US20120083895A1 - Implant components and methods - Google Patents

Abstract

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• 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.
BACKGROUND
• Joints 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.
SUMMARY
• Disclosed 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.
BRIEF DESCRIPTION OF THE DRAWINGS
• 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:
• FIGS. 1-4 show various perspectives of an illustrative rim augment or mounting member;
• FIGS. 5 and 6 schematically show the use of an illustrative pivot joint to add a mounting member to an acetabular shell;
• FIG. 7 shows an illustrative mounting member having a hook that receives a crossbar;
• FIG. 8 shows an illustrative mounting member having a split opening that receives a crossbar;
• FIG. 9 shows an illustrative T-slot into which a correspondingly-shaped receiving portion may be disposed;
• FIG. 10 shows a plurality of illustrative entry portions that may be provided around an acetabular shell;
• FIGS. 11-13 show an illustrative augment having one or more mounting members;
• FIGS. 14-19 show one or more illustrative porous pieces or surfaces provided on bendable mounting members such as bendable flanges or plates;
• FIG. 20 shows an illustrative mounting member having peripheral notches or inlets;
• FIG. 21 shows an illustrative mounting member having cross-hatches or removed material from the surface;
• FIGS. 22 and 23 show illustrative mounting members having various reduced surface area portions;
• FIG. 24 shows an illustrative mounting member having one or more porous areas that are spaced out on the member;
• FIG. 25 shows a mounting member having an illustrative orthopedic mesh;
• FIG. 26 shows an illustrative mesh portion placed on an outer portion of a shell;
• FIG. 27 shows an illustrative mesh that includes a plurality of trim lines that may be cut to separate the mounting members attached thereto;
• FIG. 28 shows illustrative separated mounting members from the mesh ofFIG. 27 placed into a patient's hip region;
• FIGS. 29 and 30 show an illustrative honeycomb design that may be provided on a mounting member or augment;
• FIG. 31-34 show illustrative cleats provided proximate to a rim of an acetabular shell or cage, mounting member, or augment;
• FIG. 35 shows illustrative cleat portions configured for securing soft tissues;
• FIGS. 36 and 37 show an illustrative augment attached peripherally to an acetabular shell or cage via a recess;
• FIGS. 38 and 39 show an illustrative mounting member attached peripherally to an acetabular shell or cage via a recess; and
• FIG. 40 shows an acetabular shell or cage having an illustrative annular protrusion.
DETAILED DESCRIPTION
• 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.
• FIGS. 1-4 show some embodiments where a rim augment or a mounting member may be configured for a left hip.Rim mounting member202 may be press-fit onto anouter diameter203 of an acetabular cup204 (e.g., acetabular shell, cup, cage, or augment). Therim mounting member202 has at least one curved or sphericalinner surface205 that matches acontour profile207 of an outer surface of theacetabular cup204 to which the mountingmember202 is attached. In some embodiments, more than one opposing curved or spherical surfaces may be provided on theinner surface205 of therim mounting member202, each curved or spherical surface comprising a similar radius of curvature. The size, shape, and profile of these one or more curved or spherical surfaces correspond to the outer diameter and outer surface profile of theacetabular cup204.
• By providing two curved or spherical surfaces, for example, therim mounting member202 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, therim mounting member202 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 mountingmember202. In the particular embodiment shown, three mountingmembers208 are shown, which extend radially from the rim of theacetabular cup204. The mountingmembers208 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 mountingmembers208 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 mountingmembers208 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.
• FIGS. 5-8 schematically illustrate the use of a pivot joint210 to add a mounting member (such as a flange, plate, or any other attachment or mounting member) to an acetabular shell, cup member, or augment according to some embodiments. For example, as shown inFIG. 5, acrossbar212 may be provided in one ormore recesses214 on an upper shell surface ofproximal rim portion216 of theacetabular shell218 and aligned generally parallel to a tangent of theshell218 adjacent its rim. The one ormore recesses214 may comprise, for instance, a V-shaped slot, although any other suitably-shaped slot may be used. A plurality of attachment sites may be provided, with each being spaced angularly about the rim or other portion of the implant. This allows a plurality of positioning options for mounting members and gives the surgeon more flexibility to position the attachments along the implant for ease of anchoring. Theacetabular shell218 includes aridge230 oninner surface228 that mates with a correspondingly-shaped ridge of a liner, for example, although any other suitable mounting member or augment may have a similarly-shaped ridge for mating withridge230. In some embodiments, theridge230 may be provided alternatively, or additionally, onouter surface226.
• A mountingmember220 has afirst end221 that anchors to the patient's bone or soft tissue and a second end or receivingportion223 that mates with the implant, such asacetabular shell218, at each of the plurality of attachment sites provided along, for example, thecrossbar212. The second end or receivingportion223 of mountingmember220 may have a hook or a split opening that receives thecrossbar212. For example, mountingmember220′ ofFIG. 7 includes ahook222, and mountingmember220″ ofFIG. 8 includes asplit opening224, which may also be referred to as a split eyelet. The mounting members shown inFIGS. 6-8 may be moved independently of the shell positioning. One of the advantages provided by this design is that the flanges and other mounting members are completely modular and do not have to be positioned in the same discrete place or in only one of a few pre-determined locations, but can instead be positioned anywhere around the rim of the shell and can pivot in a plane that is perpendicular to the plane defined by the circumference of the shell.
• FIGS. 9 and 10 illustrate some embodiments where one or more mounting members and/or augments translate or ride, or otherwise move, in a circumferentially-extending T-slot, dovetail slot, tongued groove, or undercut groove provided in anouter shell surface244 proximate to the rim. The mounting members or augments may be configured with a receiving portion that may enter a portion of theshell246 and slide within the circumferentially-extending T-slot, dovetail slot, tongued groove, or undercut groove. For example,FIG. 9 shows a T-slot240 on anouter surface244 ofshell246 into which a correspondingly-shaped receiving portion may be disposed. The mounting members or augments can revolve around the shell to the proper angular position around the rim and then be locked, retained, or otherwise secured in position. For example, the receiving portions may include a locking member or an expanding member that locks or expands, respectively, when the mounting member or augment is place in a particular location along the shell to thereby secure the mounting member or augment into position. A plurality of attachment sites may be provided, with each being spaced angularly about the rim or other portion of the implant. This allows a plurality of positioning options, as opposed to the discrete few options typically provided, for example, where the mounting member or augment must be positioned at the discrete location where attached. Similar to theacetabular shell218 ofFIG. 5,shell246 may also include aridge248 oninner surface242 that mates with a correspondingly-shaped ridge of a liner, for example, although any other suitable mounting member or augment may have a similarly-shaped ridge for mating withridge248. In some embodiments, theridge248 may be provided alternatively, or additionally, onouter surface244.
• 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 inFIG. 10, a plurality ofentry portions254 may be provided aroundshell258. A mountingmember250 that includes a receivingportion252 shaped as a key may be engaged with a reciprocally-shapedgroove256 at one ofentry portions254. The mountingmember250 may engage with the shell by placing mountingmember250 into one of thegrooves256 at anentry point254 and then positioned angularly around the shell therefrom to one of a plurality of attachment sites. Furthermore, mountingmember250 may be inserted into afirst entry point254, rotated about theshell258 to asecond entry point254, and then removed.
• In the embodiments shown inFIGS. 11-13, one or more mounting members262 (shown as flanges, but not limited thereto) are added to an acetabular augment260. The mountingmembers262 may be permanently fixed or detachable, and may be adjustably positionable about augment260 as described above. Mountingmembers262 may havefrangible portions264 between screw holes266 or other structures for receiving fasteners. Thefrangible portions264 may be provided, for example, as reduced cross-sections that allow bending or breaking or cutting of the mountingmembers262 without disturbing the internal geometries of the screw holes266. In certain embodiments, thefrangible portions264 may be prestressed or otherwise pretreated to make thefrangible portions264 weaker than other areas of the mountingmembers262. Screw holes266 may be smooth or provided with threads or other protrusions to be used with locking head screws or polyaxial screws. The screw holes266 may be conventional holes, locking holes, or slots. The holes may be threaded, unthreaded, or partially threaded, and may be fixed or polyaxial. In some embodiments, screw holes266 may include variable low-profile holes that allow for locking at a variety of angles. The augment260 and mountingmembers262 may be implanted proximate a patient's acetabulum. For example, as shown inFIGS. 12 and 13, augment260 having mountingmembers262 is implanted into an area having a posteriorcolumn defect region268.
• As shown in the embodiments depicted inFIGS. 14-19, one or more porous pieces or surfaces may be provided on bendable mounting members such as bendable flanges or plates, or any of the other mounting members. In some instances, solid or rigid augments may replace bendable mounting members. The mounting members may be modular, attachable, or integrally-provided on an acetabular implant structure such as an acetabular shell. As shown inFIG. 14, a mountingmember280 includes aporous coating282 about a periphery whiletop portion284 is substantially smooth and flat. Mountingmember280 also includes a plurality of fastening through-holes286 for receiving screws or other fastening members. Through-holes286 may include conventional holes, locking holes, or slots. The holes may be threaded, unthreaded, or partially threaded, and may be fixed or polyaxial. In some embodiments, through-holes286 may include variable low-profile holes that allow for locking at a variety of angles. Exemplary bending motion of flanges is shown with respect toFIGS. 15 and 16. A mounting member such asflange290 has afirst portion291 and asecond portion292 and is flat.Flange294 may be bent in a first direction about bendingaxis295 such that asecond portion298 is bent relative to afirst portion296. Because in some instances there may be a chance that porous structures integrally provided on mounting members (such asporous coating282 ofFIG. 14) may fracture, delaminate, or separate from the mounting members during or after bending, porous pieces may be provided separate from and/or spaced between securement devices such as screw holes, as shown inFIG. 17 andFIG. 19. InFIG. 17, a separate porous in-growth pad306 is provided, which can be secured to a bendable mountingmember300 viascrew304, so that thebendable mounting member300 may still be bent, while also featuring the desired in-growth advantages of the porous in-growth pads306, without being subject to delamination or decoupling upon bending. This allows bending of the mounting members without stressing the struts of each porous piece. The porous piece may be positioned before or after bending.Screws302 may be provided for securing the mountingmember300 to a patient's bone or soft tissue, an acetabular shell, augment, or other mounting member.
• 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,FIG. 18 shows a mountingmember270 having a plurality of screw holes272 and J-slots274. Screws or any appropriate fixation members may be used to rigidly fix the porous pieces to the augment or mounting member, or other members such as shape memory or deformable pegs (e.g., rivet structure) may be used to rigidly fix the porous pieces to the augment or mounting member. In some instances, members fixing the porous pieces to the augment or mounting member may be configured to allow the porous pieces to move during bending of the mounting members.
• As shown inFIG. 19, a mountingmember310 includes afirst portion312 that is bent in a first direction about bendingaxis320 relative to asecond portion314. Thefirst portion312 andsecond portion314 of mountingmember310 each include J-slots316 to allow adjustability of the position of theporous pieces318 attached thereto relative to mountingmember310.
• FIGS. 20-24 show various embodiments of adjustable and/or flexible mounting members. Stiff mounting members, such as stiff plates or flanges, or any other suitable stiff members that may be used to extend from a surgical implant for securing it into place, may be difficult to bend or position. It may thus be desirable in some instances to provide mounting members that are configured to bend or otherwise adjust.
• FIG. 20 shows a mountingmember340 having peripheral notches orinlets342 cut into the profile of the mountingmember340. In some embodiments, these features allow mountingmember340 to be flexed, bent, shaped, or otherwise contoured to bone or around other devices. In the embodiment shown, thenotches342 are Z-shaped, but it will be understood that any appropriate shape, such a J-slots, C-slots, V-slots, any other appropriate shapes, or any combinations thereof, may be used.FIG. 21 shows a mountingmember350 having cross-hatches or removedmaterial352 from the surface, thereby reducing the cross-sectional surface area of the member. These features may make it easier for mountingmember350 to flex, bend, shape, or contour.FIGS. 22 and 23 show further embodiments of mounting members that may have various reduced surface area portions, such as notches, indents, removed material, cut outs, or other portions of reduced surface area, or any combinations thereof. For example, mountingmember360 includesnotches362 and cross-hatches or removedmaterial364. These reduced surface area portions may have any appropriate profile or cross-sectional shape, examples of which may be circular, curved, triangular, irregularly-shaped or any other appropriate option. The reduced surface area portions may help enhance the flexibility or bendability of the member.
• FIG. 24 shows a mountingmember370 having one or moreporous areas372 that are spaced out on themember370. In certain embodiments, the mountingmember370 may be bent or otherwise configured as desired, without being limited by the porous areas, as discussed above in connection withFIGS. 14-19. For example, mountingmember370 may be bent aboutregion374 or376 without introducing bending stresses to theporous areas372 or substantially limiting the bending stresses onporous areas372. Mountingmember370 may have any of the above-discussed reduced surface area portions, or mountingmember370 may be provided as a typical, traditional mounting member.
• In the embodiments shown inFIGS. 25-28, one or more mounting members and/or augments may be integrally provided with orthopedic mesh to define one or more mesh mounts or void fillers.FIG. 25 shows a mountingmember380 having anorthopedic mesh382. InFIG. 26, theorthopedic mesh portion382 may be placed on anouter portion384 of theshell386 between bone, and a cement mantle can fill between themesh382. The cement mantle rigidly connects the mounting member380 (or, in some embodiments, an augment) to theshell386 via thesurgical mesh382. Rapid manufacturing techniques may be used to simultaneously create the mounting members or augments integrally with the orthopedic mesh portion. Themesh382 may be honeycomb, diamond, or other weave pattern, or any combination thereof, and may come in multiple thicknesses.Mesh portion382 may be oversized, customized for an individual patient, and/or standardized and trimmed by the surgeon to fit a particular patient's needs. Fasteners of all types may be inserted through one or more cells of themesh382, as well as through the one or more mounting members or augments to further secure the implant to bony anatomy. For example, as shown inFIG. 25, afirst screw388 may be inserted through cell390, and asecond screw394 may be inserted through one of the plurality of screw holes392 of mountingmember380. Screw holes392 may include conventional holes, locking holes, or slots. The holes may be threaded, unthreaded, or partially threaded, and may be fixed or polyaxial. In some embodiments, screw holes392 may include variable low-profile holes that allow for locking at a variety of angles. Soft tissues may be reattached using the porosities of themesh382 as suture anchors, or simply as a bioscaffold. If desired, preformed trim lines may be provided by forming predetermined frangible portions in various areas of the mesh, in order to help configuration of the device for a particular patient. For example, as shown inFIG. 27,mesh400 includes a plurality oftrim lines402 that may be cut to separate the mounting members attached thereto, such as mountingmembers404. The separated mountingmembers404 and themesh400 may then be placed into a patient'ship region406 as shown inFIG. 28.
• FIGS. 29 and 30 illustrate some embodiments of a honeycomb design that may be provided on a mounting member or augment in order to control cement mantle thickness and spacing between said mounting member or augment and an adjacent acetabular shell, augment, bone, or other implant. For example, mountingmember410 ofFIG. 29 includeshoneycomb portion412 provided on anattachment surface portion414 of the mountingmember410. Thehoneycomb feature412 may be provided as any desired geometric shape. The mounting member410 (or, in some embodiments, the augment) may comprise one or more securingholes416 for receiving asurgical fastener418 such as a polyaxial screw, cancellous screw, peg, or other securing device. The securing holes416 may include conventional holes, locking holes, or slots. The holes may be threaded, unthreaded, or partially threaded, and may be fixed or polyaxial. In some embodiments, securingholes416 may include variable low-profile holes that allow for locking at a variety of angles. Theattachment portion414 of the mountingmember410 may extend generally perpendicularly from anotherportion415 of the mountingmember410, and may comprise one or more concavecurved surfaces417 configured to abut anouter portion422 of anacetabular shell420, or one or more convex surfaces (not shown) configured to abut an inner portion of a prepared acetabulum.
• In the embodiments shown inFIGS. 31-34, cleats may be provided proximate to a rim of an acetabular shell, cage, mounting member, or augment. For example, in some embodiments, one ormore cleats780 and781 may extend or project from a superior aspect of arim portion782 of anacetabular shell784 as shown.Cleats780 and781 may be used to secure soft tissues to theacetabular shell784 or may serve as a means to attach secondary augments or any type of mountingmember786 to theacetabular shell784. In the particular instance shown inFIGS. 33 and 34, a “quarter-turn” fastener connector arrangement is utilized. The quarter-turn fastener arrangement may comprise, for instance, a generally T-shapedmale member790 located on one or more regions of an acetabular shell, cage, or augment, and one or more complementaryfemale members792 located on more secondary augments or mounting members. The one or more secondary augments or mounting members engage the one or moremale members790 on the acetabular shell, cage, or augment in one degree of rotation, and then are rotated by a specified or variable number of degrees (e.g., 90 degrees) to lock the one or more secondary augments or mounting members to the one or moremale members790. Of course, one of ordinary skill in the art would appreciate that the male and female members could be reversed to provide the same function. It should also be understood that other locking mechanisms may be used.
• FIG. 35 further depicts one ormore cleat portions794 located at various portions of an acetabular shell or cage796 (or, in some embodiments, an augment) configured for securing soft tissues. The one ormore cleat portions794 can be arranged in any particular fashion around theacetabular shell796; however, it is preferred that thecleats794 extend proximally from a rim portion or otherwise away from theacetabular shell796 in order to provide clearance from liner-mating surfaces, cement mantle surfaces, bone contacting surfaces, and bony anatomy, for example.Cleat portions794 may comprise suturing holes, roughened surfaces, clamps, hooks, or biologic coatings, or any other appropriate protrusions, or combinations thereof, to encourage fixation of the soft tissues to the implant (e.g., acetabular shell796). For example, as shown in the inset ofFIG. 55, sutures may be wrapped aroundcleat portion794 and then secured to surrounding soft tissues.
• FIGS. 36-40 illustrate embodiments wherein a mountingmember802 or an augment804 may be attached peripherally to an acetabular shell orcage806 via arecess800 provided proximate arim portion808 of the acetabular shell orcage806. Therecess800 is sized to accept a protrudinginsertion portion810 of the mountingmember802 or a protrudinginsertion portion812 of the augment804, and therecess800 may extend annularly circumferentially around therim portion808 to allow orbital placement of the mountingmember802 or augment804 around a periphery of the shell orcage806. The mountingmember802 or augment804 may be inserted into the acetabular shell orcage806 before or after shell/cage impaction or cementing into a prepared acetabulum. One or more screw holes in the mounting member (e.g., screw holes814) or augment (e.g., screw holes816) rigidly secure the mountingmember802 or augment804 to the bone and prevent orbital movement of the mountingmember802 or augment804 around the shell orcage806. Screw holes814 and816 may include conventional holes, locking holes, or slots. The holes may be threaded, unthreaded, or partially threaded, and may be fixed or polyaxial. In some embodiments, screw holes814 and816 may include variable low-profile holes that allow for locking at a variety of angles. Once the mountingmember802 or augment804 is positioned, the cantilever force pushes therim808 of the shell orcage806 toward bone. The protruding insertion portion of the mounting member (e.g., portion810) or augment (e.g., portion812) provides a hold-down force to the shell orcage806 after a screw is inserted through the mountingmember802 or augment804 and into surrounding pelvic bone.
• FIGS. 36 and 37 show an augment804 being positioned with respect to an acetabular shell orcage806.FIGS. 38 and 39 illustrate a mountingmember802 being positioned with respect to an acetabular shell orcage806. The mountingmember802 is shown as having multiple securingholes814 for use with fasteners. Securingholes814 may be smooth, tapered, or threaded and may be used with any appropriate fastener, including but not limited to polyaxial screws. The securing holes814 through the mounting member802 (or securingholes816 through the augment804) may be positioned at any appropriate angle, as shown, such as parallel to the member, oblique through the member, or otherwise as desired. While not shown, a honeycomb feature may be placed on outer portions of the mountingmember802 or augment804 to provide spacing for a cement mantle between the mountingmember802 or augment804 and surrounding bone. Moreover, porous structures, textured surfaces, biologic coatings, or orthopedic meshes may be integrally provided on, or incorporated between outer surfaces of the mountingmembers802 or augments804 and surrounding bone.
• In the embodiments ofFIGS. 38 and 39, arecess800 in the shell orcage806 is defined by a proximally-extendinglip818 such that the mountingmember802 will sit on bone surrounding the acetabulum. In this way, the mountingmembers802 will not interfere with the press-fit area between theshell806 and prepared acetabulum adjacent theacetabular rim808. Moreover, because the connection is configured to allow mountingmembers802 to sit on surrounding bone, the surrounding bone does not need to be countersunk or otherwise prepared to receive mountingmembers802.
• FIG. 40 depicts an acetabular shell orcage820 comprising anannular protrusion822 along arim portion824 of theacetabular shell820. Theannular protrusion822 may extend partially around (as shown) or entirely around the circumference of theacetabular shell820, or one or more protrusions may be provided in any fashion around theacetabular shell820. Theannular protrusion822 may comprise anannular lip826 defining an annular undercutgroove828 running circumferentially around theacetabular shell820 proximate therim portion824. Theannular protrusion822 may comprise one ormore openings830 for receiving sutures (e.g., for soft tissue or capsule re-attachment) orfasteners832 such as set screws for contacting and frictionally engaging surfaces (e.g., divots) provided on protrudinginsertion portions834 and836 of mountingmembers840 or augments838 alike.
• Fasteners832 may be inserted intoopenings830 located circumferentially laterally of theinsertion portions834 and836 to serve as stops for preventing or limiting rotational movement of the attached mountingmembers840 or augments838. The mountingmembers840 or augments838 may be secured down to surrounding bone after being inserted into the annular undercutgroove828 via long bone screws, thereby providing a hold-down force to the acetabular shell orcage820. 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,shell820 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 (27)

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 ofclaim 1, wherein the plurality of attachment sites include portions of a crossbar extending about an acetabular shell.

3. The device ofclaim 1, wherein the plurality of attachment sites include portions of a groove extending along a rim of the implant.

4. The device ofclaim 1, wherein the mounting member is a flange.

5. The device ofclaim 4, wherein the flange is adjustably positionable about the circumference of an acetabular implant.

6. The device ofclaim 5, wherein the flange includes a split eyelet that joins a rail or groove on the implant.

7. The device ofclaim 5, wherein the flange includes a hook that joins a rail or groove on the implant.

8. The device ofclaim 5, wherein the flange includes a key that removably inserts within a complementary rim on an acetabular shell.

9. The device ofclaim 4, wherein the flange pivots in a plane that is perpendicular to the circumference of an acetabular shell.

10. The device ofclaim 4, wherein the flange is a flexible strap.

11. The device ofclaim 4, wherein the flange includes a frangible portion that allows the flange to bend or break.

12. The device ofclaim 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 ofclaim 1, wherein the implant is an augment that mounts to a surgical shell or cage.

14. The device ofclaim 1, wherein the implant fits within one of a shoulder, hip, or ankle joint.

15. The device ofclaim 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 ofclaim 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 ofclaim 17, further comprising the step of applying a porous surface to a portion of the first mounting member.

19. The method ofclaim 17, the inserting step comprising the step of mounting an acetabular shell or cage within the patient's acetabulum.

20. The method ofclaim 17, wherein the implant is an acetabular augment.

21. The method ofclaim 20, wherein the inserting step comprises the step of mounting the acetabular augment to an acetabular shell.

22. The method ofclaim 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 ofclaim 17, wherein the selected site is chosen from a plurality of attachment sites that are angularly spaced about the implant.

24. The method ofclaim 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 ofclaim 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 ofclaim 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 ofclaim 26, wherein the mounting member comprises a flange, hook, or plate.

Images