Patent Application
20210059837
The present disclosure relates generally to customized patient-specific orthopaedic surgical instruments and, more particularly, to customized patient-specific acetabular orthopaedic surgical instruments.
Joint arthroplasty is a well-known surgical procedure by which a diseased and/or damaged natural joint is replaced by a prosthetic joint. For example, in a hip arthroplasty surgical procedure, a prosthetic hip replaces a patient's natural hip. A typical prosthetic hip includes an acetabular orthopaedic prosthesis and/or femoral head orthopaedic prosthesis. A typical acetabular orthopaedic prosthesis includes an acetabular cup, which is secured to the patient's natural acetabulum, and an associated polymer bearing or ring.
To facilitate the replacement of the natural joint with an acetabular orthopaedic prosthesis, orthopaedic surgeons may use a variety of orthopaedic surgical instruments such as, for example, reamers, guide members, drills, and/or other surgical instruments. Typically, such orthopaedic surgical instruments are generic with respect to the patient such that the same orthopaedic surgical instrument may be used on a number of different patients during similar orthopaedic surgical procedures.
According to one aspect, a customized patient-specific orthopaedic instrument for facilitating implantation of an acetabular cup prosthesis in a coxal bone of a patient may include a customized patient-specific acetabular guide assembly. The customized patient-specific acetabular guide assembly may include a guide member having a longitudinal passageway defined therethrough. The customized patient-specific acetabular reaming guide may also include a plurality of arms extending from the guide member. Additionally, the customized patient-specific acetabular guide assembly may include a plurality of mounting pads configured to contact a coxal bone of a patient. Each mounting pad of the plurality of mounting pads may be coupled to a corresponding arm of the plurality of arms. Additionally, each mounting pad of the plurality of mounting pads may be positioned relative to the guide member based on a predetermined degree of version and inclination angles of the acetabular cup prosthesis when implanted in the patient's coxal bone and on the contour of the coxal bone of the patient. Each mounting pad can be patient-specific so as to fit over a unique portion of the patient's coxal bone, and can be fabricated using any suitable additive manufacturing technique.
In some embodiments, each mounting pad of the plurality of mounting pads may include a bottom, bone-facing surface having a customized patient-specific positive contour configured to receive a portion of the patient's coxal bone having a corresponding negative contour. Additionally, in some embodiments, the longitudinal passageway of the guide member may be sized to receive a tool shaft that can be selectively coupled to a reamer and an impactor. Alternatively, the longitudinal passageway of the guide member can receive a bone guide pin.
In some embodiments, the guide member may include a bottom, bone-facing surface and each mounting pad of the plurality of mounting pads may include a top surface. The bottom, bone-facing surface of the guide member may be coplanar or non-coplanar with respect to a plane defined by the top surface of least one of the plurality of mounting pads. In some embodiments, the plurality of mounting pads includes a first mounting pad having a first top surface defining a first plane and a second mounting pad having a second top surface defining a second plane. In such embodiments, the bottom, bone-facing surface of the guide member, the first top surface, and the second top surface may be parallel and non-coplanar with respect to each other. Additionally, in some embodiments, each mounting pad of the plurality of mounting pads may include a bottom surface. The bottom, bone-facing surface of the guide member may be positioned medially with respect to the bottom surface of each mounting pad of the plurality of mounting pads when the customized patient-specific acetabular reaming guide is positioned in contact with the patient's coxal bone.
Additionally, in some embodiments, each mounting pad of the plurality of mounting pads may have a longitudinal length substantially different from each other. The guide member may also include a sidewall and each arm of the plurality of arms may include a bottom surface. Each bottom surface of the plurality of arms may define an angle with respect to the sidewall of the guide member that is different in magnitude with respect to the angle defined by each other bottom surface of the plurality of arms. Additionally, in some embodiments, an angle may be defined between each arm of the plurality of arms with respect to another adjacent arm of the plurality of arms when viewed in the top plan view. Each of such angles may be different in magnitude from each other. Additionally, each mounting pad of the plurality of mounting pads may be spaced apart from the guide member, when viewed in the top plan view, a distance different in magnitude with respect to the distance defined by each other mounting pad of the plurality of mounting pads.
In some embodiments, each arm of the plurality of arms may be coupled to the guide member via a joint such that each arm is movable relative to the guide member. Additionally or alternatively, each mounting pad of the plurality of mounting pads may be coupled to the corresponding arm via a joint such that each mounting pad is movable relative to the corresponding arm. In some embodiments, the plurality of arms may comprise at least three arms extending from the guide member. Additionally, in some embodiments, each mounting pad of the plurality of mounting pads may include a longitudinal passageway defined therein, each of the longitudinal passageways of the plurality of mounting pads being sized to receive a bone guide pin.
According to another aspect, a customized patient-specific orthopaedic instrument for facilitating implantation of an acetabular cup prosthesis in a coxal bone of a patient may include a customized patient-specific acetabular reaming guide. The customized patient-specific acetabular guide assembly may include a guide member having a longitudinal passageway defined therethrough, a plurality of arms coupled to the guide member via corresponding joints such that each arm of the plurality of arms is separately movable with respect to the guide member and a plurality of mounting pads configured to contact a coxal bone of a patient. Each mounting pad of the plurality of mounting pads may be coupled to a corresponding arm of the plurality of arms via a corresponding joint such that each mounting pad of the plurality of mounting pads is separately movable with respect to the guide member. Additionally each mounting pad of the plurality of mounting pads may include a bottom, bone-facing surface having a customized patient-specific negative contour configured to receive a portion of the patient's coxal bone having a corresponding positive contour. In some embodiments, each mounting pad of the plurality of mounting pads may include a longitudinal passageway defined therein, each of the longitudinal passageways of the plurality of mounting pads being sized to receive a bone guide pin.
According to a further aspect, a method for performing an orthopaedic bone reaming procedure on a patient's acetabulum to facilitate implantation of an acetabular cup prosthesis in a coxal bone of the patient may include positioning a customized patient-specific acetabular guide assembly on the patient's coxal bone. The customized patient-specific acetabular reaming guide may include a guide member having a longitudinal passageway defined therethrough and a plurality of mounting pads coupled to the guide member and configured to contact the coxal bone of the patient. Each mounting pad of the plurality of mounting pads may be positioned relative to the guide member based on a predetermined degree of version and inclination angles of the acetabular cup prosthesis when implanted in the patient's coxal bone.
The method may include the step of attaching a reamer to the tool shaft, and rotating a tool shaft in the passageway to ream the patient's acetabulum. The method may also include the step of removing the reamer from the tool shaft, attaching an impactor to the tool shaft, and driving the impactor against the acetabular prosthesis to secure the prosthesis to the reamed acetabulum.
In another example, the method may include drilling a pilot hole into the patient's acetabulum using the longitudinal passageway of the guide member as a drill guide. Additionally, the method may include inserting a bone guide pin into the pilot hole formed in the patient's acetabulum. The method may further include advancing a cannulated acetabular reamer over the guide pin. The method may also include reaming the patient's acetabulum with the cannulated acetabular reamer using the bone guide pin as a guide for the cannulated reamer.
According to yet a further aspect, a method for performing an orthopaedic bone reaming procedure on a patient's acetabulum to facilitate implantation of an acetabular cup prosthesis in a coxal bone of the patient may include positioning a customized patient-specific acetabular reaming guide on the patient's coxal bone. The customized patient-specific acetabular reaming guide may include a guide member having a longitudinal passageway defined therethrough and a plurality of mounting pads configured to contact the coxal bone of the patient. Each mounting pad of the plurality of mounting pads may be coupled to the guide member and may have a longitudinal passageway defined therethrough. Each mounting pad of the plurality of mounting pads may be positioned relative to the guide member based on a predetermined degree of version and inclination angles of the acetabular cup prosthesis when implanted in the patient's coxal bone.
The method may include drilling a plurality of pilot holes into the patient's coxal bone using the longitudinal passageways of the plurality of mounting pads as drill guides. The method may also include inserting a bone guide pin through each longitudinal passageway of the plurality of mounting pads and into each of the corresponding pilot holes formed in the patient's coxal bone. Additionally, the method may include securing an acetabular reamer within the longitudinal passageway of the guide member. The method may further include reaming the patient's acetabulum with the acetabular reamer using the plurality of guide pins as guides for the acetabular reamer.
In one embodiment, an acetabular guide assembly can include a generic guide member that includes a guide body and a passageway that extends through the guide body along a central axis. The acetabular guide assembly further includes at least one additively manufactured mounting pad defining a top surface and a bottom surface opposite the top surface, wherein the bottom surface has a patient-specific positive contour that matches a negative contour surface of a coxal bone proximate to an acetabulum. The acetabular guide assembly further includes a plurality of arms that are configured to extend from the guide body to the at least one mounting pad, so as to support the guide member relative to the at least one mounting pad at a predetermined position and orientation. For instance, the central axis of the guide member can have a predetermined relationship with respect to planes of anteversion and inclination. The at least one mounting pad includes a plurality of coupling members that are each configured to couple to at least one of the plurality of arms, and an entirety of the mounting pad is seamless.
In one example, the generic guide member is not patient-specific, and is designed to be used in conjunction with a plurality of mounting pads each having different patient-specific contours.
The at least one mounting pad comprises a plurality of mounting pads whose bottom surface, respectively, is contoured so to fit onto a unique portion of the coxal bone.
The coupling members can have a predetermined spatial relationship with each other such that the central axis of the guide member supported by the mounting pads has the predetermined relationship with respect to the planes of anteversion and inclination.
The upper surfaces of the mounting pads can be substantially coplanar with each other when coupled to the arms, respectively, that in turn are coupled to the guide member.
In one embodiment, the at least one mounting pad includes a plurality of mounting pads. Each of the mounting pads can be uniquely keyed to a corresponding one of the arms of the first acetabular guide assembly so as to be located at a first predetermined location and oriented in a first predetermined orientation. In one example, the mounting pads and arms define respective keyed surfaces, such that each of the mounting pads is configured to be coupled to a respective one of the arms and no other arm. The keyed surfaces allow each of mounting pads to couple to the respective one of the arms in a predetermined orientation, and prevent each of the mounting pads from coupling to the respective one of the arms in any orientation other than the predetermined orientation.
The at least one mounting pad can be configured as a single monolithic mounting pad that includes the plurality of coupling members and at least one patient-specific contour at its bottom surface.
In another embodiment, an acetabular implantation system includes the acetabular guide assembly and at least one of a reamer and an impactor that are configured to selectively couple to a tool shaft that is sized to be received in the passageway, and configured to rotate and translate in the passageway. In one example, the tool shaft has a stop member that is configured to abut the guide member so as to limit translation of the tool shaft in the passageway.
In another embodiment, first and second acetabular guide assemblies each includes a guide body that defines a longitudinal passageway, wherein the guide body of the first acetabular guide assembly is substantially identical to the guide body of the second acetabular guide assembly. The first and second acetabular guide assemblies each further includes a plurality of additively manufactured mounting pads each having respective patient-specific positive contours that match corresponding negative contoured surfaces at unique locations of a coxal bone proximate to an acetabulum. The patient-specific positive contours of the mounting pads of the first acetabular guide assembly are all different than the patient-specific positive contours of the mounting pads of the second acetabular guide assembly. The first and second acetabular guide assemblies each further includes a plurality of arms configured to extend from the guide body to the plurality of mounting pads, wherein the arms of the first acetabular guide assembly are configured to support the guide body of the first acetabular guide assembly at a first predetermined location and orientation with respect to the acetabulum of a first patient, and the arms of the second acetabular guide assembly are configured to support the guide body of the second acetabular guide assembly at a second predetermined location and orientation with respect to the acetabulum of a second patient.
Each of the mounting pads of the first acetabular guide assembly is uniquely keyed to a corresponding one of the arms of the first acetabular guide assembly so as to be located at a first predetermined location and oriented in a first predetermined orientation, each of the mounting pads of the second acetabular guide assembly is uniquely keyed to a corresponding one of the arms of the second acetabular guide assembly so as to be located at a second predetermined location and oriented in a second predetermined orientation. At least one of the second predetermined location and second predetermined orientation is different than the first predetermined location and first predetermined orientation, respectively.
The first and second acetabular guide assemblies can each further include a tool shaft configured to rotate and translate in a passageway of the guide body, the tool shaft further configured to selectively couple to a reamer and an impactor. The tool shaft includes a stop member configured to abut the guide body so as to limit translation of the tool shaft in the passageway.
In another embodiment, a method prepares an acetabulum for an implantation of an acetabular prosthesis. The method includes the step of fitting a bottom surface of at least one additively manufactured mounting pad onto a preplanned portion of a coxal bone proximate to the acetabulum, such that a guide member is supported relative to the at least one mounting pad at a predetermined location and orientation with respective to planes of anteversion and inclination. The method further includes the step of inserting a tool shaft through the passageway. The method further includes the step of rotating the tool shaft about the central axis so as to ream the acetabulum with a reamer attached to the tool shaft.
The method can further include the step of guiding the tool shaft to rotate about the central axis during the rotating step.
The method can further include the steps of removing the reamer from the tool shaft, and attaching an impactor to the tool shaft such that the impactor is translatable along the central axis so as to drive the acetabular prostheses into the acetabulum.
The method can further include the step of fitting multiple contours of at least one additively manufactured mounting pad onto respective unique predetermined locations of the coxal bone.
The method can further include the step of coupling each of the plurality of mounting pads to the respective one of a plurality of arms in a predetermined orientation while preventing each of the plurality of mounting pads from being coupled to the respective one of the plurality of arms in any orientation other than the predetermined orientation. The step of coupling each of the plurality of mounting pads to the respective one of the plurality of arms can be performed prior to the fitting step.
The detailed description particularly refers to the following figures, in which:
While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific exemplary embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. Further, the term “at least one” stated structure as used herein can refer to a single one of the stated structure and more than one of the stated structure.
Referring to
In some embodiments, the customized patient-specific acetabular orthopaedic surgical instrument may be customized to the particular patient based on the location at which the instrument is to be fit onto one or more bones of the patient. In one example, the customized patient-specific acetabular orthopaedic surgical instrument can be configured to fit onto at least a portion of the acetabulum. For example, in some embodiments, the customized patient-specific acetabular orthopaedic surgical instrument may include at least one bone-contacting or bone-facing surface having a positive contour that matches the contour of a portion of the underlying bone of the patient, which is discussed in more detail below in regard to
As such, the orthopaedic surgeon's guesswork and/or intra-operative decision-making with respect to the placement of the patient-specific acetabular orthopaedic surgical instrument are reduced. For example, the orthopaedic surgeon may not be required to locate landmarks of the patient's bone to facilitate the placement of the patient-specific acetabular orthopaedic surgical instrument, which typically requires some amount of estimation on part of the surgeon. Rather, the orthopaedic surgeon may simply locate the customized patient-specific acetabular orthopaedic surgical instrument to the patient's coxal bone in a unique location of the particular patient such that the contours of the at least one bone-contacting surface mate with the inverse contours of the patient's coxal bone. Further, the orthopaedic surgeon can couple the customized patient-specific acetabular orthopaedic surgical instrument to the patient's coxal bone in the unique location. When so coupled, the patient-specific acetabular orthopaedic surgical instrument defines a particular predetermined orientation with respect to planes of anteversion and inclination.
As shown in
In process step 14, the orthopaedic surgeon may determine any additional pre-operative constraint data. The constraint data may be based on the orthopaedic surgeon's preferences, preferences of the patient, anatomical aspects of the patient, guidelines established by the healthcare facility, or the like. For example, the constraint data may include the orthopaedic surgeon's preference for the amount of inclination and anteversion for the acetabular prosthesis, the amount of the bone to ream, the size range of the orthopaedic implant, and/or the like. In some embodiments, the orthopaedic surgeon's preferences are saved as a surgeon's profile, which may be used as a default constraint values for further surgical plans.
In process step 16, the medical images and the constraint data, if any, are transmitted or otherwise provided to an orthopaedic surgical instrument vendor or manufacturer. The medical images and the constraint data may be transmitted to the vendor via electronic means such as a network or the like. Thus, the process step 16 can also be referred to as a step of receiving the medical images and the constraint data. After the vendor has received the medical images and the constraint data, the vendor processes the images in step 18. The orthopaedic surgical instrument vendor or manufacturer process the medical images to facilitate the determination of the proper planes of inclination and anteversion, implant sizing, and fabrication of the customized patient-specific acetabular orthopaedic surgical instrument as discussed in more detail below.
In process step 20, the vendor may convert or otherwise generate three-dimensional images from the medical images. For example, in embodiments wherein the medical images are embodied as a number of two-dimensional images, the vendor may use a suitable computer algorithm to generate one or more three-dimensional images form the number of two-dimensional images. Additionally, in some embodiments, the medical images may be generated based on an established standard such as the Digital Imaging and Communications in Medicine (DICOM) standard. In such embodiments, an edge-detection, thresholding, watershed, or shape-matching algorithm may be used to convert or reconstruct images to a format acceptable in a computer aided design application or other image processing application.
In process step 22, the vendor may process the medical images, and/or the converted/reconstructed images from process step 20, to determine a number of aspects related to the bony anatomy of the patient such as the anatomical axis of the patient's bones, the mechanical axis of the patient's bone, other axes and various landmarks, bone density, and/or other aspects of the patient's bony anatomy. To do so, the vendor may use any suitable algorithm to process the images.
In process step 24, the desired inclination and anteversion planes for implantation of the acetabular orthopaedic prosthesis are determined. The planned inclination and anteversion planes may be determined based on the type, size, and position of the acetabular orthopaedic prosthesis to be used during the orthopaedic surgical procedure; the process images, such as specific landmarks identified in the images; and the constraint data supplied by the orthopaedic surgeon in process steps 14 and 16. The type and/or size of the acetabular orthopaedic prosthesis may be determined based on the patient's anatomy and the constraint data. For example, the constraint data may dictate the type, make, model, size, or other characteristic of the acetabular orthopaedic prosthesis. The selection of the acetabular orthopaedic prosthesis may also be modified based on the medical images such that an acetabular orthopaedic prosthesis that is usable with the acetabulum of the patient and that matches the constraint data or preferences of the orthopaedic surgeon is selected.
In addition to or as an alternative to the type and size of the acetabular orthopaedic prosthesis, the planned location and position of the acetabular orthopaedic prosthesis relative to the patient's bony anatomy is determined. To do so, a digital template of the acetabular orthopaedic prosthesis may be overlaid onto one or more of the processed medical images. The vendor may use any suitable algorithm to determine a recommended location and orientation of the acetabular orthopaedic prosthesis (i.e., the digital template) with respect to the patient's bone based on the processed medical images (e.g., landmarks of the patient's acetabulum defined in the images) and/or the constraint data. Additionally, any one or more other aspects of the patient's bony anatomy may be used to determine the proper positioning of the digital template.
In some embodiments, the digital template along with surgical alignment parameters may be presented to the orthopaedic surgeon for approval. The approval document may include the implant's planned inclination and anteversion planes, the orientation of the transverse acetabular ligament and labrum, and other relevant landmarks of the patient's bony anatomy.
The proper inclination and anteversion planes for the acetabular orthopaedic prosthesis may then be determined based on the determined size, location, and orientation of the acetabular orthopaedic prosthesis. In addition, other aspects of the patient's bony anatomy, as determined in process step 22, may be used to determine or adjust the planned inclination and anteversion planes. For example, the determined mechanical axis, landmarks, and/or other determined aspects of the relevant bones of the patient may be used to determine the planned inclination and anteversion planes.
In process step 26, a model of the customized patient-specific acetabular orthopaedic surgical instrument is generated. In some embodiments, the model is embodied as a three-dimensional rendering of the customized patient-specific acetabular orthopaedic surgical instrument. In other embodiments, the model may be embodied as a mock-up or fast prototype of the customized patient-specific acetabular orthopaedic surgical instrument. The patient-specific acetabular orthopaedic surgical instrument to be modeled and fabricated may be determined based on the acetabular orthopaedic surgical procedure to be performed, the constraint data, and/or the type of orthopaedic prosthesis to be implanted in the patient.
The particular shape of the customized patient-specific acetabular orthopaedic surgical instrument is determined based on the planned location and implantation angles of the acetabular orthopaedic prosthesis relative to the patient's acetabulum. The planned location of the customized patient-specific acetabular orthopaedic surgical instrument relative to the patient's acetabulum may be selected based on, in part, the planned inclination and anteversion planes of the patient's acetabulum as determined in step 24. Further, if desired, the planned location of the customized patient-specific acetabular orthopaedic surgical instrument relative to the patient's acetabulum may also be selected based on the bone density of the patient's acetabulum and surrounding bony anatomy. For example, in some embodiments, the customized patient-specific acetabular orthopaedic surgical instrument is embodied as an acetabular guide assembly. In such embodiments, the location of the acetabular guide assembly is configured to provide an acetabular reamer guide assembly that, in turn, is configured to position the acetabular orthopaedic prosthesis at the planned inclination and anteversion planes determined in process step 24. Additionally, the planned location of the orthopaedic surgical instrument may be based on the identified landmarks of the patient's acetabulum identified in process step 22. Further still, the planned location of the orthopaedic surgical instrument can be based on the bone density of the acetabulum. In this regard, it is recognized that the orthopaedic surgical instrument can be fastened to the acetabulum or surrounding bony anatomy. It can be desirable to couple the orthopaedic surgical instrument to regions of sufficient bone density.
In some embodiments, the particular shape or configuration of the customized patient-specific acetabular orthopaedic surgical instrument may be determined based on the planned location of the instrument relative to the patient's bony anatomy. That is, the customized patient-specific acetabular orthopaedic surgical instrument may include at least one bone-contacting surface having a contour that matches a corresponding inverse contour of a portion of the bony anatomy of the patient such that the orthopaedic surgical instrument may be fitted onto the bony anatomy of the patient in a unique location, which corresponds to the pre-planned location for the instrument. For instance, a three dimensional model of an orthopaedic surgical instrument can be positioned such that a portion of the instrument overlies the three-dimensional model of the underlying coxal bone at a predetermined specific location. Thus, the intersection of the surface of the underlying coxal bone and the model of the instrument can define a bone-facing or bottom surface of the instrument. Thus, the bottom surface of the instrument, when manufactured, can be contoured to fit onto the specific location of the patient's underlying coxal bone. The instrument can be configured as one or more mounting pads for an acetabular guide assembly as described below, Further, the at least one bone-contacting surface can receive a fastener that extends into the bony anatomy of the patient to temporarily couple the orthopaedic surgical instrument to the bony anatomy. When the orthopaedic surgical instrument is coupled to the patient's bony anatomy in the unique location and at a desired orientation, one or more guides (e.g., cutting or drilling guide) of the orthopaedic surgical instrument may be aligned to the inclination and anteversion planes, as discussed above.
After the model of the customized patient-specific acetabular orthopaedic surgical instrument has been generated in process step 26, the model is validated in process step 28. The model may be validated by, for example, analyzing the rendered model while coupled to the three-dimensional model of the patient's anatomy to verify the correlation of reaming guides, inclination and anteversion planes, and/or the like. Additionally, the model may be validated by transmitting or otherwise providing the model generated in step 26 to the orthopaedic surgeon for review. For example, in embodiments wherein the model is a three-dimensional rendered model, the model along with the three-dimensional images of the patient's acetabulum and area of the coxal bone proximate to the acetabulum may be transmitted to the surgeon for review. In embodiments wherein the model is a physical prototype, the model may be shipped to the orthopaedic surgeon for validation.
After the model has been validated in process step 28, the customized patient-specific acetabular orthopaedic surgical instrument is fabricated in process step 30. For instance, manufacturing instructions can be generated to fabricate the customized patient-specific acetabular orthopaedic surgical instrument at a remote location by a third party. Alternatively, the customized patient-specific acetabular orthopaedic surgical instrument can be fabricated on site. Advantageously, at least a portion up to an entirety of the customized patient-specific acetabular orthopaedic surgical instrument may be fabricated using any suitable additive manufacturing process. Additionally, the customized patient-specific acetabular orthopaedic instrument may be formed from any suitable material such as a metallic material, a plastic material, or combination thereof depending on, for example, the intended use of the instrument. The fabricated customized patient-specific acetabular orthopaedic instrument is subsequently shipped or otherwise provided to the orthopaedic surgeon. The surgeon performs the orthopaedic surgical procedure in process step 32 using the customized patient-specific acetabular orthopaedic surgical instrument. As discussed above, because the orthopaedic surgeon does not need to determine the proper location of the orthopaedic surgical instrument intra-operatively, which typically requires some amount of estimation on part of the surgeon, the guesswork and/or intra-operative decision-making on part of the orthopaedic surgeon is reduced.
It should also be appreciated that variations in the bony of anatomy of the patient may require more than one customized patient-specific acetabular orthopaedic surgical instrument to be fabricated according to the method described herein. For example, the patient may require the implantation of two acetabular orthopaedic prostheses to replace both natural hips. As such, the surgeon may follow the method 10 of
Referring now to
The illustrated acetabular guide assembly 50 includes a guide member 52, a plurality of arms 56, and a plurality of mounting pads 54. The arms 56 can extend from the guide member 52 to respective ones of the mounting pads 54. Accordingly, the arms 56 can fixedly support the guide member 52 at a predetermined position and orientation relative to the mounting pads 54. The guide member 52 includes a guide body 58 and a longitudinal passageway 60 that extends through guide body 58 from a top surface 61 of the guide body 59 to a bottom surface 62 of the guide body 59 along a central axis 63 that is oriented along a longitudinal direction L. The guide body 58 can have a substantially cylindrical shape in one example. The central axis 63 can be oriented parallel to or can be coincident with the central axis of the cylindrical guide body 58. It should be appreciated that the central axis 63 can be alternatively oriented as desired. Further, the guide body 58 can have other shapes in other embodiment or examples of the design. For instance, the guide body 58 may have a substantially rectangular, triangular, polygonal cross-section, or any suitable alternative cross-section. The cross-section can be taken along a plane that is oriented perpendicular to the longitudinal direction L.
The acetabular guide assembly 50 is configured to receive the tool shaft 53 in the longitudinal passageway 60, such that the tool shaft 53 that is movable in the longitudinal passageway 60. For instance, the tool shaft 53 can be translatable and rotatable in the longitudinal passageway 60 when the guide member 52 provides both a drill guide and an impactor guide. In other embodiments, the guide member can be configured as an impactor guide, but not as a drill guide. Thus, the longitudinal passageway 60 can permit translation of the tool shaft 53 but can prevent rotation of the tool shaft 53. In one example, the passageway 60 can have a substantially circular cross-section, or can define any suitable alternative cross-sectional shape as desired. It is recognized that the tool shaft 53 can be inserted directly into the passageway. Alternatively, the passageway 60 can retain a sleeve that, in turn, translatably and/or rotatably receives the tool shaft 53.
As used herein, the term “substantially” and derivatives thereof, and words of similar import, when used to describe a size, shape, orientation, distance, spatial relationship, or other parameter includes the stated size, shape, orientation, distance, spatial relationship, or other parameter, and can also include a range up to 10% more and up to 10% less than the stated parameter, including 5% more and 5% less, including 3% more and 3% less, including 1% more and 1% less. As illustrated in
In still other examples, the passageway 60 can be to receive a bone guide pin so as to allow the guide pin to be secured to the patient's underlying acetabulum 51. For example, the passageway 60 can have a substantially circular cross-section. In other embodiments, the guide body 58 may include a passageway 60 configured to receive a guide pin with a different cross-sectional shape.
Referring now also to
In particular, referring now to
The bottom surface 66 of each mounting pad 54 may be customized to the contour of the patient's coxal bone 71. For example, the bottom surfaces 66 of the mounting pads 54 are configured with a customized patient-specific contour 72 configured to mate with a portion of the corresponding contour of the patient's coxal bone 71 proximate to the acetabulum 51. In one example, the patient specific-contour 72 can include at least one positive contour that is configured to receive a corresponding at least one negative contour of the underlying coxal bone 71. In one example, the acetabular guide assembly 50 can include a plurality of mounting pads 54 that are each configured to be fitted onto a single coxal bone 71 that is disposed proximate to a single acetabulum. In one example, the mounting pads 54 can be positioned about the acetabulum 51 such that the bottom surfaces 66 are fitted onto the coxal bone 71 so as to mate with the coxal bone 71. Further, the bottom surfaces 66 can extend to the acetabular rim, such that they mate with a portion of the acetabular rim.
While the acetabular guide assembly 50 is illustrated as including three mounting pads 54a-54c, it should be appreciated that the acetabular guide assembly 50 can include any number of mounting pads as desired, including at least one mounting pad. The patient-specific contours 72 of the bottom surface 66 of each of the mounting pads 54 can be different than the contours of the bottom surface 66 of all others of the mounting pads 54. Each of the mounting pads 54a-54c can include a respective patient-specific contour 72a-c that are all different than each other. Thus, the patient specific contour 72a of the first mounting pad 54a is configured to mate with the coxal bone 71 at a first unique location. The patient specific contour 72b of the second mounting pad 54b is different than the patient specific contour 72a of the first mounting pad 54a, and is configured to mate with the coxal bone 71 at a second unique location different than the first unique location. The patient specific contour 72c of the third mounting pad 54c is different than the patient specific contours 72a and 72b of the first and second mounting pads 54a and 54b, respectively, and is configured to mate with the coxal bone 71 at a third unique location different than the first and second unique locations. In one example, at least a respective portion of the first, second, and third unique locations can be spaced from each other along a circumference of a circle when viewed from a top plan view. It is recognized, however, that the first, second, and third unique locations can be disposed in any alternative arrangement suitable to support the acetabular guide assembly 50 in the manner described herein.
As such, referring to
The coupling member of each of the arms 56 can be configured as an opening 69 that extends into the distal end 57. The opening 69 can be sized to receive the boss 65 of the respective mounting pad 54 so as to couple the arms 56 to the respective mounting pads 54. Thus, the arms 56 can be brought toward the mounting pads 54 until the bosses 65 are received in the openings 69, respectively, thereby coupling the arms 56 to the mounting pads 54. In one example, the arms 56 can be brought toward the mounting pads 54 along the longitudinal direction L until the bosses 65 are received in the openings 69, respectively. The arms 56 can be positionally fixed with respect to either or both of the guide member 52 and the mounting pads 54 in one example.
If the depth of the opening 69 is less than the length of the boss 65, the datum can be defined at the distal tip of the boss 65 that abuts the arm 56 in the opening 69. Alternatively, if the depth of the opening 69 is greater than the length of the boss 65, the datum can be defined at the top surface 68 of the mounting pad 54 that abuts the distal end of the arm 56. If the depth of the opening 69 is substantially equal to the length of the boss then the datum can be defined by both the distal tip of the bass 65 and the top surface 68 of the mounting pad. Thus, in all examples, each of the mounting pads 54 can define a datum. In one example, the opening 69 can extend into the distal end 57 along the longitudinal direction L. Thus, movement of the arms 56 toward the mounting pads 54 along the longitudinal direction L will cause the bosses 65 to be received in the respective openings 69, thereby coupling the arms 56 to the mounting pads 54. It should be appreciated, of course, that the arms 56 and the at least one mounting pad 54 can define any alternative coupling structure suitable to couple the arms 56 to the at least one mounting pad 54. For instance, the arms 56 can define a projection that is received by an aperture that extends into an outer surface of the at least one mounting pad 54.
Referring now to
Further, each arm 56 can be moveably coupled to either or both of the guide member 52 and the respective mounting pad 54. In particular, each arm 56 can be secured to a joint 120 of the guide member 52 and a corresponding joint 122 of the respective mounting pad 54. The joints 120 and 122 may be configured as hinges, universal joints, or the like configured to allow the openings 69 of the arms 56 to receive the bosses 65 of the mounting pads 54 when the bosses 65 are oriented angularly offset with respect to the longitudinal direction L. For instance, the openings 69 of the arms 56 can be aligned with the respective bosses 65, and then moved toward the mounting pads 54 until the bosses 65 are received in the openings 69. The joints 120 and 122 can further include a locking mechanism if desired that is capable of fixing the respective arm 56 at a desired position. For instance, the locking mechanism can fix the arm 56 at a position coupled to each of the guide member 52 and the respective mounting pad 54 while the guide member is in the predetermined position and orientation. It will be appreciated that in other embodiments not all arms 56 may be moveably secured to the guide member 52 and/or mounting pads 54. Additionally, the acetabular guide assembly 50 may include any combination of joints to position the acetabular guide assembly 50 at the planned orientation and location to establish the desired inclination and anteversion planes of the acetabular orthopaedic prosthesis.
It is further recognized that the arms 56 can be coupled to the mounting pads 54 in accordance with any suitable alternative embodiment. For instance, the mounting pads 54 can define an opening 69 that extends into the top surface 68 and is sized to receive the distal ends 57 of the respective mounting pads 54 so as to couple the arms 56 to the mounting pads 54 at the datum. The arms 56 can be coupled to respective ones of the mounting pads 54 via suitable fasteners such as screws, bolts, adhesive, or the like.
In the illustrative embodiment, each datum has a predetermined spatial relationship with respect to other datums when the mounting pads 54 are fitted onto their respective unique positions at the coxal bone 71 such that the bottom surfaces 56 mate with the coxal bone 71 in the manner described above. In one example, the datum can be substantially coplanar with each other in a plane that defines a predetermined angular relationship with the plane of inclination and the anteversion plane. In one example, the plane can be oriented substantially parallel with the anteversion plane. Alternatively, the plane can define a predetermined angle with respect to the anteversion plane. The arms 56 can all have substantially the same length from the guide member 52 to the mounting pads 54. The guide member 52 can be configured such that the central axis 63 of the passageway 60 is oriented to the plane defined by the datum when the arms 56 extend out from the guide member 52 and are coupled to the mounting pads 54.
As described above, the mounting pads 54 are configured to be fitted onto different unique locations of the underlying coxal bone 71. Further, it is recognized that the unique locations of the underlying coxal bone 71 may be non-planar with each other. Accordingly, one or more of the mounting pads 54 can define different thicknesses along the longitudinal direction L from the top surface 68 to the bottom surface 66 with respect to one or more others of the mounting pads, such that the bosses 65 that extend out from the top surface 68 can be substantially coplanar with each other in the manner described above.
Accordingly, the arms 56 and guide members 52 do not need to be customized, but rather can be used in combination with multiple kits of mounting pads 54. For instance, the guide member 52 and arms 56 can be pre-fabricated such that the central axis 63 of the passageway 60 is oriented normal to a plane along which the arms 56 are configured to attach to the mounting pads 54. Thus, if it is desired to orient the central axis 63 of the passageway 60 perpendicular to the anteversion plane, the same guide member 52 and arms 56 can be coupled to respective different kits of mounting pads 54 whose datum lie substantially in the plane that is substantially parallel to the anteversion plane when fitted onto the coxal bone 71. In this example, each kit of mounting pads 54 includes at least one mounting pad 54 configured to couple to the arms 56 so as to support a guide member 52 at a desired position and orientation as described herein. The at least one bottom surface of the at least one mounting pad 54 of each kit of mounting pads 54 can be individually and uniquely contoured as described above, but can also define datum that have the same relative positions and orientations. Alternatively, as described below, the arms 56 can be movable with respect to the guide member 52 so as to attach to the datum of respective kits of mounting pads 54 whose datum are disposed at different relative positions and orientations. As a result, the acetabular guide assembly 50 can be customized by customizing only the mounting pads 54. The guide member 52 and the arms 56 can be sterilized and reused as desired.
As a result, referring again to
It is therefore recognized that a plurality of different sets of mounting pads 54 can be produced. Each set of mounting pads 54 can be included in a different acetabular guide assembly 50 of the plurality of acetabular guide assemblies 50. The contours 72 of the mounting pads 54 of the respective sets of mounting pads 54 are configured to match, or be fitted to, respective contours of different coxal bones at unique locations of the coxal bones. The different coxal bones are defined by different patients. Further, each set of mounting pads 54 is configured to support substantially identical generic guide members 52 at a desired orientation with respect to the angles of inclination and anteversion of the respective patient. Thus, a plurality of acetabular guide assemblies 50 can be constructed using substantially identical guide members 52, different mounting pads 54, and either substantially identical arms 56 or different arms 56 to support the guide members 52 at a patient-specific orientation with respect to the angles of inclination and anteversion.
In one example, the sets of mounting pads 54 can be produced non-contemporaneously. That is, the sets of mounting pads 54 can be produced on a patient-by-patient basis at different times. For instance, the sets of mounting pads 54 can be produced days, weeks, months or even years apart. Further, the sets of mounting pads 54 can be packaged and delivered separately to different healthcare providers. Therefore, it is recognized that sets of mounting pads 54 can be produced that are not provided in a single kit. In other examples, it is recognized that sets of mounting pads 54 described herein can be provided in a kit, such that a healthcare provider can have an inventory of the mounting pads 54 with different contours 72.
In this regard, first and second acetabular guide assemblies 50 can each include a guide body 52 that defines the longitudinal passageway 60. The guide body 52 of the first acetabular guide assembly 50 is substantially identical to the guide body 52 of the second acetabular guide assembly 50. Each of the first and second acetabular guide assemblies 50 further include a plurality of additively manufactured mounting pads 54 each having respective patient-specific positive contours 72 that match corresponding negative contoured surfaces at unique locations of a coxal bone proximate to an acetabulum. The patient-specific positive contours 72 of the mounting pads 54 of the first acetabular guide assembly 50 are all different than the patient-specific positive contours 72 of the mounting pads 54 of the second acetabular guide assembly 50. Each of the first and second acetabular guide assemblies 50 includes a plurality of arms 56 configured to extend from the guide body 52 to the plurality of mounting pads 54, wherein the arms 56 of the first acetabular guide assembly 50 are configured to support the guide body 52 of the first acetabular guide assembly 50 at a first predetermined location and orientation with respect to the acetabulum of a first patient. The arms 56 of the second acetabular guide assembly 50 are configured to support the guide body 52 of the second acetabular guide assembly 50 at a second predetermined location and orientation with respect to the acetabulum of a second patient.
Further, as described below with reference to
Further still, each of the first and second acetabular guide assemblies can include a tool shaft 53 configured to rotate and translate in the passageway 60 of the guide body 52. The tool shaft 53 is configured to selectively couple to a reamer and an impactor. As described in more detail below, the tool shaft can include a stop member 81 (see
With continuing reference to
Each of the mounting pads 54 has a length, which may be determined based on the surface contour of the patient's bony anatomy such that the acetabular guide assembly 50 is positioned at the desired predetermined angles of inclination and anteversion. The length of each of the mounting pads 54 can be defined by a longest dimension of the mounting pad 54 that extends along the underlying coxal bone 71. In one example, the length of each mounting pad 54 can be substantially equal to one another. In other embodiments, the length of at least one of the mounting pads 54 can be different than the length of at least one other one of the mounting pads 54 depending, for instance, on the contours of the unique locations of the underlying bone. The unique locations can be selected to ensure that the mounting pads and arms 56 define a stable construct for the guide member 52. Further, the locations can be selected based on the porosity of the underlying bone. As the mounting pads 54 can further be coupled to the underlying bone, it may be desirable for the bone to be healthy bone. In this regard, of the mounting pads 54 can have any size and shape suitable to fit over the respective unique locations of the underlying coxal bone 71, define a stable base for the arms 56 and the guide member 52, and to receive the fasteners 77 that are driven into the underlying coxal bone 71.
Referring now to
It is recognized that the acetabular guide assembly 50 can include any number of mounting pads 54 and arms 56 as desired. Further, each mounting pad 54 can include a single datum. Therefore, the acetabular guide assembly 50 can include an equal number of arms 56 and mounting pads 54. Alternatively, one or more of the mounting pads 54 can include multiple datum. Therefore, the acetabular guide assembly 50 can include more arms 56 than mounting pads 54. Accordingly, while the acetabular guide assembly 50 is shown as including three mounting pads 54 and three arms 54, the number of arms and mounting pads can vary as desired.
Further, the mounting pads 54 can define equal mounting padprints along the underlying coxal bone 71. Alternatively, at least one or more of the mounting pads 54 can define a mounting padprint along the underlying coxal bone 71 that is different than that of at least one or more others of the mounting pads 54. For instance, at least one of the mounting pads 54 can be fitted onto a respective unique location of the coxal bone 71 that has both a healthy portion and an osteoporotic portion. The datum can overlie the osteoporotic portion, for instance when it is desirable for the datum to be equidistantly spaced from each other, and the at least one fastener 77 can be driven into the healthy portion.
Alternatively, referring now to
In some embodiments, as illustrated in
As further illustrated in
As discussed above, the arms 56 are configured to couple the mounting pads 54 to the guide member 52. In the illustrative embodiment, the arms 56 are embodied as rectangular shafts, but may have other shapes and configurations in other embodiments. For example, the arms 56 may be straight, curved or bowed, angled, or the like in other embodiments. When viewed from the side elevation perspective of
It should be appreciated that the acetabular guide assembly 50 can be adjustable by the orthopaedic surgeon to improve the coupling of the guide assembly 50 to the patient's underlying coxal bone 71. For example, when viewed from the side elevation perspective of
When viewed from the top plan of
Referring now to
The datum of the single mounting pad 54 can be equidistantly spaced about the mounting pad 54 or can be variably spaced from each other as described above. Further, the single mounting pad 54 can include any number of fixation apertures 67 as desired, including at least one that are predetermined at step 26 of
It is recognized that the mounting pads 54 can advantageously be fabricated at step 32 of
Accordingly, the mounting pads 54 can be fabricated on-demand at step 30 of
In one example, the arms 56, mounting pads 54, and guide member 52 can be each formed from separate pieces. For example, the arms 56 may be secured to the guide member 52 via suitable fasteners such as screws, bolts, adhesive, or the like. Alternatively, the arms 56 can be monolithic with the guide member 52. Alternatively, the guide member 52 and arms 56 can be formed as a monolithic component. Further, the mounting pads 54 and arms 56 can be formed as a monolithic component. Thus, the guide member 52, mounting pads 54, and arms 56 of the acetabular guide assembly 50 can all be formed as a single monolithic component. The guide member 52, mounting pads 54, and arms 56 can be formed from any suitable material such as a resilient plastic or metallic material. In one particular embodiment, the acetabular guide assembly 50 can be made from an implant-grade metallic material such as titanium or cobalt chromium.
Referring to
Further, the arms 56 can extend from the guide member 52 and be coupled to the at least one mounting pad 54 prior to fitting the at least one mounting pad 54 onto the underlying coxal bone 71. In some examples, each mounting pad 54 may be uniquely keyed to a corresponding arm 56 such that each mounting pad is configured to be coupled to only one of the arms and no others of the arms. For instance, as illustrated in
Further, the keyed surfaces 89 and 91 can be configured such that the mounting pads 54 are coupled to the respective arms 56 in respective predetermined orientations such that the customized patient-specific contour 72 of each of the mounting pads 54 mates with the contour of the predetermined underlying portion of the corresponding the patient's coxal bone 71 (see
It is recognized that the openings 69 of the arms 56 be oriented along a direction such that the coupling structure of the arm 56 can be aligned to be coupled with the corresponding coupling structure of the mounting pads 54 without moving the arms 56 relative to the guide member 52. For instance, the arms 56 can be fixed relative to the guide member 52 in some examples. In other examples, the arms 56 can be movable with respect to each of the guide member 52 and the mounting pads 54 so as to align the respective coupling members of the arms 56 to the respective mounting pads 54.
When each mounting pad 54 is fitted over the underlying coxal bone 71 and the arms are coupled to the respective at least one mounting pad and to the guide member 52, the guide member is then supported by each mounting pad at a desired position and orientation with respect to the underlying coxal bone 71. After each mounting pad 54 has been fitted onto the underlying coxal bone 71, the fasteners 77 can be driven through the fixation apertures 67 and into the underlying coxal bone 71, thereby attaching the fixation apertures 67 to the underlying coxal bone 71. Additionally, in some embodiments, the surgeon may adjust the position of the acetabular guide assembly 50 pre-operatively or intraoperatively. For example, in those embodiments wherein each arm 56 is moveably secured to the guide member 52 and each mounting pad 54, the surgeon may adjust the position of the acetabular guide assembly 50 to adjust the orientation of the central axis 63 of the passageway 60. Once positioned, the acetabular guide assembly 50 defines the desired predetermined inclination and anteversion angles relative to the patient's acetabulum 51 intended for the acetabular orthopaedic prosthesis.
Referring now also to
The surgeon can then begin reaming the patient's acetabulum 51 by rotating the tool shaft 53 in process step 106. It should be appreciated that because the guide member 52 is supported by each one mounting pad at a predetermined location and orientation, the longitudinal passageway 60 is similarly disposed in a predetermined location and orientation based on the desired anteversion and inclination angle of the acetabular prosthesis. Thus, the reaming of the patient's acetabulum 51 is guided by the longitudinal passageway 60 so as to size the patient's acetabulum 51 to receive the acetabular prosthesis according to the desired predetermined anteversion and inclination angles.
The acetabular guide assembly 50 can further include a stop member 81 that is supported by the tool shaft 53. The stop member 81 can be configured to contact the guide body 58 as the tool shaft is driven distally toward the underlying acetabulum 51, thereby preventing further distal movement of the tool shaft 53 toward the underlying acetabulum 51. For instance, the stop member 81 can be configured to contact the top surface 61 of the guide body 58 to prevent further distal movement of the tool shaft 53 toward the underlying acetabulum 51. Thus, the reamer 126 can be driven into the acetabulum a predetermined distance until the stop member 81 contacts the guide body 58. It is recognized that it can be desired to ream different patients at different depths depending on the patient's anatomy. Thus, the stop member 81 can be disposed at an adjustable position along the length of the tool shaft 53. For instance, a set screw 83 can extend into the stop member 81 and can be tightened against the tool shaft 53 so as to positionally fix the stop member 81 with respect to the tool shaft 53. The set screw 83 can be loosened to allow for the stop member 81 to translate along the tool shaft 53 to a desired stop location. The set screw 83 can be tightened against the tool shaft 53 to fix the stop member 81 at the desired stop location. The tool shaft 53 can include a plurality of markings 79 that can indicate spatial relationships with respect to the distal end of the tool shaft 53. Accordingly, when the reamer 126 is attached to the distal end of the tool shaft 53, the markings can indicate a distance to the reamer 126. Therefore, during operation, the stop member 81 can be adjusted to a position along the tool shaft 53 to determine the depth that the reamer 126 will ream into the underlying acetabulum 51.
As illustrated in
As described above with respect to
The surgeon can impact the impactor 148 (e.g., via use of a surgical hammer) to cause the acetabular prosthesis 140 to seat into the patient's surgically-prepared acetabulum 51. Of course, in other embodiments, other devices and tools may be used to implant the acetabular prosthesis 140 as will be described in more detail below. Once the acetabular prosthesis 140 is implanted, the acetabular guide assembly 50 can be removed from the coxal bone 71. In particular, tool shaft 53 is detached from the acetabular prosthesis 140. Further, the fasteners 77 are removed from the coxal bone 71 and the at least one mounting pad 54. Next, the at least one mounting pad 54 is removed from the coxal bone 71. If desired, the guide member 52 can be removed from the arms 56 prior to removing the at least one mounting pad 54 from the coxal bone 71. Alternatively or additionally, the arms 56 can be removed from the at least one mounting pad 54 prior to removing the at least one mounting pad 54 from the coxal bone 71.
Referring now to
It is recognized that the openings 69 of the arms 56 be oriented along a direction such that the coupling structure of the arm 56 can be aligned to be coupled with the corresponding coupling structure of the at least one mounting pad 54 without moving the arms 56 relative to the guide member 52. For instance, the arms 56 can be fixed relative to the guide member 52 in some examples. In other examples, the arms 56 can be movable with respect to each of the guide member 52 and the at least one mounting pad 54 so as to align the respective coupling members of the arms 56 to the respective at least one mounting pad 54.
When the at least one mounting pad 54 is fitted over the underlying coxal bone 71 and the arms are coupled to the at least one mounting pad and to the guide member 52, the guide member is then supported by the at least one mounting pad at a desired position and orientation with respect to the underlying coxal bone 71. After the at least one mounting pad 54 has been fitted onto the underlying coxal bone 71, the fasteners 77 can be driven through the fixation apertures 67 and into the underlying coxal bone 71, thereby attaching the fixation apertures 67 to the underlying coxal bone 71. Additionally, in some embodiments, the surgeon may adjust the position of the acetabular guide assembly 50 pre-operatively or interoperatively. For example, in those embodiments wherein each arm 56 is moveably secured to the guide member 52 and each mounting pad 54, the surgeon may adjust the position of the acetabular guide assembly 50 to adjust the orientation of the central axis 63 of the passageway 60. Once positioned, the acetabular guide assembly 50 defines the desired predetermined inclination and anteversion angles relative to the patient's acetabulum 51 intended for the acetabular orthopaedic prosthesis.
In process step 204, the surgeon inserts a drill bit of an orthopaedic drill through the passageway 60 of the guide member 52 of the acetabular guide assembly 50. The surgeon drills a pilot hole in the patient's acetabulum 51 using the guide member 52. It should be appreciated that the pilot hole is oriented to position the acetabular orthopaedic prosthesis at the desired inclination and anteversion angles. Thereafter, the surgeon may remove the drill bit from the passageway 60.
In process step 206, the surgeon inserts a guide pin 130 (see
In process step 208, the surgeon advances a cannulated reamer (see
In some embodiments, the guide pin 130 may also be used as a guide during the implantation of an acetabular prosthesis. That is, as illustrated in
The acetabular prosthesis 140 may be implanted via use of an impactor or inserter 148. In the illustrative embodiment, the impactor 148 is substantially cylindrical in shape and has an outer diameter substantially equal to the outer diameter of the acetabular prosthesis 140. The impactor 148 is includes a centrally-positioned passageway 149, which is sized to receive the end of the guide pin 130 such that the impactor 148 may be positioned over the acetabular prosthesis 140. When so positioned, the impactor 148 contacts the rim of the acetabular prosthesis 140. The surgeon may then impact the impactor 148 (e.g., via use of a surgical hammer) to cause the acetabular prosthesis 140 to seed into the patient's surgically-prepared acetabulum 51. Of course, in other embodiments, other devices and tools may be used to implant the acetabular prosthesis 140 using the guide pin 130 as a guide. For example, in some embodiment, the impactor may be embodied as, or otherwise include, a stem configured to be received in the aperture 146. In such embodiments, the stem and aperture 146 are threaded. In addition, the stem is cannulated and configured to receive the guide pin 130 therein. In should be appreciated that in such embodiments, the aperture 146 has a greater diameter than the guide pin 130 to allow the stem of the impactor to be received therein. Regardless, once the acetabular prosthesis 140 is implanted, the guide pin 130 may be removed. It should be appreciated that because the acetabular prosthesis 140 is implanted using the guide pin 130 as a guide, the acetabular prosthesis 140 is implanted at the predetermined location and orientation (e.g., at the predetermined inclination and anteversion angles).
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
There are a plurality of advantages of the present disclosure arising from the various features of the method, apparatus, and system described herein. It will be noted that alternative embodiments of the method, apparatus, and system of the present disclosure may not include all of the features described yet still benefit from at least some of the advantages of such features. Those of ordinary skill in the art may readily devise their own implementations of the method, apparatus, and system that incorporate one or more of the features of the present invention and fall within the spirit and scope of the present disclosure as defined by the appended claims.
