SYSTEMS FOR GUIDED REAMING OF COMPLEX SHAPES

Systems and methods for reaming an intramedullary canal of a long bone comprise a trial stem configured to extend into the long bone along an insertion axis and a guide device comprising an adapter configured to couple to the trial stem and a reaming guidepost extending from the adapter along a guide axis, wherein the guide axis and the insertion axis are non-aligned. A method of reaming an intramedullary canal of a long bone to form a complex shaped socket can comprise inserting a stem into the intramedullary canal along an insertion axis, connecting a guide device to the stem, the guide device comprising a guidepost extending along a guide axis and guiding a cannulated reamer along the guidepost to remove bone from the intramedullary canal to form the complex shaped socket, wherein the guide axis and the insertion axis are non-aligned.

TECHNICAL FIELD

This document pertains generally, but not by way of limitation, to prosthetic implant devices having stems configured to be inserted into bone. More specifically, but not by way of limitation, the present application relates to systems and methods of modifying bone to receive sleeves and cones that surround stems of tibial and femoral devices to facilitate attachment to bone when implanted.

BACKGROUND

Prosthetic implant devices, such as femoral and tibial components, sometimes include a stem extending from a bearing component such as a tibial tray. The stem can extend along a length of the diaphysis portion of the tibia, while the tray can be configured to abut a resected portion of the epiphysis portion of the tibia configured to mate with the femur. Sometimes the metaphysis portion of the tibia below the epiphysis includes damaged or unhealthy cancellous bone at the resection. As such, it is sometimes desirable to remove weakened bone material, such as with a broach or reamer, to leave a space in the metaphyseal portion of the bone larger than the stem. Sometimes a sleeve or cone is positioned in the space around a stem for the tibial or femoral component in order to facilitate attachment of the prosthesis to the bone.

Overview

The present inventors have recognized, among other things, that problems to be solved in implanting prosthetic devices can include accurately reaming or otherwise modifying bone to receive a sleeve that attaches to a stem of a tibial or femoral component. Sleeves typically comprise a conical body or a conical-like body that is elongated in the medial-lateral direction. Some sleeves have symmetry in both the medial-lateral direction and the anterior-posterior direction such that a reamer can simply be inserted into the bone and then moved medial-laterally and anterior-posteriorly to make a space in the bone that mates with the sleeve. However, such reaming motions are sometimes performed freehand and can be difficult to execute.

Furthermore, the present inventors have recognized that symmetric sleeves do not always fit the anatomy of every patient and can sometimes remove too much healthy bone. It can, therefore, be desirable to use sleeves that have asymmetry, at least with respect to one anatomic plane. For example, the sleeve can be curved such that the anterior surface is convex, and the posterior surface is concave. As such, the sleeve can be symmetric about a sagittal plane, but asymmetric about a coronal plane. Furthermore, it can be desirable to angle the anterior wall of the sleeve relative to vertical differently than the angle of the posterior wall. As such, it can be difficult to use conventional reaming systems to freehand an asymmetric or partially-symmetric sleeve shape.

Previous systems to make shaped spaces with bone reamers have involved the use of a rig that can hold a reamer in a plurality of different positions. The rig can then be used to advance the reamer axially along a plurality of different linear paths. However, the shape of the sleeve is dictated by how the rig holds the reamer and the sleeve is thus limited to shapes made by axial insertion of the reamer. Such shapes may not adequately remove undesirable bone without also removing significant portions of healthy bone. In addition to being difficult to configure and set-up, such reaming rigs require multiple reaming steps to complete the reaming operation.

The present subject matter can help provide solutions to these problem, and other problems, by providing reaming systems that allow a reamer to be moved along trajectories that are offset, angled, or variable relative to an axis of the stem with which the cone or sleeve is to be used. The reaming system can be used to produce symmetric, partially symmetric, asymmetric, offset and non-aligned spaces, as well as other complex shaped spaces, for receiving a correspondingly shaped sleeve or cone. In examples, complex shaped sockets can comprise pockets that are shaped differently than the reamer or differently than a cross-section of the reamer. The reamer can be slid along a guidepost that restricts movement of the reamer in various directions. The guidepost can be pivoted at a hinge connected to a trial stem so as to allow the reamer to sweep along a vertical reaming plane. The guidepost can be articulated at a ball joint connected to a trial stem so as to allow the reamer to be swept through a horizontal reaming envelope.

In an example, a system for reaming an intramedullary canal of a long bone can comprise a trial stem configured to extend into the long bone along an insertion axis and a guide device comprising an adapter configured to couple to the trial stem and a reaming guidepost extending from the adapter along a guide axis, wherein the guide axis and the insertion axis are non-aligned.

In another example, a method of reaming an intramedullary canal of a long bone to form a complex shaped socket can comprise inserting a stem into the intramedullary canal along an insertion axis, connecting a guide device to the stem, the guide device comprising a guidepost extending along a guide axis and guiding a cannulated reamer along the guidepost to remove bone from the intramedullary canal to form the complex shaped socket, wherein the guide axis and the insertion axis are non-aligned.

In an example, a system for reaming an intramedullary canal of a long bone can comprise a trial stem configured to extend into the long bone along an insertion axis and a guide device comprising an adapter configured to couple to the trial stem and reaming guidepost extending from the adapter along a guide axis, wherein the guide axis and the insertion axis are non-aligned.

In an additional example, a method of reaming an intramedullary canal of a long bone to form a complex shaped socket can comprise inserting a stem into the intramedullary canal along an insertion axis, connecting a guide device to the stem, the guide device comprising a guidepost extending along a guide axis and guiding a cannulated reamer along the guidepost to remove bone from the intramedullary canal to form the complex shaped socket, wherein the guide axis and the insertion axis are non-aligned.

In another example, a system for reaming an intramedullary canal of a long bone can comprise a trial stem configured to extend into the long bone along an insertion axis and a guide device comprising an adapter configured to couple to the trial stem, a reaming guidepost extending from the adapter along a guide axis and a pivoting coupler connecting the reaming guidepost to the adapter, wherein the pivoting coupler produces a projected pivot point along the insertion axis spaced longitudinally from the adapter.

In a further example, a method of reaming an intramedullary canal of a long bone to form a complex shaped socket can comprise inserting a stem into the intramedullary canal along an insertion axis, connecting a guide device to the stem, the guide device comprising a guidepost extending along a guide axis, guiding a cannulated reamer along the guidepost to remove bone from the intramedullary canal to form the complex shaped socket and pivoting the guidepost relative to the stem with the cannulated reamer, wherein a projected pivot point along the insertion axis spaced longitudinally from the guide device along the insertion axis.

In yet another example, a system for reaming an intramedullary canal of a long bone can comprise a trial stem configured to extend into the long bone along an insertion axis, an angled stem extension comprising, a shaft and a coupler configured to rotatably attach the shaft to the trial stem at an angle to the insertion axis, and a fastener for selectively locking rotation of the angled stem extension relative to the trial stem.

In yet an additional example, a method of reaming an intramedullary canal of a long bone to form a bone pocket can comprise inserting a stem into the intramedullary canal along an insertion axis, orienting an angled stem extension post relative to the stem, attaching a template to the angled stem extension post, rotating the template along with the angled stem extension to align the template with anatomic features of the long bone, locking a rotational position of the angled stem extension post relative to the stem, removing the template, and reaming the intramedullary canal along the angled stem extension.

DETAILED DESCRIPTION

Tibial stem14is configured to be attached to tibial tray12and sleeve16is configured to surround tibial stem14and stem housing24. Lockdown post30of tibial stem14can be inserted into stem housing socket26of tibial tray12. Stem housing socket26can include lip40that can engage head42of lockdown post30to hold tibial stem14within stem housing socket26. Outer surface44of stem housing24and interior channel38of sleeve16can be configured to engage each other to secure sleeve16to tibial tray12. In examples, outer surface44can be configured to have a Morse taper and interior channel38can be configured to have a corresponding shape to seat on the Morse taper of outer surface44, as shown inFIG.4. Retaining features22can be used to secure various bearing components against bearing surface20of tibial component10to engage a femoral component. For example, retaining features22can include flanges having lips into which mating components of mobile or fixed bearings can be fitted to engage condylar surfaces of a femoral component.

Tibial stem14is configured to be pushed down into an intramedullary canal of a tibia bone to anchor tibial tray12so that bone-facing surface18contacts a resected bone surface of the tibia. Furthermore, sleeve16can be positioned around stem housing24to provide additional anchoring. For example, tibial stem14can be inserted into one or both of cancellous and cortical bone and sleeve16can be pushed into engagement with one or both of cancellous and cortical bone. Exterior surface32can be porous to promote bone in-growth, as is known in the art. The systems, devices and methods of the present disclosure can allow for the use of sleeves or cones that have asymmetric or partially-symmetric shapes to be implanted into a long bone to better match anatomic shapes, remove undesirable bone and preserve healthy bone. The various reaming systems, devices and methods described herein can produce bone pockets having complex shapes, including irregular, varied, offset, non-aligned, partially-symmetric or asymmetric geometries, that can receive sleeves or cones having a corresponding shape or another shape. Such shapes can encompass shapes that are better contoured to match with anatomy of a general patient population. In examples, patient-specific bone pockets can be produced with the systems, devices and methods described herein.

FIG.2is a side cross-sectional view of proximal end P of tibia T having reaming tool50inserted into metaphysis region of tibia T along an axis extending along intramedullary canal C of tibia T to form reaming channel52. Reaming channel52can intersect stem channel54, which can also extend along the axis of intramedullary canal C. Reaming tool50can comprise reamer shaft56and reaming head58. Reamer shaft56and reaming head58can be cannulated to include an internal passage that receives stem extension post60, which is connected to stem provisional62and extension post64. Stem extension post60and extension post64can be co-axially aligned and fixed relative to each other. In other embodiments, stem provisional62and extension post64can be combined into a single piece.

With reaming head58inserted into tibia T, reamer shaft56can be reciprocated in an up-and-down motion relative to the orientation ofFIG.1to widen reaming channel52along the axis of intramedullary canal C. As shown inFIG.2, reaming head58can include various cutting surfaces, serrations, teeth, lands, edges or the like to chip away, cut away or otherwise remove bone. In embodiments, reaming head58can be inserted into reaming channel52to widen stem channel54into reaming channel52. Stem channel54can be produced using a broach or a reamer in any suitable manner before or after reaming tool50is used to form reaming channel52.

Stem channel54can comprise a generally cylindrical shaped passage extending longitudinally along an axis of tibia T. Stem channel54can extend into and through cancellous bone of tibia T. The cancellous bone of tibia T is surrounded by an outer layer of harder cortical bone. Stem channel54can form a passage for receiving a tibial post or stem that extends from a tibial component. For example, stem provisional62and extension post64can be inserted into stem channel54. Furthermore, tibial stem14ofFIG.1can be inserted into stem channel54after trialing and straight or offset stem provisional62and extension post64are removed. Tibial stem14can provide anchoring of tibial component10to tibia T.

Tibial component10can be further anchored to tibia T using sleeve16ofFIG.1. Reaming channel52can comprise a widened and tapered portion of stem channel54shaped to receive sleeve16. Reaming head58can have the same outer angular dimensions as sleeve16. That is, the angles of the side walls relative to the inferior and superior wall can be the same. As shown inFIG.3, the shape of reaming channel52is typically symmetric to accommodate a similarly shaped sleeve16. For example, the anterior-posterior thickness of sleeve16can be uniform in the central portion of the device. Additionally, the slope on the anterior and posterior walls can be the same. With the present disclosure, sleeves or cones having non-uniform thicknesses or differently sloped sidewall can be used.

FIG.3is a side cross-sectional view of the proximal end of tibia T ofFIG.2with reaming tool50removed and epiphysis end E of tibia T resected at resected surface70. Reaming channel52can include tapered portion72and longitudinal portion74. Longitudinal portion74can have length L1, which can be measured from resected surface70. In other words, tapered portion72can begin a distance equal to length L1below resected surface70. Tapered portion72can have a longitudinal length L2equivalent to the height of reaming head58. Additionally, the angle between longitudinal portion74and tapered portion72can match with the geometry of reaming head58. After reaming with reaming head58, epiphysis E is resected to provide a planar, or nearly planar, surface for engaging flush with tibial tray12(FIG.1) at resected surface70. Additionally, re-sectioning of tibia T can be performed prior to reaming. Note, longitudinal portion74typically results from reaming tool50being advanced in a straight superior-inferior direction. With the reaming systems of the present disclosure, longitudinal portion74can be eliminated, partially or fully, by the introduction of pivoting and articulating between stem extension post60and stem provisional62.

FIG.4is a side cross-sectional view of tibial component10and sleeve16ofFIG.1inserted into reamed intramedullary canal C ofFIG.3. In the configuration ofFIG.4, sleeve16is attached to stem housing24. Sleeve16can be attached to stem housing24in a variety of configurations, such as via threaded engagement, ribbed coupling (e.g., where shallow ribs on stem housing24engage with shallow ribs on sleeve16), snap fit, force fit, press fit, Morse taper, or via use of additional fasteners. In the illustrated embodiment, sleeve16is attached to stem housing24via Morse taper. In examples, outer surface44of stem housing24is configured to have a Morse taper and interior channel38of sleeve16is configured to have a mating recess such that a self-holding connection is made. Such a configuration is discussed in greater detail in U.S. Pat. No. 6,911,100 to Gibbs et al., which is hereby incorporated by reference in its entirety for all purposes. In other examples, other tapered connections can be used, such as described in U.S. Pub. No. 2015,0216667 to Monaghan, which is hereby incorporated by reference in its entirety for all purposes. In yet other examples, sleeve16can be coupled to bone-facing surface18rather than stem housing24.

With sleeve16connected to stem housing24, sleeve16contacts tibia T at tapered portion72of reaming channel52. Longitudinal portion74is small to permit exterior surface32to engage tapered portion72while still allowing gap G1to be present between bone-facing surface18of tibial tray12and proximal portion34of sleeve16. Gap G1can be filled with bone cement. For example, gap G1and reaming channel52can be filled with bone cement prior to insertion of tibial stem14into reaming channel52. This can permit gap G2along distal portion36to fill with bone cement.

Sleeve16can be attached to stem housing24in a coupled configuration as discussed. Sleeve16can additionally be inserted into reamed intramedullary canal C ofFIG.3in an un-coupled configuration. As such, sleeve16can be not attached to stem housing24. In such a configuration (e.g., unattached to stem housing24), sleeve16can be referred to as a cone.

In either case, it can be desirable to have exterior surface32closely conform to walls of a bone pocket reamed or otherwise formed into a bone in order to, among other things, facilitate bone growth into sleeve16. Rather than having a simple cylindrical shaped sleeve, conical shaped sleeve or a symmetric oblong sleeve, it can be desirable to have curved, partially-symmetric or asymmetric sleeves so that more diseased bone can be removed from a medial or lateral side of the intramedullary canal without removing healthy bone on the opposite side. The systems, devices and methods of the present disclosure facilitate production of different shaped bone pockets.FIGS.1-4are discussed with reference to reaming a tibia. However, the systems, devices and methods of the present disclosure can be used in other bones, particularly other long bones, such as femurs.

FIG.5is a perspective view of reaming system100comprising articulating guide device102configured to produce bone pockets (e.g., spaces within bone), or sleeve sockets, that can accept uniformly shaped, partially-symmetric or asymmetrically shaped sleeves, as illustrated by bone-removal envelope104. Articulating guide device102can comprise cap106and guidepost108. Articulating guide device102can couple to trial stem110, which can comprise elongate body112. Cannulated reamer114can slide along guidepost108. Cap106can comprise coupler116and limiter118. Cannulated reamer114can comprise cannulated shaft120, which can include window121, and cannulated cutter122, which can include teeth123. Guidepost108can comprise stem124and ball126.

Trial stem110can be implanted into an intramedullary canal of a long bone, similarly as tibial stem14ofFIGS.1-4. Trial stem110can be configured to extend along insertion axis A1. Articulating guide device102can couple to trial stem110. Stem124of guidepost108can extend along reaming axis A2. Ball126of guidepost108can allow stem124to articulate in a multi-directional fashion so that cannulated reamer114can be moved not only in a superior-inferior direction along stem124, but in a transverse plane encompassing anterior-posterior and medial-lateral angulation. Limiter118of cap106can control, e.g., limit, movement of stem124so that cannulated cutter122can produce bone-removal envelope104of a desired shape.

FIG.6is a perspective view of the articulating guide device102ofFIG.5coupled to trial stem110via cap106. Cap106can comprise coupler116and limiter118. Guidepost108can comprise stem124and ball126. Limiter118can comprise bone-removal template128, upper surface129and torque face130. Coupler116can be attached to elongate body112of trial stem110via a threaded engagement and limiter118can be attached to coupler116via a threaded engagement to retain guidepost108, as shown inFIG.7. Ball126can be retained within limiter118via upper surface129of limiter118. Ball126can permit stem124to multi-directionally articulate to allow cannulated reamer114to change orientation relative to trial stem110such that axis A2(FIG.1) can change angles relative to axis A1.

Bone-removal template128can comprise a shape to which a cross-section of a bone pocket is made to receive a sleeve or cone. In the illustrated example, bone-removal template128can have curved front wall131A, straight back wall131B, curved side wall131C and curved side wall131D. Curved front wall131A can be configured to face in the anterior direction and extend proximate a cortical bone wall at an anterior of a tibial plateau and straight back wall131B can be configured to face in the posterior direction and extend proximate a cortical bone wall at a posterior of a tibial plateau. However, bone-removal template128can have other shapes. Walls131A-131D can limit movement of stem124, and therefore cannulated reamer114, so that cutter122produces bone-removal envelope104.

Coupler116and limiter118can be assembled to capture ball126such that stem124protrudes from bone-removal template128. External threading on coupling head136can be engaged with internal threads140on sidewall138. Sidewall138can be shaped to retain ball126against coupler116. For example, sidewall138can be increase in thickness at upper surface129, such as by having a flange or being tapered. Coupler116can be attached to trial stem110. External threading on coupling head132of elongate body112can be engaged with internal threads within socket134of coupler116.

Assembled as such, cannulated reamer114can be moved axially along axis A2by sliding up and down along stem124to control the depth of bone-removal envelope104. The depth of cannulated reamer114can be controlled by the length of stem124and the position of end stop144. For example, stem124can be longer than guide channel142to prevent cannulated reamer114from engaging articulating guide device102. Stem124can be viewed through window121(FIG.5) so a user can verify proper assembly of cannulated reamer114with articulating guide device102.

Additionally, cannulated reamer114can be articulated by rotating ball126within limiter118to cause changes in the angle between axis A1and axis A2. As discussed with reference toFIG.8, the extent that cannulated reamer can be angled in the anterior-posterior direction, medial-lateral direction and directions in-between is controlled by the shape of template128. The greater the amount of articulation, e.g., the greater the angle between axis A1and axis A2, the greater the angle of the surface of bone-removal envelope104in the direction of the angulation with a corresponding reduction in the angle of the surface of bone-removal envelope104in the direction away from the angulation. However, stem124can be angled in a three-hundred-sixty-degree range of motion relative to axis A1such that the slope of the walls of bone-removal envelope104can be controlled in any direction.

FIG.8is a perspective cross-sectional view of reaming system100ofFIG.5showing bone-removal envelope104relative to bone-removal template128. Bone-removal envelope104can have outer wall146comprising curved front wall148A, straight back wall148B, curved side wall148C and curved side wall148D. Curved wall148A can be configured to face in the anterior direction and straight wall148B can be configured to face in the posterior direction. Bone-removal envelope104can have a shape that is the inverse of a shape of a sleeve socket reamed within bone and that corresponds to the shape of a sleeve to be inserted in the sleeve socket. Bone-removal envelope104can correspond to the shape of a sleeve or cone to be implanted into the sleeve socket.

Teeth123of cannulated cutter122can engage with bone matter to produce envelope104. The outer radial extent of teeth123can produce outer wall146as cannulated reamer114is articulated about ball126. Ball126can allow stem124to be moved side-to-side and front-to-back or in circular motions to remove bone. Bone-removal template128can limit movement of stem124so that the shape of outer wall146matches the shape of bone-removal template128, but on a larger scale.

Reaming system100ofFIGS.5-8can be used to produce complex shaped bone pockets to receive correspondingly or similarly shaped sleeves and cones. The complex shaped bone pockets can be produced in a single reaming step. The complex shaped bone pockets can have different shapes on medial and lateral portion and anterior and posterior portions of the bone pocket.

FIG.9Ais a perspective exploded view of insertion tool160for inserting trial stem110into bone via attachment to limiter118. Insertion tool160can comprise shaft162, handle164, collar166and window168.FIG.9Bis a perspective bottom view of insertion tool160ofFIG.9Ashowing shoulder170for engaging torque face130of limiter118.FIG.9Cis a cross-sectional view of insertion tool160ofFIGS.9A and9Bshowing channel172having end face174.FIGS.9A-9Care discussed concurrently.

After articulating guide device102is attached to trial stem110, insertion tool160can be attached to articulating guide device102. Stem124can be inserted into channel172and shaft162can be slid down around stem124until collar166engages sidewall138of limiter118. In particular, sidewall138of limiter118can be inserted into counterbore176within collar166so that torque face130engages shoulder170. The tip of stem124can be viewed in window168to allow a user to know that insertion tool160is fully seated on limiter118. Engagement of torque face130and shoulder170can allow torque applied to shaft162, such as from handle164, can be transmitted to limiter118. As such, insertion tool160can be used to push trial stem110down into bone or can be used to attach articulating guide device102to trial stem110already inserted into bone. As discussed with reference toFIG.10, various features of insertion tool160or attachments thereto can be used to align insertion tool160, and articulating guide device102therein, with anatomy.

FIG.10is a perspective view of insertion tool160of reaming system100ofFIG.9Ahaving alignment guide180attached to insertion tool160. Alignment guide180can comprise frame182that forms slot184. Frame182can define an outer perimeter shape that approximates the shape of bone-removal envelope104. Frame182can have an oblong shape with major axis A3and minor axis A4. Frame182can provide a visual indication to a user of insertion tool160as to the orientation of articulating guide device102, a minimum depth for a cone application or proper depth for a sleeve application. Frame182can have an outer perimeter that generally matches the shape of template128(FIG.6).

In a first example, insertion tool160can be configured so that handle164extends along an axis that is parallel to face130. Handle164can be configured to extend medial-laterally across the bone into which trial stem110is inserted. Face130can additionally extend parallel to straight back wall131B of bone-removal template128. As such, the user can know that straight back wall131B of bone-removal template128and, hence, straight back wall148B of bone-removal envelope104will be oriented medial-laterally. The user can adjust the position of handle164to any desirable orientation of straight back wall131B, such as according to a surgical plan for implanting a prosthesis.

In a second example, alignment guide180can be attached to shaft162to provide a visual indication of the shape of bone-removal envelope104. Alignment guide180can have a racetrack shape that mimics the travel path of the reamer. Alignment guide180can be positioned so that axis A3is configured to extend medial-laterally across the bone into which trial stem110is inserted, and axis A4is configured to extend anterior-posteriorly across the bone into which trial stem110is inserted. Axis A3can extend parallel to straight back wall131B of bone-removal template128. As such, the user can know that straight back wall131B of bone-removal template128and, hence, straight back wall148B of bone-removal envelope104will be oriented medial-laterally. The user can adjust the position of handle164to any desirable orientation of straight back wall131B, such as according to a surgical plan for implanting a prosthesis. Furthermore, the position of alignment guide180along shaft162can provide a visual indication of a minimum depth for a cone application or proper depth for a sleeve application. For example, alignment guide180can be positioned so that when reaming has been performed to a suitable depth, alignment guide180can be flush with a resected bone surface, such as resected surface70ofFIG.3.

FIG.11Ais a perspective view of pivoting guide device200of the present disclosure connected to trial stem202. Pivoting guide device200can be used with cannulated reamer114. Pivoting guide device200can comprise cap204and guidepost206.FIG.11Bis a side view of pivoting guide device200ofFIG.11Aillustrating angling of guidepost206relative to cap204.FIG.11Cis a side cross-sectional view of pivoting guide device200ofFIG.11Ashowing stop surfaces226A and226B of guidepost206. Cap204can comprise base208, stem210and bracket212. Bracket212can comprise flanges214A and214B, which can each have a bore for receiving pivot pin215(FIG.11C). Stem210can comprise a threaded body configured for coupling to trial stem202. Trial stem202can comprise elongate body216and socket218. Guidepost206can comprise eyelet220and stem222. Eyelet220can comprise bore224, first stop surface226A and second stop surface226B. Trial stem202can be inserted into bone along axis A6. Stem222can extend from bracket212along axis A7.FIGS.11A-11Care discussed concurrently.

As can be seen inFIG.11C, pivoting guide device200can move cannulated reamer114within a plane encompassing stem222such that angle α1 is variable. In particular, pivoting guide device200can sweep cannulated reamer114along a single plane determined by the hinge formed at pin215extended through flange214A, flange214B and eyelet220. Flanges214A and214B can prevent rotation of stem222about axis A6such that stem222is restricted to pivoting in a single plane. The amount of angulation of stem222relative to cap204can be controlled by stop surfaces226A and226B on the bottom or distal surface of eyelet220. The greater amount that stop surfaces226A and226B are angled inward toward stem222, the more amount of articulation of stem222is permitted. Thus, stem222can be coaxial with trial stem202and can be articulated at pin215to allow angle α1 to be increased or decreased amounts controlled by stop surfaces226A and226B. In examples, stop surfaces226A and226B can be symmetric such that angle α1 can be varied equally in both directions relative to vertical. In other examples, stop surfaces226A and226B can be asymmetric or complex such that angle α1 can be varied disproportionately on either side of vertical.

As can be seen inFIG.11B, stem222can be angled relative to trial stem202such that angle α2 is between axis A6and axis A7, i.e., axes A6and A7are non-parallel. Angle α2 between stem222and trial stem202can be controlled by the thickness of base208. Base208can comprise a disk having a flat bottom surface and a flat top surface. The top surface can be closer to the bottom surface on one side of base208to form thickness T1and the top surface can be further away from the bottom surface on an opposite side of base208to form thickness T2, wherein T2is greater than T1. As such, base208can be wedge shaped. In additional examples, axes A6and A7can be parallel.

In examples, pivoting guide device200can be configured such that angle α1 can be varied in a medial-lateral or coronal plane of the anatomy and angle α2 can lie in an anterior-posterior or sagittal plane. However, pivoting guide device200can be configured to have other orientations for angle α1 and angle α2. In the illustrated example, cap204is configured such that stem222extends from the center of base208. However, cap204can be configured such that stem222is offset from the center of base208.

FIG.12Ais a perspective view of pivoting guide device250of the present disclosure connected to trial stem202. Pivoting guide device250can be used with cannulated reamer114. Cannulated reamer114can comprise socket190within cutter122to allow pivoting guide device250to be recessed within cutter122to allow cutter122to be brought closer to pivot point PP. Pivoting guide device250can comprise cap254and guidepost256. Cap254can comprise base258, stem260and bracket262. Bracket262can comprise rail264, which can have slot266for receiving a slide body or a pair of pivot pins. Stem260can comprise a threaded body configured for coupling to trial stem202. Trial stem202can comprise elongate body216and socket218. Guidepost256can comprise shuttle270, which can comprise flanges272A and272B (FIG.12B), and guidepost273. Flanges272A and272B can comprise bores274A and274B for receiving slide pins (not shown).FIG.12Bis a side view of shuttle270ofFIG.12Aoffset of guidepost273relative to elongate body216.FIGS.12A and12Bare discussed concurrently.

In the example ofFIGS.12A and12B, the effective pivot point of guidepost273can be lower relative to the examples ofFIGS.5-8and11A-11C. For example, the effective pivot point of the example ofFIGS.5-8is where ball126is located directly between stem124and trial stem110. Likewise, in the example ofFIGS.11A-11C, the effective pivot point is at pin215. However, in the example ofFIGS.12A and12B, the effective pivot point PP is located at the center of the curve for arcuate slot266. It can be desirable to have pivot point PP further down along the length of elongate body216to be closer to where lines LL extending inwardly of the sides of bone-removal envelope276would converge to, for example, allow the shape of cutter122to closer match the shape of bone-removal envelope276without articulation of cannulated reamer114, but without having to extend pivoting guide device250deep down into the bone.

Furthermore, as can be seen inFIG.12B, axis A8of guidepost273can be offset and angled relative to axis A6of elongate body216. Base258can be constructed to have varying thickness similar to base208ofFIG.11B. As discussed herein, offsetting of axis A6and axis A8relative to a horizontal plane an angling of axis A8relative to axis A6can be factors in producing complex shaped bone pockets for receiving sleeves and cones, along with the depth of pivot point PP, the angulation provided by bracket262and shuttle270in a single plane, the articulation of articulating guide device102ofFIGS.5-8in multiple planes, and the shape of cutter122(which can be cylindrical or conical with different wall angles). In additional examples, guidepost273can be aligned or parallel to axis A6.

FIG.13Ais a perspective view of fixed guide device300of the present disclosure connected to trial stem202. Fixed guide device300can be used with cannulated reamer114. Fixed guide device300can comprise base302, coupler304and guidepost306.FIG.13Bis a cross-sectional view of fixed guide device300ofFIG.13Ashowing guidepost306extending along axis A9parallel to and offset from axis A6of trial stem202distance D1.FIGS.13A And13Bare discussed concurrently.

FIG.14Ais a perspective view of a fixed guide device350of the present disclosure connected to trial stem202. Fixed guide device350can be used with cannulated reamer114. Fixed guide device350can comprise base352, coupler354and guidepost356.FIG.13Bis a cross-sectional view of fixed guide device350ofFIG.14Ashowing guidepost356extending along axis A10angled to axis A6at angle3and offset from axis A6of trial stem202distance D2.FIGS.14A and14GBare discussed concurrently.

FIGS.13A-14Billustrate examples of fixed guide devices without pivoting or articulation. Thus, distances D1and D2and angle α3 can be fixed. The devices ofFIGS.13A-14Bcan comprise simpler, e.g., non-pivoting, devices than those ofFIGS.5-12B, but that still can form offset, angled, partially-symmetric or asymmetric bone pockets.

FIG.15is a line diagram illustrating steps of method500for reaming or otherwise forming offset, angled, variable, non-aligned, partially-symmetric and asymmetric bone pockets using the instrumentation described in the present disclosure.

At operation502, a bone can be prepared to receive a stem of a prosthetic device. For example, a long bone, such as a tibia of a femur can be resected to expose an intramedullary canal. Tibia T ofFIG.4can be modified to produce resected surface70.

At operation504, a bone bore can be formed in the bone of operation502. For example, the intramedullary canal can be broached or reamed to form an elongate passage to receive the stem of the prosthetic device. Tibia T ofFIG.4can be modified to produce stem channel54.

At operation506, a reaming alignment device of the present disclosure can be attached to a stem. In examples, the stem can be a stem provisional. For example, device102ofFIG.5, device200ofFIG.11A, device250ofFIG.12A, device300ofFIG.13Band device350ofFIG.14Bcan be attached to trial stem110or trial stem202.

At operation508, an inserter can be attached to the stem. For example, the inserter can be positioned over the reaming alignment device of operation506. Insertion tool160ofFIGS.9A-9Ccan used. Additionally, alignment guide180can be attached to insertion tool160at this point of the procedure.

At operation510, the stem can be inserted into the bone bore formed at operation504. Trial stem110or trial stem202can be pushed into the bone bore with or without insertion tool160. Likewise, an alignment device, such as alignment guide180, can be inserted into the bone bore.

At operation512, the alignment device can be oriented relative to the anatomy of the bone to additionally align the stem attached to the inserter. For example, the inserted can be rotated to orient. Handle164of insertion tool160can be aligned with the medial-lateral direction. Alignment guide180can also be oriented to match the shape of frame182with anatomy, e.g., to position frame182over resected surface70in the desired location for the bone removal envelope, e.g., bone-removal envelope104ofFIG.5.

At operation514, the inserter can be removed, such as by being detached from the stem. Insertion tool160can be uncoupled from trial stem110or trial stem202.

At operation516, a reaming tool can be attached to the reaming alignment device of operation506. Cannulated reamer114can slid over stem124, stem222, guidepost273, guidepost306or guidepost356via insertion into channel142.

At operation518, the reaming tool can be operated to ream axially along the reaming alignment device. Cannulated reamer114can be moved distally along one of stem124, stem222, guidepost273, guidepost306or guidepost356to remove bone.

At operation520, the reaming alignment device can be pivoted using the reaming tool to perform reaming along a vertical plane. The reaming tool can be pivoted along a plane or within a bone removal template as described herein. For example, cannulated reamer114can be pivoted using device102ofFIG.5, device200ofFIG.11Aor device250ofFIG.12A.

At operation522, the reaming alignment device can be articulated using the reaming tool in multiple directions to perform reaming within a horizontal plane. For example, cannulated reamer114can be articulated using device102ofFIG.5.

At operation524, the reaming tool can be removed from the reaming alignment device. Cannulated reamer114can be withdrawn from stem124, stem222, guidepost273, guidepost306or guidepost356.

At operation526, the reaming alignment device can be removed from the stem. For example, device102ofFIG.5, device200ofFIG.11A, device250ofFIG.12A, device300ofFIG.13Band device350ofFIG.14Bcan be removed from trial stem110or trial stem202.

As such, a cone or sleeve can be temporarily positioned around the stem to evaluate the reaming of operations518-522. If the cone or sleeve fits the produced bone pocket produced by operations502-526, the trial stem can be removed and the cone or sleeve and a stem can be assembled and inserted into the bone for implantation. If the cone or sleeve is found to not adequately match or mate with the reamed bone pocket, additional reaming can be performed if desired before the final prosthetic construct is positioned for implantation.

FIGS.16A-19Cshow an example of articulating guide device600having a spherical racetrack reamer guide, wherein a guidepost is configured to spherically pivot relative to a trial stem via an effective pivot point that is projected downward along the trial stem. Articulating guide device600can be configured to produce bone pockets or envelopes (e.g., spaces within bone), or sleeve sockets, that can accept uniformly shaped, partially-symmetric, asymmetric and complex shaped sleeves or cones.

FIG.16Ais a perspective view of articulating guide device600coupled to trial stem602.FIG.16Bis a cross-sectional view of articulating guide device600ofFIG.16A.FIGS.16A and16Bare discussed concurrently. Articulating guide device600can comprise cap604and reamer guidepost606. Reamer guidepost606and cap604can be connected by spherical racetrack interface608. Trial stem602can be constructed similarly as trial stem202described herein and can include elongate body610and head612, which can include socket613(FIG.16B). Elongate body610can extend along axis A11.

Shaft628of coupler614can be attached to socket613of trial stem602, such as by threaded engagement or interference fit. Wall634of limiter616can be attached to head632of coupler614. Spherical knob624of reamer guidepost606can be positioned within wall634such that spherical plate636of limiter616is positioned within spherical socket627, thereby positioning spherical ledge622against spherical plate636. In examples, limiter616can be formed of two separate pieces that are coupled together around spherical knob624. In additional examples, limiter616and reamer guidepost606can be simultaneously manufactured using additive manufacturing processes. In examples, spherical knob624can be separately attached to post626via a fastener or other coupling means.

Spherical limiter620can permit guidepost606to multi-directionally articulate to allow cannulated reamer650(FIG.19A) to change orientation relative to trial stem602such that axis A11can change angles relative to axis A12. In particular, spherical plate636can engage with spherical knob624to allow reamer guidepost606to move within a spherical-shaped envelope or semi-spherical shaped envelope. Specifically, the envelope can comprise a portion of a sphere defined by the shape of template638.

FIG.17is a perspective view of articulating guide device600ofFIG.16Awith reamer guidepost606removed. Cap604can be attached to trial stem602. In particular, coupler614can be attached to trial stem602and limiter616can be attached to coupler614. Limiter616can include spherical plate636in which template638is located.

Template638can comprise a bone-removal template that comprises a shape to which a cross-section of a bone pocket is made to receive a sleeve or cone. In the illustrated example, template638can have curved front wall640A, straight back wall640B, curved side wall640C and curved side wall640D. Curved front wall640A can be configured to face in the anterior direction and extend proximate a cortical bone wall at an anterior of a tibial plateau and straight back wall640B can be configured to face in the posterior direction and extend proximate a cortical bone wall at a posterior of a tibial plateau. Walls640A-640D can form a D-shaped oval. However, template638can have other shapes. Walls640A-640D can limit movement of stem618, and therefore cannulated reamer650(FIGS.19A-19C), so that cannulated reamer650can produce a bone-removal envelope.

Spherical socket627can receive spherical plate636to allow post626to move within template638. In particular, an upper surface of spherical plate636can engage with a lower surface of spherical ledge622and a lower surface of spherical plate636can engage with an upper surface of spherical knob624. However, spherical socket627can be taller than spherical knob624such that all surfaces need not be touching and to facilitate articulation of reamer guidepost606. The spherical surfaces can have the same center point to allow reamer guidepost606to move in a spherical pattern, as shown inFIG.18.

FIG.18is a cross-sectional view of articulating guide device600ofFIGS.16A-17showing spherical guide path644and effective pivot point646. Spherical guide path644can comprise a surface revolved around axis A11having curvature that matches the curvature of spherical ledge622, spherical plate636and spherical knob624. Due to the spherical curvature of spherical ledge622, spherical plate636and spherical knob624, the center of movement for reamer guidepost606can be located at effective pivot point646below spherical racetrack interface608.

In the example ofFIGS.16A-18, effective pivot point646of reamer guidepost606can be lower relative to the examples ofFIGS.5-8and11A-11C. For example, the effective pivot point of the example ofFIGS.5-8is where ball126is located directly between stem124and trial stem110. Likewise, in the example ofFIGS.11A-11C, the effective pivot point is at pin215. However, in the example ofFIGS.16A-18, effective pivot point646can be located at the center of curvature of spherical ledge622, spherical plate636and spherical knob624. It can be desirable to have effective pivot point646further down along the length of elongate body610to more closely match the shape of cannulated reamer650, as shown inFIGS.19A-19C. As such, angled reaming can be performed further down within tibia T (FIG.2) to more closely match the angles of cortical bone within tibia T and without compromising the integrity of tibia T, e.g., without coming close to the exterior of cortical bone.

FIG.19Ais a cross-sectional view of cannulated reamer650positioned around reamer guidepost606of articulating guide device600ofFIG.16A.FIG.19Bis a cross-sectional view of cannulated reamer650and articulating guide device600ofFIG.19Bwith cap604shown in full to illustrate spherical racetrack interface608.FIG.19Cis a cross-sectional view of cannulated reamer650with reamer guidepost606shown in phantom to show spherical racetrack interface608.FIGS.19A-19Care discussed concurrently.

Cannulated reamer650can be constructed similarly to other reamers described herein, such as cannulated reamer114. Cannulated reamer650can slide along reamer guidepost606. Cannulated reamer650can comprise cannulated shaft652and cannulated cutter654, which can include teeth656. Cannulation658can extend through cannulated cutter654and into cannulated shaft652. Cannulation658can include receptacle portion660that can fit over cap604and head612of trial stem602. Walls of cannulated cutter654can extend along lines L3to form a trapezoidal bone-removal envelope. In examples, lines L3can be configured to converge at or near effective pivot point646. In additional examples, lines L3can be configured to converge distal, e.g., further into the bone, of effective pivot point646. As such, the curvatures of spherical ledge622, spherical plate636and spherical knob624can be based on the angle between lines L3. Thus, the shape of cannulated cutter654can more closely match the shape of a cone or sleeve without having to extend spherical racetrack interface608deep down into the bone.

As can be seen inFIGS.19B and19C, post626can be configured to engage walls640A-640D of template638. Post626can have a cylindrical profile and walls640A-640D can be planar. The surfaces of post626and walls640A-640D can be arranged parallel to axis A11. However, in other examples, the surfaces of post626and walls640A-640D can be angled to conform with the angle between axis A12and walls640A-640D. As can be seen inFIGS.19B and19C, the cross-sectional area of post626can be smaller than the cross-sectional area of template638, thereby allowing reamer guidepost606to move between walls640A-640D. The surface of post626can be curved relative to axis A11to allow reamer guidepost606to move smoothly along walls640A-640D.

In the illustrated example, cap604is configured to position axis A11of reamer guidepost606co-axial with axis A12of trial stem602. However, in other configurations, cap604can position axis A11offset from axis A12.

FIGS.20A-23show an example of articulating guide device700having an arcuate slide pad reamer guide, wherein a guidepost is configured to arcuately pivot relative to a trial stem via an effective pivot point that is projected downward along the trial stem. Articulating guide device700can be configured to produce bone pockets or envelopes (e.g., spaces within bone), or sleeve sockets, that can accept uniformly shaped, partially-symmetric, asymmetric and complex shaped sleeves or cones.

Shaft710can be attached to socket740, such as via threaded engagement or interference fit. Arcuate base712can rest flush against head738. Sidewall714can extend proximally from arcuate base712. Arcuate plate716can extend laterally from sidewall714. Thus, arcuate track742can be located between arcuate base712and arcuate plate716. As discussed with reference toFIG.22, arcuate track742can be angled and offset relative to axis A14.

Arcuate knob718can be placed within arcuate track742to engage both arcuate base712and arcuate plate716. Sidewall720can extend proximally from arcuate knob718and arcuate ledge722can extend laterally from sidewall720to extend over arcuate plate716. The lower surface of arcuate ledge722can engage the upper surface of arcuate plate716. The lower surface of arcuate plate716can engage the upper surface of arcuate knob718. The lower surface of arcuate knob718can engage the upper surface of arcuate base712. The arcuate surfaces can have the same center point to allow guide stem706to move in an arcuate pattern, as shown inFIG.20B.

Arcuate knob718can permit guide stem706to uni-planarly articulate to allow cannulated reamer750(FIGS.22and23) to change orientation relative to trial stem702such that axis A13can change angles relative to axis A14. In particular, arcuate knob718can engage with arcuate base712and arcuate plate716to allow reamer guide stem706to move within an arcuate envelope. Specifically, the envelope can comprise a segment of a circle defined by the shape of arcuate track742.

Arcuate guide path744can comprise a surface extending into and out of the plane ofFIG.20Bhaving curvature that matches the curvature of arcuate base712, arcuate knob718, arcuate plate716and arcuate ledge722. Due to the arcuate curvature of arcuate base712, arcuate knob718, arcuate plate716and arcuate ledge722, the center of movement for guide stem706can be located at effective pivot point746below arcuate slide pad interface703. Additionally, the curvature of slot726for pin730can match the curvature of arcuate base712, arcuate knob718, arcuate plate716and arcuate ledge722.

In the example ofFIGS.20A-238, the effective pivot point of guide stem706can be lower relative to the examples ofFIGS.5-8and11A-11C. For example, the effective pivot point of the example ofFIGS.5-8is where ball126is located directly between stem124and trial stem110. Likewise, in the example ofFIGS.11A-11C, the effective pivot point is at pin215. However, in the example ofFIGS.20A-23, effective pivot point746can be located at the center of curvature of arcuate base712, arcuate knob718, arcuate plate716and arcuate ledge722. It can be desirable to have effective pivot point746further down along the length of elongate body736more closely match the shape of cannulated reamer750, as shown inFIGS.22and23. As such, angled reaming can be performed further down within tibia T (FIG.2) to more closely match the angles of cortical bone within tibia T and without compromising the integrity of tibia T, e.g., without coming close to the exterior of cortical bone.

FIG.21AandFIG.21Bare exploded views of articulating guide device700ofFIGS.20A and20Bshowing cap704and guide stem706. Pin730can be inserted into arcuate slot726and bore728. Specifically, shaft732can be inserted through arcuate slot726and into bore728. Shaft732can be secured to bore728, such as via a threaded connection or interference fit. Head734can pull sidewall714toward sidewall720. Head734can rest against ledge735when fully seated to prevent counter rotation of pin730relative to the direction of threading, for example. As such, guide stem706can remain engaged with cap704. Shaft732can have a diameter approximately equal to the height of arcuate slot726to keep guide stem706and cap704aligned. Furthermore, arcuate knob718can be fit against surfaces of arcuate plate716, sidewall714and arcuate base712to maintain guide stem706oriented relative to trial stem702. However, the width of arcuate slot726can be smaller than the diameter of shaft732so that guide stem706can move along arcuate track742relative to cap704.

FIG.22is a side view of articulating guide device700ofFIGS.20A-21Bwith cannulated reamer750.FIG.23is a perspective view of articulating guide device700ofFIG.22with cannulated reamer750shown in phantom over articulating guide device700. Cannulated reamer750can be constructed similarly to other reamers described herein, such as cannulated reamer114. Cannulated reamer750can slide along guidepost724. Cannulated reamer750can comprise cannulated shaft752and cannulated cutter754, which can include teeth. Cannulation758can extend through cannulated cutter754and into cannulated shaft752. Cannulation758can include receptacle portion760that can fit over cap704and head738of trial stem702.

Walls of cannulated cutter754can extend along lines L4to form a trapezoidal bone-removal envelope. In examples, lines L4can be configured to converge at or near effective pivot point746. In additional examples, lines L4can be configured to converge distal, e.g., further into the bone, of effective pivot point746. As such, the curvatures of arcuate base712, arcuate knob718and arcuate plate716and arcuate ledge722can be based on the angle between lines L4. Thus, the shape of cannulated cutter754can more closely match the shape of a cone or sleeve without having to extend arcuate slide pad interface703deep down into the bone.

As can be seen inFIG.22, axis A13of guidepost724of guide stem706can be angled relative to axis A14of elongate body736of trial stem702. Furthermore, axis A13can be laterally offset from axis A14. Specifically, guidepost724can extend along axis A13, which can be disposed at angle α4 relative to axis A14and can be offset distance D3from axis A14. As discussed herein, angle α4 and distance D3can be utilized to provide various complex shapes for bone pockets or envelopes configured to receive sleeves and cones.

FIG.24is a perspective view of system800comprising angled stem extension post802attached to trial stem804.FIG.25is a cross-sectional view of system800ofFIG.24.FIGS.24and25are discussed concurrently.

Trial stem804can be constructed similarly as trial stem202described herein and can include elongate body806and head808, which can include socket810. Elongate body806can extend along axis A15. Angled stem extension post802can comprise coupler812, shaft814and head816. Shaft814can extend along axis A16. Angled stem extension post802can further comprise socket818and access port820.

Angled stem extension post802can be attached to trial stem804to guide reaming along axis A16at an angle to axis A15. Angled stem extension post802can be fastened to trail stem804via fastener822, which can comprise shaft824and head826. Faster822can immobilize angled stem extension post802relative to trial stem804so that a reaming operation can be performed without angled stem extension post802moving and adversely affecting the reaming operation. In particular, fastener822can restrain axial movement of angled stem extension post802along axis A15. However, as discussed below, angled stem extension post802can be allowed to rotate about fastener822along axis A15to allow for alignment of angled stem extension post802relative to the tibia.

In examples, angled stem extension post802can be pre-assembled with trial stem804before trial stem804is inserted into bone. Fastener822can be attached to trial stem804by inserting shaft824into socket810, such as be engaging mating threading. Fastener822can be fit radially through socket818, such as via a force fit, to attach coupler812to fastener822. Thus, coupler812can comprise a c-shaped body that wraps partially around shaft824underneath head826. Socket822can have a profile shape of fastener822and a portion of head808. Initially, fastener822can be tightened down such that head826is spaced from coupler812. As such, angled stem extension post802can rotate about axis A15as coupler812rotates about shaft824. In additional examples, angled stem extension post802can be attached to trial stem804while trial stem804is inserted in bone. Socket818can comprise an opening in coupler812to allow angled stem extension post802to be moved onto and off of fastener822. Socket818can comprise a T-shaped window that allows angled stem extension post802to be moved laterally, relative to axis A15, into engagement with head826of fastener822.

FIG.26is a perspective view of driver instrument830inserted into access port820of the angled stem extension post802ofFIG.24.FIG.27is a cross-sectional view of angled stem extension post802, trial stem804and driver instrument830ofFIG.26. Driver instrument830can comprise handle832and shaft834. Shaft834can include tip836.FIGS.26and27are discussed concurrently. Tip836of shaft834can comprise a hex head or other features that fit into a mating socket within head826to permit transfer of rotational force from driver instrument830to fastener822. Tip836can extend into access port820. Access port820can be formed by removal of material from shaft814that obstructs access to head826along axis A15. Access port820can intersect socket818.

After both trial stem804is inserted into a tibia and angled stem extension post802is assembled to trial stem808, a template device comprising handle840and template842can be attached to angled stem extension post802to provide alignment of angled stem extension post802relative to anatomy, as explained with reference toFIGS.28and29, and, thereafter, fastener822can be tightened down to immobilize angled stem extension post802using driver device830, as explained with reference toFIGS.30and31.

FIG.28is a perspective view of angled stem extension post802and trial stem804ofFIGS.24-27with template handle840having template842attached to angled stem extension post802. Template handle840can comprise shaft844, grip846and head848. Shaft844can comprise window850to allow for visual inspection of shaft814of angled stem extension post802. Grip846can comprise features to facilitate handling of template842. Grip846can extend along an axis that extends perpendicularly to shaft844. Grip846can comprise front face852located on the same side of shaft844as window850. Head848can include aperture854to allow for insertion of shaft834of driver instrument830. Head848can also include track856(FIG.30) for coupling with template842. Template842can comprise body858, slot860and extension862. Track856can be configured to align template perpendicular to axis A15(FIG.24). Shaft844can be keyed to shaft814to allow handle840to slide over shaft814in only one relative rotational orientation. For example, the interior of head848can include cut-outs to sit atop coupler812in only one orientation. Furthermore, aperture854can be configured to align with access port820. In examples, shaft844and shaft814can be keyed so that grip846extends in the medial-lateral direction when shaft814is angled posteriorly.

FIG.29is a close-up view of template842ofFIG.28showing outer perimeter864of template842relative to alignment marks866. Template842can further comprise windows868A and868B. Outer perimeter864can have the shape of a cone or sleeve configured to be positioned within a resected plane of a tibia. Thus, outer perimeter864can have medial and lateral curved sided with slot860being positioned therebetween on a posterior side. Extension862can be positioned the medial and lateral curved sides in an anterior location at a tibial tuberosity. Slot860can also allow template to be positioned on track856(FIG.30). Alignment marks866can be provided to visualize where template842should be positioned relative to a tibial tuberosity. Extension862can also provide a grip to allow a surgeon a place to handle template842. Windows868A and868B can be provided allow for visual inspection of bone underneath template842. For example, windows868A and868B can be positioned to allow for viewing of a cortical bone wall. Additionally, windows868A and868B can be positioned to allow for visualization of where an implant to be positioned in the resected tibial surface is to be positioned.

Once template handle840and template842are attached to shaft814of angled stem extension post802, grip846can be rotated to align template842in the desired location relative to the anatomy, such as when the tibial tuberosity is within alignment marks866. A surgeon can therefore verify that outer perimeter864is adequately surrounded by cortical bone, so as to not be positioned outside of the tibia. If outer perimeter864is too close to cortical bone, grip846can be rotated clockwise or counterclockwise to move outer perimeter864within the cortical bene while keeping the tibial tuberosity within alignment marks866.

FIG.30is a perspective view of angled stem extension post802, trial stem804and driver instrument830ofFIG.29with template handle840positioned over angled stem extension post802.FIG.31is a cross-sectional view of angled stem extension post802, trial stem804, driver instrument830and template handle840ofFIG.30. Once template842is properly positioned as discussed above, a surgeon can know that reaming can be performed with angled stem extension post802. Thus, driver instrument830can be inserted through aperture854and access port820to access fastener822. Driver instrument830can then be rotated while engaged with head826to tighten fastener822down onto trial stem804, thereby immobilizing angled stem extension post802. Thereafter, a cannulated reamer, similar to cannulated reamer750ofFIG.23, for example, can be slid over shaft814of angled stem extension post802to ream a bone pocket within the resected tibial surface.

FIG.32is a perspective view of secondary ream guide870having first secondary ream post872A and second secondary ream post872B that can be inserted into a bone socket produced with the devices ofFIGS.24-31. Secondary ream guide870can comprise further comprise broach body874, base876and extension878.FIG.33is a perspective view of secondary ream guide870ofFIG.32with secondary reamer880positioned over first secondary ream post872A. Broach body874can include pocket865and teeth879. Pocket875can interrupt the outer perimeter of broach body874to form anterior wall877A and posterior wall877B. Secondary reamer880can comprise cannulated shaft882and ream head884, which can include teeth886.

Trial stem804along with angled stem extension post802can be removed from the tibial. Broach body874can be positioned within a bone pocket formed by sliding cannulated reamer750(FIG.23) over shaft814. Broach body874can have a similar shape as cannulated cutter754of cannulated reamer750, but with pocket875interrupting the outer perimeter shape. Broach body874can include teeth879to facilitate cutting into bone, e.g., displacing cancellous bone matter. Extension878can be connected to a stem that can be inserted into the space formed and vacated by stem804to provide stability. Secondary reamer880can be positioned over each of secondary ream posts872A and872B to form widening of the bone pocket formed by cannulated reamer750. Cannulated shaft882can be positioned over each of secondary ream posts872A and872B in to perform sequential reaming operations using ream head884. Ream head884can be cannulated to allow receiving of secondary ream posts872A and872B. Ream head884can be smaller than cannulated cutter754of cannulated reamer750. Ream head884can fit into spaces within broach body874to allow for secondary reaming within the same apace as was performed with cannulated reamer750. Thus, secondary ream posts872A and872B can help produce a complex reamed shape within the tibia. For example, ream head884can provide a different radius of curvature than cannulated cutter754, such as by being smaller.

Additionally, ream head884can be provided along different axes, such as the axes817A and817B of secondary ream posts872A an872B that are at different angles than axis A16relative to axis A15(FIG.24). Thus, secondary ream guide870can produce a multi-lobed bone pocket within the proximal tibial having outer walls disposed at different angles relative to axis A15, as evidenced by the protrusion of ream head884outside the perimeter of broach body874. The angles of axis A16, A17A and A17B can be configured in different embodiments to match with different shaped cones and sleeves, thereby allowing such cones and sleeves to be engaged with cortical or healthy bone for different patients.

The present disclosure includes devices, systems and methods for reaming or otherwise modifying bone to produce various shaped sockets to receive prosthetic devices, such as cones and sleeves. The devices, systems and methods can produce complex shapes of precise dimensions to allow for precise removal of diseases or damaged bone, minimize removal of healthy bone, and allow for flush or tight fits between the modified bone and the prosthetic device when implanted. The devices, systems and methods can eliminate use of freehand reaming and minimize the use of complicated reaming mechanisms.

Various Notes & Examples

Example 1 is a system for reaming an intramedullary canal of a long bone, the system comprising: a trial stem configured to extend into the long bone along an insertion axis; and a guide device comprising: an adapter configured to couple to the trial stem; and a reaming guidepost extending from the adapter along a guide axis; wherein the guide axis and the insertion axis are non-aligned.

In Example 2, the subject matter of Example 1 optionally includes wherein the reaming guidepost is in a fixed position relative to the adapter such that the insertion axis is offset from the guide axis.

In Example 3, the subject matter of Example 2 optionally includes wherein the insertion axis and the guide axis are parallel.

In Example 4, the subject matter of any one or more of Examples 2-3 optionally include wherein the insertion axis and the guide axis are oblique.

In Example 5, the subject matter of any one or more of Examples 1-4 optionally include wherein the reaming guidepost is rotatable relative to the adapter such that an angle between the insertion axis and the guide axis is variable.

In Example 6, the subject matter of Example 5 optionally includes wherein the reaming guidepost is pivotable in multiple directions relative to the adapter.

In Example 7, the subject matter of Example 6 optionally includes wherein the reaming guidepost is coupled to the adapter via a ball joint.

In Example 8, the subject matter of Example 7 optionally includes wherein the adapter comprises a socket from which the reaming guidepost extends, the socket comprising a perimeter defining an asymmetric shape.

In Example 9, the subject matter of any one or more of Examples 7-8 optionally include wherein the adapter comprises: a coupler comprising a threaded component configured to mate with the trial stem; and a limiter comprising: an attachment feature for attaching to the coupler; a sidewall extending from the attachment feature to define a chamber for receiving a ball of the ball joint, wherein the reaming guidepost extends from the ball; and a ledge extending from the sidewall to trap the ball within the chamber, the ledge overhanging the chamber to define an opening through which the reaming guidepost can extend.

In Example 10, the subject matter of any one or more of Examples 5-9 optionally include wherein the reaming guidepost is pivotable in a single plane relative to the adapter.

In Example 11, the subject matter of Example 10 optionally includes wherein the reaming guidepost is coupled to the adapter via a hinge device having a pivot pin that defines a pivoting point.

In Example 12, the subject matter of Example 11 optionally includes wherein the pivoting point is positioned outward of the trial stem.

In Example 13, the subject matter of any one or more of Examples 11-12 optionally include wherein the hinge device comprises a pair of flanges between which an eyelet of the reaming guidepost is disposed to receive the pivot pin, wherein the eyelet includes stop surfaces configured to limit pivoting of the reaming guidepost.

In Example 14, the subject matter of any one or more of Examples 10-13 optionally include wherein the reaming guidepost is coupled to the adapter via a slide device having a slide pin that defines a pivoting point.

In Example 15, the subject matter of Example 14 optionally includes wherein the pivoting point is positioned within the trial stem.

In Example 16, the subject matter of Example 15 optionally includes wherein the slide device comprises an arcuate track in which the slide pin is configured to move.

In Example 17, the subject matter of any one or more of Examples 10-16 optionally include wherein the guide axis is offset from the insertion axis.

In Example 18, the subject matter of any one or more of Examples 10-17 optionally include wherein the single plane in which the reaming guidepost pivots is angled relative to the insertion axis.

In Example 19, the subject matter of any one or more of Examples 1-18 optionally include an insertion tool configured to attach to the trial stem by sliding over the reaming guidepost; and an alignment device couplable to the insertion tool to indicate alignment of the reaming guidepost relative to the trial stem.

In Example 20, the subject matter of any one or more of Examples 1-19 optionally include a cannulated reamer configured to slide along the reaming guidepost.

Example 21 is a method of reaming an intramedullary canal of a long bone to form a complex shaped socket, the method comprising: inserting a stem into the intramedullary canal along an insertion axis; connecting a guide device to the stem, the guide device comprising a guidepost extending along a guide axis; and guiding a cannulated reamer along the guidepost to remove bone from the intramedullary canal to form the complex shaped socket; wherein the guide axis and the insertion axis are non-aligned.

In Example 22, the subject matter of Example 21 optionally includes wherein non-aligned comprises at least one of offset, angled, and pivotable relationships between the stem and the guidepost.

In Example 23, the subject matter of Example 22 optionally includes wherein non-aligned comprises at least two of offset, angled, and pivotable relationships between the stem and the guidepost.

In Example 24, the subject matter of any one or more of Examples 21-23 optionally include wherein guiding the cannulated reamer along the guidepost comprises guiding the cannulated reamer along a fixed guidepost.

In Example 25, the subject matter of Example 24 optionally includes wherein the fixed guidepost is offset relative to the stem.

In Example 26, the subject matter of Example 25 optionally includes wherein the fixed guidepost is parallel to the stem.

In Example 27, the subject matter of any one or more of Examples 25-26 optionally include wherein the fixed guidepost is angled relative to the stem.

In Example 28, the subject matter of any one or more of Examples 21-27 optionally include pivoting the guidepost relative to the stem using the cannulated reamer.

In Example 29, the subject matter of Example 28 optionally includes sweeping the cannulated reamer along an arc to move the cannulated reamer in a fixed vertical plane.

In Example 30, the subject matter of any one or more of Examples 28-29 optionally include articulating the cannulated reamer within a conical reaming envelope to move the cannulated reamer in a fixed horizontal plane.

In Example 31, the subject matter of Example 30 optionally includes moving the guidepost against a reaming template.

In Example 32, the subject matter of any one or more of Examples 28-31 optionally include engaging stops of the guidepost with the guide device to limit pivoting of the guidepost.

In Example 33, the subject matter of any one or more of Examples 21-32 optionally include connecting the guide device to the stem before inserting the stem into the intramedullary canal; sliding an insertion tool over the guidepost; and attaching the insertion tool to the stem.

In Example 34, the subject matter of Example 33 optionally includes positioning an alignment device attached to the insertion tool to rotationally align the guide device with long bone.

Example 35 is a system for reaming an intramedullary canal of a long bone, the system comprising: a trial stem configured to extend into the long bone along an insertion axis; and a guide device comprising: an adapter configured to couple to the trial stem; a reaming guidepost extending from the adapter along a guide axis; and a pivoting coupler connecting the reaming guidepost to the adapter; wherein the pivoting coupler produces a projected pivot point along the insertion axis spaced longitudinally from the adapter.

In Example 36, the subject matter of Example 35 optionally includes wherein the pivoting coupler comprises a spherical articulating interface.

In Example 37, the subject matter of Example 36 optionally includes wherein the spherical articulating interface comprises: a spherical plate on the adapter; and a spherical ledge on the reaming guidepost against which the spherical ledge is configured to slide.

In Example 38, the subject matter of Example 37 optionally includes wherein a center of curvature for the spherical plate and the spherical ledge are coincident with the projected pivot point.

In Example 39, the subject matter of any one or more of Examples 37-38 optionally include wherein the spherical plate comprises a template through which a post of the reaming guidepost extends.

In Example 40, the subject matter of Example 39 optionally includes wherein the template comprises a D-shaped oval.

In Example 41, the subject matter of any one or more of Examples 39-40 optionally include a spherical knob extending from the post of the reaming guidepost, wherein the spherical knob and the spherical ledge form a spherical socket in which the spherical plate is disposed.

In Example 42, the subject matter of Example 41 optionally includes wherein the adapter comprises: a coupler configured to engage the trial stem; and a limiter having the spherical plate; wherein the spherical knob is configured to be positioned between the coupler and the limiter.

In Example 43, the subject matter of any one or more of Examples 37-42 optionally include wherein the spherical plate and the spherical ledge have concentric spherical surfaces disposed about centerlines of the reaming guidepost and the trial stem, respectively.

In Example 44, the subject matter of any one or more of Examples 36-43 optionally include wherein an axis of the reaming guidepost is configured to coaxially align with an axis of the trial stem.

In Example 45, the subject matter of any one or more of Examples 35-44 optionally include wherein the pivoting coupler comprises an arcuate articulating interface.

In Example 46, the subject matter of Example 45 optionally includes wherein the arcuate articulating interface comprises: an arcuate plate on the adapter; and an arcuate ledge on the reaming guidepost against which the arcuate ledge is configured to slide.

In Example 47, the subject matter of Example 46 optionally includes wherein a center of curvature for the arcuate plate and the arcuate ledge are coincident with the projected pivot point.

In Example 48, the subject matter of any one or more of Examples 46-47 optionally include wherein the reaming guidepost comprises: a first sidewall extending from the arcuate ledge; and an arcuate knob extending from the first sidewall.

In Example 49, the subject matter of Example 48 optionally includes wherein the adapter comprises: a second sidewall extending from the arcuate plate; and an arcuate base extending from the second sidewall; wherein the arcuate base and the arcuate plate form an arcuate channel to receive the arcuate knob.

In Example 50, the subject matter of Example 49 optionally includes an arcuate channel in the second sidewall; a bore in the arcuate knob; and a pin configured to extend through the arcuate channel to engage the bore.

In Example 51, the subject matter of any one or more of Examples 46-50 optionally include wherein the arcuate plate and the arcuate ledge have concentric arcuate surfaces disposed about centerlines of the reaming guidepost and the trial stem, respectively.

In Example 52, the subject matter of any one or more of Examples 45-51 optionally include wherein an axis of the reaming guidepost is angled relative to an axis an axis of the trial stem in a direction separate from the arcuate articulating interface.

In Example 53, the subject matter of any one or more of Examples 45-52 optionally include wherein an axis of the reaming guidepost is offset from an axis of the trial stem.

In Example 54, the subject matter of any one or more of Examples 35-53 optionally include a reamer having a trapezoidal shaped reaming head, wherein angulation of the pivoting coupler corresponds to angles walls of the trapezoidal shaped reaming head.

Example 55 is a method of reaming an intramedullary canal of a long bone to form a complex shaped socket, the method comprising: inserting a stem into the intramedullary canal along an insertion axis; connecting a guide device to the stem, the guide device comprising a guidepost extending along a guide axis; guiding a cannulated reamer along the guidepost to remove bone from the intramedullary canal to form the complex shaped socket; and pivoting the guidepost relative to the stem with the cannulated reamer; wherein a projected pivot point along the insertion axis spaced longitudinally from the guide device along the insertion axis.

In Example 56, the subject matter of Example 55 optionally includes wherein pivoting the guidepost relative to the stem comprises moving the guidepost along an arcuate path in a spherical envelope.

In Example 57, the subject matter of Example 56 optionally includes wherein pivoting the guidepost relative to the stem comprises moving the guidepost three-hundred-sixty degrees about the insertion axis.

In Example 58, the subject matter of any one or more of Examples 56-57 optionally include wherein pivoting the guidepost relative to the stem comprises sliding a spherical plate of the guide device against a spherical ledge of the guidepost.

In Example 59, the subject matter of Example 58 optionally includes wherein pivoting the guidepost relative to the stem comprises engaging a post of the guidepost with a template in the spherical plate.

In Example 60, the subject matter of any one or more of Examples 55-59 optionally include wherein pivoting the guidepost relative to the stem comprises moving the guidepost along an arcuate path in a planar envelope.

In Example 61, the subject matter of Example 60 optionally includes wherein pivoting the guidepost relative to the stem comprises moving the guidepost back and forth across the insertion axis.

In Example 62, the subject matter of any one or more of Examples 60-61 optionally include wherein pivoting the guidepost relative to the stem comprises sliding an arcuate plate of the guide device against an arcuate ledge of the guidepost.

In Example 63, the subject matter of Example 62 optionally includes wherein pivoting the guidepost relative to the stem comprises sliding an arcuate knob of the guidepost with an arcuate channel of the guide device.

Example 64 is a system for reaming an intramedullary canal of a long bone, the system comprising: a trial stem configured to extend into the long bone along an insertion axis, an angled stem extension comprising: a shaft; and a coupler configured to rotatably attach the shaft to the trial stem at an angle to the insertion axis; and a fastener for selectively locking rotation of the angled stem extension relative to the trial stem.

In Example 65, the subject matter of Example 64 optionally includes wherein the fastener axially couples the angled stem extension to the trial stem.

In Example 66, the subject matter of Example 65 optionally includes wherein the fastener can be threadedly engaged with the trial stem to rotationally immobilize the angled stem extension.

In Example 67, the subject matter of any one or more of Examples 64-66 optionally include wherein the coupler includes a slot shaped to fit around a head of the fastener in a radial direction.

In Example 68, the subject matter of Example 67 optionally includes wherein the shaft includes a first aperture to allow access to the head of the fastener.

In Example 69, the subject matter of any one or more of Examples 64-68 optionally include a template device comprising: a handle configured to slide over the angled stem extension; and a template attached to the handle, the template having an outline of an implant to be inserted into the long bone.

In Example 70, the subject matter of Example 69 optionally includes wherein the handle comprises: a cannulated shaft; a grip located at a proximal end of the shaft; and a head located at a distal end of the shaft to which the template is attached.

In Example 71, the subject matter of Example 70 optionally includes wherein the shaft of the handle comprises: a second aperture configured to allow access to the fastener; and a window configured to allow viewing of the angled stem extension within the cannulated shaft.

In Example 72, the subject matter of any one or more of Examples 70-71 optionally include wherein: the grip extends perpendicular to the insertion axis; and the template is connected to the head so as to extend in a plane perpendicular to the insertion axis when the template device is attached to the angled stem extension.

In Example 73, the subject matter of any one or more of Examples 70-72 optionally include wherein the template includes markers configured to indicate a tolerance band for a portion of the template to be placed at the anterior-most point of the long bone.

In Example 74, the subject matter of any one or more of Examples 64-73 optionally include a secondary reaming guide comprising: a broach body configured to inserted into a bone pocket produced by a cannulated reamer sliding over the angled stem extension; a first angled broach guidepost extending from the broach body; and a second angled broach guidepost extending form the broach body; wherein the first and second angled broach guideposts extend in medial-posterior and lateral-posterior directions relative to the insertion axis, respectively.

Example 75 is a method of reaming an intramedullary canal of a long bone to form a bone pocket, the method comprising: inserting a stem into the intramedullary canal along an insertion axis; orienting an angled stem extension post relative to the stem; attaching a template to the angled stem extension post; rotating the template along with the angled stem extension to align the template with anatomic features of the long bone; locking a rotational position of the angled stem extension post relative to the stem; removing the template; and reaming the intramedullary canal along the angled stem extension.

In Example 76, the subject matter of Example 75 optionally includes wherein orienting the angled stem extension post relative to the stem comprises roughly aligning the angled stem extension toward a posterior side of the long bone.

In Example 77, the subject matter of any one or more of Examples 75-76 optionally include wherein rotating the template along with the angled stem extension to align the template with anatomic features of the long bone comprises positioning a perimeter of the template within an outer perimeter of the long bone.

In Example 78, the subject matter of any one or more of Examples 75-77 optionally include wherein attaching the template to the angled stem extension post further comprises: sliding a shaft of a template handle over the angled stem extension, wherein the template is attached to an exterior of the shaft.

In Example 79, the subject matter of Example 78 optionally includes wherein rotating the template along with the angled stem extension to align the template with anatomic features of the long bone comprises: rotating a grip attached to the shaft to extend in the medial-lateral direction relative to the long bone.

In Example 80, the subject matter of any one or more of Examples 75-79 optionally include wherein reaming the intramedullary canal along the angled stem extension comprises sliding a cannulated reamer along the angled stem extension to form the bone pocket in the long bone.

In Example 81, the subject matter of Example 80 optionally includes removing the stem along with the angled stem extension from the intramedullary canal, inserting a secondary ream guide into the bone pocket; and performing a secondary reaming operation using the secondary ream guide to modify the bone pocket.

In Example 82, the subject matter of Example 81 optionally includes wherein performing the secondary reaming operation using the secondary ream guide comprises: sliding a secondary reamer over a first guidepost of the secondary ream guide to widen the bone pocket in a medial direction; and sliding the secondary reamer over a second guidepost of the secondary ream guide to widen the bone pocket in a lateral direction.

In Example 83, the subject matter of any one or more of Examples 81-82 optionally include wherein the secondary ream guide comprises: a broach portion configured to broach the bone pocket; and first and second secondary ream guideposts extending from the broach portion; wherein the first and second secondary ream guideposts extend in medial-posterior and lateral-posterior directions relative to the insertion axis, respectively.