FEMORAL HIP STEM IMPLANT AND CORRESPONDING ORTHOPEDIC BROACH
20240341977 ยท 2024-10-17
Assignee
- Smith & Nephew, Inc. (Memphis, TN, US)
- SMITH & NEPHEW ORTHOPAEDICS AG (Zug, CH)
- SMITH & NEPHEW ASIA PACIFIC PTE. LIMITED (Singapore, SG)
Inventors
- David W. Rister (Nesbit, MS, US)
- Mouhsin El-Chafei (Arlington, TN, US)
- Marc Wright (Memphis, TN, US)
- Kara McCluskey (Memphis, TN, US)
Cpc classification
A61F2002/3092
HUMAN NECESSITIES
A61F2002/3631
HUMAN NECESSITIES
A61F2/30942
HUMAN NECESSITIES
A61F2/3609
HUMAN NECESSITIES
A61F2310/00407
HUMAN NECESSITIES
A61F2002/30332
HUMAN NECESSITIES
A61F2002/30948
HUMAN NECESSITIES
International classification
Abstract
Orthopaedic implants and corresponding instrumentation are disclosed. More particularly, a femoral implant and a corresponding broach are presented for surgically repairing a hip joint. The femoral implant includes an elongated stem configured to be inserted within an intramedullary canal of a patient's femur. The femoral implant configured to maximize fit within the intramedullary canal. The orthopedic broach may include differential tooth patterns. For example, the broach may include first, second, and third separate and unique tooth patterns. In use, the various tooth patterns are located in specific locations on the broach to achieve a specific purpose to thereby optimize engagement between the patient's intramedullary canal and the femoral implant. In various embodiments, the broach is specifically matched to mimic the femoral implant, and specifically the teeth (compaction teeth) formed on the proximal region of the broach are matched to the porous coating formed on the implant.
Claims
1. A femoral hip stem kit comprising: a hip stem implant configured to be implanted within an intramedullary canal, the hip stem implant including a proximal region, a distal region, an anterior side, a posterior side, a medial side, and a lateral side, the proximal region including a porous coated surface applied thereto; and an orthopedic broach used to prepare the intramedullary canal for receipt of the hip stem implant, the broach including a proximal region, a distal region, an anterior side, a posterior side, a medial side, and a lateral side, the broach including a plurality of uniquely arranged tooth patterns formed thereon, the plurality of uniquely arranged tooth patterns including compaction teeth formed on the proximal region thereof; wherein the proximal region of the broach including the compaction teeth is sized and configured to mimic a size and configuration of the porous coated surface formed on the hip stem implant.
2. The system of claim 1, wherein the proximal region of the broach including the compaction teeth has a shape and location and the porous coated surface defining the proximal region of the hip stem implant has a shape and location, the shape and location of the proximal region of the broach including the compaction teeth having the same shape and location as the porous coated region formed on the proximal region of the hip stem implant.
3. The system of claim 1, wherein the proximal region of the hip stem implant includes a plurality of grooves formed on the anterior and posterior sides thereof, the grooves formed on the anterior side wrapping around a corner onto the medial side.
4. The system of claim 3, wherein the grooves formed on the anterior and posterior sides of the hip stem implant are angled relative to a longitudinal axis of the hip stem implant.
5. The system of claim 4, wherein the compaction teeth formed on the anterior and posterior sides of the broach are arranged and configured as annular teeth extending perpendicularly relative to a longitudinal axis of the broach so that the compaction teeth are angled relative to the grooves formed on the anterior and posterior sides of the hip stem implant.
6. The system of claim 5, wherein the compaction teeth extend horizontally from the lateral side to medial side of the broach.
7. The system of claim 1, wherein the plurality of uniquely arranged tooth patterns further include: a plurality of extraction teeth formed on the distal region of the broach arranged and configured to cut or remove the patient's bone; and a plurality of extraction teeth formed on anteromedial, anterolateral, posteromedial, and posterolateral aspects of proximal region of the broach.
8. The system of claim 7, wherein the plurality of extraction teeth formed on the distal region of the broach includes diamond or pyramid shaped teeth.
9. The system of claim 8, wherein the plurality of extraction teeth formed on the medial and lateral sides of the proximal region of the broach define interrupted cuts formed along edges of the medial and lateral sides of the broach.
10. The system of claim 1, wherein the broach includes a connection mechanism, the connection mechanism configured as cavity for receiving a male component.
11. The system of claim 1, wherein the anterior side and the posterior side of the hip stem implant are tapered towards a central longitudinal axis of the hip stem implant.
12. The system of claim 11, wherein the hip stem implant includes a dual-tapered anterior-posterior taper arrangement including a first anterior-posterior taper extending from a shoulder to a transition point and a second anterior-posterior taper extending from the transition point towards the distal tip, the second anterior-posterior taper being different than the first anterior-posterior taper.
13. The system of claim 1, wherein the medial side of the proximal region of the hip stem implant includes a constant arc of curvature configured to provide a press-fit.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] By way of example, specific embodiments of the disclosed device will now be described, with reference to the accompanying drawings, in which:
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[0064] The drawings are not necessarily to scale. The drawings are merely representations, not intended to portray specific parameters of the disclosure. The drawings are intended to depict various embodiments of the disclosure, and therefore are not to be considered as limiting in scope. In the drawings, like numbering represents like elements.
DETAILED DESCRIPTION
[0065] Various features or the like of orthopedic implants, instruments, and corresponding systems will now be described more fully hereinafter with reference to the accompanying drawings, in which one or more features of the orthopedic implants, instruments, and corresponding systems will be shown and described. In some embodiments, various features, geometries, and/or dimensions of a femoral hip stem implant, a hip stem implant, a femoral implant, an implant, etc. (terms used interchangeably herein without the intent to limit or distinguish) or a set of femoral hip stem implants will now be described more fully herein with reference to the accompanying drawings, in which one or more features, geometries, and/or dimensions of the femoral hip stem implant will be shown and described. In addition, and/or alternatively, various features or the like of orthopedic instruments such as, for example, an orthopedic broach, will now be described more fully herein with reference to the accompanying drawings, in which one or more features of the broach will be shown and described. It should be appreciated that the various features of the femoral hip stem implant and orthopedic broach may be used independently of, or in combination, with each other. It will be appreciated that a femoral hip stem implant and/or broach as disclosed herein may be embodied in many different forms and may selectively include one or more features, geometries, and/or dimensions described herein. As such, the femoral hip stem implant and/or broach should not be construed as being limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will convey certain features, geometries, and/or dimensions to those skilled in the art.
[0066] As will be described in greater detail herein, in accordance with one or more features, geometries, and/or dimensions of the present disclosure, the femoral hip stem implant is arranged and configured to be implanted within an intramedullary canal of a patient's femur adjacent to the proximal end of the femur. In use, the femoral hip stem implant includes one or more features, geometries, and/or dimensions to optimize (e.g., maximize) fit within a greater population of patients. In addition, the femoral hip stem implant includes one or more features arranged and configured to ensure improve short-term and long-term fixation within the intramedullary canal of the patient's femur.
[0067] In addition, and/or alternatively, in accordance with one or more features of the present disclosure, an orthopedic broach arranged and configured to optimize removal and/or preparation of the patient's bone to facilitate improved engagement with a subsequently implanted orthopedic implant such as, for example, the femoral hip stem implant, will be shown and described.
[0068] In some embodiments, the orthopedic broach includes a body having a differential tooth pattern. That is, in some embodiments, the broach includes different teeth patterns arranged and configured to prepare the patient's bone. For example, in some embodiments, the broach includes first, second, and third different teeth patterns. In use, as will be described in greater detail herein, the broach includes a proximal region and a distal region. In addition, the broach includes medial and lateral sides, and anterior and posterior sides. In some embodiments, the distal region includes extraction teeth such as, for example, diamond shaped teeth, arranged and configured to optimize reaming of the intramedullary canal (e.g., diamond shaped teeth arranged and configured to remove any bone that the leading distal end of the broach comes into contact with to facilitate easier insertion of the subsequent hip stem implant and to produce an envelope that minimizes or avoids press fit of the distal aspect ore region of the femoral hip stem implant within the intramedullary canal to create a preferential press fit in the proximal portion of the femoral hip stem implant in the region corresponding to the anterior-posterior grooves and porous coated region.
[0069] In addition, the anterior, posterior, medial and lateral sides of the proximal region of the broach include a second tooth pattern arranged and configured to compact and/or rake (as opposed to removing or extracting the patient's bone) the corresponding inner surface of the patient's intramedullary canal to optimize engagement with the anterior and posterior grooves formed on the hip stem implant and/or the porous coated and/or roughened surface formed on the hip stem implant. In addition, the medial and lateral sides (e.g., anteromedial, anterolateral, posteromedial and posterolateral aspects) of the broach include a third tooth pattern arranged and configured to extract any bone of the patient's intramedullary canal to promote improved clearance and/or to prevent lateralization.
[0070] In accordance with one or more features of the present disclosure, a system and/or kit is provided including one or more femoral hip stem implants and one or more orthopedic broaches wherein the orthopedic broach is matched to the femoral hip stem implant. That is, in accordance with one or more features of the present disclosure, the proximal region formed on the broach including the compaction teeth formed thereon has a shape and location (e.g., dimensions) that substantially matches or mimics the shape and location (e.g., dimension) of the porous coated and/or roughened region formed on the proximal region of the hip stem implant. Thus arranged, the proximal region of the broach mimics or matches the porous coated and/or roughened region of the hip stem implant (e.g., placement of the compaction teeth on the broach mimics or matches placement of the porous coated and/or roughened region on the hip stem implant to facilitate improved long-term stability by facilitating improved bony on-growth).
[0071] Referring to
[0072] As will be appreciated by one of ordinary skill in the art, in use, the patient's femur is initially prepared for implantation of the femoral hip implant 100 by, for example, resecting the proximal femur and broaching the intramedullary canal in the patient's femur. The femoral hip implant 100 is then inserted into the intramedullary canal of the prepared femur. In use, the elongated insertion region 120 may facilitate insertion of the femoral hip implant 100, or otherwise associating the femoral hip implant 100 with, the bony anatomy. For example, in some embodiments, the elongated insertion region 120 may be at least partially inserted into a prepared or natural intramedullary canal of the bony anatomy.
[0073] In various embodiments as described herein, the femoral hip implant 100 includes one or more features, geometries, and/or dimensions to optimize (e.g., maximize) fit within a greater population of patients. In addition, the femoral hip implant 100 includes one or more features arranged and configured to ensure improved short-term and long-term fixation with the intramedullary canal of the patient's femur. Moreover, in some embodiments, the femoral hip implant 100 may include one or more features, geometries, and/or dimensions to facilitate a direct anterior surgical approach. In use, an anterior approach is often preferred by various surgeons since it provides the most direct access to the anterior aspects of the patient's hip. In any event, in use, the femoral hip implant 100 is arranged and configured to optimize (e.g., maximize) fit within a greater population of patients regardless of the surgical approach being utilized (e.g., the implant is agnostic relative to surgical approach being used).
[0074] Referring to
[0075] In various embodiments, the resection plane Rp may be positioned a distance of between 18 mm and 23 mm away from the shoulder 130 (e.g., intersection of the resection plane Rp with the medial side or surface 150 of the implant 100 illustrated by Rp1 in
[0076] In some embodiments, the neck 112 may have an angle ? as measured between a central longitudinal axis of the elongated insertion region or stem 120 and a central longitudinal axis of the neck 112. In some embodiment, angle ? may be approximately 125 to 135 degrees. In one preferred embodiment, angle ? may be 131 degrees, although other angles are envisioned.
[0077] In use, the neck 112 may be provided in a standard configuration and a high offset configuration. In various embodiments, the neck 112, in the standard configuration, may include a neck offset No between 32 mm and 44 mm, a neck length N.sub.L between 27.9 mm and 35.5 mm, and a neck height N.sub.H between 26 mm and 33 mm. In various embodiments, the neck 112, in the high offset configuration, may include a neck offset No between 38 mm and 52 mm, a neck length N.sub.L between 31.7 mm and 40.5 mm, and a neck height N.sub.H between 26 mm and 33 mm. Although these are just a few of the available configurations and other dimensions are envisioned.
[0078] With continued reference to the FIGS., the femoral hip implant 100 also includes a medial surface or side 150, a lateral surface or side 160, an anterior surface or side 170, and a posterior surface or side 180.
[0079] With reference to
[0080] As illustrated, in some embodiments, the lateral surface or side 160 includes a proximal region 162 and a distal region 164. The lateral surface or side 160 in the proximal region 162 extending distally from a lateral end portion of the upper portion or shoulder 130 to the proximal end of the distal region 164. As illustrated, the lateral surface or side 160 may taper away from the medial surface or side 150 in the proximal region 162. Meanwhile, in the distal region 164, the lateral surface or side 160 may taper towards the medial surface or side 150. Thus arranged, the lateral surface or side 160 may define an apex or a lateral flare L.sub.F. With reference to
[0081] The medial surface or side 150 may also include a proximal region 152 and a distal region 154. In use, the proximal region 152 may generally correspond to the metaphysis and the distal region 154 may generally correspond to the diaphysis when the femoral hip implant 100 is implanted into the patient's femur's intramedullary canal.
[0082] As illustrated, the proximal region 152 of the medial surface or side 150 may include a medial arc or curvature M.sub.A. As illustrated, in various embodiments, the medial arc or curvature M.sub.A may be a constant radius of curvature, although this is not necessary. The distal region 154 of the medial surface or side 150 may taper towards the lateral surface or side 160. Thus arranged, the elongated insertion region or stem 120 of the femoral hip implant 100 may include a maximum medial-lateral size or width (ML Width) between the medial surface or side 150 and the lateral surface or side 160 at the resection plane Rp (
[0083] Referring to
[0084] As illustrated, the anterior-posterior distal region 174 may include an AP Taper. In some embodiments, in accordance with one or more features of the present disclosure and contrary to conventionally known prior art femoral hip implants, as the length of the femoral hip implant increases, the AP Taper decreases. As such, larger length femoral hip implants 100 in accordance with the present disclosure have a shallower profile. Alternatively, in some embodiments, the AP Taper may increase as the length of the femoral hip implant increases. However, in accordance with one or more features of the present disclosure and contrary to conventionally known prior art femoral hip implants, the AP Taper may not increase sequentially as the length of the femoral hip implant increases. That is, as the length of the femoral hip implant increases, the AP Taper may increase non-proportionally. For example, in some embodiments, the femoral hip implant may have an AP Taper of between 3.5 degrees to 6.5 degrees. However, as the length of the implant increases, the AP Taper between one set of sequentially sized implants within the kit may increase by 0.15 degree, while the AP Taper between other sequentially sized implants within the kit may increase by 0.20 degrees or 0.25 degrees. Although these are just a few of the available configurations and other dimensions are envisioned.
[0085] In various embodiments, the femoral hip implant 100 may include a porous coating and/or roughened surface 125 (
[0086] With reference to
[0087] In addition, within the porous coated region 320, the anterior and posterior sides 302, 304 of the implant 300 include grooves 325 formed therein to facilitate improved engagement with the remaining patient's bone. As illustrated, in some embodiments, the grooves 325 are angled downwards from the lateral side 308 toward the medial side 306, although it is envisioned that the grooves may be angled upwards (e.g., grooves 325 formed on the anterior and posterior sides 302, 304 are angled relative to a central longitudinal axis of the implant 300). In some embodiments, in accordance with one or more features of the present disclosure, the grooves 325 may extend to, and along, at least a portion of the medial side 306 of the femoral hip implant 300. That is, as illustrated in
[0088] In addition, with reference to
[0089] In addition, in some embodiments, the implant 300 is optimized so that, in use, when positioned within the intramedullary canal IM of the patient's bone B, a portion of the lateral side 308 of the implant 300 positioned beneath the patient's lesser trochanter is arranged and configured to provide a press-fit with the patient's bone remaining from the broaching process (
[0090] In addition, with reference to
[0091] In addition, with continued reference to
[0092] Thus arranged, by combining various features of the present disclosure (e.g., medial-lateral press-fit and anterior-posterior point of contacts), optimized placement and engagement of the implant 300 within the intramedullary canal IM of the patient's bone B has been discovered. That is, improved fit between the implant 300 and the patient's bone B has been discovered regardless of insertion approach and/or patient femur type.
[0093] In some embodiments, the implant 300 may also include a collar 350 (
[0094] As described herein, in accordance with one or more features of the present disclosure, a femoral hip implant 300 arranged and configured with an optimized fit within the intramedullary canal IM of a patient's bone B is described. In accordance with features of the present disclosure, the implant 300 may be provided in a kit including, inter alia, a plurality of different sized implants thereby enabling the surgery to select the best fitting implant for the patient's bone B. Alternatively, the implant 300 may be patient-specific (e.g., utilizing scans of the patient's bone, the implant 300 may be specifically designed and manufactured for the patient).
[0095] In either event, with reference to
[0096] In a preferred embodiment, the implant 300 is arranged and configured to fill a certain percentage of the cross-sectional area of the patient's intramedullary canal IM to reduce the likelihood of subsidence and avoid loosening. In preferred embodiments, the fill ratio or percentage can best be characterized as:
[0097] As used herein, the volume of cancellous bone (SVC) is the volume of femoral bone whose density is differentiably lower than cortical bone. The subtracted volume of cancellous bone represents the volume of bone removed from the intermedullary canal through the broaching process. If the volume of the broach protrudes excessively into denser cortical bone, the volume of cancellous bone will be less than the volume of the broach and stem and the ratio will be less than one.
[0098] In use, the implant 300 is arranged and configured to fill the greatest proportion of the three-dimensional (3D) cross-sectional area of the patient's intramedullary canal IM with the least amount of interference with the patient's cortical bone. By minimizing the amount of cortical bone needing removal, ease of insertion is provided while still ensuring a good-fit between the implant 300 and the cortical bone B. In some embodiments, the SFE may be between 0.90?SFE?0.995.
[0099] For example, in some embodiments, CT scans of the patient's bone B may be taken along various cross-sectional areas, which may be selected based on established cross-sectional areas defined within the art within established literature. Volumes of the patient's intramedullary canal IM can be measured or calculated using the scans. Thereafter, an optimized (e.g., best-fitting) implant 300 may be selected. Alternatively, in case of patient-specific implants, an implant 300 may be designed and manufactured via, for example, three-dimensional printing techniques. In either event, an optimized implant 300 based on the volume of the patient's intramedullary canal IM may be selected and implanted. That is, in selecting an optimized implant 300 for insertion into the patient's intramedullary canal IM, the implant 300 is evaluated and/or optimized in both the medial-lateral direction and the anterior-posterior direction (e.g., result is an implant 300 that has an increased fill ratio ensuring improved long-term stability of the implant 300 within the patient's intramedullary canal IM while avoiding excess bone removal during the broaching process).
[0100] Thus arranged, a femoral hip implant 300 may be selected to optimize fit within the patient's intramedullary canal IM while avoiding, or at least minimizing, the amount of cortical bone needing to be removed during the broaching process.
[0101] With reference to
[0102] As previously described, the hip stem implant 300 may include a proximal region 310 and a distal region 330. In addition, the hip stem implant 300 includes an anterior side 302, a posterior side 304, a medial side 306, and a lateral side 308. As illustrated, in various embodiments, the proximal region 310 includes, and is defined by, a porous coated and/or roughened surface or region 320 (terms used interchangeably herein). In addition, within the porous coated region 320, the anterior and posterior sides 302, 304 include grooves 325 formed therein to facilitate improved engagement with the remaining patient's bone following the broaching process. As illustrated, in some embodiments, the grooves 325 are angled (e.g., angled downwards) along the anterior and posterior sides 302, 304 of the implant 300 from the lateral side 308 toward the medial side 306. In some embodiments, in accordance with one or more features of the present disclosure, the grooves 325 may extend to, and along, at least a portion of the medial side 306 of the hip stem implant 300.
[0103] As shown, in accordance with one or more features of the present disclosure, the broach 400 includes a body 401 having a proximal region 410 and a distal region 430. In addition, the body 401 includes an anterior side 402, a posterior side 404, a medial side 406, and a lateral side 408, wherein the anterior and posterior sides 402, 404 extend between the medial and lateral sides 406, 408 as will be appreciated by one of ordinary skill in the art. As illustrated, in use, the body 401 includes an outer surface having a size and shape substantially similar to the hip stem implant 300. As will be described in greater detail below, in accordance with one or more features of the present disclosure, the broach 400 includes differential teeth or tooth patterns. In one preferred embodiment, the broach 400 includes three different types of teeth including extraction or cutting teeth (e.g., diamond teeth), compaction teeth (e.g., annular teeth), and proximal-lateral teeth (e.g., chip-breakers or annular teeth with interrupted cuts).
[0104] As illustrated in
[0105] As illustrated, in some embodiments and as previously mentioned, the distal region 430 includes teeth 432 having a first tooth pattern. The proximal region 410 includes teeth 412 having a second tooth pattern and teeth 414 having a third tooth pattern. As illustrated, teeth 412 having the second tooth pattern may be positioned on the anterior, posterior, medial, and lateral sides 402, 404, 406, 408 while teeth 414 having the third tooth pattern are positioned on or adjacent to the medial and lateral surfaces 406, 408 (e.g., teeth 414 having the third tooth pattern are positioned along the corners, edges, or intersection between the anterior and posterior sides 402, 404 and the medial and lateral sides 406, 408). That is, the proximal region 410 may include teeth 414 having a third tooth pattern formed on the anteromedial, anterolateral, posteromedial and posterolateral aspects thereof.
[0106] Thus, as will be described in greater detail herein, in use, each of the first, second, and third tooth patterns is specifically arranged and configured, depending on its location, to optimize improved engagement of the prepared bone with the subsequently implanted hip stem implant 300 and/or implantation of the hip stem implant 300.
[0107] Referring to
[0108] In addition, in some embodiments, the teeth 432 may be arranged and configured with a first tooth pattern that differs from the second and third tooth pattens, as will be described in greater detail below. In preferred embodiments, the teeth 432, or first tooth pattern, are pyramid or diamond shaped teeth arranged and configured to provide improved distal cutting of the patient's bone B upon insertion. Thus arranged, in use, the first tooth pattern (e.g., extraction teeth 432) formed on the distal region 430 of the broach 400 are arranged and configured to penetrate into and remove any bone that they come into contact with to create an envelope to facilitate proper positioning of the distal region 330 of the subsequently implanted hip stem implant 300 while avoiding bony fixation of the distal region 330 of the subsequently implanted hip stem implant 300 within the intramedullary canal. As such, the teeth 432 may be characterized as extraction or rasping teeth arranged and configured to cut or remove the patient's bone, and thus are optimized to remove diaphyseal bone. That is, in use, the pyramid or diamond shaped teeth 432 formed on the distal region 430 of the broach 400 optimizes the broach 400 to facilitate removal of any bone portions protruding on the inner surface of the intramedullary canal IM of the patient's bone B during insertion of the broach 400 therein (e.g., pyramid or diamond shaped teeth 432 have been found to perform better in reaming the patient's bone B as compared to other shaped teeth that have been found better to prepare the bone for press-fitting). In addition, in use, the blunt, diamond tooth pattern may provide a lower coefficient of friction with bone, which would provide an advantage for the portion of the broach intended to penetrate into the patient's tissue.
[0109] In use, the pyramid or diamond shaped teeth 432 formed on the distal region 430 of the broach 400 are arranged and configured to produce an envelope that minimizes or avoids press fit of the distal aspect or region 330 of the femoral hip stem implant 300 within the intramedullary canal to create a preferential press fit in the proximal portion 310 of the femoral hip stem implant 300 in the region corresponding to the anterior-posterior grooves 325 and porous coated region 320. That is, the distal region 430 of the broach 400 is patterned to remove bone leaving an envelope or a contact condition between the distal region 330 of the hip stem implant 300 that extends from the distal tip 340 of the hip stem implant 300 up to the termination of the porous coating 320 formed on the proximal region 310 of the hip stem implant 300. This transition is intended to avoid any kind of press fit condition with the distal region 330 of the hip stem implant 300 by providing a distal clearance between the inner surface of the patient's intramedullary canal and the distal region 330 of the subsequently implanted hip stem implant 300. In turn, this helps achieve and/or promote a proximal press fit hip stem implant 300 (e.g., loosely fitted distal region). As a result, excessive fit in long term on-growth, which may result in distal thigh pain or loosening of the distal stem due to proximal stem stress shielding can be avoided. Also, extending the pyramid or diamond shaped teeth 432 on the distal region 430 of the broach 400 allows for cortical bone removal at the mid-body of the hip stem implant 300, proximal to the isthmus and distal to the lesser trochanter.
[0110] Referring to
[0111] In use, the greater number and size of boney residue particles from the compaction teeth 412 provide greater degree of broaching residue such that the angled geometry of the anteriorposterior grooves create a generally positive rake angle to more effectively peel residue into the anterior and posterior grooves. This process is intended to provide the opportunity for osseoinduction into the anteriorposterior grooves to provide long term implant stability. Greater densification depth from the compaction teeth 412 is also intended to provide a firmer boney interface for initial femoral stem press-fit fixation.
[0112] In some embodiments, as illustrated, teeth 412 extend horizontally across the anterior, posterior, medial and lateral sides 402, 404, 406, 408 of the proximal region 410 of the broach 400. For example, as illustrated, the teeth 412 may extend horizontally across the anterior and posterior sides 402, 404 between the medial and lateral sides 406, 408 (e.g., teeth 412 include, or form, annular, parallel ledges or steps). The teeth 412 are arranged and configured as annular teeth extending horizontally between the medial and lateral sides 406, 408 of the broach 400. The annular teeth 412 being configured as compaction teeth to enable bone preservation and stability. In use, during insertion of the broach 400 into the patient's intramedullary canal IM, the proximal annular teeth 412 pushes or compacts the patient's bone (e.g., compacts or moves the patient's bone to make an improved envelope for subsequent implantation of the hip stem implant 300).
[0113] In addition, in accordance with one or more features of the present disclosure, the proximal region 410 formed on the broach 400 including teeth 412 having the second tooth pattern has a shape and location that substantially matches or mimics the porous coated region 320 formed on the proximal region 310 of the hip stem implant 300. Thus arranged, the proximal region 410 of the broach 400 mimics or matches the porous coated region 320 of the hip stem implant 300 (e.g., the placement of the teeth 412 having the second tooth pattern mimics or matches the placement of the porous coated region 320 on the hip stem implant 300). That is, the proximal region 410 formed on the broach 400 include teeth 412 having the second tooth pattern is identical, or substantially identical, to the porous coated region 320 formed on the hip stem implant 300.
[0114] In use, during insertion of the broach 400, the proximal annular teeth 412 leave a pocket in the patient's bone arranged and configured to interact with the porous coated region 320 and the anterior-posterior grooves 325 formed on the hip stem implant 300. That is, the proximal annular teeth 412 are arranged and configured to compact and move the contacted bone while also leaving some cancellous bone to engage the porous coated region 320 and the anterior-posterior grooves 325 formed on the subsequently implanted hip stem implant 300.
[0115] As best illustrated in
[0116] That is, the parallel ridges formed on the patient's intramedullary cavity IM by the broaching process can be subsequently raked during implantation of the hip stem implant 300 (e.g., implantation of the hip stem implant 300 with anterior-posterior grooves 325 rake the patient's inner surface of the intramedullary canal IM again), which has been found to minimize any gaps that may remain between the raked bone and the anterior-posterior grooves 325 in the hip stem implant 300 thereby facilitating improved long term stability.
[0117] Thus, in accordance with one or more features of the present disclosure, by matching or aligning the porous coated region 320 of the hip stem implant 300 with the annular compaction teeth 412 formed on the proximal region 410 of the broach 400, the interface between the hip stem implant 300 and the patient's bone (cortical/cancellous) is addressed. The result is to compact and densify the bony apposition to the porous coated region 320 formed on the subsequently implanted hip stem implant 300 while clearing the diaphysis of the intramedullary canal of the patient's bone to contact/support the distal region 330 of the hip stem implant 300 without a press fit. Thereby, allowing a differential press fit to the proximal in-growth surface on the hip stem implant 300 and avoiding a distal pedastool or press fit which may lead to long term stress shielding of the proximal femur and implant loosening.
[0118] As best illustrated in
[0119] In some embodiments, the teeth 414, or third tooth pattern, are arranged and configured as corner teeth to cut and/or remove the patient's bone that contacts the teeth during broaching. As such, the teeth 414 may be referred to as cutting teeth, extraction teeth, or chip-breakers, which are arranged and configured to cut into the patient's bone (e.g., optimized to remove cancellous bone). In some embodiments, as illustrated, the teeth 414, or third tooth pattern, are arranged and configured to provide the proximal-lateral region with interrupted cuts to create or provide a press fit in the corresponding proximal-lateral region of the subsequently implanted hip stem implant 300 while also providing reduced densification of the bone. The interrupted cuts facilitate a path for bone extrusion during broaching and a more aggressive pattern that allows relief of proximal cortical bone in the patient's femur. As illustrated, the teeth 414 may be configured to provide an annular grind, while incorporating a relief to allow material to flow out during the broaching process.
[0120] Thus arranged, in use, the teeth 414 are arranged and configured to extract the patient's bone on the medial and lateral sides of the intramedullary canal of the patient's bone. In particular, the teeth 414, or third tooth pattern, are arranged and configured to extract or remove any bone on the lateral side of the intramedullary canal on the patient's bone to promote clearance (e.g., prevent lateralization, which may cause the broach to be inserted crooked (e.g., at an angle)). As such, the teeth 414 facilitate clearance during implantation of the hip stem implant 300 by preventing, or at least minimizing, lateralization.
[0121] In accordance with features of the present disclosure, with reference to
[0122] While particular embodiments of the orthopedic broach have been shown and described, alternative configurations are envisioned. For example, in some embodiments, reduction or enlargement of the broaching surfaces can be provided to enable differential press fit with the opposing surfaces formed on the hip stem implant. In some embodiments, this may include gradual drafting of the surface(s) or direct offsets. This may also be achieved by differential coating thickness formed on the hip stem implant to create a targeted press fit potentially relating to gruene zones historically known to resorb due to stress shielding. In addition, and/or alternatively, it is envisioned that additional interrupted cuts may be provided distally on the diamond shaped tooth pattern to remove bone along the medial and lateral sides of the distal region.
[0123] In summary, in various embodiments, in accordance with one or more features of the present disclosure, the broach includes a differential tooth pattern including first, second, and third different tooth patterns wherein the broach includes (i) proximal compaction teeth along the anterior and posterior sides thereof to facilitate an envelope densification, (ii) extraction teeth formed along the corners of the proximal region to facilitate chip breakers/flutes, and (iii) distal extraction teeth to clear cortical bone. Thus arranged, the broach is optimized to provide a proximal press fitted hip stem implant, which establishes a crossing pattern between the ridges formed on the patient's intramedullary canal by the proximal annular teeth and the anterior-posterior grooves formed on the hip stem implant to promote raking of the bone during implantation of the hip stem implant into the grooves.
[0124] The femoral hip implant may be manufactured from any suitable biocompatible material now known or hereafter developed used to manufacture orthopedic implants. For example, the femoral hip implant may be made from cobalt chromium, stainless steel, titanium, oxidized zirconium, or other metal alloys. Alternatively, the femoral hip implant may be manufactured from standard polyethylene, cross-linked polyethylene, ultra-high molecular weight plastic, other plastics, ceramics, or a composite material. Similarly, the broach may be manufactured from any suitable material now known or hereafter developed. For example, the broach may be manufactured entirely from stainless steel. Alternatively, other metals may be used. Additionally, in some embodiments, the broach may be made from a hard plastic, such as PEEK.
[0125] The femoral hip implant and broach may be formed using any desired or appropriate methodologies or technologies now known or hereafter developed. For example, in some embodiments, the femoral hip implant and broach may be manufactured using any now known or hereafter developed additive manufacturing technique. By way of some, non-limiting known techniques, the femoral hip implant and broach could be manufactured from selective laser sintering (SLS), direct metal laser sintering (DMLS), electron beam melting (EBM), selective laser melting (SLM), three-dimensional printing, or the like. For instance, in some embodiments, the entire femoral hip implant and broach may be formed as a monolithic or integral component (including any porous or other in-growth promoting surfaces or materials formed on the implant). In some embodiments, portions of the femoral hip implant may be formed and then additional in-growth materials, surfaces, and/or treatments could be added or applied to the implant. In other embodiments, an additive manufacturing technique such as, for example, electron beam melting methods or methods that use lasers to subtract or remove select portions of material from an initially solid material may be used. In other embodiments, portions or all of the femoral hip implant and broach can be formed using casting or other technologies or methods. In some embodiments, a non-porous implant such as a femoral hip implant may be formed using an additive manufacturing technique such as, for example, SLS technologies and subsequently that implant may be subjected to acid etching, grit blasting, plasma spraying (e.g., of titanium oxide or another metal to promote in-growth) or other treatments.
[0126] While the present disclosure refers to certain embodiments, numerous modifications, alterations, and changes to the described embodiments are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claim(s). Accordingly, it is intended that the present disclosure not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof. The discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these embodiments. In other words, while illustrative embodiments of the disclosure have been described in detail herein, it is to be understood that the inventive concepts may be otherwise variously embodied and employed, and that the appended claims are intended to be construed to include such variations, except as limited by the prior art.
[0127] The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more embodiments or configurations for the purpose of streamlining the disclosure. However, it should be understood that various features of the certain embodiments or configurations of the disclosure may be combined in alternate embodiments, or configurations. Any embodiment or feature of any section, portion, or any other component shown or particularly described in relation to various embodiments of similar sections, portions, or components herein may be interchangeably applied to any other similar embodiment or feature shown or described herein. Additionally, components with the same name may be the same or different, and one of ordinary skill in the art would understand each component could be modified in a similar fashion or substituted to perform the same function.
[0128] Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.
[0129] As used herein, an element or step recited in the singular and proceeded with the word a or an should be understood as not excluding plural elements or steps, unless such exclusion is explicitly recited. Furthermore, references to one embodiment of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.
[0130] The phrases at least one, one or more, and and/or, as used herein, are open-ended expressions that are both conjunctive and disjunctive in operation. The terms a (or an), one or more and at least one can be used interchangeably herein. All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of this disclosure. Connection references (e.g., engaged, attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative to movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. All rotational references describe relative movement between the various elements. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority but are used to distinguish one feature from another. The drawings are for purposes of illustration only and the dimensions, positions, order and relative to sizes reflected in the drawings attached hereto may vary.