Augmented glenoid and method for preparation

A system for augmenting a glenoid in preparation for implantation of a glenoid implant includes an augment guide block. The augment guide block includes a body having a guide slot angularly extending from a first surface to a second surface at an angle α, a plurality of alignment members extending from the first surface of the body that couple the body to the glenoid at locations that correspond to locations where a central peg and a peripheral peg will couple the glenoid implant to the glenoid. The system also includes an augmenting device that is configured to be received within the slot, and that is operable to augment the glenoid at the angle α, wherein the angle α corresponds to a surface of the glenoid implant.

FIELD

The present disclosure relates to system and method for augmenting a glenoid in preparation for a shoulder arthroplasty procedure where a shoulder implant including an augment is to be fixed to the glenoid.

BACKGROUND

In cases of severe glenoid wear, it can be difficult to return the shoulder joint to a near neutral version using a standard glenoid implant. In these instances, the surgeon performing shoulder arthroplasty needs to compromise by inserting the glenoid implant at a non-ideal angle, or by removing a significant amount of native bone from the shoulder joint. Recently, glenoid implants with augments have been developed to account for glenoids having severe wear or defects.

SUMMARY

According to a first aspect of the present disclosure, a guide device is provided for augmenting an anatomic structure. The guide device includes a body including an upper surface, a lower surface, and a peripheral surface that connects each of the upper and lower surfaces. A guide slot extends between the upper surface and the lower surface of the body at an angle α that is non-parallel and non-perpendicular relative to the upper and lower surfaces, and the guide slot is configured for receipt of a shaping device that shapes the anatomic structure at the angle α. A plurality of alignment members extends from the lower surface that removably couple the body to the anatomic structure.

According to the first aspect, the alignment members include a central alignment member and a peripheral alignment member.

According to the first aspect, the angle α is in the range of 10 degrees to 75 degrees.

According to the first aspect, the body is trapezoidal-shaped.

According to the first aspect, the guide device further includes a handle for orienting the body relative to the anatomic structure.

According to the first aspect, the body includes a boss for attachment with the handle.

According to the first aspect, the shaping device is a burr.

According to the first aspect, the anatomic structure is a glenoid.

According to the first aspect, the guide slot is linear.

According to the first aspect, the guide slot includes an inlet and an outlet, and includes radius of curvature between the inlet and the outlet.

According to a second aspect of the present disclosure, a method for performing shoulder arthroplasty is provided. The method includes preparing the glenoid for receipt of a glenoid implant; and attaching an augment guide block to the glenoid. The augment guide block includes a guide slot extending between a upper surface and a lower surface of the augment guide block at an angle α that is non-parallel and non-perpendicular relative to the upper and lower surfaces, and that is configured for receipt of a shaping device that shapes the glenoid at the angle α. The method also includes augmenting the glenoid with the shaping device at the angle α; and attaching the glenoid implant to the glenoid after augmenting the glenoid.

According to the second aspect, the angle α is in the range of 10 degrees to 75 degrees.

According to the second aspect, the method further comprises orienting the augment guide block relative to the glenoid using a handle.

According to the second aspect, the method further comprises selecting the augment guide block from a plurality of augment guide blocks that each include a guide slot having a different angle α.

According to the second aspect, the guide slots are linear or curved.

According to the second aspect, the method further comprises determining pre-operatively a portion of the glenoid that requires shaping.

According to the second aspect, the method further comprises selecting the augment guide block from a plurality of augment guide blocks that each include a guide slot having a different angle α based on the portion of the glenoid that requires the shaping.

According to a third aspect of the present disclosure, a system for augmenting a glenoid in preparation for implantation of a glenoid implant including a central peg and a peripheral peg is provided. The system includes an augment guide block. The augment guide block includes a body having a guide slot angularly extending from a first surface to a second opposing surface at an angle α, a plurality of alignment members extending from the first surface of the body that removably couple the body to the glenoid at locations that correspond to locations where the central peg and peripheral peg will couple the glenoid implant to the glenoid, and a boss formed on the second surface. A handle is configured to mate with the boss, and is operable to orient the augment guide block relative to the glenoid. The system also includes an augmenting device that is configured to be received within the slot, and that is operable to augment the glenoid at the angle α, wherein the angle α corresponds to a surface of the glenoid implant.

According to the third aspect, the alignment members include a central alignment member and a peripheral alignment member.

According to the third aspect, the angle α is in the range of 10 degrees to 75 degrees.

According to the third aspect, the body is trapezoidal-shaped.

According to the third aspect, the augmenting device is a burr.

According to the third aspect, the guide slot is linear.

According to the third aspect, the guide slot includes an inlet and an outlet, and includes radius of curvature between the inlet and the outlet.

DETAILED DESCRIPTION

FIG. 1illustrates a prior art anatomic shoulder implant10. The anatomic shoulder implant10includes a humeral stem12, a humeral head14and a glenoid implant or bearing16with peripheral pegs18and a removable or non-removable central peg20. To attach glenoid implant16, a guiding pin22(FIG. 3) must first be inserted into glenoid face24. Based on the operative shoulder, a sizer pin guide26is placed in the center of glenoid face24at the correct orientation (FIG. 2A). Slots28in sizer pin guide26are provided for visualization of glenoid face24(FIG. 2B). The guiding pin22may be inserted through center aperture30of pin guide26and carefully drilled into glenoid face24until the pin22has engaged the medial cortex of the glenoid vault. Once the pin22is securely placed, the sizer pin guide26is slidably removed from over pin22.

Next, the glenoid face24is prepared. A reamer32(FIG. 3) is selected based on the sizer pin guide26selected to insert guiding pin22. The reamer32is inserted into the joint over the pin22. Then, the glenoid face24is reamed to accommodate the glenoid implant16. Once the desired amount of reaming is completed, a central peg cutter34(FIG. 4) is used to prepare the newly reamed glenoid face24for a geometry and size of the central peg20. In this regard, the central peg cutter34is placed over pin22and glenoid face24is further reamed to prepare a central bore35into the glenoid face24for the central peg20. After forming the central bore35in the glenoid face24for the central peg20, the central peg cutter34is removed from over pin22.

Then, an appropriate cannulated peripheral peg drill guide36is selected and inserted over pin22and into the joint until it is fully seated against the glenoid face24(FIG. 5). Peripheral peg drill guide36includes apertures38that correspond to peripheral pegs18of the glenoid implant16. With the drill guide36correctly in place, drilling is conducted with a drill38at each of the desired peripheral peg locations to prepare the glenoid face24for receipt of the peripheral pegs18. After the peripheral peg locations are prepared, peripheral peg drill guide36is removed from over guiding pin22. Each of the above-noted steps of preparing the glenoid face24and tools associated therewith may be found in the COMPREHENSIVE® Total Shoulder Replacement System manufactured by BIOMET® of Warsaw, Ind.

In cases of severe glenoid wear, it can be difficult to return the joint to near neutral version using a standard glenoid implant like bearing16. In these instances, the surgeon has to compromise by inserting the implant16at a non-ideal version angle, or by removing a significant amount of native bone to gain complete backside coverage of the glenoid24. To account for severe glenoid wear, glenoid implants40including an integral or modular augment42have been developed. For example, various augmented glenoid implants are described in U.S. patent application Ser. No. 14/459,935 filed Aug. 11, 2014, which is hereby incorporated by reference in its entirety. The glenoid face24must be shaped to correspond to the augment42of the augmented implant40(FIG. 11).

To shape the glenoid face24to correspond to the augment42of an augmented implant40, the present disclosure provides an augment guide block44as illustrated inFIGS. 7-10. Augment guide block44includes a body portion46having a central alignment member or stem48, and a peripheral alignment member or peg50. While augment guide block44is generally shown and described herein as being monolithic or otherwise integrally formed, it should be understood that body portion46, stem48, and alignment peg50may be formed as separate components and thereafter mechanically coupled together.

Augment guide block44can be formed from any biocompatible material including ceramic, metals such as stainless steel or titanium, or combinations thereof. Augment guide block44can be formed using any suitable manufacturing process including machining, directly compression molding, and/or additive manufacturing that enables forming multiple guide blocks44in a single build and decreases manufacturing time. Once formed, the guide block44can be further processed (e.g., polished, blasted, machined, etc.) as desired. Guide block44may be a single-use device that is patient-specific, or may be sterilized and re-used, if desired.

Body portion46may include a peripheral surface52, an upper surface54, and a lower or bone-engaging surface56opposite from upper surface54. As illustrated, in one exemplary configuration, the peripheral surface52may define a trapezoidal-shaped body46. It should be understood, however, that body46may be parallel-piped shaped, cylindrical, oval, or any other shape desired by one skilled in the art. Upper surface54is generally planar and includes a pair of bosses58. Bosses58allow for attachment of a handle60, as will be described in more detail below. It should be understood, however, that bosses58may be replaced by recesses (not shown) without departing from the scope of the present disclosure. Lower or bone-engaging surface56may also be generally planar, with stem48and alignment peg50extending outward therefrom. Alternatively, as illustrated, lower surface56may include a slight curvature that assists in nesting guide block44with glenoid24. Preferably, stem48extends from a center62of lower surface56and alignment peg50extends from a location positioned radially outward from stem48. In addition, stem48is configured to mate with central bore35formed in glenoid face24by central peg cutter34and alignment peg50is configured to mate with a recess51formed using peripheral peg drill guide36, as described above. In this manner, augment guide block44cannot rotate during augmentation of glenoid face24.

The stem48may include a cylindrical proximal portion64unitary or connected to body portion46, a cylindrical middle portion66unitary or connected to proximal portion64, and a cylindrical distal portion68unitary or connected to middle portion66. As illustrated, proximal portion64may include a diameter that is greater than middle portion66, and middle portion66may include a diameter that is greater than distal portion68. In this manner, stem48is shaped similarly to central peg20of anatomic implant10. The present disclosure, however, should not be limited to such a configuration. In this regard, stem48may include a constant diameter along an entire length L1thereof without departing from the scope of the present disclosure.

The alignment peg50may be cylindrically shaped, and have a constant diameter along an entire length L2thereof similar to peripheral pegs18of implant10. It will be appreciated, however, that alignment peg50may be shaped similarly to stem48. Further, although alignment peg50is illustrated as having a length L2that is less than that of stem48, it will also be appreciated that alignment peg50may have a length L2equal to that of stem48. Alignment peg50and stem48are illustrated as being solid members, but may be hollow without departing from the scope of the present disclosure.

Augment guide block44includes an angled slot70that extends between upper surface54and lower surface56at an angle α relative to upper surface54. The angle α is neither parallel nor perpendicular relative to each of the upper54and lower surfaces56of the body46. Preferably, the angle α lies in the range of 10 degrees to 75 degrees relative to the upper surface54, and is selected according to the desired amount that glenoid face24needs to be augmented. In this regard, the surgeon performing the shoulder arthroplasty may select the desired angle α by selecting a specific augment guide block44from a plurality of augment guide blocks44in a kit (not shown) each having slots70arranged at different angles α. The glenoid face24, therefore, can be patient-specifically shaped or augmented at the appropriate angle α that is patient-specifically determined pre-operatively. Slot70has a length L3that may be 50% to 80% of a width W of body46, and may be sized for receipt of an augmenting device or burr71that is operable to shape or augment glenoid face24. Further, an inlet72of slot70at upper surface54may be positioned proximate a first edge74of body46, and an outlet76at lower surface56may be positioned proximate a second opposing edge78of body46such that slot70traverses body46at angle α from first edge74in length L4direction toward second edge78.

In the illustrated embodiment, angled slot70allows for preparation of a posterior surface P of the glenoid. It will be appreciated, however, that angled slot70can be used for preparation of an anterior surface A, a superior surface S, or an inferior surface I of glenoid face24(see, e.g.,FIG. 3) without departing from the scope of the present disclosure. In this manner, augment guide block44can be used to prepare the glenoid24face for any defect location by rotating guide block44to the appropriate defect location. Alternatively, the appropriate augment guide block44for anterior surface A, superior surface S, or inferior surface I can be selected from the plurality of augment guide blocks in the kit (not shown) referenced above.

Although slot70is illustrated as being linear to prepare glenoid24to include a planar surface80for mating with the augmented glenoid implant40, it should be understood that slot70may include a radius of curvature82(FIG. 12) to allow glenoid24to prepared to mate with a correspondingly curved augmented glenoid implant (not shown). In this regard, the burr71used to prepare the glenoid24may be flexible, which allows the burr71to pass through curved slot82.

Once the correct augment guide block44is selected based on the patient's anatomy, the augment guide block44is positioned on the glenoid face24using the handle60, and the burr71is inserted into inlet72of slot70in the augment guide block44. Under power, the burr71is used to remove bone at the defect location on the glenoid face24and, as illustrated, form planar surface80. Also, as illustrated, the burr71is used to remove bone from the posterior aspect P of the glenoid24. Once the burring is complete, the burr71is removed from the angled slot70, and the augment guide block44is removed from the glenoid24. A trial may then be conducted to determine fit and full seating of the augmented glenoid implant40on the thus-prepared glenoid face24. If the augmented glenoid implant40properly mates with the augmented glenoid surface80, the augmented glenoid implant40may then be implanted and fixed to the augmented glenoid surface80using cement or some other fixative devices such as a fastener (e.g., a bone screw, not shown).