IMPLANT COMPONENTS AND METHODS
Systems, devices, and methods are provided for orthopedic implants. The implants may include a base member, such as an acetabular shell or an augment, that is configured to couple with an augment, flange cup, mounting member, or any other suitable orthopedic attachment. A mounting member may be used to attach to an implant and anchor the implant to a patient's bone or soft tissue. The mounting member may be integral with the implant or may be provided as a separate component. A mounting member may be adjustably positionable around the implant to provide flexibility and allow the mounting member to meet needs of a particular patient and implant.
Latest Smith & Nephew, Inc. Patents:
- METHODS AND SYSTEMS FOR CALIBRATING SURGICAL INSTRUMENTS FOR SURGICAL NAVIGATION GUIDANCE
- MEDICAL DEVICE SYSTEMS AND METHODS INCLUDING IMPLANT DELIVERY DEVICE
- TISSUE REPAIR DEVICES AND METHODS OF USE
- Controlled randomized porous structures and methods for making same
- Automatic placement of reference grids and estimation of anatomical coordinate systems
This application claims the benefit of U.S. Provisional Patent Application No. 61/352,705, filed Jun. 8, 2010, U.S. Provisional Application No. 61/352,722, filed Jun. 8, 2010, U.S. Provisional Application No. 61/422,903, filed Dec. 14, 2010, and U.S. Provisional Application No. 61/466,817, filed Mar. 23, 2011, which are hereby incorporated by reference herein in their entireties.
BACKGROUNDJoints often undergo degenerative changes due to a variety of reasons. When joint degeneration becomes advanced or irreversible, it may become necessary to replace the natural joint with a prosthetic joint. Artificial implants, including hip joints, shoulder joints, and knee joints are widely used in orthopedic surgery. Specifically, hip joint prostheses are common. The human hip joint acts mechanically as a ball and socket joint, wherein the ball-shaped head of the femur is positioned within the socket-shaped acetabulum of the pelvis. Various degenerative diseases and injuries may require replacement of all or a portion of a hip using synthetic materials, typically metals, ceramics, or plastics.
More particularly, natural hips often undergo degenerative changes, requiring replacement of the hip joint with a prosthetic joint. Often, the hip is replaced with two bearing surfaces between the femoral head and the acetabulum. The first bearing surface is typically a prosthesis shell or acetabular cup, which may be formed of metal, ceramic material, or as otherwise desired. A liner (conventionally formed of polyethylene material such as ultra high molecular weight polyethylene, a ceramic material, or in some cases, even a metal liner) is then fit tightly within the shell to provide an inner bearing surface that receives and cooperates with an artificial femoral head in an articulating relationship to track and accommodate the relative movement between the femur and the acetabulum.
The cup (or a cup and liner assembly) is typically fixed either by placing screws through apertures in the cup or by securing the cup with cement. In some cases, only a liner is cemented in a patient due to poor bone stock. In other cases, a cup having a porous surface may be press fit into the reamed acetabular surface.
It may become necessary to conduct a second or subsequent surgery in order to replace a prosthetic joint with a (often larger) replacement joint. Such surgeries often become necessary due to further degeneration of bone or advancement of a degenerative disease, requiring removal of further bone and replacement of the removed, diseased bone with a larger or enhanced prosthetic joint, often referred to as a revision prosthesis. For example, bone is often lost around the rim of the acetabulum, and this may provide less rim coverage to securely place a press-fit cup. Such surgeries may thus be referred to as revision surgeries.
In acetabular revision surgery, an acetabular prosthesis generally includes additional mounting elements, such as augments, flanges, hooks, plates, or any other attachment or mounting points or members that provide additional support and/or stability for the replacement prosthesis once positioned. These additional mounting or attachment members are often required due to bone degeneration, bone loss, or bone defects in the affected area (in this instance, the hip joint).
Various types of these mounting members (which term is intended to include but not be limited to flanges, blades, plates and/or hooks) may be provided in conjunction with a prosthesis system in order to help the surgeon achieve optimal fixation, non-limiting examples of which include iliac flanges (providing securement and fixation in and against the ilium region of the pelvis), ischial blades (providing securement and fixation in and against the ischium), and obturator hooks (providing securement and inferior fixation by engaging the obturator foramen). Although there have been attempts to provide such mounting attachments with modularity, the solutions to date have generally fallen short of providing true modularity. Instead, they typically provide a few discrete positions at which the mounting members may be positioned, without providing the surgeon a fuller range of decision options.
Additionally, in some primary surgeries and more often in revision surgeries, the acetabulum may have a bone defect or void that the surgeon must fill with bone grafts before inserting a new shell. This can be time consuming and expensive, and may subject the patient to additional health risks. Some techniques use an augment in connection with the acetabular shell, which can be coupled to or otherwise attached to the outer surface of the shell.
With current augments, the surgeon can attach the augment to the bone and then implant the cup. However, many acetabular shells rely on bone screws to achieve proper fixation and the augment often gets in the way of a screw. In short, surgeons need the freedom to place screws in the best location, but this compromises their ability to use augments. With current systems, it also takes an increased amount of time surgical time to trial the component orientation and then try to find good bone fixation for the cup. The surgeon will often have to free-hand the amount of bone removed while estimating the size of augment needed. In the cases where bone is often deficient, surgeons are hesitant to take away any more bone than necessary.
Various additional features and improved features intended for use and application with various types of joint implants are also described herein, such as improved bone screws, improved coatings, and various augment removal and insertion options.
SUMMARYDisclosed herein are systems, devices, and methods for providing modular orthopedic implants. The implants may include a base member, such as an acetabular shell or an augment, that is configured to couple with an augment, flange cup, mounting member, any other suitable orthopedic attachment, or any combinations thereof. Mounting members include, for example, flanges, blades, hooks, and plates. In some embodiments, the orthopedic attachments may be adjustably positionable about the base member or other attachments thereby providing modularity for assembling and implanting the device. Various securing and/or locking mechanisms may be used between the components of the implant. In certain embodiments, the orthopedic attachments are removably coupled to the base member or other components. In certain embodiments, the orthopedic attachments are integrally provided on the base member or other components, yet may still be adjustably positionable thereabout. In some embodiments, expandable augments, base members, or other bone filling devices are provided. In some embodiments, surface features are provided that create friction and allow for surrounding bone ingrowth at the interface of the implants and a patient's bone.
Systems, devices, and methods described herein provide implants having attachment mechanisms that provide a plurality of positioning options for the orthopedic attachments. In certain embodiments, an orthopedic device includes an implant structured to fit with and stabilize a patient's orthopedic joint, the implant having a plurality of attachment sites, and a mounting member having a first end that anchors to the patient's bone or soft tissue and a second end that mates with the implant at each of the plurality of attachment sites. The plurality of attachment sites can include portions of a crossbar extending about an acetabular shell. Alternatively or additionally, the attachment sites can include a groove extending along a rim of the implant. In some embodiments, attached mounting members may include conventional holes, locking holes, or slots. The sites may be threaded, unthreaded, or partially threaded, and may be fixed or polyaxial. In some embodiments, attachment sites may include variable low-profile holes that allow for locking at a variety of angles. In some embodiments, a porous surface is disposed on a portion of the mounting member. In some embodiments, the mounting member is a flange that is adjustably positionable about the circumference of an acetabular implant. For example, the flange (or any other suitable mounting member) can pivot in a plane that is perpendicular to the circumference of an acetabular shell. The flange can include a split eye-let and/or a hook that joins a rail or groove on the implant. The flange can also include a key that removably inserts within a complementary rim on an acetabular shell. In certain embodiments, the flange is a flexible strap, or the flange may include a frangible portion that allows the flange to bend or break. In certain embodiments, the implant includes an annular recessed slot with an overhanging lip, where the mounting member includes a distal portion that fits within the annular recessed slot. The implant can be an augment that mounts to a surgical shell or cage, and the implant can fit within one of a shoulder, hip, or ankle joint. In certain embodiments, the mounting member includes a plurality of flanges, at least one flange being adjustably positionable with respect to more than one of the attachment sites.
In certain embodiments, a method of installing an orthopedic implant within a patient includes the steps of inserting the implant into the patient, selecting a site along the inserted implant to receive a first mounting member, attaching the first mounting member to the selected site, and anchoring the first mounting member to the patient. The selected site may be chosen from a plurality of attachment sites that are angularly spaced about the implant. The method may further include the step of applying a porous surface to a portion of the first mounting member. In some embodiments, the inserting step may include the step of mounting an acetabular shell or cage within the patient's acetabulum. In some embodiments, the implant may be an acetabular augment, and the inserting step may include the step of mounting the acetabular augment to an acetabular shell. The method may further include the step of detaching a detachable portion of the first mounting member after attaching the first mounting member to the selected site. In some embodiments, the anchoring step includes the step of anchoring the first mounting member to a first entry point within the selected site. The method may further include the step of cementing the implant into the patient's acetabulum prior to attaching the first mounting member to the selected site. The method may further include the step of adjustably positioning the mounting member about the circumference of the implant and along the selected site. In some embodiments, the mounting member may include a flange, hook, or plate.
In certain embodiments, mounting members or augments shown and described in the figures contained herein may comprise tacks, spikes, coatings, or textured surfaces so as to improve initial fixation. The geographic locations of tacks, spikes, coatings, or textured surface structures may be strategically placed on select portions of a mounting member or implant so as to evenly load the mounting member or implant assembly and obtain the best biologic response initially, and over an extended period of time.
The foregoing and other objects and advantages will be apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which:
To provide an overall understanding of the systems, devices, and methods described herein, certain illustrative embodiments will be described. Although the embodiments and features described herein are specifically described for use in connection with acetabular systems, it will be understood that all the components, connection mechanisms, adjustable systems, fixation methods, manufacturing methods, coatings, and other features outlined below may be combined with one another in any suitable manner and may be adapted and applied to medical devices and implants to be used in other surgical procedures, including, but not limited to: spine arthroplasty, cranio-maxillofacial surgical procedures, knee arthroplasty, shoulder arthroplasty, as well as foot, ankle, hand, and other extremity procedures.
Various implants and other devices described herein in their various embodiments may be used in conjunction with any appropriate reinforcement material, non-limiting examples of which include bone cement, appropriate polymers, resorbable polyurethane, and/or any materials provided by PolyNovo Biomaterials Limited, or any suitable combinations thereof. Further non-limiting examples of potential materials that may be used are described in the following references: U.S. Patent Application Publication No. 2006/0051394, entitled “Biodegradable Polyurethane and Polyurethane Ureas,” U.S. Patent Application Publication No. 2005/0197422, entitled “Biocompatible Polymer Compositions for Dual or Multi Staged Curing,” U.S. Patent Application Publication No. 2005/0238683, entitled “Biodegradable Polyurethane/Urea Compositions,” U.S. Patent Application Publication No. 2007/0225387, entitled “Polymer Compositions for Dual or Multi Staged Curing,” U.S. Patent Application Publication No. 2009/0324675, entitled “Biocompatible Polymer Compositions,” U.S. Patent Application Publication No. 2009/0175921, entitled “Chain Extenders,” and U.S. Patent Application Publication No. 2009/0099600, entitled “High Modulus Polyurethane and Polyurethane/Urea Compositions.” Each of the prior references is incorporated by reference herein in its entirety.
By providing two curved or spherical surfaces, for example, the rim mounting member 202 may be configured for universal use and, therefore, may be flipped or inverted in order to allow its use with a left to a right acetabular cup. In other words, the rim mounting member 202 may be inverted when used in conjunction with a contralateral hip. It may further be provided in any suitable number of available sizes in order to fit multiple cup sizes (e.g., acetabular cups having outer diameter sizes ranging between approximately 30 mm and 90 mm).
One or more flanges or other mounting members, or any combinations thereof, may be provided on mounting member 202. In the particular embodiment shown, three mounting members 208 are shown, which extend radially from the rim of the acetabular cup 204. The mounting members 208 are configured to be bent, cut, or otherwise shaped as needed in order to conform to the pelvis of a particular patient's anatomy. Alternatively or additionally, one or more of the mounting members 208 may be oriented at predetermined radial locations circumferentially around the rim of the acetabular cup to correspond with, engage, or otherwise accommodate the ilium, ischium, superior ramus, or any other suitable patient anatomy. It should further be understood that any of the alternate and adjustable mounting and securement mechanisms described herein may also be used with these embodiments. The described rim mounting members are of particular use in acetabulums having defects and damage along the acetabular rim. The holes of the mounting members 208 may be threaded, unthreaded, or partially threaded, and may be fixed or polyaxial. In some embodiments, attachment sites may include variable low-profile holes that allow for locking at a variety of angles.
A mounting member 220 has a first end 221 that anchors to the patient's bone or soft tissue and a second end or receiving portion 223 that mates with the implant, such as acetabular shell 218, at each of the plurality of attachment sites provided along, for example, the crossbar 212. The second end or receiving portion 223 of mounting member 220 may have a hook or a split opening that receives the crossbar 212. For example, mounting member 220′ of
One or more entry points may be provided within the T-slot, dovetail slot, tongued groove, undercut groove, or other attachment site to allow quick insertion, placement, access, or removal of the flanges, plates, or augments with respect to the shell. Particularly, multiple entry portions may be configured to allow one or more mounting members or augments to be engaged with the shell and positioned angularly around the shell even after the shell has been impacted into a prepared acetabulum and portions of the shell proximate to the rim are obstructed by bone, grafts, or cement. For example, as shown in
In the embodiments shown in
As shown in the embodiments depicted in
In lieu of screw holes, or in addition to screw holes, in some embodiments spikes, tacks, or other appropriate fasteners may be utilized. J-slots may be provided in the porous pieces or the mounting members to allow adjustability of the position of the porous piece relative to the augment or mounting member in both rotation and translation. For example,
As shown in
In the embodiments shown in
In the embodiments shown in
In the embodiments of
Fasteners 832 may be inserted into openings 830 located circumferentially laterally of the insertion portions 834 and 836 to serve as stops for preventing or limiting rotational movement of the attached mounting members 840 or augments 838. The mounting members 840 or augments 838 may be secured down to surrounding bone after being inserted into the annular undercut groove 828 via long bone screws, thereby providing a hold-down force to the acetabular shell or cage 820. The hold-down forces provided may complement the press fit, threaded fit, or cemented fixation between the acetabular shell or cage and surrounding prepared acetabular bone. In the instance shown, shell 820 is provided as a “hooded” shell similar to a cage, and may act as a buttress for a cemented or pressed-in liner to support various liner inclinations in varying degrees of acetabular or pelvic degradation, although it will be understood that these features may be provided on any other type of shell or cage.
The foregoing is merely illustrative of the principles of the disclosure, and the systems, devices, and methods can be practiced by other than the described embodiments, which are presented for purposes of illustration and not of limitation. It is to be understood that the systems, devices, and methods disclosed herein, while shown for use in acetabular systems, may be applied to medical devices to be used in other surgical procedures including, but not limited to, spine arthroplasty, cranio-maxillofacial surgical procedures, knee arthroplasty, shoulder arthroplasty, as well as foot, ankle, hand, and extremities procedures.
Variations and modifications will occur to those of skill in the art after reviewing this disclosure. The disclosed features may be implemented, in any combination and subcombinations (including multiple dependent combinations and subcombinations), with one or more other features described herein. The various features described or illustrated above, including any components thereof, may be combined or integrated in other systems. Moreover, certain features may be omitted or not implemented.
Examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the scope of the information disclosed herein. All references cited herein are incorporated by reference in their entirety and made part of this application.
Claims
1. An orthopedic device comprising:
- an implant structured to fit with and stabilize a patient's orthopedic joint, the implant having a plurality of attachment sites; and
- a mounting member having a first end that anchors to the patient's bone or soft tissue and a second end that mates with the implant at each of the plurality of attachment sites.
2. The device of claim 1, wherein the plurality of attachment sites include portions of a crossbar extending about an acetabular shell.
3. The device of claim 1, wherein the plurality of attachment sites include portions of a groove extending along a rim of the implant.
4. The device of claim 1, wherein the mounting member is a flange.
5. The device of claim 4, wherein the flange is adjustably positionable about the circumference of an acetabular implant.
6. The device of claim 5, wherein the flange includes a split eyelet that joins a rail or groove on the implant.
7. The device of claim 5, wherein the flange includes a hook that joins a rail or groove on the implant.
8. The device of claim 5, wherein the flange includes a key that removably inserts within a complementary rim on an acetabular shell.
9. The device of claim 4, wherein the flange pivots in a plane that is perpendicular to the circumference of an acetabular shell.
10. The device of claim 4, wherein the flange is a flexible strap.
11. The device of claim 4, wherein the flange includes a frangible portion that allows the flange to bend or break.
12. The device of claim 1, wherein the implant includes an annular recessed slot with an overhanging lip, and wherein the mounting member includes a distal portion that fits within the annular recessed slot.
13. The device of claim 1, wherein the implant is an augment that mounts to a surgical shell or cage.
14. The device of claim 1, wherein the implant fits within one of a shoulder, hip, or ankle joint.
15. The device of claim 1, wherein the mounting member includes a plurality of flanges, at least one flange being adjustably positionable with respect to more than one of the attachment sites.
16. The device of claim 1, comprising a porous surface disposed on a portion of the mounting member.
17. A method of installing an orthopedic implant within a patient, comprising the steps of:
- inserting the implant into the patient;
- selecting a site along the inserted implant to receive a first mounting member;
- attaching the first mounting member to the selected site; and
- anchoring the first mounting member to the patient.
18. The method of claim 17, further comprising the step of applying a porous surface to a portion of the first mounting member.
19. The method of claim 17, the inserting step comprising the step of mounting an acetabular shell or cage within the patient's acetabulum.
20. The method of claim 17, wherein the implant is an acetabular augment.
21. The method of claim 20, wherein the inserting step comprises the step of mounting the acetabular augment to an acetabular shell.
22. The method of claim 21, further comprising the step of detaching a detachable portion of the first mounting member after attaching the first mounting member to the selected site.
23. The method of claim 17, wherein the selected site is chosen from a plurality of attachment sites that are angularly spaced about the implant.
24. The method of claim 17, wherein the anchoring step includes the step of anchoring the first mounting member to a first entry point within the selected site.
25. The method of claim 17, further comprising the step of cementing the implant into the patient's acetabulum prior to attaching the first mounting member to the selected site.
26. The method of claim 17, further comprising the step of adjustably positioning the mounting member about the circumference of the implant and along the selected site.
27. The method of claim 26, wherein the mounting member comprises a flange, hook, or plate.
Type: Application
Filed: Jun 8, 2011
Publication Date: Apr 5, 2012
Applicant: Smith & Nephew, Inc. (Cordova, TN)
Inventors: Justin Steve Conway (Olive Branch, MS), Luke Andrew Gibson (Southhaven, MS), Jeffrey A. Sharp (Salt Lake City, UT), Jeffrey Joel Shea (Memphis, TN), Brian Ronald Yokoo (Riverton, UT)
Application Number: 13/156,240
International Classification: A61F 2/34 (20060101);