IMPLANT EXTRACTOR

A implant extractor for removing an implant is provided. The implant extractor includes an extractor head having a laterally extending blade, an intermediate portion adjacent to the blade, and a laterally extending strike plate adjacent to the intermediate portion, the blade including a proximal side for mating with the implant; a shaft having proximal and distal ends, the distal end of the shaft being coupled to the extractor head; and a handle coupled to the proximal end of the shaft.

BACKGROUND OF THE INVENTION

Various medical conditions, such as arthritis, may necessitate joint arthroplasty whereby a surgeon implants artificial structures (known as implants) within a human joint, such as a knee joint, to compensate for degradation in structure or function of the joint. Depending on the level of degradation, a full or partial joint arthroplasty may be necessary. Implants are typically press-fit onto bone within the joint or affixed to bone using a fast-acting cement, such as polymethylmethacrylate. In some instances, it may be advantageous to remove or replace an implant, for instance, when the implant wears out or the joint becomes infected.

BRIEF SUMMARY OF THE INVENTION

In accordance with an exemplary embodiment of the subject disclosure, an implant extractor for removing an implant is provided. The implant extractor includes an extractor head having a laterally extending blade having a proximal side for mating with the implant, an intermediate portion adjacent to the blade, and a laterally extending strike plate adjacent to the intermediate portion; a shaft having a distal end coupled to the extractor head and a proximal end opposite the distal end; and a handle coupled to the proximal end of the shaft.

In accordance with one aspect of the subject disclosure, the proximal side of the blade is completely planar.

In accordance with another aspect of the subject disclosure, the blade is an elongated blade.

In accordance with still another aspect of the subject disclosure, the blade is an elongated tapered blade.

In accordance with yet another aspect of the subject disclosure, the blade comprises a distal side having a beveled surface.

In accordance with still another aspect of the subject disclosure, the beveled surface extends along lateral edges of the blade.

In accordance with yet another aspect of the subject disclosure, the blade comprises a rounded tip about its laterally extending end.

In accordance with still another aspect of the subject disclosure, the strike plate is substantially prism-shaped.

In accordance with yet another aspect of the subject disclosure, the extractor head has an overall length of about 60 to 63 mm.

In accordance with still another aspect of the subject disclosure, the blade has a longitudinal length of about 29 to 30 mm, the intermediate portion has a longitudinal length of about 22 to 23 mm, and the strike plate has longitudinal length of about 9 to 10 mm.

In accordance with yet another aspect of the subject disclosure, the intermediate portion includes a distally facing planar surface.

In accordance with still another aspect of the subject disclosure, the blade further includes a transition surface curving distally from the distal side and terminating at the distally facing planar surface of the intermediate portion.

In accordance with yet another aspect of the subject disclosure, the shaft includes a key, and wherein the handle is removably couplable to the shaft via the key.

In accordance with still another aspect of the subject disclosure, the shaft includes a key about ⅔ of an overall length of the shaft from the distal end of the shaft.

In accordance with yet another aspect of the subject disclosure, the shaft includes a substantially plus-shaped key about its proximal end for engaging the handle.

In accordance with still another aspect of the subject disclosure, the substantially plus-shaped key is an elongated key having a beveled proximal end.

In accordance with yet another aspect of the subject disclosure, the distal end of the shaft includes screw threads for coupling the shaft to the extractor head.

In accordance with still another aspect of the subject disclosure, a proximal end of the handle includes a strike plate.

In accordance with yet another aspect of the subject disclosure, a distal end of the handle is spaced from the extractor head about 276 to 294 mm.

In accordance with another exemplary embodiment of the subject disclosure, an implant extractor for removing an implant is provided. The implant extractor has an extractor head that includes a laterally extending elongated tapered blade having a planar proximal side for mating with the implant, a distal side having a beveled surface extending along lateral edges of the blade, and a rounded tip about its laterally extending end, an intermediate portion adjacent to the blade, the intermedia portion having a distally facing planar surface, wherein the blade includes a transition surface curving distally from the distal side and terminating at the distally facing planar surface of the intermediate portion, and a laterally extending prism-shaped strike plate adjacent to the intermediate portion; a shaft having a distal end coupled to the extractor head, a proximal end opposite the distal end, and a key spaced from the distal end about ⅔ of an overall length of the shaft; and a handle coupled to the proximal end of the shaft about the key and having a strike plate about its proximal end.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to an exemplary embodiment of the subject disclosure illustrated in the accompanying drawings. Wherever possible, the same or like reference numbers will be used throughout the drawings to refer to the same or like features. It should be noted that the drawings are in simplified form and are not drawn to precise scale. In reference to the disclosure herein, for purposes of convenience and clarity only, directional terms such as upper, lower, top, bottom, above, below and diagonal, are used with respect to the accompanying drawings. Such directional terms used in conjunction with the following description of the drawings should not be construed to limit the scope of the subject disclosure in any manner not explicitly set forth. Additionally, the term “a,” as used in the specification, means “at least one.” The terminology includes the words above specifically mentioned, derivatives thereof, and words of similar import.

“Substantially” as used herein shall mean considerable in extent, largely but not wholly that which is specified, or an appropriate variation therefrom as is acceptable within the field of art.

“Exemplary” as used herein shall mean serving as an example.

Furthermore, the described features, advantages and characteristics of the exemplary embodiments of the subject disclosure may be combined in any suitable manner in one or more exemplary embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the subject disclosure can be practiced without one or more of the specific features or advantages of a particular exemplary embodiment. In other instances, additional features and advantages may be recognized in certain exemplary embodiments that may not be present in all exemplary embodiments of the present disclosure.

Referring now toFIGS.1-9, there is shown an implant extractor100in accordance with an exemplary embodiment of the subject disclosure. Implant extractor100may be used, for example, to extract structures implanted within or adjacent to bone, such as, for example, a partial or uni-compartmental knee implant. It should be appreciated that implant extractor100may be employed also to remove other types of implants (such as a total knee, hip or shoulder implants) and/or other implants installed at other locations in a human body, such as, for example, in an elbow joint, shoulder joint, etc.

As best shown inFIGS.1-6, implant extractor100includes an extractor head105, a shaft110coupled at a proximal end112to extractor head105, and a handle120with a strike plate125coupled to a proximal end130of shaft110. In the embodiments illustrated in the Figures, shaft110is coupled to extractor head105via screw threads115, though it should be appreciated that shaft110may be formed integrally with extractor head105or coupled to extractor head105in other ways, such as via screws, blots, cement, or the like. It should also be appreciated that implant extractor100may be constructed from any materials suitable for its intended use, such as, for example, stainless steel, titanium, cobalt chrome, various combinations of these and/or other materials, etc.

Shaft110of implant extractor100further includes key114structured to permit shaft110to be removably coupled to handle120. In the exemplary embodiments illustrated in the Figures, shaft110with key114is structured to removably couple to one or more handles as disclosed in U.S. Patent Pub. No. 2020/0060693 A1 to Sweitzer, the entire contents of which are expressly herein incorporated by reference for all purposes. It should be appreciated, however, that shaft110may alternatively be formed integrally with handle120and/or be structured to couple to different handles (including those without strike plates) or to other structures. Further, in at least some embodiments, key114is positioned at a position about two-thirds of an overall length of shaft110from the distal end of the shaft, but can be more or less e.g., +/−⅙ from said two-thirds position. The key114can also be substantially plus-shaped, but can also take on additional shapes suitable for its intended purpose. The key114can also be an elongated key having a beveled proximal end.

As best shown inFIGS.3-6, extractor head105includes an elongated and tapered blade205extending laterally relative to shaft110, an intermediate portion210with a distally facing planar surface215adjacent to blade205and a laterally facing strike plate220(which may be substantially prism-shaped) adjacent to intermediate portion210. In the embodiments illustrated in the Figures, blade205, intermediate portion210and strike plate220of extractor head105are formed integrally into one structure, though it should be appreciated that extractor head105may be formed from multiple separate structures coupled to one another, for example, via cement, screws, bolts, or the like. Further, in at least some embodiments, extractor head105has an overall longitudinal length of about 60 to 63 mm, including 61.91 mm, intermediate portion has a longitudinal length of about 22 to 23 mm including 22.54 mm, blade205has a longitudinal length of about 29 to 30 mm, including 29.85 mm and/or strike plate220has a longitudinal length of about 9 to 10 mm, including 9.53 mm, though it should be appreciated that any or all of these features may be dimensioned differently. In accordance with another aspect, a distal end or most distally extending end of handle120is spaced from extractor head105about 276 to 294 mm, including 293.2 mm, though it should be appreciated that different spacings may be provided.

Blade205includes a proximal side225for mating with an implant to be extracted and a distal side230having a beveled surface235extending along the lateral edges of blade205, a rounded tip240about a laterally extending end, and a transition surface245curving distally and terminating at planar surface215of intermediate portion210. In the illustrated embodiments, proximal side225of blade205includes a planar mating surface250structured to mate with a corresponding planar portion of an implant, though it should be appreciated that mating surface250may be structured and/or shaped differently to mate with one or more differently shaped surfaces of an implant.

Referring now toFIG.10, there is seen a flow diagram detailing a process1000for using implant extractor100to remove a partial knee implant300from e.g. a human knee joint305. Process1000begins at step1005and proceeds to step1010, at which a user (such as a surgeon) positions blade205of implant extractor100adjacent to a boundary310(with or without cement) between partial knee implant300and a leg bone315(seeFIG.7). The process then proceeds to step1015. At this step, the surgeon impacts strike plate220of implant extractor100using a mallet, hammer or other suitable device. The impact force of the mallet is channeled through blade205and focused by rounded tip240to drive blade205of implant extractor100into boundary310between partial knee implant300and leg bone315(seeFIG.8). As best shown inFIG.8, beveled surface235of blade205helps maintain planar mating surface250of blade205against implant300while blade205is driven into boundary310.

After blade205is driven a sufficient distance into boundary310between implant300and bone315, the process proceeds to step1020. At this step, the surgeon applies a lateral force320to handle120to pivot implant extractor100about contact point325and pry implant300off bone310. In addition to or in lieu of applying lateral force320, the surgeon may use a mallet, hammer or the like to strike and/or impact strike plate125of handle120to pivot implant extractor100. The process then ends at step1025.

WhileFIG.10describes process1000for employing implant extractor100to remove a partial knee implant300, it should be appreciated that implant extractor100may be employed to remove other types of implants, such as total knee implants or implants installed at other locations within a human body.