Prosthetic implant, trial and associated method
A kit (100) for use in performing joint arthroplasty on a head of a long bone (4) is provided. The kit (100) includes a first trial (102) including a first trial articulating surface (106) and an opposed first trial mounting surface (108) having a first trial location feature (110). The kit (100) also includes a second trial (104) including a second trial articulating surface (112) and an opposed second trial mounting surface (114) having a second trial location feature (116). The first trial articulating surface (106) and the second trial articulating surface (112) have different geometries and the first trial location feature (110) and the second trial location feature (116) have substantially identical geometries whereby different trials may be used with a common location feature.
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Cross reference is made to the following applications: DEP 755 entitled “ARTHROPLASTY SIZING GAUGE”, DEP 756 entitled “ARTICULATING SURFACE REPLACEMENT PROSTHESIS”, DEP 789 entitled “MODULAR ARTICULATING SURFACE REPLACEMENT PROSTHESIS”. DEP 5041 entitled “ARTHROPLASTY INSTRUMENT AND ASSOCIATED METHOD” and DEP 5042 entitled “EXTENDED ARTICULATION ORTHOPAEDIC IMPLANT AND ASSOCIATED METHOD” filed concurrently herewith which are incorporated herein by reference.
TECHNICAL FIELD OF THE INVENTIONThe present invention relates generally to the field of orthopaedics, and more particularly, to an implant for use in arthroplasty.
BACKGROUND OF THE INVENTIONThe invention relates to implantable articles and methods for implanting such articles. More particularly, the invention relates to a bone prosthesis and a method for implanting the same.
There are known to exist many designs for and methods for implanting implantable articles, such as bone prostheses. Such bone prostheses include components of artificial joints, such as elbows, hips, knees and shoulders. An important consideration in the design and implanting of virtually any implantable bone prosthesis is that the bone have adequate fixation when implanted within the body.
Earlier designs of implantable articles relied upon the use of cement, such as polymethylmethacrylate (PMMA) to anchor the implant. The use of such implants can have some advantages, such as providing a fixation that does not develop free play or does not lead to erosion of joining faces postoperatively. However, the current trend is to use the cement to a lesser extent because of its tendency to lose adhesive properties over time. There is also a possibility that cement contributes to wear debris within a joint.
Recently, implantable bone prostheses have been designed to encourage the growth of hard bone tissue around the implant. Such implants are often implanted without cement and the bone grows around surface irregularities, for example, porous structures on the implant.
One such implantable prosthesis is a shoulder prosthesis. During the lifetime of a patient, it may be necessary to replace the natural humeral head and associated glenoid cavity with a prosthesis. Such a shoulder replacement procedure may be necessary to be performed on a patient as a result of, for example, diseases such asosteoarthritis and rheumatoid arthritis, or trauma.
Most shoulder replacement surgeries today involve the implantation of a total shoulder prosthesis. In a total shoulder replacement procedure, a humeral component having a head portion is utilized to replace the natural head portion of the upper arm bone or humerus. The humeral component typically has an elongated intramedullary stem which is utilized to secure the humeral component to the patient's humerus. In such a total shoulder replacement procedure, the natural glenoid surface of the scapula is restructured or otherwise replaced with a glenoid component that provides a bearing surface for the head portion of the humeral component.
With the average age of patients requiring shoulder arthroplasty surgery decreasing, orthopaedic implant manufacturers are developing “bone-sparing” implants for the initial treatment of the degenerative arthritis. While bone-sparing implants for the treatment hip and knee arthroplasty are becoming quite common, bone-sparing shoulder arthroplasty techniques and prostheses are also being developed.
Shoulder surface replacement prostheses are being developed to replace the articulating surface of the proximal humerus with a minimal bone resection and minimal disruption of the metaphysis and the diaphysis. Current designs use a semi-spherical articular dome with a small stem for rotational stability. The under surface of the articular head is also semi-spherical and meets with a spherically machined humeral head.
Typically, however, arthritis of the gleno-humeral joint causes flattening of the humeral head with a large medial osteophyte. The flat humeral head can cause voids in the bone under the prosthesis resulting in limited contact between the prosthesis and the resected bone and may limit the load transfer capability between the prosthesis and the humerus.
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Due to variations in the size and bone configuration of patients, as well as, to the variations in the progress of the diseased long bone and the resultant amount of flattening of the humeral head, a wide variety of sizes and shapes of prostheses are necessary to have a proper fitting prosthesis for most patients.
So that a surgeon may determine and have available the proper prosthesis for a patient, preoperatively, the surgeon may use radiographic techniques such as x-rays to obtain an image of the bone and from that image select the appropriate size prosthesis.
Typically, the surgeon will have available at the operating room the predetermined prosthesis and perhaps the next available size or two both smaller and larger. To verify that the preselected prosthesis is best suited for the patient, orthopaedic prosthesis manufacturers have developed non-implanting substitute prostheses or trials that have the same dimensions as the respective implants and are used to replicate a prosthesis. After the surfaces and cavities are prepared for receiving the prosthesis, the trial is implanted. The arm is then moved through the normal range of motion to determine the appropriateness of the trial and the resulting prosthesis. Such a procedure is called a trial reduction.
Sometimes, the trial reduction will determine that the preselected prosthesis is not optimum for the patient. A larger and sometimes a smaller prosthesis will be more optimum than that preselected. Trials are available with proportional dimensions as they become larger. Thus, a conservative or bone sparing humeral head prosthesis for a smaller articulating surface may also have a smaller stem.
The surgeon first prepares the cavity to receive the stem and the surface to receive the head. If a prosthesis smaller than that originally predicted is required for the patient, the resulting smaller prosthesis and a similarly sized smaller prosthetic trial needs to be placed in the patient. Such a smaller trial does not fit snugly in the prepared cavity. Thus, bone graft needs to be placed in the cavity and the prosthesis placed between the bone graft material and the bone. Such a procedure takes added time in the operating room, causes greater expense and may cause error in positioning, as well as, may not optimize the fixation of the prosthesis.
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The present invention provides for a surgical technique, as well as, for a kit of trials and a kit of implants that eliminate excess reaming of the cavity to receive a conservative or bone sparing long bone head prosthesis. Trials and prostheses with different articulating surface dimensions utilize a common stem geometry such that the prepared cavity can be identical for a range of implant trials and resultant prosthesis. This method provides for an elimination of the excess reaming due to different size trial stems.
According to one embodiment of the present invention, a kit for use in performing joint arthroplasty on a head of a long bone is provided. The kit includes a first trial including a first trial articulating surface and an opposed first trial mounting surface having a first trial location feature. The kit also includes a second trial including a second trial articulating surface and an opposed second trial mounting surface having a second trial location feature. The first trial articulating surface and the second trial articulating surface have different geometries and the first trial location feature and the second trial location feature have substantially identical geometries whereby different trials may be used with a common location feature.
According to another embodiment of the present invention, a kit for use in performing joint arthroplasty on a head of a long bone is provided. The kit includes a first implant including a first implant articulating surface and an opposed first implant mounting surface having a first implant location feature. The kit also includes a second implant including a second implant articulating surface and an opposed second implant mounting surface having a second implant location feature. The first implant articulating surface and the second implant articulating surface have different geometries and the first implant location feature and the second implant location feature have substantially identical geometries whereby different implants may be used with a common location feature.
According to a further embodiment of the present invention, a kit for use in selecting one of a plurality of humeral shoulder joint implants for use in shoulder arthroplasty is provided. The kit includes an instrument for preparing a surface on a humerus and a first trial. The first trial cooperates with the humerus. The first trial has a first trial first portion fittable with the surface of the humerus and has a first trial second portion for cooperation with the glenoid cavity. The kit also includes a second trial for cooperation with the humerus. The second trial has a second trial first portion fittable with the surface of the humerus and has a second trial second portion for cooperation with the glenoid cavity. The first portion of the first trial and the first portion of the second trial are substantially identical and the second portion of the first trial and the second portion of the second trial are substantially different.
According to yet another embodiment of the present invention a kit for use in shoulder arthroplasty is provided. The kit includes a first trial for cooperation with the humerus. The first trial has a first trial first portion fittable with the surface of the humerus and has a first trial second portion for cooperation with the glenoid cavity. The kit also includes a second trial for cooperation with the humerus. The second trial has a second trial first portion fittable with the surface of the humerus and has a second trial second portion for cooperation with the glenoid cavity. The first portion of the first trial and the first portion of the second trial are substantially identical and the second portion of the first trial and the second portion of the second trial being substantially different.
According to a further embodiment of the present invention, a method for providing joint arthroplasty is provided. The method includes the steps of providing an instrument for preparing a surface on a long bone, providing a plurality of trials, each of said trials being adapted to mate with the surface, selecting one of the plurality of trials, performing a trial reduction on said one of said plurality of trials, determining if said one of said plurality of trials is satisfactory, performing additional trial reductions as required, selecting one of a plurality of joint prostheses corresponding to one of said plurality of trials based upon the trial reductions, and implanting the selected one prosthesis onto the long bone.
According to a yet another embodiment of the present invention, a humeral trial for use in performing joint arthroplasty on the head of a long bone is provided. The trial includes a body having an arcuate articulating surface and an opposed mounting surface. The mounting surface includes a portion of the mounting surface which is generally planar.
According to another embodiment of the present invention, there is provided an implant for use in performing joint arthroplasty on the head of a long bone. The implant includes a body having arcuate articulating surface and an opposed mounting surface. The mounting surface includes a portion of the mounting surface which is generally planar.
The technical advantages of the present invention include improved positioning of the trial and implant during the surgery. For example, according to one aspect of the present invention, various size implants and trials all use a common stem size. By providing the common stem size, a stem cavity can be prepared and utilized, not only for the preselected and trial size, but for a smaller trial which may otherwise be in a condition of moving into an offset center position or not perfectly positioned with the bone graft is placed to fill the space between the over-reamed cavity and the smaller stem. Thus, the present invention provides for improved location of the trial.
The technical advantages of the present invention further include improved support for the prosthesis and resultant improved fixation. For example, according to another aspect of the present invention, a plurality of trials and a plurality of corresponding implants are provided with a common size and geometry stem. The long bone is prepared with a common cavity to receive the plurality of trials and resulting stems. Thus, for a variety of trials, even a smaller trial which would otherwise have a smaller stem and require bone graft between the cavity and the stem, the trial stems and implant stems are firmly fitted to the cavity and provide adequate support for the trial and the implant and improved fixation. Thus, the present invention provides for improved support and improved fixation of the prosthesis.
Another technical advantage of the present invention includes reduced time in the operating room. For example, according to one aspect of the present invention, a plurality of trial sizes and implant sizes utilize a common size stem. Thus, the change in the trial size determined by a trial reduction will result in a smaller trial with the same size stem. The use of the same size stem will obviate the need of bone graft material being placed between the stem and the cavity and thus reduce the amount of time to perform such bone grafting in the operating room. Thus, the present invention reduces time in the operating room.
The technical advantages of the present invention further include a reduction in cost in performing the arthroplasty. For example, according to one aspect of the present invention, a plurality of trials and prostheses utilize a common stem. The stem may be provided with a common reamer. Since a common reamer can be used for various size trials and prostheses, the costs associated with a greater number of reamers can be reduced.
Other technical advantages of the present invention will be readily apparent to one skilled in the art from the following figures, descriptions and claims.
BRIEF DESCRIPTION OF THE DRAWINGSFor a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description taken in connection with the accompanying drawings, in which:
Embodiments of the present invention and the advantages thereof are best understood by referring to the following descriptions and drawings, wherein like numerals are used for like and corresponding parts of the drawings.
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The second trial 104 includes a second trial articulation surface 112 and an opposed second trial mounting surface 114. The second trial mounting surface 114 includes a second trial location feature 116. The first trial articulating surface 106 and the second trial articulating surface 112 have different geometries. The first trial location feature 110 and the second trial location feature 116 have substantially identical geometries.
Since the first trial 102 and the second trial 104 have location features 110 and 116, respectively, which are substantially identical, a common reamer 680 (see
The first trial 102 and the second trial 104 may have any suitable shape capable of performing the trial function. For example and as shown in
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Similarly, the planar portion 126 of the first trial mounting surface 108 is defined by a diameter PD positioned at a dimension PDH from periphery 138 of the body 118. The planar portion 130 of the second trial mounting surface 114 is identical in size and shape to the planar portion 126 of the first trial mounting surface 108. The second trial mounting surface planar portion 130 is thus defined by diameter PD located at a distance PDH from periphery 140 of the second body 120.
The tapered protrusion 110 of the first trial mounting surface 108 is identical in size and shape to the location feature 116 of the second trial mounting surface 114. The location feature 110 of the first trial mounting surface 108 may be defined by diameter TSD and the height TSL. The location feature 110 is further defined by an included angle α. Similarly, the location feature 116 of the second trial mounting surface is identically defined by location feature diameter TSD and location feature height TSL. The location feature 116 is further defined by included angle α.
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While the trials, according to the present invention, may include planar portions, conifrustrical portions and arcuate portions as shown in the trials 102 and 104 of
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The second implant 204 includes a second implant articulating surface 212, and an opposed second implant mounting surface 214. The second implant mounting surface 214 includes a second implant location surface 216.
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The first implant 202 and the second implant 204 may have any geometry suitable for resurfacing the head of a long bone. For example, as shown in
The bodies 220 and 224 of the implants 202 and 204, respectively, may have any suitable shape and may, for example, be in the form of a truncated hollow sphere. The stems 222 and 226 of the first implant 202 and the second implant 204, respectively, may have any suitable shape and may be in the form of, for example, a tapered cylinder.
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To provide for the optimum securing of the implants, the securing portions may be longer than the corresponding trial stems to provide for adequate fixation. Also, since most bone configurations are proportional, the larger implants should have a corresponding longer stem. Thus, the use of a longer stem with a larger prosthesis is still possible with the common trial locating features and generally common implant features of the kit and method of the present invention.
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The implants 202 and 204 may be made of any suitable, durable material that is compatible with the human body. The implants 202 and 204 may, for example, be made of a metal, for example, a cobalt chromium alloy, a stainless steel alloy or a titanium alloy.
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Similarly, the first implant 202 has an articulating surface 206 that is substantially smaller than articulating surface 212 of the second implant 204. The first implant 202 has a locating feature 210 that is substantially the same in size and shape as location feature 216 of the second implant 204. It should be appreciated that the location features 110, 116, 210 and 216 are all of substantially the same size and shape. The articulating surface 106 of the first trial 102 corresponds to articulating surface 206 of the first implant 202 and similarly the articulating surface 112 of the second trial 104 corresponds to the articulating surface 212 of the second implant 204.
It should be appreciated that using the trial and implant kit 400 of the present invention provides for the ability to switch from a first trial to a second trial without affecting the fit of the trial to the cavity formed in the head of the humerus. Therefore, a surgeon in the operating room can freely pick from a range of trials without a need to re-ream or to fit bone graft around a cavity to change from a larger to a smaller trial.
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The trial 1033 may be removed and replaced with the corresponding prosthesis. The trial 1033 may be reused after sterilization. The trial 1033 may therefore be made of any suitable durable material and may, for example, be made of a durable plastic that may be sterilized by standard sterilization methods, such as an autoclave.
The trial 1033 mimics the size and shape of the prosthesis. The trial 1033 therefore includes an articulating surface 1035 and an opposed support surface 1037. The trial 1033 further includes a stem 1039 extending outwardly from the support surface 1037. As shown in
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The stem 1122 may include a positioning portion 1128 adjacent the planar portion 1144 of the mounting surface 1108. The positioning portion 1128 may be generally conifrustrical. The stem 1122 may further include a securing portion 1130 extending from the positioning portion 1128 of the stem 1122. The securing portion 1130 may include a plurality of spaced apart lands 1142. Each of the lands 1142 may be separated by recesses 1144. The stem 1122 may further include a nose 1150 extending outwardly from the securing portion 1130.
The nose 1150 and the lands 1142 and the recesses 1144 of the securing portion 1130 serve to reduce the force necessary to implant the implant 1100. Further, the lands 1142 and the recesses 1144 serve to provide rotational stability for the implant 1100.
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The second trial 1404 includes a second trial articulating surface 1412 and an opposed second trial mounting surface 1414. The second trial mounting surface 1414 includes a second trial location feature 1416. The first trial articulating surface 1206 and the second trial articulating surface 1412 have different geometries. The first trial location feature 1210 and the second trial location feature 1416 have substantially identical geometries. It should be appreciated that for the trial kit 1400, the mounting surfaces 1208 and 1414 of trials 1202 and 1404 may be similar to the mounting surface 108A of FIGURE A1 and not have a planar portion.
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Similarly, the first implant 1302 has an articulating surface 1306 that is substantially smaller than the articulating surface 1512 of the second implant 1504. The first implant 1302 has a locating feature 1310 that is substantially the same in size and shape as the location feature 1516 of the second implant 1504. It should be appreciated that the location features 1210, 1416, 1310 and 1516 are all of substantially the same size and shape. The articulating surface 1206 of the first trial 1202 corresponds to articulating surface 1306 of the first implant 1302 and similarly the articulating surface 1412 of the second trial 1404 corresponds to the articulating surface 1512 of the second implant 1504.
It should be appreciated that using the trial and implant kit 1600 of the present invention provides for the ability to switch from a first trial to a second trial without affecting the fit of the trial to the cavity formed in the head of the humerus. Therefore, a surgeon in the operating room can freely pick from a range of trials without a need to re-ream or to fit bone graft around a cavity to change from a larger to a smaller trial.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions, and alterations can be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.
Claims
1. A kit for use in performing joint arthroplasty on a head of a long bone, said kit comprising:
- a first implant including a first implant articulating surface and an opposed first implant mounting surface having a first implant location feature; and
- a second implant including a second implant articulating surface and an opposed second implant mounting surface having a second implant location feature, the first implant articulating surface and the second implant articulating surface having different geometries and the first implant location feature and the second implant location feature having substantially identical geometries whereby different implants may be used with a common location feature.
2. The kit of claim 1, wherein the first implant location feature and the second implant location feature comprise a tapered protrusion.
3. The kit of claim 1:
- wherein the first implant articulating surface defines a first surface periphery thereof; and
- wherein the second implant articulating surface defines a second surface periphery thereof, the first surface periphery being greater than the second surface periphery.
4. The kit of claim 1, wherein at least one of the first implant articulating surface and the second implant articulating surface is generally hemispherical.
5. The kit of claim 1, further comprising:
- a first trial, corresponding to said first implant; and
- a second trial corresponding to said second implant.
6. The kit of claim 7:
- wherein said first trial includes a first trial articulating surface and an opposed first trial mounting surface having a first trial location feature; and
- wherein said second trial includes a second trial articulating surface and an opposed second trial mounting surface having a second trial location feature, the first trial articulating surface and the second trial articulating surface having different geometries and the first trial location feature and the second trial location feature having substantially identical geometries whereby different trials may be used with a common location feature.
7. The kit of claim 1, wherein the long bone is one of a humerus and femur.
8. An implant for use in performing joint arthroplasty on a head of a long bone, said implant comprising a body having an arcuate articulating surface and an opposed mounting surface, the mounting surface including a portion thereof being generally planar.
9. The implant of claim 8, further comprising a generally tapered cylindrical stem extending from the planar portion of the mounting surface of said body.
10. The implant of claim 9, wherein said stem includes a first portion extending from the planar portion of the mounting surface of said body and a second portion extending from the first portion, the first portion adapted to position the implant in a humerus and the second portion adapted to secure the implant to the humerus.
11. The implant of claim 10, wherein the second portion of said stem includes longitudinal flutes and a distal pointed nose.
12. The implant of claim 8, wherein said body is generally a hollow hemisphere.
13. The implant of claim 10, wherein the mounting surface of said body includes a portion thereof which is concave.
14. The implant of claim 8, wherein the long bone is one of a humerus and a femur.
15. A kit for use in selecting one of a plurality of humeral shoulder joint implants for use in shoulder arthroplasty, said kit comprising:
- an instrument for preparing a surface on a humerus;
- a first trial for cooperation with the humerus, said first trial having a first trial first portion fittable with the surface of the humerus and having a first trial second portion for cooperation with the glenoid cavity; and
- a second trial for cooperation with the humerus, said second trial having a second trial first portion fittable with the surface of the humerus and having a second trial second portion for cooperation with the glenoid cavity, said first portion of said first trial and said first portion of said second trial being substantially identical and said second portion of said first trial and said second portion of said second trial being substantially different.
16. The kit of claim 15, wherein the first trial first portion and the second trial first portion comprise a tapered protrusion.
17. The kit of claim 15:
- wherein the first trial second portion defines a first surface periphery thereof; and
- wherein the second trial second portion defines a second surface periphery thereof, the first surface periphery being greater than the second surface periphery.
18. The kit of claim 15, wherein at least one of the first trial second portion and the second trial second portion is generally hemispherical.
19. A method for providing joint arthroplasty comprising:
- providing an instrument for preparing a surface on a long bone;
- providing a plurality of trials, each of said trials being adapted to mate with the surface;
- selecting one of the plurality of trials;
- performing a trial reduction on said one of said plurality of trials;
- determining if said one of said plurality of trials is satisfactory;
- performing additional trial reductions as required;
- selecting one of a plurality of joint prostheses corresponding to one of said plurality of trials based upon the trial reductions; and
- implanting the selected one prosthesis onto the long bone.
Type: Application
Filed: Sep 13, 2007
Publication Date: Mar 13, 2008
Applicant: DePuy Products, Inc. (Warsaw, IN)
Inventors: Jack Long (Warsaw, IN), Joseph Iannotti (Maryfield Heights, OH), Gerald Williams (Villanova, PA)
Application Number: 11/900,682
International Classification: A61F 2/40 (20060101); A61B 17/68 (20060101); A61F 2/46 (20060101); A61F 2/30 (20060101);