Implant insertion tool for use in a surgical procedure to implant a stemless humeral component

A stemless humeral component for replacing the humeral head of a patient's humerus includes a support flange having a number of cantilevered legs extending distally away from a bottom surface thereof. Instruments and methods for surgically installing the stemless humeral component are also disclosed.

CROSS REFERENCE

Cross reference is made to copending U.S. patent application Ser. No. 13/803,272 entitled “STEMLESS HUMERAL COMPONENT OF AN ORTHOPAEDIC SHOULDER PROSTHESIS”; copending U.S. patent application Ser. No. 13/803,526 entitled “SURGICAL METHOD FOR IMPLANTING A STEMLESS HUMERAL COMPONENT TO THE HUMERUS OF A PATIENT”; copending U.S. patent application Ser. No. 13/803,514 entitled “SIZING INSTRUMENT AND PUNCH FOR USE IN A SURGICAL PROCEDURE TO IMPLANT A STEMLESS HUMERAL COMPONENT”; and copending U.S. patent application Ser. No. 13/803,496 entitled “DRILL GUIDE FOR USE IN A SURGICAL PROCEDURE TO IMPLANT A STEMLESS HUMERAL COMPONENT”, each of which is assigned to the same assignee as the present application, each of which is filed concurrently herewith, and each of which is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates generally to orthopaedic implants, instruments, and surgical methods, and more particularly to a stemless humeral component of an orthopaedic shoulder implant, along with its associated surgical instruments and methods.

BACKGROUND

During the lifetime of a patient, it may be necessary to perform a shoulder replacement procedure on the patient as a result of, for example, disease or trauma. In a shoulder replacement procedure, a humeral prosthesis is used to replace the natural head of the patient's humerus. The humeral prosthesis typically includes an elongated stem component that is implanted into the intramedullary canal of the patient's humerus and a generally hemispherically-shaped prosthetic head component that is secured to the stem component. In some shoulder replacement procedures, the natural glenoid surface of the scapula may be resurfaced or otherwise replaced with a glenoid component that provides a bearing surface upon which the prosthetic head component of the humeral prosthesis articulates.

SUMMARY

According to one aspect, a stemless humeral component is used as a substitute for a conventional humeral intramedullary stem component. In such a way, the stemless humeral component functions as a mounting structure for a humeral head component, but does so without removal of bone tissue from the intramedullary canal of the patient's humerus as would be the case with a conventional humeral stem component.

In an embodiment, the stemless humeral component includes a support flange having a number of cantilevered legs extending distally away from a bottom surface thereof. Each of the legs may be generally T-shaped when viewed from a bottom elevational view.

The stemless humeral component may have a number of viewing windows formed therein to allow the surgeon to visualize the surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head) to ensure the stemless humeral component is fully seated during surgical implantation thereof. The stemless humeral component may have a number of revision slots formed therein that permit a surgeon to pass an osteotome or other cutting instrument to cut or otherwise break the bony ongrowth, thereby facilitating removal of the stemless humeral component during a revision procedure.

The stemless humeral component may also include an elongated sleeve extending distally away from the bottom surface of its support flange. The sleeve may have a tapered bore formed therein. A tapered post of the humeral head component may be inserted into, and thereafter further urged into, the tapered bore of the stemless humeral component's elongated sleeve so as to taper lock the humeral head component to the stemless humeral component.

According to another aspect, an impaction handle may be used in a surgical procedure to implant the stemless humeral component. The impaction handle includes an attachment mechanism that allows the handle to be secured to a number of different instruments used during a surgical procedure to implant the stemless humeral component.

According to another aspect, an alignment handle may be used in a surgical procedure to implant the stemless humeral component. Like the impaction handle, the alignment handle includes an attachment mechanism that allows the handle to be secured to a number of different instruments used during a surgical procedure to implant the stemless humeral component.

According to another aspect, a sizing instrument may be used in a surgical procedure to implant the stemless humeral component. The sizing instrument is generally dome-shaped and may be secured to the patient's surgically-prepared humeral surface during a procedure to implant the stemless humeral component to function as both a sizing trial and a punch and drill guide.

According to another aspect, a trial head component is used for fit assessment during a surgical procedure to implant the stemless humeral component. It may also function as a trial instrument for the humeral head component, and, as such, includes a generally hemispherically-shaped body. The trial head component may also function as a drill guide for guiding a drill bit used to drill (or pre-drill) the holes in the patient's surgically-prepared humeral surface to receive the legs of the stemless humeral component.

According to yet another aspect, a surgical punch may be used to punch holes in the patient's surgically-prepared humeral surface to receive the legs of the stemless humeral component. In an embodiment, the surgical punch is generally fork-shaped and includes a number of tines that correspond in shape, size, and location with the legs of the stemless humeral component.

According to another aspect, a center drill bit may be used to surgically drill (or pre-drill) a hole in the patient's surgically-prepared humeral surface to receive the elongated sleeve of the stemless humeral component. A peripheral drill bit, on the other hand, may be used to drill (or pre-drill) the holes in the patient's surgically-prepared humeral surface to receive the legs of the stemless humeral component.

According to another aspect, an adjustable head resection guide may be used as a cutting guide to guide the advancement of a bone saw blade to resect the humeral head of the patient. The head resection guide may include an arcuate-shaped, stationary cutting guide secured and a movable cutting guide that is movable in a direction toward and away from the stationary cutting guide. In such a way, the adjustable head resection guide may function as a universally-sized instrument.

According to another aspect, a non-adjustable head resection guide may be used as a cutting guide to guide the advancement of a bone saw blade to resect the humeral head of the patient. The head resection guide may include a generally rectangular-shaped base having a circular-shaped ring secured thereto. The ring may extend outwardly from the base and define a circular-shaped opening. The patient's humeral head may be captured in the opening during resection thereof.

According to a further aspect, an implant insertion tool may be used to facilitate implantation of the stemless humeral component into the patient's surgically-prepared humeral surface. In an embodiment, the implant insertion tool functions as a “quick connect” instrument having a locked position in which the stemless humeral component is locked thereto, and an unlocked position in which the stemless humeral component is released therefrom. In another embodiment, the implant insertion tool may include a locking rod configured to be threadingly-engaged with the stemless humeral component. In another embodiment, the implant insertion tool may include a threaded end that is configured to engage the stemless humeral component and an aperture sized to receive a connecting pin of an impaction handle. In yet another embodiment, the implant insertion tool may include a locking rod configured to be threadingly-engaged with the stemless humeral component and an aperture sized to receive a connecting pin of an impaction handle.

According to another aspect, a head impaction tool may be used to impact, and hence taper lock, the head component to the stemless humeral component. The head impaction tool may include a rounded, concave impact surface that is sized, shaped, and positioned to closely conform to the convex, generally hemispherically-shaped outer surface of the head component.

DETAILED DESCRIPTION OF THE DRAWINGS

Terms representing anatomical references, such as anterior, posterior, medial, lateral, superior, inferior, etcetera, may be used throughout this disclosure in reference to both the orthopaedic implants described herein and a patient's natural anatomy. Such terms have well-understood meanings in both the study of anatomy and the field of orthopaedics. Use of such anatomical reference terms in the specification and claims is intended to be consistent with their well-understood meanings unless noted otherwise.

Referring now toFIGS. 1-5, there is shown a stemless humeral component10. As will be described in more detail below, the stemless humeral component10is used as a substitute for a conventional humeral intramedullary stem component. In such a way, the stemless humeral component10functions as a mounting structure for a humeral head component12(seeFIGS. 35 and 36), but does so without removal of bone tissue from the intramedullary canal of the patient's humerus as would be the case with a conventional humeral stem component.

The stemless humeral component10includes a support flange14having a number of legs16extending distally away from a bottom surface18thereof. In the illustrative embodiment described herein, the support flange14is circular in shape. The top surface20of the support flange14includes an annular-shaped, beveled surface22. An annular ring24extends around the periphery of the support flange's beveled surface22. The annular ring24has a number of suture holes26formed therein. The suture holes26may be used to suture bone wafers or soft tissue to the stemless humeral component10. For example, the natural attachment of the patient's rotator cuff may be preserved by harvesting a bone wafer around it and then suturing such a bone wafer to the stemless humeral component10by use of the suture holes26.

The support flange's annular ring24also has a number of revision slots28formed therein. As can be seen inFIGS. 1 and 4, one of the revision slots28is positioned on the annular ring24at a location above, and radially outwardly from, each of the legs16. In such a way, an osteotome or other cutting instrument may be passed through the revision slots to cut or otherwise break the bony ongrowth to the legs16thereby facilitating removal of the stemless humeral component10during a revision procedure.

The support flange14also has a number of viewing windows30formed therein. The viewing windows30allow the surgeon to visualize the surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head) to ensure the stemless humeral component10is fully seated during surgical implantation thereof. It should be appreciated that the viewing windows30may also function as additional revision slots through which the surgeon may pass an osteotome or other cutting instrument slots to cut or otherwise break the bony ongrowth to the legs16thereby facilitating removal of the stemless humeral component10during a revision procedure.

As can be seen inFIGS. 2 and 5, an elongated sleeve36extends distally away from a bottom surface18of the support flange14in the same general direction as the legs16. The sleeve36includes a tapered distal end38that functions as a lead-in to facilitate insertion into a hole drilled or otherwise formed in the patient's surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head). The elongated sleeve36has a tapered bore40formed therein. A tapered post42extends laterally out of the backside surface of the humeral head component12(i.e., the side opposite the humeral head component's generally hemispherically-shaped outer bearing surface) and is received into the tapered bore40of the stemless humeral component's elongated sleeve36(seeFIG. 36). As will be discussed below in greater detail below, urging the tapered post42of the humeral head component12into contact with the sidewall defining the tapered bore40of the elongated sleeve36taper locks the humeral head component12to the stemless humeral component10. As can be seen inFIG. 5, the upper end44of the tapered bore40opens into the top surface20of the support flange14, with the lower, distal end46of the tapered bore40opening into a threaded bore48. The threaded bore48extends distally away from the distal end46of the tapered bore40and opens into the distal end38of the elongated sleeve36. As can be seen inFIG. 5, a number of threads50are formed in the sidewall that defines the threaded bore48. The threads50are sized to match, and hence threadingly receive, the threads of an implant retraction tool (not shown) or, as discussed in more detail below, an implant insertion tool.

As can be seen inFIGS. 2, 4, and 5, each of the legs16is cantilevered and, as a result, includes one end secured to the bottom surface18of the support flange14with the other end of the leg16being free (i.e., not secured to the support flange14, any of the other legs16, or any other structure of the stemless humeral component10). As can also be seen inFIGS. 2, 4, and 5, each of the legs16is generally T-shaped when viewed from a bottom elevational view (i.e., a view that is orthogonal to the longitudinal axis of the leg16) and, as a result, has a T-shaped lateral cross section (i.e., a cross section taken in the plane orthogonal to the longitudinal axis of the leg). In such an arrangement, each of the legs16has a bone-engaging plate52having a number of serrations54formed in a side thereof that faces outwardly from the elongated sleeve36(and hence the center of the support flange14). As can be seen best inFIG. 5, each of the serrations54is angled upwardly in a direction toward the support flange14(i.e., in a direction away from the distal end56of the leg16). When implanted in bone tissue, such upwardly angled serrations54engage the bone tissue in a manner that resists pullout of the stemless humeral component10. An elongated rib58extends along the length of the engaging plate52and, as such, forms the “trunk” of the T-shaped leg16, with the bone-engaging plate52forming its “cross bar”. Specifically, the rib58is secured to the backside of the leg's engaging plate52(i.e., the side opposite the serrations54) and extends inwardly in the direction toward the center of the support flange14. The longitudinal axis of the rib58is parallel with the longitudinal axis of the engaging plate52. As can be seen inFIGS. 2 and 5, each of the legs16includes a beveled distal end62that functions as a lead-in to facilitate insertion of the leg16into a hole punched or otherwise formed in the patient's surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head).

As can be seen best inFIGS. 2 and 4, the bottom surface18of the stemless humeral component's support flange14has a number of undercuts70formed therein. In the illustrative embodiment described herein, the undercuts70are positioned radially around the elongated sleeve36about 90° from one another. As can be seen inFIGS. 2 and 4, the position of the undercuts70coincides with the radial position of each of the viewing windows30. Specifically, the undercuts70are formed in the same sidewall72that defines the radially inner surface of each of the viewing windows30(i.e., the surface defining the viewing windows30closest to the center of the stemless humeral component10). Each of the undercuts70takes the form of a lip74that extends radially inwardly into its corresponding viewing window30. In such an arrangement, as will be discussed below in more detail, the lips74of the undercuts70are positioned to be engaged by a locking pawl of an implant insertion tool.

The stemless humeral component10may be constructed with an implant-grade biocompatible metal, although other materials may also be used. Examples of such metals include cobalt, including cobalt alloys such as a cobalt chrome alloy, titanium, including titanium alloys such as a Ti6Al4V alloy, and stainless steel. Such a metallic stemless humeral component10may also be coated with a surface treatment, such as hydroxyapatite, to enhance biocompatibility. Moreover, the surfaces of the stemless humeral component10that engage the natural bone, such as the bottom surface18of the support flange14, the outer surfaces of the elongated sleeve36, and the legs16, may be textured to facilitate securing the component to the bone. Such surfaces may also be porous coated to promote bone ingrowth for permanent fixation.

The stemless humeral component10and the head component12may be provided in various different configurations to provide the flexibility necessary to conform to varying anatomies from patient to patient. For example, the stemless humeral component10and the head component12may be provided in various diameters to match the needs of a given patient. It should be appreciated that the head thickness changes with the diameter of the head.

Referring now toFIGS. 6-24, there is shown a set of surgical instruments that may be used for the surgical preparation of the patient's humerus and the subsequent implantation of the stemless humeral component10. The first of such instruments is an impaction handle80shown inFIGS. 6 and 7. As will be described below in more detail, the impaction handle80may be secured to a surgical punch or the stemless humeral component10to facilitate implantation of the stemless humeral component10into the patient's surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head). The impaction handle80includes an elongated body82having an impact head84on one end and an attachment mechanism86on its other end. A sleeve88is positioned around, and immovably coupled to, the outer surface of the impaction handle's body82such as by, for example, overmolding. The sleeve88functions as a grip for allowing the surgeon to hold the impaction handle80during a surgical procedure to implant the stemless humeral component10.

The impact head84of the impaction handle80includes a circular metal plate90having an extraction flange92extending therefrom. In use, the surgeon holds the impaction handle80via the grip88and strikes the metal plate90with a surgical mallet, sledge, or other impaction tool to drive the surgical punch240(seeFIG. 14) or the stemless humeral component10into the patient's surgically-prepared humeral surface.

The attachment mechanism86of the impaction handle80includes a lever94pivotally coupled to the impaction handle's body82. The lever94includes a latching arm96and an actuation arm98extending at an angle from one end of the latching arm96. A locking pawl102is positioned at an opposite end of the latching arm96and extends downwardly therefrom. The locking pawl102is configured to engage a lip or similar structure formed in one of the surgical instruments described herein (e.g., the surgical punch or the implant insertion tool) to selectively secure such instruments to the impaction handle80. A connecting pin104is formed in the distal end of the impaction handle's body82. The connecting pin104extends outwardly from an annular face106and has a cross section that substantially matches the shape of the corresponding opening defined in a number of the surgical instruments described herein (e.g., the surgical punch or the implant insertion tool). As shown inFIG. 6, the connecting pin104is substantially D-shaped in cross section and, as a result, includes a flat face108.

The latching arm96of the lever94extends beyond the annular face106such that the locking pawl102is positioned over the connecting pin104and extends toward its flat face108. This arrangement permits the locking pawl102to engage a lip or similar structure formed in a number of the surgical instruments described herein (e.g., the surgical punch or the implant insertion tool) to selectively secure such instruments to the impaction handle80.

As shown inFIG. 7, a biasing element, such as spring110is coupled to the lever94. The spring110biases the lever's locking pawl102toward the flat face108of the connecting pin104. In doing so, the bias of the spring110locks the locking pawl102, and hence the impaction handle80, to a number of the surgical instruments described herein (e.g., the surgical punch or the implant insertion tool). When a surgeon or other user presses down on the lever's actuation arm98, the bias exerted by the spring110is overcome, thereby causing the lever94to pivot. As the lever94is pivoted, the locking pawl102is moved in a direction away from the flat face108of the connecting pin104. In such a way, the impaction handle80may be released from the surgical instrument to which it is coupled.

The metallic components of impaction handle80(e.g., the impact handle's body82) may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used. The grip88may be constructed from a polymer such as silicone.

Referring now toFIGS. 8 and 9, there is shown an alignment handle120. As will be described below in more detail, the alignment handle120may be secured to a sizing instrument or cutting guide during a procedure to implant the stemless humeral component10into the patient's surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head). The alignment handle120includes an elongated body122having an attachment mechanism126on its distal end. A sleeve128is positioned around, and immovably coupled to, the outer surface of the impaction handle's body122such as by, for example, overmolding. The sleeve128functions as a grip for allowing the surgeon to hold the alignment handle120during a surgical procedure to implant the stemless humeral component10.

The attachment mechanism126of the alignment handle120is similar to the attachment mechanism86of the impaction handle80and, as such, includes a lever134pivotally coupled to the impaction handle's body122. The lever134includes a latching arm136and an actuation arm138extending at an angle from one end of the latching arm136. A locking pawl142is positioned at an opposite end of the latching arm136and extends downwardly therefrom. The locking pawl142is configured to engage a lip or similar structure formed in the sizing instrument160(seeFIG. 10) to secure the sizing instrument160to the alignment handle120. A keying pin144is formed in the distal end of the alignment handle's body122. The keying pin144extends outwardly from an annular face146and has a cross section that substantially matches the shape of the corresponding key-hole shape opening184defined in the sizing instrument160(seeFIG. 10). As shown inFIG. 8, the keying pin144is key-shaped in cross section and, as a result, includes a round portion having a rectangular portion secured thereto.

The latching arm136of the lever134extends beyond the annular face146such that the locking pawl142is positioned over the keying pin144and extends toward its upper surface. This arrangement permits the locking pawl142to engage a lip or similar structure formed in the sizing instrument160(seeFIG. 10) to secure the sizing instrument160to the alignment handle120.

As shown inFIG. 7, a biasing element, such as spring150is coupled to the lever134. The spring150biases the lever's locking pawl142toward the upper surface of the keying pin144. In doing so, the bias of the spring150locks the locking pawl142, and hence the alignment handle120, to the sizing instrument160. When a surgeon or other user presses down on the lever's actuation arm138, the bias exerted by the spring150is overcome, thereby causing the lever134to pivot. As the lever134is pivoted, the locking pawl142is moved in a direction away from the upper surface of the keying pin144. In such a way, the alignment handle120may be released from the sizing instrument160.

The metallic components of alignment handle120(e.g., the alignment handle's body122) may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used. The grip128may be constructed from a polymer such as silicone.

Referring now toFIGS. 10 and 11, there is shown the sizing instrument160. As will be described below in more detail, the sizing instrument160may be secured to the patient's surgically-prepared humeral surface during a procedure to implant the stemless humeral component10to function as both a sizing trial and a punch and drill guide.

The sizing instrument160includes a generally dome-shaped body162having flattened upper surface164and a substantially planar lower surface166. An elongated bore168extends through the center of the sizing instrument160from its upper surface164to its lower surface166. As will be described below in greater detail, the elongated bore168functions as a drill guide for drilling a hole in the patient's surgically-prepared humeral surface to receive the elongated sleeve36of the stemless humeral component10(seeFIGS. 2 and 5).

The sizing instrument160also includes a number of generally triangular-shaped punch guide holes170. As can be seen inFIG. 10, each of the punch guide holes170is located in one of the four quadrants of the sizing instrument's round flange172. As such, each of the punch guide holes170is positioned about 90° from one another. As can be seen inFIGS. 2 and 4, the position of the punch guide holes170coincides with the position of the legs16of the stemless humeral component10. As such, the holes170function as a punch guide for punching holes in the patient's surgically-prepared humeral surface to receive the legs16of the stemless humeral component10(seeFIG. 29). To that end, the position of the punch guide holes170also coincides with the position of each of the tines252of the surgical punch240(seeFIG. 14). As such, each of the tines252may be aligned with, and advanced through, one of the punch guide holes170. In such a way, the sizing component160guides the surgeon's use of the surgical punch240while surgically preparing the patient's humeral surface to receive the legs16of the stemless humeral component10(seeFIG. 29).

As can be seen inFIG. 11, the sizing instrument160has a number of spikes174extending downwardly from its lower surface166. Each of the spikes174has a pointed distal tip176. The spikes174are pressed or otherwise driven into the bone tissue of the patient's surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head) to secure the sizing instrument160in place during its use. A number of pin holes178are also formed in the sizing instrument's body162near its outer periphery. When a surgeon desires to supplement the attachment functionality of the spikes174, surgical pins (not shown) may be inserted through the pin holes178to pin the sizing instrument160to the bone tissue of the patient's surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head).

Like the stemless humeral component10, the sizing instrument's flange172also has a number of viewing windows180formed therein. The viewing windows180allow the surgeon to visualize the surgically-prepared humeral surface (i.e., the surface created by surgically resecting the humeral head) to ensure the sizing instrument160is fully seated during its use in the surgical procedure.

As can be seen inFIG. 10, the sizing instrument160has a connector182that may be engaged by the attachment mechanism126of the alignment handle120to secure the sizing instrument160to the alignment handle120. The connector182has a key-hole shaped opening184formed therein. The key-hole opening184is sized and shaped to receive the keying pin144formed in the distal end of the alignment handle's body122. The connector182also has a channel186formed therein. The connector182has an undercut188formed along the length of the channel186. The undercut188takes the form of a lip190positioned at the top of the channel186and extending outwardly into the channel186. The lip190is engaged by the locking pawl142of the alignment handle's attachment mechanism126(seeFIGS. 8 and 9) to secure the sizing instrument160to the alignment handle120.

As can be seen inFIG. 10, the connector182is confined within the sizing instrument's dome-shaped profile. As will be described below in greater detail, such an arrangement allows a trial humeral head to be installed on the sizing instrument without interference from the connector182.

Like the other instruments and implants described herein, the sizing instrument160may be provided in a number of different sizes. For example, in the illustrative embodiment described herein, the sizing instrument160may be embodied in different diameters so as to mimic the various possible diameters of the stemless humeral component10.

The sizing instrument160may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used. The polymers may be injection molded as well.

Referring now toFIGS. 12 and 13, there is shown a trial head component210. The trial head component210is used for fit assessment during a surgical procedure to implant the stemless humeral component10and the humeral head component12. In essence, the trial head component210is used to ensure proper size selection of the ultimate humeral head component12(i.e., the humeral head component12that is ultimately implanted in the patient's humerus). As will be discussed below in greater detail, the trial head component also functions as a drill guide for guiding a drill bit used to drill (or pre-drill) the holes in the patient's surgically-prepared humeral surface to receive the legs16of the stemless humeral component10(seeFIGS. 31 and 32).

In the illustrative embodiment described herein, the trial head component210is embodied as a polymer trial instrument. As such, the trial head component210may be made of any suitable medical-grade polymeric material. Examples of such polymeric materials include polyethylene such as polyetheretherketone (PEEK) or acetal. In other embodiments, the trial head component may be formed from metal.

As a trial instrument for the humeral head component12, the trial head component210includes a generally hemispherically-shaped body212. As can be seen inFIG. 12, trial head component's body212includes a smooth, rounded, outer surface214that emanates from an annular rim216that defines the great circle of body's generally hemispherical shape. As can be seen inFIG. 12, the trial head component's body212is hollow. A center lug218extends downwardly from the center of the body's concave underside surface220. The center lug218has a number of annular bands222formed in its outer surface224. As will be described in greater detail, the trial head component210may be installed on the sizing instrument160or the stemless humeral component10by inserting the center lug218into the sizing instrument's elongated bore168or the stemless humeral component's tapered bore40. The center lug's annular bands222frictionally engage the stemless humeral component's tapered bore40to frictionally secure the center lug, and hence the trial head component210to the stemless humeral component10.

As can be seen inFIG. 12, the trial head component's body212also has a number of cylindrically-shaped bosses226extending downwardly from the center of the body's concave underside surface220. Each of the bosses226has a cylindrically-shaped metallic sleeve228insert molded or otherwise positioned therein. The sleeves228have an elongated bore230formed therein, with such bores230extending throughout the entire length of the sleeves228. The bores230function as drill guides for guiding a drill bit used to drill (or pre-drill) the holes in the patient's surgically-prepared humeral surface to receive the legs16of the stemless humeral component10(seeFIGS. 31 and 32). As such, the position of each of the guide bores230coincides with, and is received into, the punch guide holes170of the sizing instrument160when the trial head component210is secured to the sizing instrument160(seeFIG. 28). In particular, when the trial head component210is fully seated on the sizing instrument160, the distal end of each of the bosses226formed in the trial head component210is received into a corresponding punch guide hole170of the sizing instrument160thereby aligning the guide bores230in the proper location.

Like the other instruments and implants described herein, the trial head component210may be provided in a number of different sizes. For example, in the illustrative embodiment described herein, the trial head component210may be embodied in different diameters (e.g., 15 mm, 18 mm, or 21 mm) so as to mimic a the diameter of the selected humeral head component12.

Referring now toFIG. 14, there is shown a surgical punch240that is used to punch holes in the patient's surgically-prepared humeral surface to receive the legs16of the stemless humeral component10(seeFIGS. 29 and 30). Similarly to the other instruments described herein, the surgical punch240may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used.

The surgical punch240is generally fork-shaped and includes a metal body242that includes an attachment shaft244. The proximal end of the attachment shaft244has a D-shaped socket260formed therein. The D-shaped socket260is sized, shaped, and positioned to receive the D-shaped connecting pin104of the attachment mechanism86of the impaction handle80(seeFIG. 6). The outer surface of the attachment shaft244has a channel246formed therein. The sidewalls of the shaft244into which the channel246is formed define an undercut248that extends along the length of the channel246. The undercut248takes the form of a lip250positioned at the top of the channel246. When the impaction handle's connecting pin104is inserted in the D-shaped socket260of the surgical punch240and thereafter advanced downwardly, the lip250is engaged by the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to secure the surgical punch240to the impaction handle80.

At the end of the shaft244opposite the channel246, the surgical punch's body242includes a number of tines252. Each of the tines252is secured to the shaft244by a strut268. The tines252function to punch holes in the patient's surgically-prepared humeral surface to receive the legs16of the stemless humeral component10(seeFIGS. 29 and 30) and, as such, correspond in shape, size, and location with the legs16of the stemless humeral component10. Like the legs16of the stemless humeral component10, each of the surgical punch's tines252is generally T-shaped when viewed from a bottom elevation view (i.e., a view that is orthogonal to the longitudinal axis of the tine252). In such an arrangement, each of the tines252has a bone-shaping plate254and an elongated rib256. The elongated rib256extends along the length of the engaging plate254and, as such, forms the “trunk” of the T-shaped tine252, with the engaging plate254forming the “cross bar” of the T-shaped tine252. Specifically, the outer surface of the engaging plate254faces outwardly from the other tines (and hence the longitudinal axis of the surgical punch), with the rib256being secured to the backside of the tine's engaging plate254and extending inwardly in the direction toward the other tines252. The longitudinal axis of the rib256is parallel with the longitudinal axis of the engaging plate254. As can be seen inFIG. 14, each of the tines252includes a beveled distal end258that functions as a lead punch surface. The beveled distal end258also functions as a lead-in surface to facilitate insertion of the tine252into a pre-drilled hole in the patient's surgically-prepared humeral surface.

The position of the tines252coincides with the position of the punch guide holes170of the sizing instrument160. As such, the punch guide holes170function to guide the advancement of the tines252to punch holes in the patient's surgically-prepared humeral surface to receive the legs16of the stemless humeral component10(seeFIGS. 29 and 30). As such, each of the tines252may be aligned with, and advanced through, the punch guide holes170.

The surgical punch's body242also includes a center spike262extending downwardly from the shaft244into the area between the tines252. The center spike262is centered on the longitudinal axis of the surgical punch240. The center spike262includes a pointed distal tip264. The tip264of the center spike262makes a divot in the patient's surgically-prepared humeral surface during use of the surgical punch240to punch holes to receive the legs16of the stemless humeral component10. Such a divot is positioned to receive the elongated sleeve36of the stemless humeral component10.

Referring now toFIGS. 15 and 16, there is shown a center drill bit270and a peripheral drill bit272. The center drill bit270is used to surgically drill a hole in the patient's surgically-prepared humeral surface to receive the elongated sleeve36of the stemless humeral component10. The peripheral drill bit272, on the other hand, is used to drill (or pre-drill) the holes in the patient's surgically-prepared humeral surface to receive the legs16of the stemless humeral component10(seeFIGS. 31 and 32). Each of the drill bits270,272includes an elongated shank274having a proximal end276that fits into the chuck of a rotary power tool (not shown) or a manual handle (not shown). The drill bits270,272also include a cutting head278located at the opposite, distal end of the shank274. The cutting head278of the drill bits270,272includes a sharp cutting tip280with a plurality of helical cutting flutes282extending therefrom.

Each of the drill bits270,272also includes an annular collar284positioned above the cutting head278at the upper end of the cutting flutes282. The collar284functions as a depth stop to ensure the drill bits270,272drill their respective holes at the desired depths. In the case of the center drill bit270, the collar has an outer diameter that is larger than the diameter of the elongated bore168of the sizing instrument160. Hence, the center drill bit270may be advanced into the bone tissue until the lower surface286of the collar284bottoms out or otherwise engages the flattened upper surface164of the sizing instrument160. Likewise, the peripheral drill bit272may be advanced into the bone tissue until the lower surface286of the collar284bottoms out or otherwise engages a rim or shelf within the sleeves228of the trial head component210.

The drill bits270,272may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used.

Referring now toFIGS. 17-19, there is shown a head resection guide290. The head resection guide290is used as a cutting guide to guide the advancement of a bone saw blade to resect the humeral head of the patient. The head resection guide290includes a base292having a pair of rails294extending outwardly therefrom. An arcuate-shaped, stationary cutting guide296is secured to the end of the rails296opposite the base292. Specifically, one end of the stationary cutting guide296is secured to one of the rails294, with the other end of the stationary cutting guide296being secured to the other rail294.

A movable cutting guide298is captured on the rails294and is movable back and forth along the rails294. Specifically, the movable cutting guide298includes a guide body302having a pair of holes304formed therein. One of the guide rails294is positioned in one of the holes304, with the other rail294being positioned in the other hole304. As such, the movable cutting guide298may be moved along the rails294in a direction toward and away from the stationary cutting guide296.

A biasing element, such as a coiled spring306, is captured on each of the rails294. The springs306are positioned between an upper surface308of the base292and the lower surface310of the movable cutting guide's body302. As such, the springs306assert a spring bias on the movable cutting guide298so as to urge it in the direction toward the stationary cutting guide296.

The movable cutting guide's body302also has a finger grip312formed therein. In the illustrative embodiment described herein, the finger grip312is embodied as a flange extending outwardly in a direction that is generally orthogonal to the rails294. A surgeon or other user may grip the finger grip312and the lower surface314of the base292and thereafter squeeze his or her fingers. Doing so overcomes the spring bias of the springs306and urges or otherwise moves the movable cutting guide298in the direction away from the stationary cutting guide296(i.e., in a direction toward the base292). Once the surgeon releases the finger grip312, the spring bias of the springs306urges or otherwise moves the movable cutting guide298in the direction away back toward the stationary cutting guide296(i.e., in a direction away from the base292).

As can be seen best inFIG. 18, both the stationary cutting guide296and the movable cutting guide298include rounded surfaces that cooperate to define a circular-shaped surface for capturing the patient's humeral head therein. Specifically, the stationary cutting guide296includes a rounded, generally semicircular-shaped posterior surface318that faces an rounded, generally semicircular-shaped anterior surface320of the movable cutting guide298. As can be seen inFIGS. 17 and 18, a number of spikes322extend outwardly from each of the semicircular-shaped surfaces318,320toward the opposite semicircular-shaped surface318,320. The spikes322engage the bone tissue of the patient's humerus to maintain the head resection guide290in a desired location and orientation during its use. As such, when a surgeon squeezes the finger grip312and the lower surface314of the base292, the semicircular-shaped surfaces318,320are moved away from one another thereby creating clearance to position the patient's humeral head between them. Thereafter, when the surgeon releases the finger grip312and the lower surface314of the base292, the semicircular-shaped surfaces318,320are toward one another thereby capturing the patient's humeral head therebetween with the spikes322.

As can be seen inFIGS. 17 and 18, the movable cutting guide298has a number of pin holes324formed therein. The axis of each of the pin holes324extends in a direction that is oblique or angled relative to the rails294and the spikes322. As will be discussed in more detail, surgical pins may be inserted through the pin holes324to pin the head resection guide290to the patient's humerus during resection of the patient's natural humeral head.

As can be seen best in the side view ofFIG. 19, both the stationary cutting guide296and the movable cutting guide298include planar surfaces that cooperate to define a cutting guide surface for guiding a bone saw blade to resect the patient's natural humeral head. Specifically, the stationary cutting guide296includes a planar posterior guide surface326that aligns in a coplanar relationship with a planar anterior guide surface328of the movable cutting guide298. Collectively, the two guide surfaces326,328define a cutting surface upon which a bone saw blade may be supported (i.e., guided) during a cutting operation to resect the patient's natural humeral head. As can be seen inFIG. 19, the two guide surfaces326,328lie in a plane that is generally parallel to the rails294and perpendicular to the finger grip312and the lower surface314of the base292.

The head resection guide290may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used.

Referring now toFIGS. 20-23, there is shown an implant insertion tool330. The implant insertion tool330may be secured to the stemless humeral component10to facilitate implantation of the stemless humeral component10into the patient's surgically-prepared humeral surface. The implant insertion tool330includes an elongated body332that defines a cylindrically-shaped shaft334having a connector336on its proximal end. The connector336includes a D-shaped socket338formed in its proximal end. The D-shaped socket338is sized, shaped, and positioned to receive the D-shaped connecting pin104of the attachment mechanism86of the impaction handle80(seeFIG. 6). The outer surface of the body's connector336has a channel340formed therein. The sidewalls of the connector336into which the channel340is formed define an undercut342that extends along the length of the channel340. The undercut342takes the form of a lip344positioned at the top of the channel340. When the impaction handle's connecting pin104is inserted in the D-shaped socket338of the implant insertion tool330and thereafter advanced downwardly, the lip344is engaged by the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to secure the implant insertion tool330to the impaction handle80.

The end of the of the implant insertion tool's body332opposite its connector336has an alignment flange346formed therein. The alignment flange346is embodied as an annular face having a number of protrusions or alignment keys348extending downwardly therefrom. The alignment keys348are sized, shaped, and positioned to be received into the viewing windows30formed in the stemless humeral component10. The alignment flange346also has an alignment pin350extending downwardly from its annular face. The alignment pin350is sized, shaped, and positioned to be received into the tapered bore40formed in the stemless humeral component10.

As can be seen inFIGS. 20 and 21, a pair of locking arms352are pivotally coupled to the insertion tool's body332. Each of the locking arms352has a cam follower354formed in its proximal end, and a generally L-shaped locking pawl356formed in its opposite, distal end. Each of the locking arms352is pivotally coupled to the implant insertion tool's body332at a location near its annular face346by a pivot pin358positioned in a bore360formed in the body332. The locking arms352pivot about the pivot pins358such that movement of the cam followers354in the direction toward one another, and hence toward the shaft334of the insertion tool's body332, causes movement of the locking pawls356in the direction away from one another, and hence away from the alignment pin350of the insertion tool's body332. On the other hand, movement of the cam followers354in the direction away from one another, and hence away from the shaft334of the insertion tool's body332, causes movement of the locking pawls356in the direction toward one another, and hence toward the alignment pin350of the insertion tool's body332.

Such movement of the locking arms352may be used as part of a “quick connect” arrangement to selectively lock and release the stemless humeral component10from the implant insertion tool330. In particular, when the insertion tool's alignment flange346is engaged with the stemless humeral component10such that its alignment pin350and alignment keys348are positioned in the stemless humeral component's tapered bore40and viewing windows30, respectively, the locking pawls356of the locking arms352are positioned in the stemless humeral component's remaining viewing windows30(i.e., the viewing windows30not occupied by the alignment keys348). So positioned, the locking pawls356may be moved into and out of engagement with the lips74of the undercuts70formed in the bottom surface18of the stemless humeral component's support flange14(seeFIGS. 2 and 4). Specifically, the locking pawls356may be moved in the direction toward one another (i.e., toward the alignment pin350of the insertion tool's body332) such that the locking pawls356engage the lips74of the undercuts70formed in the bottom surface18of the stemless humeral component's support flange14thereby securing the stemless humeral component10to the implant insertion tool330. Oppositely, the locking pawls356may be moved in the direction away from one another (i.e., away from the alignment pin350of the insertion tool's body332) such that the locking pawls356disengage the lips74of the undercuts70formed in the bottom surface18of the stemless humeral component's support flange14thereby releasing the stemless humeral component10from the implant insertion tool330.

As can be seen inFIGS. 20 and 21, a rotating locking collar362is captured on the shaft334of the insertion tool's body332. In particular, the locking collar362has a bore364extending through its center, with the shaft334of the insertion tool's body332being received (i.e., positioned) in the bore364. As such, the locking collar362may be rotated both clockwise and counterclockwise about the shaft334of the insertion tool's body332. As can be seen best inFIG. 20, the locking collar362has a pair of channels366formed in its underside. The cam followers354of the locking arms352ride in the channels366as the locking collar362is rotated about the shaft334. The sidewall defining the inner side of the channels366defines a cam surface368. As can be seen inFIG. 20, one end370of the cam surface368is nearer the locking collar's bore364(and hence the shaft334of the insertion tool's body332) than the other end372of the cam surface368. As such, as each of the cam followers354rides along its corresponding cam surface368in the direction from its inner end370to its outer end372, the cam followers354move in the direction away from one another, and hence away from the shaft334of the insertion tool's body332, thereby causing the locking arms352to pivot such that the locking pawls356are moved in a direction toward one another, and hence toward the alignment pin350of the insertion tool's body332. As described above, such movement of the locking pawls356is used to lock the stemless humeral component10to the implant insertion tool330. As can be seen inFIG. 20, in the illustrative embodiment described herein, clockwise rotation of the locking collar362causes the cam followers354to move along the cam surfaces368in such a direction (i.e., in a direction from the cam surface's inner end370to its outer end372).

Oppositely, as each of the cam followers354rides along the corresponding cam surface368in the direction from its outer end372to its inner end370, the cam followers354move in the direction toward one another, and hence toward the shaft334of the insertion tool's body332, thereby causing the locking arms352to pivot such that the locking pawls356are moved in a direction away from one another, and hence away from the alignment pin350of the insertion tool's body332. As described above, such movement of the locking pawls356is used to release the stemless humeral component10from the implant insertion tool330. As can be seen inFIG. 20, in the illustrative embodiment described herein, counterclockwise rotation of the locking collar362causes the cam followers354to move along the cam surfaces368in such a direction (i.e., in a direction from the cam surface's outer end372to its inner end370).

As can be seen inFIGS. 20 and 21, the locking collar362has a pair of guide pins374extending therethrough. The outer end of the guide pins374is positioned near the outer surface of the locking collar362, with its inner end (not shown) positioned in an annular channel (not shown) formed on the outer surface of the shaft334of the insertion tool's body332. The inner end of the guide pins374rides in such a channel during rotation of the locking collar362. The shaft334of the insertion tool's body332also has a pair of linear channels376formed in its outer surface. The linear channels376are arranged parallel to both one another and the longitudinal axis of the shaft334of the insertion tool's body332. When the inner ends of the guide pins374are aligned with, and received into, the linear channels376, the locking collar362may be slid along the shaft334of the insertion tool's body332in the direction toward the connector336(i.e., away from the alignment flange346). In doing so, each of the cam followers352of the locking arms350escape from their respective channels366of the locking collar362. Such an arrangement allows the cam followers352and the channels366of the locking collar362to be fully exposed to cleaning fluid during cleaning of the implant insertion tool330between uses. The cam followers352may be slipped back into their respective channels366of the locking collar362by aligning them with the inner ends370of channels366as the locking collar362is slid along the shaft334of the insertion tool's body332in the direction away from the connector336(i.e., toward the alignment flange346). Thereafter, the locking collar362may be rotated to recapture the cam followers352in their respective channels366of the locking collar362.

The components of the implant insertion tool330(e.g., its body332, locking arms352, and locking collar362) may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used.

Referring now toFIG. 24, there is shown an head impaction tool380. The head impaction tool380may be used to impact, and hence taper lock, the head component12to the stemless humeral component10. The head impaction tool380includes a generally conically-shaped body382having a connector384formed in its proximal end. The connector384includes a round opening386that is sized, shaped, and positioned to receive the connecting pin104of the attachment mechanism86of the impaction handle80(seeFIG. 6). The connector384of the head impaction tool380also has three channels388formed therein. The sidewalls of the head impaction tool's body382into which the channels388are formed define undercuts390that extend along the length of the channels388. Each of the undercuts390takes the form of a lip392positioned at the top of the respective channels388. The lips392may be selectively engaged by the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to secure head impaction tool380to the impaction handle80.

The end of the head impaction tool's body382opposite the connector384has a rounded, concave impact surface396formed therein. The concave impact surface396is sized, shaped, and positioned to closely conform to the convex, nearly generally hemispherically-shaped outer surface of the head component12. As will be described below in greater detail in regard toFIG. 35, when installing the head component12to the stemless humeral component10, the head impaction tool380is first coupled to the impaction handle80and thereafter positioned such that the impact surface396of the head impaction tool380is placed in contact with the outer surface of the head component12. The surgeon may then strike the impact handle's metal strike plate90with a surgical mallet, sledge, or other impaction tool to drive the head component12into taper lock attachment to the stemless humeral component10. It should be appreciated that the head impaction tool380may be constructed from a polymer such as polyetheretherketone (PEEK), acetal, radel, or other polymer.

Referring now toFIGS. 25-36, there is shown a surgical procedure in which the various instruments described herein in regard toFIGS. 6-24are used to surgically prepare the patient's humerus400for implantation of the stemless humeral prosthesis10ofFIGS. 1-5. The surgical procedure begins with preoperative planning in which, amongst other things, a CT scan (2D or 3D) or other type of preoperative image (e.g., X-ray) may be obtained to plan the placement location and orientation of the stemless humeral component10and humeral head component. If the procedure being planned is a shoulder replacement procedure, the CT scan or other type of preoperative images will also be used to plan the placement location and orientation of a prosthetic glenoid component (not shown) to be implanted in the patient's glenoid. With the preoperative planning complete, the patient's soft tissue is dissected and retracted in order to allow access to the shoulder joint. Full (i.e., 360°) exposure of the patient's humeral head402is typically achieved.

Once the patient's humeral head402has been surgically exposed, the surgeon may then begin the process of resecting it. As shown inFIG. 25, the surgeon first installs the head resection guide290on the patient's humerus400. To do so, the surgeon grips the finger grip312and the lower surface314of the head resection guide's base292and thereafter squeezes his or her fingers. Doing so overcomes the spring bias of the springs306and urges or otherwise moves the movable cutting guide298in the direction away from the stationary cutting guide296(i.e., in a direction toward the base292) thereby creating clearance to position the patient's humeral head402between their respective semicircular-shaped surfaces318,320.

The surgeon then positions the head resection guide290around the patient's humeral head402such that the stationary cutting guide296rests on the posterior cuff insertion site of the patient's rotator cuff. Doing so protects the posterior rotator cuff during head resection and is a step in placing the guide296at the correct height and version. The surgeon then positions the anterior surface320of the movable cutting guide298against the anterior surface404of the patient's humerus400at the desired resection angle and height. The surgeon positions cutting guide298on the patient's humeral head402such that the anterior guide surface328is aligned with the articular margin of the humeral head402. The surgeon then gently releases the finger grip312and the lower surface314of the base292. In doing so, the respective semicircular-shaped surfaces318,320of the movable cutting guide298and the stationary cutting guide296are moved toward one another thereby capturing the patient's humeral head402therebetween with the spikes322.

Once the surgeon has placed the movable cutting guide298in the desired resection angle and height, the surgeon may insert a surgical pin406through each of the pin holes324to pin the head resection guide290to the patient's humerus400to maintain the anterior guide surface328of the movable cutting guide298in its desired position, as shown inFIG. 25.

As shown inFIG. 26, the surgeon then operates a bone saw, such as an oscillating power saw408, to resect the patient's humeral head402. To do so, the surgeon positions the saw blade410of the power saw408on the planar anterior guide surface328of the movable cutting guide298. The surgeon then actuates the oscillating power saw408and applies pressure on it so that it advances posteriorly and into contact with the anterior surface404of the patient's humerus400. As the saw blade410is advanced posteriorly into contact with the anterior surface404of the humerus400and thereafter through its midsection in the direction toward its posterior surface412, the oscillating motion of the bone saw408abrades the bone tissue of the humeral head402.

The surgeon continues to posteriorly advance the power saw408until the saw blade410exits the bone. Specifically, the surgeon continues to operate the bone saw408until the distal tine of its blade410passes beyond the posterior surface412of the humeral head402. Upon exit from the posterior surface412of the bone, the saw blade410is supported and guided by the posterior guide surface326of the stationary cutting guide296. In such a way, the posterior guide surface326of the stationary cutting guide296prevents the saw blade410from contacting the patient's posterior rotator cuff. Once the saw blade410has exited the bone and advanced onto the posterior guide surface326of the stationary cutting guide296, the surgeon may deactuate the bone saw408and thereafter then lift away the resected portion of the patient's humeral head402. As can be seen inFIG. 26, the surgically resected surface414of the humerus400is substantially planar.

As shown inFIG. 27, the surgeon now determines the appropriate size stemless humeral component10to implant on the surgically resected surface414of the humerus400. To do so, the surgeon uses the sizing instrument160. Specifically, as will now be described in more detail, the sizing instrument160may be secured to the patient's surgically resected surface414of the humerus400to function as both a sizing trial and a punch and drill guide. To do so, the surgeon selects an initial one of the differently-sized sizing instruments160that the surgeon estimates is the proper size for the patient. The surgeon then couples the selected sizing instrument160to the alignment handle120. Specifically, the surgeon inserts and advances the keying pin144formed in the distal end of the alignment handle's body122into the key-hole shaped opening184formed in the sizing instrument160until the lip190of the sizing instrument's connector182is engaged by the locking pawl142of the alignment handle's attachment mechanism126(seeFIGS. 8 and 9) thereby securing the sizing instrument160to the alignment handle120. The surgeon then places the selected sizing instrument160onto the surgically resected surface414of the humerus400and assesses coverage. If the surgeon determines the selected sizing instrument160is not the proper size, the initial sizing instrument160is removed and a sizing instrument160having a different diameter is attached to the alignment handle120and assessed.

Once the sizing instrument160of the proper diameter has been determined, the surgeon secures the sizing instrument160to the surgically resected surface414of the humerus400. To do so, the surgeon utilizes the alignment handle120to position the sizing instrument160in a desired location and orientation for the final implant (i.e., the stemless humeral component10) with the spikes174of the sizing instrument160facing downwardly toward the surgically resected surface414of the humerus400. The surgeon then presses or otherwise urges the sizing instrument160downwardly into the cancellous bone of the surgically-resected surface414of the humerus400thereby securing it in place as shown inFIG. 27. The surgeon may utilize the sizing instrument's viewing windows180to visualize the surgically-resected surface414of the humerus400to ensure the sizing instrument160is fully seated thereon.

Once the sizing instrument160has been installed on the surgically resected surface414of the humerus400, the surgeon may then perform a pre-trial of the fit of the final humeral head component12. To do so, the surgeon selects an initial one of the differently-sized trial head components210that the surgeon estimates is the proper size for the patient and thereafter installs the selected trial head component210to the sizing instrument160(seeFIG. 28). The surgeon installs the trial head component210on the sizing instrument160by inserting its center lug218(seeFIGS. 12 and 13) into the sizing instrument's elongated bore168and thereafter pressing or otherwise urging the trial head component210downwardly until it fully seats on the sizing instrument160.

The trial head component210is used to ensure proper size selection of the ultimate humeral head component12(i.e., the humeral head component12that is ultimately implanted in the patient's humerus). As such, once the trial head component210is installed on the sizing instrument160, the surgeon can visually assess its size and fit to get a sense of the size and fit of the final implant (i.e., the stemless humeral component10and the humeral head component12). If the surgeon is not satisfied with the assessed size and fit, either one or both of the trial head component210and the sizing instrument160may be replaced. If the surgeon is satisfied with the assessed size and fit, the trial head component210is removed from the sizing instrument160and subsequent bone preparation of the patient's surgically resected humeral surface414is performed.

As shown inFIG. 29, the surgeon may then use the surgical punch240to punch holes in the patient's surgically-resected humeral surface414to receive the legs16and the elongated sleeve36of the stemless humeral component10. It should be appreciated that the surgeon may utilize a number of fixation pins (not shown) inserted through the pin holes178to secure the sizing instrument160to the bone tissue of the patient's surgically-resected humeral surface414prior to use of the surgical punch240. To perform the punching procedure, the surgeon first secures the surgical punch240to the impaction handle80by inserting the D-shaped connecting pin104into the D-shaped socket260formed in the attachment shaft244of the surgical punch240until the lip250formed in the attachment shaft244is engaged by the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to secure the surgical punch240to the impaction handle80.

Thereafter, the surgeon uses the impaction handle80to position the surgical punch240such that each of its tines252is aligned with one of the punch guide holes170of the sizing instrument160. Doing so also aligns the surgical punch's center spike262with the elongated bore168of the sizing instrument160. In such a way, the punch guide holes170and the elongated bore168function to guide the advancement of the tines252and the center spike262, respectively.

Once the surgical punch240is positioned in the sizing instrument160in such a manner, the surgeon strikes the metal plate90of the impaction handle80with a surgical mallet, sledge, or other impaction tool to drive the surgical punch240into the patient's surgically-resected humeral surface414until the surgical punch bottoms out on the sizing instrument160. As shown inFIG. 30, doing so creates a number of punched holes416in the patient's surgically-resected humeral surface414corresponding in shape, size, and location with the legs16of the stemless humeral component12. As also shown inFIG. 30, impacting the surgical punch240in such a manner also creates a recess in the form of a divot418in the patient's surgically-resected humeral surface414corresponding in shape, size, and location to the elongated sleeve36of the stemless humeral component10.

The surgeon then backs out the surgical punch240from the patient's surgically-resected humeral surface414to expose the surgically created holes416and divot418, as shown inFIG. 30. If necessary, the surgeon may strike the underside of the impaction handle's extraction flange92to facilitate such extraction of the surgical punch240.

Referring now toFIGS. 31 and 32, there is shown a pre-conditioning procedure to the punching procedure described in regard toFIGS. 29 and 30. In other words, the drilling procedure may be performed as a pre-drilling procedure in which holes are pre-drilled in the patient's surgically-prepared humeral surface414, with such pre-drilled holes then being punched by use of the surgical punch240in the manner described above to receive the legs16of the stemless humeral component10. To perform such a drilling procedure, the surgeon utilizes the trial head component210with the installed sizing instrument160. In bone preparation (as opposed to trialing), the trial head component210is used as a drill guide for guiding drill bits used to drill (or pre-drill) holes in the patient's surgically-prepared humeral surface414to receive the legs16and the elongated sleeve36of the stemless humeral component10. To begin such a drilling procedure, the surgeon first selects the trial head component210corresponding in size to the installed sizing instrument160and thereafter installs the selected trial head component210to the sizing instrument160(seeFIG. 31). The surgeon installs the trial head component210on the sizing instrument160by inserting its center lug218(seeFIGS. 12 and 13) into the sizing instrument's elongated bore168and thereafter pressing or otherwise urging the trial head component210downwardly until it fully seats on the sizing instrument160.

When the trial head component210is installed to the sizing instrument160, the position of each of the trial head component's guide bores230coincides with, and is received into, the punch guide holes170of the sizing instrument160. In particular, when the trial head component210is fully seated on the sizing instrument160, the distal end of each of the bosses226formed in the trial head component210(seeFIGS. 12 and 13) is received into a corresponding punch guide hole170of the sizing instrument160thereby aligning the guide bores230in the proper location.

The proximal end of the peripheral drill bit272is then inserted into the chuck of a rotary power tool (not shown) or a manual handle (not shown). The surgeon then inserts the tip280of the peripheral drill bit's cutting head278into one of the guide bores230of the trial head component210and actuates the power drill (or turns the manual handle). The surgeon advances the peripheral drill bit272into the bone tissue of the patient's surgically-resected humeral surface414until the lower surface286of the bit's collar284bottoms out or otherwise engages the rim or shelf in the sleeve228of the trial head component210. The surgeon then removes the drill bit272from the guide bore230corresponding to the newly drilled peripheral hole and repeats the process in the remaining guide bores230. The surgeon then removes the trial head component210from the sizing instrument160to expose the surgically-drilled peripheral holes420corresponding in location to where the legs16of the stemless humeral component10(seeFIG. 32) will be implanted.

With the trial head component210removed, the surgeon then drills a hole in the patient's surgically-resected humeral surface414to receive the elongated sleeve36of the stemless humeral component10. To do so, the surgeon secures the proximal end of the center drill bit270in the chuck of a rotary power tool (not shown) or a manual handle (not shown). The surgeon then inserts the tip280of the center drill bit's cutting head278into the elongated bore168of the sizing instrument160and actuates the power drill (or turns the manual handle). The surgeon advances the center drill bit270into the bone tissue of the patient's surgically-resected humeral surface414until the lower surface286of the bit's collar284bottoms out or otherwise engages the flattened upper surface164of the sizing instrument160. The surgeon then removes the drill bit270from the elongated bore168of the sizing instrument160.

As shown inFIG. 32, the surgeon then removes the sizing instrument160to expose the surgically-drilled peripheral holes420corresponding in location to where the legs16of the stemless humeral component10will be implanted, along with the surgically-drilled center hole422corresponding in location to where the elongated sleeve36of the stemless humeral component10will be implanted.

Once the patient's surgically-resected humeral surface414has been prepared, the surgeon may then implant the stemless humeral component10. To do so, as shown inFIG. 33, the surgeon first secures the implant insertion tool330to the impaction handle80by inserting the handle's D-shaped connecting pin104into the D-shaped socket338of the implant insertion tool's connector336until the connector's lip344is engaged by the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to secure the implant insertion tool330to the impaction handle80.

Thereafter, the surgeon secures the appropriately sized stemless humeral component10(i.e., a component10having a diameter selected through trialing as described above) to the implant insertion tool330. The surgeon first positions the locking collar362of the implant insertion tool330in an unlocked or release position in which the cam followers354of implant insertion tool's locking arms352are positioned near the inner end370of the locking collar's cam surface368thereby positioning the locking pawls356at their greatest distance away from one another. The surgeon then positions the insertion tool's alignment flange346in engagement with the stemless humeral component10such that its alignment pin350and alignment keys348are positioned in the stemless humeral component's tapered bore40and viewing windows30, respectively. Doing so positions the locking pawls356of the implant insertion tool's locking arms352in the stemless humeral component's remaining viewing windows30(i.e., the viewing windows30not occupied by the alignment keys348).

The surgeon rotates the locking collar362clockwise to move the locking collar362from its unlocked position to its locked position. Such rotation of the locking collar362causes each of the cam followers354of the implant insertion tool's locking arms352to ride along its corresponding cam surfaces368in the direction from its inner end370to its outer end372. Doing so causes the cam followers354to move in the direction away from one another thereby causing the locking arms352to pivot such that the locking pawls356are moved in a direction toward one another. Such movement of the locking pawls356in the direction toward one another causes the locking pawls356to engage the lips74of the undercuts70formed in the bottom surface18of the stemless humeral component's support flange14thereby securing the stemless humeral component10to the implant insertion tool330.

Thereafter, as shown inFIG. 33, the surgeon uses the impaction handle80to position the stemless humeral component10such that each of its legs16is aligned with, and inserted into, one of the punched holes416formed in the patient's surgically-resected humeral surface414. Doing so also aligns the elongated sleeve36of the stemless humeral component10with the divot418/drilled hole422formed in the patient's surgically-resected humeral surface414(or the drilled center).

Once the stemless humeral component10is positioned in the punched holes416and the divot418/drilled hole422in such a manner, the surgeon strikes the metal plate90of the impaction handle80with a surgical mallet, sledge, or other impaction tool to drive the stemless humeral component10into the bone tissue until the stemless humeral component10is fully seated on the patient's planar surgically-resected humeral surface414. The surgeon may use the viewing windows30to visualize the surgically-resected humeral surface414to ensure the stemless humeral component10is fully seated thereon.

The surgeon then releases the stemless humeral component10from the implant insertion tool330. To do so, the surgeon rotates the locking collar362of the implant insertion tool330counterclockwise from its locked position to its unlocked position. Such rotation of the locking collar362causes each of the cam followers354of the implant insertion tool's locking arms352to ride along its corresponding cam surfaces368in the direction from its outer end372to its inner end370. Doing so causes the cam followers354to move in the direction toward one another thereby causing the locking arms352to pivot such that the locking pawls356are moved in a direction away from one another. Such movement of the locking pawls356in the direction away from one another causes the locking pawls356to release the lips74of the undercuts70formed in the bottom surface18of the stemless humeral component's support flange14thereby releasing the stemless humeral component10from the implant insertion tool330. As shown inFIG. 34, the surgeon then lifts the impaction handle80, and hence the implant insertion tool330, away thereby exposing the implanted stemless humeral component10.

Once the stemless humeral component10has been implanted on the surgically resected surface414of the humerus400, the surgeon may then perform a trial of the fit of the final humeral head component12. To do so, the surgeon installs an appropriately sized trial head component210(i.e., the size selected during the earlier trialing steps) to the implanted stemless humeral component10. The surgeon installs the trial head component210on implanted stemless humeral component10by inserting its center lug218(seeFIGS. 12 and 13) into the tapered bore40of the implanted stemless humeral component10and thereafter pressing or otherwise urging the trial head component210downwardly until it fully seats on the implanted stemless humeral component10. The center lug's annular bands222frictionally engage the sidewalls of the tapered bore40to frictionally secure the center lug, and hence the trial head component210, to the implanted stemless humeral component10. The surgeon then utilizes the trial head component210to assess coverage, soft tissue tension, and range of motion.

Once the surgeon is satisfied, the trial head component210is then removed and replaced with the ultimate humeral head component12. In particular, as shown inFIG. 35, the surgeon then installs an appropriately sized humeral head component12(i.e., the size selected during the earlier trialing steps) to the implanted stemless humeral component10. The surgeon installs the humeral head component12on implanted stemless humeral component10by inserting its tapered post42into the tapered bore40of the stemless humeral component's elongated sleeve36(seeFIG. 36).

The head impaction tool380may be used to impact, and hence taper lock, the head component12to the stemless humeral component10. To do so, as shown inFIG. 35, the surgeon first secures the head impaction tool380to the impaction handle80by inserting the handle's D-shaped connecting pin104into the round opening386of the head impaction tool's connector384until one of the connector's lip392is engaged by the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to secure the head impaction tool380to the impaction handle80.

The surgeon then positions the impaction handle80that the head impaction tool's concave impact surface396is placed in contact with the generally hemispherically-shaped outer surface of the head component12. The surgeon then strikes the impact handle's metal strike plate90with a surgical mallet, sledge, or other impaction tool to drive the humeral head component12downwardly so as to urge the tapered post42of the humeral head component12into contact with the sidewall defining the tapered bore40of the elongated sleeve36thereby taper locking the humeral head component12to the stemless humeral component10. Such final assembly of the humeral head component12to the stemless humeral component10is shown inFIG. 36.

Referring now toFIG. 37, there is shown another embodiment of an implant insertion tool540that may be secured to the stemless humeral component10to facilitate implantation of the stemless humeral component10into the patient's surgically-prepared humeral surface414. The implant insertion tool540includes a body542having an elongated bore544extending therethrough. A locking rod548is captured in the bore544. In such an arrangement, the locking rod548rotates freely within the bore544.

A knob550is secured to the proximal end of the locking rod548. In addition to being used to secure the implant insertion tool540to the stemless humeral component10, the knob550is also used as an impact surface. Namely, the surgeon strikes the upper surface552of the knob550to drive the stemless humeral component10into the bone tissue of the patient's surgically-prepared humeral surface414.

The locking rod548has a set of locking threads556formed in its distal end (i.e., the end opposite the knob550). The threads556are sized to be received into the complimentary threads50of the threaded bore48formed in the elongated sleeve36of the stemless humeral component10. When a surgeon or other user rotates the knob550, the locking screw's threads556are likewise rotated. Rotation in one direction (e.g., clockwise) may be used to tighten, and hence secure, the implant insertion tool540to the stemless humeral component10, with rotation in the opposite direction (e.g., counterclockwise) being used to loosen, and hence, uncouple the implant insertion tool540from the stemless humeral component10.

As can be seen inFIG. 37, a number of straight flutes or ridges558are formed in the end of the of the implant insertion tool's body542near the knob550of the locking rod548. The ridges558function as a grip for allowing the surgeon to hold the implant insertion tool540during implantation of the stemless humeral component10.

The end of the of the implant insertion tool's body542near the threads556of the locking rod548has an alignment collar560formed therein. The alignment collar560is embodied as an annular flange extending outwardly from the longitudinal axis of implant insertion tool's body542. The alignment collar560has a number of protrusions or alignment keys562extending downwardly from its lower surface564. As can be seen inFIG. 37, the alignment keys562are sized, shaped, and positioned to be received into the viewing windows30formed in the stemless humeral component10. With the alignment keys562positioned in the viewing windows30, the stemless humeral component10is prevented from rotating relative the implant insertion tool540during rotation of the implant insertion tool's knob550thereby allowing the implant insertion tool's threads556to engage (or disengage) the stemless humeral component's threads50.

In a manner similar to as described above inFIG. 33, the surgeon secures the stemless humeral implant10to the implant insertion tool540then uses the implant insertion tool540to align the stemless humeral component's legs16and elongated sleeve36to the punched holes416and the divot418/drilled hole422, respectively, formed in the surgically-resected humeral surface414. Once the stemless humeral component10is positioned in the punched holes416and the divot418/drilled hole422in such a manner, the surgeon strikes the upper surface552of the knob550with a surgical mallet, sledge, or other impaction tool to drive the stemless humeral component10into the bone tissue until the stemless humeral component10is fully seated on the patient's planar surgically-resected humeral surface414. The surgeon may use the viewing windows30to visualize the surgically-resected humeral surface414to ensure the stemless humeral component10is fully seated thereon.

The components of the implant insertion tool540(i.e., its body542and the locking rod548) may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used.

Referring now toFIG. 38, there is shown another embodiment of an implant insertion tool580. The implant insertion tool580may be secured to the stemless humeral component10to facilitate implantation of the stemless humeral component10into the patient's surgically-prepared humeral surface. The implant insertion tool580includes a body582having an elongated bore584extending therethrough. A locking rod such as a locking screw588is captured in the bore584. In such an arrangement, the locking screw588rotates freely within the bore584, but is prevented from being removed from the bore584(i.e., it is not removable from the implant insertion tool's body582).

A D-shaped drive head590is formed in the proximal end of the locking screw588, with a number of locking threads592being formed in its opposite, distal end. The threads582are sized to be received into the complimentary threads50of the threaded bore48formed in the elongated sleeve36of the stemless humeral component10. The D-shaped drive head590is sized, shaped, and positioned to receive a D-shaped head of a rachet or other surgical tool. As such, when the head of the racket is inserted in the implant insertion tool's drive head590and rotated, the locking screw's threads592are likewise rotated. Rotation in one direction (e.g., clockwise) may be used to tighten, and hence secure, the implant insertion tool580to the stemless humeral component10, with rotation in the opposite direction (e.g., counterclockwise) being used to loosen, and hence, uncouple the implant insertion tool580from the stemless humeral component10.

The end of the of the implant insertion tool's body582near the drive head590of the locking screw588has a channel596formed therein. The sidewalls of implant insertion tool's body582into which the channel596is formed define an undercut598that extends along the length of the channel596. The undercut598takes the form of a lip602positioned at the top of the channel596. The lip602is engaged by the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to secure the implant insertion tool580to the impaction handle80.

In a manner similar to as described above inFIG. 33, the surgeon secures the implant insertion tool580to the impaction handle80and thereafter secures the stemless humeral implant10to the implant insertion tool580or vice versa. The surgeon then uses the impaction handle80to align the stemless humeral component's legs16and elongated sleeve36to the punched holes416and the divot418/drilled hole422formed in the surgically-resected humeral surface414. Once the stemless humeral component10is positioned in the punched holes416and the divot418/drilled hole422in such a manner, the surgeon strikes the metal plate90of the impaction handle80with a surgical mallet, sledge, or other impaction tool to drive the stemless humeral component10into the bone tissue until the stemless humeral component10is fully seated on the patient's planar surgically-resected humeral surface414. The surgeon may use the viewing windows30to visualize the surgically-resected humeral surface414to ensure the stemless humeral component10is fully seated thereon.

The components of the implant insertion tool580(i.e., its body582and the locking screw588) may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used. In other embodiments, the implant insertion tool580may be formed as a single monolithic component. In such embodiments, the implant insertion tool580may be threaded onto the implant or clipped onto the impaction handle for threading onto the implant. In other embodiments, the implant insertion tool580may include a connecting collar that surrounds the D-shaped drive socket. As such, the D-shaped drive socket630may be rotatable relative to the connecting collar.

Referring now toFIGS. 39 and 40, there is shown another embodiment of an implant insertion tool620. The implant insertion tool620may be secured to the stemless humeral component10to facilitate implantation of the stemless humeral component10into the patient's surgically-prepared humeral surface414. The implant insertion tool620includes a somewhat ring-shaped body622having an upper bore624extending through an upper portion of its body622and lower bore626extending through a lower portion of its body622. The two bores624,626are coaxial with one another (i.e., they share a common central axis). A locking rod628is captured in the bores624,626. In such an arrangement, the locking rod628rotates freely within the bores624,626, but is prevented from being removed from the bores624,626(i.e., it is not removable from the implant insertion tool's body622).

A D-shaped drive socket630is formed in the proximal end of the locking rod628, with a number of locking threads632being formed in its opposite, distal end. The threads632are sized to be received into the complimentary threads50of the threaded bore48formed in the elongated sleeve36of the stemless humeral component10(seeFIG. 5). The D-shaped drive socket630is sized, shaped, and positioned to receive the D-shaped connecting pin104of the attachment mechanism86of the impaction handle80(seeFIG. 6).

As can be seen inFIGS. 39 and 40, the ring-shaped body622of the implant insertion tool620includes a connecting collar634that surrounds the D-shaped drive socket630of the locking rod628. As such, the D-shaped drive socket630of the locking rod628is rotatable relative to the connecting collar634of the implant insertion tool's ring-shaped body622. The outer surface of the connecting collar634has a number of ratchet slots636formed therein. One end638of the ratchet slots636is wider than its other end640thereby giving the ratchets slots636a generally L-shaped configuration. The sidewall642defining the narrow end640of the ratchet slots636defines a ramped-shaped or otherwise angled cam surface644, whereas the sidewall646defining the wide end638of the ratchet slots636defines a vertical stop surface648. When the impaction handle's connecting pin104is inserted in the implant insertion tool's D-shaped drive socket630, the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) is positioned in one of the ratchet slots636. The configuration of the ratchet slots636permits rotation of the impaction handle80(and hence the locking rod628) relative to the ring-shaped body622of the implant insertion tool620in one direction (e.g., clockwise), but prevents rotation in the opposite direction (e.g., counterclockwise). In particular, rotation of the impaction handle80(and hence the locking rod628) relative to the ring-shaped body622in the clockwise direction causes the leading edge of the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to contact the ramped-shaped cam surface644that defines the narrow end640of the ratchet slot636in which the locking pawl102is captured. Continued clockwise rotation causes the locking pawl102to ride up the ramped-shaped cam surface644(as the spring bias of the spring impaction handle's110is overcome) and out of the ratchet slot636. The locking pawl102rides on the outer surface of the connecting collar634between two adjacent ratchet slots636until the trailing edge of the locking pawl102clears the vertical stop surface648of the ratchet slot636adjacent to the one just exited by the locking pawl102at which point the spring bias of the spring impaction handle's110urges the locking pawl102downwardly into the ratchet slot636.

Conversely, rotation of the impaction handle80(and hence the locking rod628) relative to the ring-shaped body622in the counterclockwise direction causes the leading edge of the locking pawl102of the impaction handle's attachment mechanism86(seeFIGS. 6 and 7) to contact the vertical stop surface648of the ratchet slot636that defines the wide end638of the ratchet slot636in which the locking pawl102is captured. Such contact with the vertical stop surface648prevents further rotation of the impaction handle80(and hence the locking rod628) relative to the ring-shaped body622in the counterclockwise direction.

Such ratchet-type clockwise rotation of the impaction handle80(and hence the locking rod628) relative to the ring-shaped body622is used to secure the stemless humeral component10to the implant insertion tool620. In particular, when the impaction handle80is installed on the implant insertion tool620and rotated, the locking rod's threads632are likewise rotated. Rotation in one direction (e.g., clockwise) may be used to tighten, and hence secure, the implant insertion tool580to the stemless humeral component10. Rotation in the opposite direction (e.g., counterclockwise) is used to loosen, and hence, uncouple the implant insertion tool620from the stemless humeral component10. In order to perform such counterclockwise rotation, the surgeon presses and holds down on the actuation arm98of the impaction handle's lever94thereby lifting the impaction handle's locking pawl102out of the ratchets slots636of the implant insertion tool620.

The end of the of the implant insertion tool's ring-shaped body622near the threads632of the locking rod628has an alignment collar652formed therein. The alignment collar652is embodied as an annular flange formed in the distal end654of the implant insertion tool's body622. The alignment collar652has a number of protrusions or alignment keys656extending downwardly from its lower surface658. As can be seen inFIG. 40, the alignment keys656are sized, shaped, and positioned to be received into the viewing windows30formed in the stemless humeral component10. With the alignment keys656positioned in the viewing windows30, the stemless humeral component10is prevented from rotating relative the implant insertion tool620during rotation of the implant insertion tool's locking rod628thereby allowing the implant insertion tool's threads632to engage (or disengage) the stemless humeral component's threads50.

In a manner similar to as described above inFIG. 33, the surgeon secures the implant insertion tool620to the impaction handle80and thereafter secures the stemless humeral implant10to the implant insertion tool620. The surgeon then uses the impaction handle80to align the stemless humeral component's legs16and elongated sleeve36to the punched holes416and the divot418/drilled hole422formed in the surgically-resected humeral surface414. Once the stemless humeral component10is positioned in the punched holes416and the divot418in such a manner, the surgeon strikes the metal plate90of the impaction handle80with a surgical mallet, sledge, or other impaction tool to drive the stemless humeral component10into the bone tissue until the stemless humeral component10is fully seated on the patient's planar surgically-resected humeral surface414. The surgeon may use the viewing windows30to visualize the surgically-resected humeral surface414to ensure the stemless humeral component10is fully seated thereon.

The components of the implant insertion tool620(i.e., its body622and the locking rod628) may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used.

Referring now toFIGS. 41 and 42, there is shown another embodiment of an head resection guide670that may be used as a cutting guide to guide the advancement of a bone saw blade to resect the humeral head of the patient. Unlike the head resection guide290described above in regard toFIGS. 17-19, the head resection guide670is not adjustable, but rather is provided in a number of varying sizes (i.e., varying diameters) to fit the needs of a given patient. The head resection guide670includes a generally rectangular-shaped base672having a circular-shaped ring674secured thereto. The ring674extends outwardly from the base672and defines a circular-shaped opening676. As will be described in more detail below, the patient's humeral head is captured in the opening676during resection thereof.

The head resection guide670has a connector678that may be engaged by the attachment mechanism126of the alignment handle120to secure the head resection guide670to the alignment handle120. The connector678has a key-hole shaped opening680formed therein. The key-hole opening680is sized and shaped to receive the keying pin144formed in the distal end of the alignment handle's body122. The connector678also has a channel682formed therein. An undercut684is formed along the length of the channel682. The undercut684takes the form of a lip686positioned at the top of the channel682and extending outwardly into the channel682. The lip686is engaged by the locking pawl142of the alignment handle's attachment mechanism126(seeFIGS. 8 and 9) to secure the head resection guide670to the alignment handle120.

The head resection guide's base672has a number of pin holes692formed therein. As will be discussed in more detail, surgical pins may be inserted through the pin holes692to pin the head resection guide670to the patient's humerus during resection of the patient's natural humeral head.

As can be seen inFIG. 42, both the base672and the ring674include planar surfaces that cooperate to define a cutting guide surface for guiding a bone saw blade to resect the patient's natural humeral head. Specifically, the base672includes a planar anterior guide surface694that aligns in a coplanar relationship with a planar posterior guide surface696of the ring674. As described above, in the illustrative embodiment described herein, the head resection guide670is embodied as a monolithic structure. Hence, the two guide surfaces694,696are embodied as a common surface that collectively defines a cutting surface upon which a bone saw blade may be supported (i.e., guided) during a cutting operation to resect the patient's natural humeral head.

In use, the surgeon installs the head resection guide670to the alignment handle120by inserting the keying pin144formed in the distal end of the alignment handle's body122into the key-hole opening680of the head resection guide's connector678. In doing so, the connector's lip686is engaged by the locking pawl142of the alignment handle's attachment mechanism126(seeFIGS. 8 and 9) thereby securing the head resection guide670to the alignment handle120.

In a similar manner to as described above in regard toFIG. 26, the surgeon then uses the head resection guide670as a cutting guide to facilitate the surgical resection of the patient's humeral head402. To do so, the surgeon uses the alignment handle120to position the head resection guide670around the patient's humeral head402such that the posterior section702of the ring674rests on the posterior cuff insertion site of the patient's rotator cuff. Doing so protects the posterior rotator cuff during head resection and acts as a step in placing the guide at the correct height and version. The surgeon then positions the anterior guide surface694of the base672relative to the anterior surface404of the patient's humerus400at the desired resection angle and height. The surgeon may then make any necessary minor adjustments to the positions of the anterior surface of the base relative to the anterior surface404and the anterior guide surface694relative to the articular margin to finalize the desired resection angle and height. Thereafter, the surgeon may insert a surgical pin406(seeFIG. 26) through each of the pin holes692to pin the head resection guide670to the patient's humerus400to maintain the anterior guide surface694in its desired position. Once pinned in place, the surgeon disconnects the alignment handle120from the head resection guide670.

Similar to as described in regard toFIG. 26, the surgeon then operates a bone saw, such as an oscillating power saw408, to resect the patient's humeral head402. To do so, the surgeon positions the saw blade410of the power saw408on the planar anterior guide surface694of the head resection guide's base672. The surgeon then actuates the oscillating power saw408and applies pressure on it so that it advances posteriorly and into contact with the anterior surface404of the patient's humerus400. As the saw blade410is advanced posteriorly into contact with the anterior surface404of the humerus400and thereafter through its midsection in the direction toward its posterior surface412, the oscillating motion of the bone saw408abrades the bone tissue of the humeral head402.

The surgeon continues to posteriorly advance the power saw408until the saw blade410exits the bone. Specifically, the surgeon continues to operate the bone saw408until the distal end of its blade410passes beyond the posterior surface412of the humeral head402. Upon exit from the posterior surface412of the bone, the saw blade410is supported and guided by the posterior guide surface696of the ring674. In such a way, the posterior guide surface696of the ring674prevents the saw blade410from contacting the patient's posterior rotator cuff. Once the saw blade410has exited the bone and advanced onto the posterior guide surface696of the ring674, the surgeon may deactuate the bone saw408and thereafter then lift away the resected portion of the patient's humeral head402.

The head resection guide670may be constructed from a medical-grade metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. Moreover, in some embodiments, rigid polymers such as polyetheretherketone (PEEK) may also be used.

Referring now toFIGS. 43 and 44, there is shown another embodiment of the stemless humeral component10. The features of the embodiment illustrated inFIGS. 43 and 44are substantially similar to those discussed above in reference to the embodiment ofFIGS. 1-5. Such features are designated inFIGS. 43 and 44with the same reference numbers as those used inFIGS. 1-5. In essence, the embodiment ofFIGS. 43 and 44is substantially the same as the embodiment ofFIGS. 1-5with a few exceptions. For example, the suture holes26have been removed from the stemless humeral component ofFIGS. 43 and 44. In such a case, the surgeon may use the viewing windows30in lieu of the removed suture holes26to suture bone wafers or soft tissue to the stemless humeral component10. To accommodate such use of the viewing windows30, the edges of the stemless humeral component's support flange14defining the viewing windows30may be rounded.

Referring now toFIGS. 45 and 46, there is shown another embodiment of the sizing instrument160. The features of the embodiment illustrated inFIGS. 45 and 46are substantially similar to those discussed above in reference to the embodiment ofFIGS. 10 and 11. Such features are designated inFIGS. 45 and 46with the same reference numbers as those used inFIGS. 10 and 11. In essence, the embodiment ofFIGS. 45 and 46is substantially the same as the embodiment ofFIGS. 10 and 11with a few exceptions. For example, the viewing windows180have been removed from the sizing instrument160ofFIGS. 45 and 46.

Moreover, the geometry of the punch guide holes170has been altered. In particular, the punch guide holes170are substantially T-shaped in the embodiment of the sizing instrument160shown inFIGS. 45 and 46. In such a way, the geometry of the punch guide holes170more closely corresponds with the geometry of the T-shaped tines252of the surgical punch240.

In addition, the geometry of the connector182has been altered in the embodiment of the sizing instrument160shown inFIGS. 45 and 46. To accommodate such a change, the attachment mechanism126of the alignment handle120may also be altered to secure the sizing instrument160thereto.

Referring now toFIG. 47, there is shown another embodiment of the surgical punch240. The features of the embodiment illustrated inFIG. 47are substantially similar to those discussed above in reference to the embodiment ofFIG. 14. Such features are designated inFIG. 47with the same reference numbers as those used inFIG. 14. In essence, the embodiment ofFIG. 47is substantially the same as the embodiment ofFIG. 14with a few exceptions. For example, the center spike262has been removed from the surgical punch240ofFIG. 47. In such a case, the surgeon may use the center drill270to drill a hole in the patient's surgically-prepared humerus to accommodate the elongated sleeve36of the stemless humeral component10in the manner discussed above.

Moreover, the struts268have been removed such that the tines252are more integrally formed in the surgical punch's body242. In addition, the geometry of the surgical punch's connecting socket260and connecting channel246have been altered in the embodiment of the surgical punch240shown inFIG. 47. To accommodate such a change, the attachment mechanism86of the impact handle80may also be altered to secure the surgical punch240thereto.

Moreover, as can be seen inFIG. 47, the proximal end266of each of the ribs256of the tines252(i.e., the end secured to the punch's shaft244) is wider than the opposite, distal end288of each rib256. As such, the corresponding shape of the punched holes formed in the patient's surgically-prepared humerus is wider at its open end than at its blind end. Such a widened opening facilitates insertion of the cantilevered legs16of the stemless humeral component10.

Referring now toFIG. 48, there is shown another embodiment of the implant insertion tool540. The features of the embodiment illustrated inFIG. 48are substantially similar to those discussed above in reference to the embodiment ofFIG. 37. Such features are designated inFIG. 48with the same reference numbers as those used inFIG. 37. In essence, the embodiment ofFIG. 48is substantially the same as the embodiment ofFIG. 37with a few exceptions. For example, the size of the knob552is larger in the embodiment ofFIG. 48to facilitate use thereof by the surgeon. Moreover, the implant insertion tool's grip is overmolded to the tool's body542.

Referring now toFIGS. 49-52, there is shown a drill guide710that may be used to pre-drill the patient's surgically-prepared humeral surface prior to implantation of the stemless humeral component10. In such a case, the surgeon may opt to subsequently punch the patient's surgically-prepared humeral surface prior to implantation of the stemless humeral component10in the manner described above (i.e., use the surgical punch240after such pre-drilling). Alternatively, the surgeon may drill the patient's surgically-prepared humeral surface in lieu of the punch procedure.

As described above, the stemless humeral component10may be provided in various sizes (i.e., diameters) to fit the needs of a given patient. For example, the stemless humeral component10may be provided in nine different sizes. Each of such differently-sized components10has legs of different thicknesses and lengths. As such, if discrete drill guides are used for each differently-sized stemless humeral component10, multiple differently-sized drill guides would be required (e.g., nine differently sized drill guides would be required for nine differently-sized stemless humeral components10). Moreover, to avoid overly thick drill guides for the smaller sizes of stemless humeral components10, multiple different drill sizes may be required. As will be discussed below in more detail, the drill guide710avoids the need for such differently-sized drill guides and drills.

The drill guide710includes a body712having a generally planar lower surface714, and an opposite, stepped upper surface716. As can be seen inFIG. 49, the stepped upper surface716is spiral shaped and, being stepped, includes a plurality of discrete generally planar drill-stop surfaces718. Each of the drill-stop surfaces718is spaced apart from the lower surface714of the drill guide's body712by a different length. As a result, the drill guide's body712has a different thickness at the locations corresponding to each of the different drill-stop surfaces718.

As can be seen inFIGS. 49 and 50, each of the drill-stop surfaces718has a number of guide bores730formed therein. The guide bores730are configured to guide the peripheral drill bit272during drilling of the patient's surgically-prepared humeral surface. As such each of the guide bores730extends throughout the entire thickness of the guide body712. In other words, one end of each of the guide bores730opens into the drill-stop surface718, with the other end opening into the lower surface714. As described above, the collar284of the peripheral drill bit272functions as a depth stop to ensure the drill bit272drills surgically-prepared holes at a desired depth. As such, the peripheral drill bit272may be advanced through one of the guide bores730and into the bone tissue until the lower surface286of the collar284bottoms out or otherwise engages the selected drill-stop surface718.

Each of the drill-stop surfaces718corresponds to a differently-sized stemless humeral component10. For example, a drill-stop surface720at the “bottom” end722of the spiral-shaped stepped upper surface716corresponds to the largest size of stemless humeral component10, with the a drill-stop surface724at the “top” end726of the spiral-shaped stepped upper surface716corresponding to the smallest size of stemless humeral component10. The remaining drill-stop surfaces718correspond to the remaining sizes of the stemless humeral component10with the size of the corresponding component10increasing along the stepped upper surface716in the direction from its top end726to its bottom end722.

Because each of the drill-stop surfaces718is spaced apart from the lower surface714of the drill guide's body712by a different length, the peripheral drill bit272will drill to different depths of the patient's surgically-prepared humeral surface depending on which drill-stop surface718is used by the surgeon. For example, if the surgeon utilizes the guide holes730of the drill-stop surface724at the “top” end726of the spiral-shaped stepped upper surface716, shallower drilled holes will be produced than if the surgeon utilizes the guide bores730of the drill-stop surface720at the “bottom” end722of the spiral-shaped stepped upper surface716since the collar284of the drill bit272will bottom out on the drill-stop surface724prior to when it will bottom out on the lower-positioned drill-stop surface720. As such, the drill bit272will progressively drill deeper at the drill-stop surfaces718along stepped upper surface716in the direction from its top end726to its bottom end722.

As can be seen inFIGS. 50 and 51, the guide bores730of each of the drill-stop surfaces718are arranged in a unique hole pattern relative to the remaining drill-stop surfaces718. For example, the drill-stop surface720at the “bottom” end722of the spiral-shaped stepped upper surface716corresponding to the largest size of stemless humeral component10has a relatively large hole pattern (i.e., the guide bores730are more spread out relative to the other hole patterns), whereas the drill-stop surface724at the “top” end726of the spiral-shaped stepped upper surface716corresponding to the smallest size of stemless humeral component10has a relatively small hole pattern (i.e., the guide bores730are more compact relative to the other hole patterns). In such a way, the hole pattern corresponds to the size of the cantilevered legs16of the differently-sized stemless humeral components10, with larger hole patterns corresponding to larger component legs16and smaller hole patterns corresponding to smaller component legs16. That is, the drill-stop surfaces718correspond to the sizes of the stemless humeral component10with the size of the corresponding component10increasing along the stepped upper surface716in the direction from its top end726to its bottom end722.

As can be seen inFIGS. 49 and 51, the guide body712has an elongated boss732secured to, and extending downwardly from, its lower surface714. The elongated boss732is configured to be received into the elongated bore168of the sizing instrument160to secure the drill guide710thereto. An elongated grip734is secured to, and extends upwardly from, the stepped upper surface716. The grip734has a number of grooves736formed therein and is used by the surgeon to grasp the drill guide710.

As shown inFIG. 51, the guide body712has a number of alignment keys738formed in its lower surface714. The alignment keys738are received into a number of alignment slots740formed in the sidewall of the sizing instrument's elongated bore168(seeFIG. 52) to correlate the proper drill-stop surface718with the correct size of the sizing instrument160. In particular, the alignment slots740of each of the differently-sized sizing instruments160are placed in annular locations unique to the particular sizing instrument160(i.e., each of the differently-sized sizing instruments has a unique slot configuration). When the alignment keys738of the drill guide710are advanced into the uniquely-positioned alignment slots740, the proper drill-stop surface718corresponding to the particular size of the sizing instrument160will be positioned over one of the sizing instrument's guide punch holes170thereby “keying” the stepped upper surface716of the drill guide710to the particular size of the sizing instrument160.

Like other of the instruments described herein, the drill guide710may be constructed with a biocompatible metal such as stainless steel, cobalt chrome, or titanium, although other metals or alloys may be used. The drill guide710may also be embodied as a polymer instrument. As such, drill guide710may be made of any suitable medical-grade polymeric material such as polyetheretherketone (PEEK). In such an embodiment, the polymer drill guide710may include metallic inserts (e.g., sleeves) positioned in the drill guide bores730.

In operation, the surgeon may use the drill guide710to drill a number of holes in the patient's surgically-prepared humeral surface. To do so, the surgeon first selects a size of the stemless humeral component10to implant in the patient's humerus in the manner described above. Such a selection may be performed preoperatively or as a result of intra-operative changes based on use of the sizing instrument160. The surgeon then secures a sizing instrument160that corresponds to the selected size of the stemless humeral component10to the surgically-prepared surface of the patient's humerus in the manner described above in regard toFIG. 27.

The surgeon then selects a drill-stop surface718of the drill guide710that corresponds to the selected size of the stemless humeral component10from the plurality of drill-stop surfaces718formed in the drill guide's stepped upper surface716. The surgeon may then attach the drill guide710to the sizing instrument160by advancing the drill guide's elongated boss732into the elongated bore168of the sizing instrument160. During such advancement, the alignment keys738of the drill guide710are advanced into the uniquely-positioned alignment slots740of the sizing instrument160thereby causing the drill-stop surface718corresponding to the particular size of the selected sizing instrument160to be positioned over one of the sizing instrument's guide punch holes170.

The surgeon may then advance the peripheral drill272through each of the guide bores730of the selected drill-stop surface718and into the bone tissue until the drill's collar284bottoms out or otherwise engages the selected drill-stop surface718. The surgeon may then rotate the drill guide710such that the selected drill-stop surface718is positioned over a different one of the remaining punch guide holes170of the sizing instrument160. Thereafter, the surgeon advances the peripheral drill272through each of the guide bores730and repeats the process at each of the remaining punch guide holes170.

The surgeon may then utilize the surgical punch240in a similar manner to as described above in regard toFIG. 29to punch the now pre-drilled surgically-prepared surface of the patient's humerus and thereafter implant the stemless humeral component10in a similar manner to as described above in regard toFIG. 33. Alternatively, the surgeon may implant the stemless humeral component10into the drilled surgically-prepared surface of the patient's humerus without first utilizing the surgical punch240.