US 20050234462 A1
A broaching instrument and method using a segmented broach head. First and second broach segments are laterally engageable with each other in vivo, and are aligned with each other on a common longitudinal axis when so engaged. The method involves making a small anterior incision adjacent a patient's femur, inserting the broach segments sequentially through the anterior incision, interconnecting the plurality of broach segments in vivo, connecting the broach handle to the broach segments, and broaching the proximal medullary canal with the assembled multi-part broach instrument.
1. A broach instrument for preparing the proximal medullary canal of a femur for receiving a hip stem implant, comprising:
a first broach segment defining a longitudinal axis; and
a second broach segment laterally engageable with said first broach segment in vivo, said second broach segment being aligned with said first broach segment on said longitudinal axis when engaged therewith.
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9. A method of preparing the proximal medullary canal of a patient's femur for receiving a hip stem implant, comprising:
providing a multi-part broach instrument including a broach handle and a segmented broach head having a plurality of broach segments;
making an anterior incision adjacent a patient's femur;
inserting said broach segments sequentially through said anterior incision;
interconnecting said plurality of broach segments in vivo;
connecting said broach handle to said broach segments; and
broaching said proximal medullary canal with the assembled multi-part broach instrument.
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This application claims the benefit of U.S. Provisional Patent Application No. 60/534,270, filed Jan. 5, 2004, and U.S. patent application Ser. No. 10/912,644, filed Aug. 5, 2004, both of which applications are hereby incorporated by reference along with the following applications filed on Jan. 5, 2005: Attorney Docket No. 13007-24B entitled Method And Instrumentation For Performing Minimally Invasive Hip Arthroplasty and filed in the name of Troy W. Hershberger and Kimberly S. Parcher, and Attorney Docket No. 13007-24C entitled Method And Instrumentation For Performing Minimally Invasive Hip Arthroplasty and filed in the name of Troy W. Hershberger.
This invention relates to methods and instruments for performing hip arthroplasty, and more particularly to broach instruments and methods for preparing the proximal femur to receive a femoral implant as part of an implantable hip prosthesis.
In one popular method of performing a total hip arthroplasty through two incisions, the femur is prepared by passing instrumentation through a small posterior lateral incision. This posterior incision is similar to the incision made when performing a conventional femoral intramedullary nailing procedure except that the incision is located somewhat more superior. A second, anterior incision is made to facilitate the introduction of instrumentation for preparation of the acetabulum as well as to expose the femur from the anterior side. The surgeon is able to view the femur and resect the femoral head from this anterior side. Access along the femoral axis for reamers and broaches is most readily accomplished, however, through the posterior lateral incision. The surgeon bluntly divides the fibers of the gluteus maximus through the posterior incision to develop a small tunnel through which he may pass the femoral broaches, reamers and, eventually, the femoral implant. The femur is broached through the posterior lateral incision while the femur is viewed through the anterior incision.
There are disadvantages associated with the prior method and instrumentation described above. These include the necessity of making the posterior lateral incision large enough to accommodate passage of the femoral broach and other instrumentation. Also, damage may be caused to the muscle fibers as well as the skin margins by excessive stretching of tissue and by repeatedly passing the broach and other instrumentation into and out of the posterior lateral incision.
According to one aspect of the present invention, a broach instrument for preparing the proximal medullary canal of a femur for receiving a hip stem implant comprises a segmented broach head which includes a first broach segment defining a longitudinal axis, and a second broach segment laterally engageable with the first broach segment in vivo, the second broach segment being aligned with the first broach segment on the longitudinal axis when engaged therewith.
Another aspect of the present invention is a novel method of preparing the proximal medullary canal of a patient's femur using a multi-part broaching instrument which includes a broach handle and a segmented broach head having a plurality of broach segments. The method comprises making a small anterior incision adjacent a patient's femur, inserting the broach segments sequentially through the anterior incision, interconnecting the plurality of broach segments in vivo, connecting the broach handle to the broach segments, and broaching the proximal medullary canal with the assembled multi-part broach instrument.
The objects and advantages of the present invention will be more apparent upon reading the following detailed description in conjunction with the accompanying drawings.
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
It is desired to reduce the size of incisions necessary to perform a total hip arthroplasty in order to minimize trauma to the gluteus muscles and other underlying tissue adjacent the hip joint. According to the present invention, one approach to reducing the size of the incisions is to divide the broaching instrument used to broach the proximal medullary canal of the patient's femur into separate pieces, allowing the size of the incisions necessary to accommodate passage of the broach pieces to be reduced. The multi-piece broach instrument may include a laterally segmented broach head that may be inserted through the incisions and assembled within the patient, further reducing the size of the incisions necessary to accommodate passage of the broach segments into the patient.
In a first embodiment of the present invention, shown in
The broach head 14 may be laterally divided or segmented into a plurality of broach segments as shown in
The instrument 10 is assembled during a total hip arthroplasty procedure as shown in
When the broaching procedure is completed, the instrument 10 is preferably removed and disassembled in reverse order. First, the core shaft 12 is preferably rotated so that the threaded end portion 20 disengages the threaded aperture 36 of the distal broach segment 32 and is then removed from the broach segments 32, 40, 48 and broach handle 16. Next, the broach handle 16 is preferably removed from the posterior incision 58 of the patient 56. Finally, the broach segments 32, 40, 48 are then preferably removed from the patient 56 through the anterior incision 54 one at a time.
In another embodiment of the present invention, shown in
A push-type design may alternatively be implemented with oppositely threaded portions on the two opposite ends of the core shaft. For example, instead of having an unthreaded distal tip, core shaft 112 may have left-hand threads on its distal end which act in opposition to the right-hand threads on its proximal end in the handle. That is, when rotated clockwise, the core shaft tends to back out of the distalmost broach segment and thereby further pushes on that segment as the threaded proximal end of the core shaft moves distally in the broach handle. The same core shaft may alternatively be used to put the broach segments in compression, by rotating the core shaft sufficiently in the counter-clockwise direction and thereby tending to draw the broach segments tightly together. In another alternative embodiment, the core shaft may have a hook-type end which engages the distalmost broach segment and pulls it toward the other broach segments as the core shaft is retracted in the broach handle. The broaching instrument is otherwise assembled and used in the same way as broaching instrument 10 previously described and illustrated.
In a further embodiment of the invention, shown in
The instrument 210 is assembled during a total hip arthroplasty procedure as shown in
When the broaching procedure is completed, the instrument 210 is preferably removed and disassembled in reverse order. First, the flexible core shaft 212 is preferably rotated so that the threaded end 220 disengages the threaded aperture 236 of the distal broach segment 232 and is then removed from the broach segments 232, 240, 248 and offset broach handle 216. Next, the offset broach handle 216 is preferably removed from the anterior incision 254 in the body of the patient 256.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. For example, while a core shaft is described above as a preferred means for applying an axial force to the parts of the segmented broach head, alternative means are contemplated, such as a peripheral strap, a pair of peripheral straps, or other device extending alongside the broach segments, e.g., in a longitudinal groove therein, for creating a compression force. Rigid and semi-rigid rods and other peripheral devices are also contemplated in certain embodiments for creating tension in the broach segments.