Humeral Head Preserving Implant
A modular humeral implant for implantation into a humerus that includes a natural humeral shaft and a natural humeral head. The implant includes a humeral stem implantable into the natural humeral shaft, and an adapter couplable to the humeral stem, the adapter including an anchoring projection forming a disk directly insertable into an underside of the natural humeral head.
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This application is a divisional of U.S. patent application Ser. No. 10/916,102 filed on Aug. 11, 2004. The entire disclosure of the above application is incorporated herein by reference.
INTRODUCTIONA humeral prosthesis for total shoulder joint replacement generally includes a prosthetic humeral stem and a prosthetic humeral head which replaces the natural humeral head and is disposed within the shoulder socket. For three and four-part humeral head split fractures in which the blood supply to the fragments is compromised, a hemiarthroplasty can be performed, also replacing the humeral head with a prosthetic head.
In some humeral fractures, however, blood supply to the head fragment may be adequate, such as, for example, when the head is still attached to one of the tuberosities. In such cases, repairing and salvaging the natural head is preferable to replacing it. Accordingly, prostheses that allow retention and/or repair of the natural humeral head are still desirable.
SUMMARYVarious aspects of the invention teach a modular humeral implant and associated kit and method for implantation into a humerus that includes a natural humeral shaft and a natural humeral head. The modular implant includes a humeral stem for implantation into the natural humeral shaft, and an adapter. The adapter includes an anchoring projection and is operable for coupling to the humeral stem. The anchoring projection is adapted for insertion into an underside of the natural humeral head.
The present teachings also provide a method for implanting a modular humeral prosthesis to repair a humeral fracture in which the natural humeral head is still attached to a portion of the natural humeral shaft. The method includes rotating the natural humeral head to expose the proximal surface of the natural humeral shaft without severing the attachment. A longitudinal bore is prepared into the humeral shaft. An adapter is coupled to one of the natural humeral head and a humeral stem, and the humeral stem is implanted into the longitudinal bore. The natural humeral head is rotated onto the natural humeral shaft such that the adapter is inserted into the other of the natural humeral head and the humeral stem, and the natural humeral head substantially contacts the natural humeral shaft.
The present teachings also provide a modular humeral implant for implantation into a humerus that includes a natural humeral shaft and a natural humeral head. The implant includes a humeral stem for implantation into the natural humeral shaft, and a plurality of fasteners fastening the natural humeral shaft through the humeral stem to the natural humeral head.
The present teachings also provide a method for implanting a modular humeral prosthesis to repair a humeral fracture in which the natural humeral head is still attached to a portion of the natural humeral shaft. The method includes rotating the natural humeral head to expose a proximal surface of the natural humeral shaft without severing the attachment, preparing a longitudinal bore into the natural humeral shaft; inserting the humeral stem into the bore, rotating the natural humeral head onto the proximal surface of the natural humeral shaft, drilling a plurality of angled bores extending from natural humeral shaft though the humeral stem to the natural humeral head, and inserting fasteners through the angled bores to attach the natural humeral shaft to the natural humeral head.
In another aspect, the present teachings provide a modular humeral implant for implantation into a humerus that includes a natural humeral shaft and a natural humeral head. The implant includes a humeral stem implantable into the natural humeral shaft, and an adapter couplable to the humeral stem, the adapter including an anchoring projection forming a disk directly insertable into an underside of the natural humeral head.
In another aspect the implant includes a humeral stem for implantation into the natural humeral shaft, and an anchoring portion in the form of a substantially planar plate including a plurality of suturing holes, the planar plate coupled to the humeral stem with a taper lock connection and adapted for insertion into an underside of the natural humeral head.
In yet another aspect, the implant includes a humeral stem for implantation into the natural humeral shaft, and an anchoring portion in the form of a substantially planar circular disk including a plurality of suturing holes. The anchoring portion includes a tapered projection received in a tapered recess of the humeral stem, and the disk is adapted for insertion into a recess formed in an underside of the natural humeral head.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
The following description of various embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.
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The threaded screw 112 can be directly threaded into cancellous bone through the underside surface 120 of the natural humeral head 84. To receive the bulbous projection 110, the natural humeral head 84 can be prepared by removing, if necessary, cancellous bone from the underside surface 120 of the natural humeral head 84 to create a snugly-fitting recess 122. Alternatively, a cancellous bone impactor (not shown) can be used to define a recess 122 that snugly matches the bulbous projection 110.
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In operation and with reference to
When the selected adapter 104 has a bulbous projection 110, the adapter 104 can be first taper-locked with the humeral stem 102, which is then inserted into the longitudinal bore 88, as shown in
When the selected adapter 104 has an anchoring projection 113 of the threaded screw 112 type, the adapter 104 can be first threaded into the underside surface 120 of the natural humeral head 84, which is then taper-locked with the humeral stem 102, after the humeral stem 102 has been inserted into the longitudinal bore 88, as shown in
The humeral stem 102 and the adapter 104 can be manufactured from a variety of biocompatible materials such as, for example, Ti6Al4V or CoCrMo. The adapter 104 can also be a hybrid combination of titanium or cobalt chromium with bioabsorbable materials, such as polylactides, plyglycolides, calcium phosphate, hydroxyapatite, etc.
The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
Claims
1. A modular humeral implant for implantation into a humerus that includes a natural humeral shaft and a natural humeral head, the implant comprising:
- a humeral stem implantable into the natural humeral shaft; and
- an adapter couplable to the humeral stem, the adapter comprising an anchoring projection forming a disk directly insertable into an underside of the natural humeral head.
2. The humeral implant of claim 2, wherein the disk defines at least one suturing hole.
3. The humeral implant of claim 1, wherein the disk defines a plurality of suturing holes along a periphery of the anchoring portion for suturing the disk in the natural humeral head.
4. The humeral implant of claim 2, wherein the disk is a substantially circular plate.
5. The humeral implant of claim 2, wherein the disk is a substantially polygonal plate.
6. The humeral implant of claim 1, wherein the adapter includes a tapered projection receivable in a tapered recess of the humeral stem.
7. The humeral implant of claim 6, wherein the tapered projection is substantially conical.
8. The humeral implant of claim 1, wherein the disk is substantially planar.
9. The humeral implant of claim 2, wherein the disk is insertable into a recess in the natural humeral head, and upon implantation, the disk is flush with the underside of the natural humeral head.
10. The humeral implant of claim 1, wherein the stem includes a porous coating.
11. The humeral implant of claim 1, wherein the stem includes a plurality of suturing holes.
12. A humeral implant for implantation into a humerus that includes a natural humeral shaft and a natural humeral head, the implant comprising:
- a humeral stem for implantation into the natural humeral shaft; and
- an anchoring portion in the form of a substantially planar plate including a plurality of suturing holes, the planar plate coupled to the humeral stem with a taper lock connection and adapted for insertion into an underside of the natural humeral head.
13. The humeral implant of claim 12, wherein the planar plate is substantially circular.
14. The humeral implant of claim 13, wherein the suturing holes are arranged along a circular periphery of the planar plate.
15. The humeral implant of claim 12, wherein the planar plate is polygonal.
16. The humeral implant of claim 12, wherein the stem includes a porous coating.
17. The humeral implant of claim 16, wherein the stem includes a plurality of suturing holes.
18. A humeral implant for implantation into a humerus that includes a natural humeral shaft and a natural humeral head, the implant comprising:
- a humeral stem for implantation into the natural humeral shaft; and
- an anchoring portion in the form of a substantially planar circular disk including a plurality of suturing holes, the anchoring portion including a tapered projection received in a tapered recess of the humeral stem, the disk adapted for insertion into a recess formed in an underside of the natural humeral head.
19. The humeral implant of claim 18, wherein the suturing holes are arranged along a circular periphery of the disk.
20. The humeral implant of claim 18, wherein the stem includes a porous coating and a plurality of suturing holes.
Type: Application
Filed: Jan 7, 2009
Publication Date: Apr 30, 2009
Applicant: BIOMET MANUFACTURING CORP. (Warsaw, IN)
Inventors: Edward V. Craig (New Canaan, CT), Russell F. Warren (Greenwich, CT), Nathan A. Winslow (Warsaw, IN)
Application Number: 12/349,550
International Classification: A61F 2/40 (20060101);