone in the femoral canal, for use in venting the femoral canal during subsequent insertion of the prosthetic femoral stem component.
A method of preparing a femur for hemi arthroplasty or total hip replacement, the femur comprising a lateral femoral condyle, a femoral canal and a proximal end, the method comprising:
- cutting into a non-distal portion of the lateral femoral condyle to form a part of a vent path;
- introducing a cutting tool into the part of the vent path, the cutting tool comprising a hollow tube having a cutting blade mounted at a tip thereof;
- inserting a rod into the hollow tube of the cutting tool, the rod having a substantially straight shaft and a curved tip configured to guide the cutting blade in a curved path;
- manoeuvring the cutting tool, in conjunction with the inserted rod, in order to extend the vent path, along the curved path defined by the curved tip, until the cutting blade is substantially aligned with a longitudinal axis of the femoral canal;
- removing the rod and advancing the cutting tool along the femoral canal, to extend the vent path in a direction towards the proximal end of the femur;
- removing the cutting tool from the vent path;
- and
- inserting a vent tube into the vent path such that a tip of the vent tube is located in soft cancellous bone in the femoral canal, for use in venting the femur during subsequent hemi arthroplasty or total hip replacement.
A method of cementing a prosthetic femoral stem component into a femur, wherein the prosthetic femoral stem component comprises:
- a substantially longitudinal stem portion;
- a neck portion having a longitudinal axis intersecting the longitudinal stem portion;
- and a vent hole extending through the longitudinal stem portion from a proximal surface to a distal tip;
- wherein the vent hole comprises an enlarged portion adjacent to the proximal surface, for accommodating an end of a suction device during use;
- the method comprising:
- inserting a cement restrictor, having a bore there-through, into a femoral canal at a position determined to be below a position of the distal tip of the prosthetic femoral stem component, when located therein;
- inserting an extension tube into the bore of the cement restrictor;
- operating a suction device through a proximal end of the extension tube whilst injecting liquid cement into the femoral canal around the extension tube;
- removing the suction device from the proximal end of the extension tube;
- inserting the distal tip of the prosthetic femoral stem component into the proximal end of the extension tube;
- inserting the suction device into the enlarged portion of the vent hole of the prosthetic femoral stem component;
- and
- operating the suction device whilst inserting the prosthetic femoral stem component into the femoral canal and waiting for the cement to cure to fix the prosthetic femoral stem component in the femoral canal.
A method of implanting an uncemented prosthetic femoral stem component into a femur, wherein the prosthetic femoral stem component comprises:
- a substantially longitudinal stem portion;
- a neck portion having a longitudinal axis intersecting the longitudinal stem portion;
- and a vent hole extending through the longitudinal stem portion from a proximal surface to a distal tip;
- wherein the vent hole comprises an enlarged portion adjacent to the proximal surface, for accommodating an end of a suction device during use;
- the method comprising:
- preparing the femur for insertion of the prosthetic femoral stem component;
- inserting a suction device into the enlarged portion of the vent hole of the prosthetic femoral stem component;
- and
- operating the suction device whilst inserting the prosthetic femoral stem component into the femur.
A prosthetic femoral stem comprising:
- a neck portion and a stem portion;
- the stem portion having a distal tip and a vent hole through the stem portion from a proximal surface to the distal tip;
- the stem portion comprising a concavely curved medial surface having a single radius of curvature extending from a junction between the neck portion and the stem portion to a region a third of the distance from the distal tip;
- and wherein the vent hole is located centrally through the stem portion in said region.
Dependencies are inferred from the claim text.