# Patent

## Title
Humeral cut guide

## Abstract

A humeral cut guide system for resectioning or resurfacing a humeral head. The humeral cut guide system includes a primary cut guide member configured to be removably coupled to the humeral head. The primary cut guide member includes a patient-specific bone-engaging surface, a primary elongate slot that defines a primary cutting plane, and a pair of cylindrical apertures configured to receive a pair of guide pins. A secondary cut guide member includes a pair of through-holes configured to mate with the pair of guide pins, and the secondary cut guide member includes a secondary elongate slot that defines a secondary cutting plane.

## Background
FIELD
The present disclosure relates to humeral cut guide members.
BACKGROUND
This section provides background information related to the present disclosure which is not necessarily prior art.
During shoulder arthroplasty, the humeral bone may require resurfacing to resectioning for receipt of a shoulder implant. Prior to surgery, it is common for the surgeon to take various images via X-ray, CT, ultrasound, MRI, or PET of the surgical area including the humeral bone. Based on these images, the surgeon can determine the best course of action for resurfacing or resectioning the humeral bone, as well as determine whether the primary procedure for shoulder repair is an anatomical or reverse arthroplasty. During the surgery, however, it is not uncommon for the surgeon to determine that the preselected courses of action are not suitable for the patient. If the course of action changes during surgery, new instruments may be required to properly complete the resurfacing or resectioning of the humeral bone before completing the arthroplasty procedure.
SUMMARY
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
The present disclosure provides a humeral cut guide system for resectioning or resurfacing a humeral head. The cut guide system includes a primary cut guide member configured to be removably coupled to the humeral head. The primary cut guide member includes a patient-specific bone-engaging surface, a primary elongate slot that defines a primary cutting plane, and a pair of cylindrical apertures configured to receive a pair of guide pins. The cut guide system also includes a secondary cut guide member that includes a pair of through-holes configured to mate with the pair of guide pins, wherein the secondary cut guide member includes a secondary elongate slot that defines a secondary cutting plane.
The present disclosure also provides a method of resectioning or resurfacing a humeral head. The method includes affixing a primary cut guide member to a humeral head. The primary cut guide member includes a patient-specific bone-engaging surface, a primary elongate slot that defines a primary cutting plane, and a pair of cylindrical apertures. The method also includes determining whether the primary cutting plane is sufficient for the resectioning or the resurfacing of the humeral head. If the primary cutting plane is sufficient, the resectioning or the resurfacing of the humeral head is conducted. If the primary cutting plane is not sufficient for the resectioning or the resurfacing of the humeral head, a pair of guide pins are coupled to the humeral head through the cylindrical apertures, the primary cut guide slot is removed, and a secondary cut guide member including a secondary elongate slot that defines a secondary cutting plane is attached to the pins.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.



DRAWINGS
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
FIG. 1 is an exploded view of a prior art implant for reverse shoulder arthroplasty;
FIG. 2 is an environmental view of the prior art implant of FIG. 1;
FIG. 3 is a perspective environmental view of a humeral cut guide system according to a principle of the present disclosure;
FIG. 4 is a perspective environmental view of a humeral cut guide member according to a principle of the present disclosure;
FIG. 5 is a perspective view of an exterior of the humeral cut guide illustrated in FIG. 3;
FIG. 6 is another perspective view of an interior of the humeral cut guide illustrated in FIG. 3;
FIG. 7 is a perspective view of a secondary cut guide according to a principle of the present disclosure;
FIG. 8 is a perspective environmental view of the pins illustrated in FIG. 4, with the humeral cut guide in FIG. 4 removed;
FIG. 9 is a perspective environmental view of the secondary cut guide illustrated in FIG. 7 mounted to the pins illustrated in FIG. 8;
FIG. 10 is a perspective environmental view of a humeral cut guide system according to a principle of the present disclosure;
FIG. 11 is another perspective environmental view of the humeral cut guide system illustrated in FIG. 10;
FIG. 12 is a perspective environmental view of a humeral mating member that forms part of the humeral cut guide system illustrated in FIG. 10;
FIG. 13 is a perspective view of a humeral cut guide member that forms part of the humeral cut guide system illustrated in FIG. 10;
FIG. 14 is a perspective view of the humeral mating member illustrated in FIG. 12;
FIG. 15 is a perspective environmental view of another humeral cut guide system according to a principle of the present disclosure;
FIG. 16 is another perspective environmental view of the humeral cut guide system illustrated in FIG. 15;
FIG. 17 is a perspective view of a humeral cut guide member illustrated in FIG. 15; and
FIG. 18 is another perspective view of the humeral cut guide member illustrated in FIG. 15.



Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
DETAILED DESCRIPTION
Example embodiments will now be described more fully with reference to the accompanying drawings.
The present disclosure generally provide patient-specific surgical instruments that include, for example, alignment guides, drill guides, and other tools for use in shoulder joint replacement, shoulder resurfacing procedures and other procedures related to the shoulder joint or the various bones of the shoulder joint, including the humeral head. The present disclosure can be applied to anatomic shoulder replacement and reverse shoulder replacement or resurfacing. The patient-specific instruments can be used either with conventional implant components or with patient-specific implant components and/or bone grafts that are prepared using computer-assisted image methods according to the present disclosure. Computer modeling for obtaining three-dimensional images of the patient's anatomy using medical scans of the patient's anatomy (such as MRI, CT, ultrasound, X-rays, PET, etc.), the patient-specific prosthesis components and the patient-specific guides, templates and other instruments, can be prepared using various commercially available CAD programs and/or software available, for example, by Object Research Systems or ORS, Montreal, Canada.
The patient-specific instruments and any associated patient-specific implants and bone grafts can be generally designed and manufactured based on computer modeling of the patient's 3-D anatomic image generated from medical image scans including, for example, X-rays, MRI, CT, PET, ultrasound or other medical scans. The patient-specific instruments can have a three-dimensional engagement surface that is complementary and made to substantially mate and match in only one position (i.e., as a substantially negative or mirror or inverse surface) with a three-dimensional bone surface with or without associated soft tissues, which is reconstructed as a 3-D image via the aforementioned CAD or software. Very small irregularities need not be incorporated in the three-dimensional engagement surface. The patient-specific instruments can include custom-made guiding formations, such as, for example, guiding bores or cannulated guiding posts or cannulated guiding extensions or receptacles that can be used for supporting or guiding other instruments, such as drill guides, reamers, cutters, cutting guides and cutting blocks or for inserting guiding pins, K-wire, or other fasteners according to a surgeon-approved pre-operative plan.
In various embodiments, the patient-specific instruments of the present disclosure can also include one or more patient-specific guide members for receiving and guiding a tool, such as a drill or saw or guidewire at corresponding patient-specific insertion points and orientations relative to a selected anatomic or reverse axis for the specific patient. The patient-specific instruments can include guiding or orientation formations and features for guiding the implantation of patient-specific or off-the-shelf implants associated with the surgical procedure. The geometry, shape and orientation of the various features of the patient-specific instruments, as well as various patient-specific implants and bone grafts, if used, can be determined during the pre-operative planning stage of the procedure in connection with the computer-assisted modeling of the patient's anatomy. During the pre-operative planning stage, patient-specific instruments, custom, semi-custom or non-custom implants and other non-custom tools, can be selected and the patient-specific components can be manufactured for a specific-patient with input from a surgeon or other professional associated with the surgical procedure.
In the following discussion, the terms “patient-specific”, “custom-made” or “customized” are defined to apply to components, including tools, implants, portions or combinations thereof, which include certain geometric features, including surfaces, curves, or other lines, and which are made to closely conform substantially as mirror-images or negatives or complementary surfaces of corresponding geometric features or anatomic landmarks of a patient's anatomy obtained or gathered during a pre-operative planning stage based on 3-D computer images of the corresponding anatomy reconstructed from image scans of the patient by computer imaging methods. Further, patient-specific guiding features, such as, guiding apertures, guiding slots, guiding members or other holes or openings that are included in alignment guides, drill guides, cutting guides, rasps or other instruments or in implants are defined as features that are made to have positions, orientations, dimensions, shapes and/or define cutting planes and axes specific to the particular patient's anatomy including various anatomic or mechanical axes based on the computer-assisted pre-operative plan associated with the patient.
The patient-specific guide members can be configured to mate in alignment with natural anatomic landmarks by orienting and placing the corresponding alignment guide intra-operatively on top of the bone to mate with corresponding landmarks. The anatomic landmarks function as passive fiducial identifiers or fiducial markers for positioning of the various alignment guide members, drill guides or other patient-specific instruments.
The various patient-specific alignment guide members can be made of any biocompatible material, including, polymer, ceramic, metal or combinations thereof. The patient-specific alignment guide members can be disposable and can be combined or used with reusable and non-patient-specific cutting and guiding components.
More specifically, the present disclosure provides various embodiments of patient-specific humeral cut guide members for anatomic and reverse arthroplasty. The humeral cut guides of the present disclosure can have patient-specific engagement surfaces that reference various portions of the shoulder joint and include tubular drill guides, guiding bores or sleeves or other guiding formations that can accurately position guide pins for later humeral preparation and implantation procedures and for alignment purposes, including implant position control, implant version control, implant inclination control for both anatomic and reverse arthroplasty.
In the following, when a portion of a humeral guide member is described as “referencing” a portion of the anatomy, it will be understood that the referencing portion of the humeral guide member is a patient-specific portion that mirrors or is a negative of the corresponding referenced anatomic portion.
In some embodiments the humeral guide member can have built-in holes, openings or windows that allow the surgeon to mark the humeral bone or a model of the humeral bone with a marking pen, burr, scalpel, or any other device that can create markings to be used as landmarks on or in the humeral bone or humeral model. These landmarks can be used for the orientation of a secondary guide.
Referring to FIGS. 1 and 2, a prior art reverse shoulder implant 10 is illustrated. The reverse shoulder implant 100 includes a humeral stem 12, a humeral tray 14, a humeral bearing 16, a glenosphere 18 and a baseplate 20 having a plate portion 22 and a central boss 24. The humeral stem 12 is implanted in the humeral bone 26 and has a proximal end 28 coupled via a Morse taper connection to a male taper 30 extending from a plate 32 of the humeral tray 14. The glenosphere 18 can be modular and include a head 34 articulating with the bearing 16 and an offset double-taper component 36. The double-taper component 36 has a first tapered portion 38 coupled to a corresponding tapered opening 40 of the head 34 and a second tapered portion 42 coupled to the central boss 24 of the glenoid baseplate 20. A central screw 44 passes through the baseplate 20 into the glenoid face 46 of the patient's scapula. Peripheral screws 48 are used to lock the baseplate 20 in the glenoid face 46.
As best illustrated in FIG. 2, humeral bone 26 must include a planar surface 50 for abutment with plate 32 of humeral tray 14. To provide planar surface 50, humeral bone 26 must first be cut using a tool such as a bone saw (not shown). To properly orient the saw at the correct angle relative to humeral bone 26, the present disclosure provides a humeral cut guide system 52.
Referring to FIGS. 3-9, an exemplary humeral cut guide system 52 according to an aspect of the present disclosure is illustrated. Humeral cut guide system 52 includes a patient-specific primary cut guide member 54 and a secondary cut guide member 56. Primary cut guide member 54 is configured to be patient-specific such that primary guide member 54 mates with humeral bone 26. In this regard, primary cut guide member 54 includes an interior or bone-engagement surface 58 that is complementary and made to substantially mate and match in only one position (i.e., as a substantially negative or mirror or inverse surface) with a three-dimensional bone surface 60 of humeral bone 26 with or without associated soft tissues, which is reconstructed as a 3-D image via the aforementioned CAD or software.
An exterior surface 62 of primary cut guide member 54 is substantially pie-shaped and includes a pair of apertures 64. Apertures 64 provide lines of sight for the surgeon to see through to humeral bone 26. In addition, apertures 64 reduce the amount of material needed to form primary cut guide 54. It should be understood, however, that primary cut guide member 54 may be formed without apertures 64 without departing from the scope of the present disclosure. Regardless, if primary cut guide member 54 is provided with apertures 64, a rib 65 extends between apertures 64 and includes a protrusion 66 that extends therefrom. Protrusion 66 provides a curved contact surface 68 that allows humeral guide member 54 to be manipulated by the surgeon into correct alignment on humeral bone 26. In other words, the surgeon may place a finger-tip upon contact surface 68, which allows the surgeon to more easily orient primary cut guide member 54 in a manner that bone-engagement surface 58 properly aligns with bone surface 60 of humeral bone 26. Primary cut guide member 54 may include protrusion 66 regardless whether primary cut guide member 54 includes apertures 64.
Primary cut guide member 54 may include a distal end 70 that defines a patient-specific pin guide aperture 72. Pin guide aperture 72 is aligned per the specific patient and allows for passage of a drill, Steinmann pin, or guidewire (not shown), that allows humeral bone 26 to be reamed at the appropriate location for any desired resurfacing of humeral bone 26. In addition, pin guide aperture 72 allows humeral bone 26 to be reamed with a reaming device (not shown) for stemless prosthetic resections, if desired.
A proximal end 74 of primary cut guide member 54 defines a patient-specific primary elongate slot 76. Primary elongate slot 76 is for receipt of a blade from a cutting tool such as a bone saw (not shown) that allows humeral bone 26 to be resurfaced or resected to provide planar surface 50. Primary elongate slot 76 is formed in a shelf 78 that extends outward from exterior surface 62. Shelf 78 includes an upper surface 80 and an opposing lower surface 82. Shelf 78 extends along substantially an entire length of proximal end 74. By providing primary elongate slot 76 in shelf 78 rather than simply forming primary elongate slot 76 in exterior surface 62, the tool blade is substantially prevented from being improperly angled during resurfacing of humeral bone 26 to form planar surface 50.
Primary cut guide member 54 may include a tab 83 (FIG. 6) extending outward from shelf 78. Tab 83 includes an outer surface 84 facing away from humeral bone 26, and an inner surface 85 that faces humeral bone 26. Similar to bone-engagement surface 58, inner surface 85 of tab 83 is configured to be patient-specific such that inner surface 85 mates with humeral bone 26. In particular, tab 83 including inner surface 85 is configured to sit within and mate with a groove bicipital groove in the humeral bone 26. Accordingly, tab 83 may serve as an alignment device for primary cut guide member 54 when primary cut guide member 54 is mated with humeral bone 26.
Once the surgeon has correctly affixed primary guide member 54 to humeral bone 26, the surgeon can decide whether to resect humeral bone 26. That is, before performing shoulder arthroplasty, the surgeon will plan for a primary procedure and a secondary procedure. For example, the primary procedure may be to resect humeral bone 26 for reverse shoulder implant 10. Alternatively, the secondary procedure may be to resect humeral bone 26 for an anatomic shoulder implant (not shown), which requires resecting a different section of humeral bone 26. Regardless, once the surgeon has affixed primary cut guide member 54 for conducting the primary procedure, the surgeon may decide that the primary procedure is not satisfactory for the patient. In contrast, the surgeon may decide that the secondary procedure would be more beneficial for the patient. Regardless which procedure is selected, primary cut guide member 54 allows for practicing the primary and secondary procedures, as desired.
More specifically, in addition to including elongate slot 76, primary cut guide member 54 includes a pair of patient-specific tubular guide apertures 86. Tubular guide apertures 86 may be positioned proximate opposing ends of shelf 78, and allow for passage of a drill for reaming humeral bone 26. After reaming of humeral bone 26, a pair of pins 88 may be implanted in humeral bone 26. Pins 88 may be, for example, Steinman pins or K-wires. Any type of pin known to one skilled in the art, however, may be implanted.
After implantation of pins 88, primary cut guide member 54 may be removed from humeral bone 26 with pins 88 remaining in place. Secondary cut guide member 56 may then be mated with pins 88. Secondary cut guide member 56 is a substantially parallel piped-shaped member including a first, second, third, and fourth major surfaces 90, 92, 94, and 96. Side surfaces 98 may be formed on opposing ends of cut guide member 56. Corners that connect each major surface 90-96, as well as connect major surfaces 90-96 to side surfaces 98, may be curved or chamfered as best illustrated in FIG. 7.
A pair of though-holes 99 extend between second and fourth major surfaces 92 and 96 for receipt of pins 88. In addition, a secondary elongate slot 100 may extend between second and fourth major surfaces 92 and 96. Although only a single secondary slot 100 is illustrated, it should be understood that secondary cut guide member 56 may include a plurality of secondary elongate slots 100. Providing a plurality of secondary elongate slots 100 allows cut guide member 56 to be reusable, and allows the surgeon to select the appropriate secondary elongate slot 100 for resecting humeral bone 26. Secondary elongate slots 100 may be formed on either side of through holes 99, without limitation. Once secondary cut guide member 56 is mated with pins 88, humeral bone 26 may be resurfaced as desired using the selected secondary elongate slot 100 as a guide for the cutting tool such as a bone saw. It should be understood that secondary elongate slot 100 may be used if the surgeon determines intra-operatively that a different cut height should be used instead of the cut height provided by primary elongate slot 76. It should also be understood that pins 88 are not necessarily oriented relative to humeral bone 26 to provide a different cut height. In contrast, guide apertures 86 may include an orientation that provides a different (i.e., non-parallel) cutting plane once pins 88 are mated with humeral bone 26 and secondary cut guide member 56 is coupled to pins 88.
According to the above-described embodiment, humeral cut guide system 52 allows for a plurality of cutting heights and planes to be selected by the surgeon performing humeral resurfacing. Because primary cut guide member 54 is patient-specific and includes primary elongate slot 76 as well as tubular guide apertures 86, primary cut guide member 54 can be used to prepare the patient for each of the primary and secondary procedures that are determined before surgery.
Now referring to FIGS. 10 to 14, another exemplary humeral cut guide system 200 is illustrated. Humeral cut guide system 200 includes a primary cut guide member that includes humeral mating member 202 and a humeral cut guide member 204. Humeral mating member 202 includes a plurality of grasping members 206. In the illustrated embodiment, humeral mating member 202 includes three grasping members 208, 210 and 212 that extend outward from a central hub 214. It should be understood, however, that any number of grasping members 206 may be used without departing from the scope of the present disclosure.
Each grasping member 206 includes a proximal end 216 fixed to central hub 214 and a distal end 218 positioned away from central hub 214. Central hub 214 and grasping members 206 each include an interior or bone-engagement surface 217 and an exterior surface 219 that faces away from humeral bone 26. Similar to humeral cut guide system 52, bone-engagement surface 217 is complementary and made to substantially mate and match in only one position (i.e., as a substantially negative or mirror or inverse surface) with a three-dimensional bone surface 60 of humeral bone 26 with or without associated soft tissues, which is reconstructed as a 3-D image via the aforementioned CAD or software.
Grasping members 206 may be differently sized. In the illustrated embodiment, for example, grasping members 208 and 210 are substantially the same size, while grasping member 212 is wider than grasping members 208 and 210. Grasping member 212, however, has a length that is less than that of grasping members 208 and 210. Regardless, grasping member 212 provides a greater amount of contact with humeral bone 26 that assists in locating humeral mating member 202 on humeral bone 26. Due to grasping members 208 and 210 having a greater length than grasping member 212, grasping members 208 and 210 can include patient-specific hooks 215 that mate with various protrusions of humeral bone 26.
Central hub 214 may be oval shaped, and include a planar exterior surface 220. Central hub 214 can include a pair of recesses 222 and 224 having different depths and trajectories. For example, recess 222 may have a greater depth than recess 224. The different depths of recesses 222 and 224 are so that humeral mating member 202 can be used in each of an anatomical shoulder replacement or reverse shoulder replacement procedure. That is, recess 222 having the greater depth may be used for anatomical shoulder replacement, and recess 224 having the shallower depth may used for reverse shoulder replacement. It should be understood, however, that the recess 222 having the greater depth may be used for reverse shoulder replacement, that recess 224 having the lesser depth may be used for anatomical shoulder replacement as determined by the surgeon pre-operatively. Moreover, it should be understood that recesses 222 and 224 are not necessarily arranged in parallel. That is, recess 222 can be angled relative to recess 224, or vice versa. Regardless, recesses 222 and 224 can be oriented in the desired manner according to patient-specific pre-operative planning.
Recesses 222 and 224 are designed to mate with humeral cut guide member 204. As best shown in FIG. 13, humeral cut guide member 204 includes a guide arm 226 and an attachment arm 228. Guide arm 226 and attachment arm 228 are illustrated as being unitary, but may be separately formed and attached without departing from the scope of the present disclosure. Guide arm 226 includes an outer face 228 and an opposing inner face 230 that are connected by side faces 232. A patient-specific primary elongate slot 234 extends between outer face 228 and inner face 230 for receipt of a cutting blade of, for example, a bone saw for resurfacing humeral bone 26. Although only a single primary elongate slot 234 is illustrated, it should be understood that a plurality of elongate slots 234 may be provided that provide the surgeon with different cutting planes to select for the patient to adjust for the cutting height intraoperatively. Guide arm 226 may include a through-hole 236. Through-hole 236 provides a line of sight for the surgeon to ensure that humeral cut guide member 204 is properly aligned relative to humeral bone 26.
Attachment arm 228 extends substantially orthogonally outward from guide arm 226, and includes a proximal end 238 that is attached to guide arm 226 and a distal free end 240. Attachment arm 228 includes a planar upper surface 242 and a planar lower surface 244, with the planar upper and lower surfaces 242 and 244 being connected by side surfaces 246. An elongate aperture 248 extends between the planar upper and lower surfaces 242 and 244. Similar to through-hole 236, elongate aperture 248 provides a line of sight for the surgeon to ensure that humeral cut guide member 204 is properly aligned relative to humeral bone 26.
A projection 250 extends outward from planar lower surface 244 at distal free end 240. Projection 250 is sized to mate with either recess 222 or recess 224 depending on whether an anatomical or reverse shoulder arthroplasty is being performed. Because these procedures are conducted at different cutting planes, the different depths of recesses 222 and 224 allow for primary elongate slot 234 of guide arm 226 to be arranged at different cutting planes dependent on the recess 222 or 224 selected. Projection 250 also allows cut guide member 204 to pivot relative to humeral bone 26. This allows the surgeon to position cut guide member 204 at the appropriate position of humeral bone 26 before beginning resurfacing or resecting of humeral bone 26. Alternatively, it should be understood that projection 250 and recesses 222 and 224 can be shaped to not allow cut guide member 204 to pivot relative to humeral bone 26. Rather, because cut guide system 200 is patient-specific, the correct orientation of cut guide member 204 relative to humeral bone 26 can be selected before attachment of humeral cut guide system 200 to humeral bone 26.
Cut guide member 204 can be configured similar to humeral guide member 54. That is, cut guide member 204 additionally includes a pair of patient-specific cylindrical apertures 252 that allow for passage of a drill for reaming humeral bone 26. After reaming of humeral bone 26, a pair of pins 88 may be implanted in humeral bone 26. Pins 88 may be, for example, Steinman pins or K-wires. Any type of pin known to one skilled in the art, however, may be implanted. After implantation of pins 88, humeral mating member 202 and cut guide member 204 may be removed from humeral bone 26 with pins 88 remaining in place. Secondary cut guide member 56 may then be mated with pins 88 to provide yet another cutting plane for the surgeon to select. Similar to previously described embodiments, it should also be understood that pins 88 are not necessarily oriented relative to humeral bone 26 to provide a different cut height. In contrast, cylindrical apertures 252 may include an orientation that provides a different (i.e., non-parallel) cutting plane once pins 88 are mated with humeral bone 26 and secondary cut guide member 56 is coupled to pins 88.
According to the above-described embodiment, humeral cut guide system 200 allows for a plurality of cutting heights and planes to be selected by the surgeon performing humeral arthroplasty. Because humeral mating member 202 is patient-specific and includes recesses 222 and 224 for different procedures that are designed to mate with cut guide member 204, humeral cut guide system 200 can be used to prepare the patient for each of the primary and secondary procedures (e.g., anatomical or reverse shoulder arthroplasty) that are determined before surgery.
Now referring to FIGS. 15 to 18, another exemplary humeral cut guide system 300 is illustrated. Cut guide system 300 is similar to humeral cut guide system 200 in that cut guide system 300 includes a primary cut guide member including a humeral mating member 302 and a humeral cut guide member 304. In the present embodiment, however, humeral mating member 302 and humeral cut guide member 304 are unitary. Humeral mating member 302 includes a plurality of grasping members 306. In the illustrated embodiment, humeral mating member 302 includes two grasping members 308 and 310 that extend outward from a central hub 314. It should be understood, however, that any number of grasping members 306 may be used without departing from the scope of the present disclosure.
Each grasping member 306 includes a proximal end 316 fixed to central hub 314 and a distal end 318 positioned away from central hub 314. Central hub 314 and grasping members 306 each include an interior or bone-engagement surface 315 and an exterior surface 317 that faces away from humeral bone 26. Similar to humeral cut guide system 52, bone-engagement surface 315 is complementary and made to substantially mate and match in only one position (i.e., as a substantially negative or mirror or inverse surface) with a three-dimensional bone surface 60 of humeral bone 26 with or without associated soft tissues, which is reconstructed as a 3-D image via the aforementioned CAD or software. In the illustrated embodiment, grasping members 308 and 310 are substantially the same size. It should be understood, however, that grasping members 306 may be differently sized without departing from the scope of the present disclosure.
Central hub 314 may include cylindrical base portion 320. A tubular shaft 322 may extend outward from base portion 320 that defines a patient-specific pin guide aperture 324. Pin guide aperture 324 allows for passage of a drill (not shown), that allows humeral bone 26 to be reamed at the appropriate location for any desired resurfacing of humeral bone 26. In addition, pin guide aperture 324 allows humeral bone 26 to be reamed for stemless prosthetic resections, if desired.
As best shown in FIGS. 16-18, humeral cut guide member 304 includes outer face 328 and an opposing inner face 330 that are connected by side faces 332. A patient-specific primary elongate slot 334 extends between outer face 328 and inner face 330 for receipt of a cutting blade of, for example, a bone saw for resurfacing humeral bone 26. Although only a single primary elongate slot 334 is illustrated, it should be understood that a plurality of elongate slots 334 may be provided that provide the surgeon with different cutting planes to select for the patient.
Cut guide member 304 is configured similar to humeral guide member 54. That is, cut guide member 304 additionally includes a pair of patient-specific cylindrical apertures 352 that allow for passage of a drill for reaming humeral bone 26. After reaming of humeral bone 26, a pair of pins 88 may be implanted in humeral bone 26. Pins 88 may be, for example, Steinman pins or K-wires. Any type of pin known to one skilled in the art, however, may be implanted. After implantation of pins 88, humeral mating member 302 and cut guide member 304 may be removed from humeral bone 26 with pins 88 remaining in place. Secondary cut guide member 56 may then be mated with pins 88 to provide yet another cutting plane for the surgeon to select. Again, it should be understood that pins 88 are not necessarily oriented relative to humeral bone 26 to provide a different cut height. In contrast, cylindrical apertures 352 may include an orientation that provides a different (i.e., non-parallel) cutting plane once pins 88 are mated with humeral bone 26 and secondary cut guide member 56 is coupled to pins 88.
According to the above-described embodiment, humeral cut guide system 300 allows for a plurality of cutting heights and planes to be selected by the surgeon performing humeral resurfacing. Because humeral mating member 302 and humeral cut guide member 304 are patient-specific and include patient-specific elongate slot 322 and patient-specific cylindrical apertures 352, humeral cut guide system 300 can be used to prepare the patient for each of the primary and secondary procedures (e.g., anatomical or reverse shoulder arthroplasty) that are determined before surgery.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

## Claims

1. A humeral cut guide system for resectioning or resurfacing a humeral head, comprising:
a primary cut guide member configured to be removably coupled to the humeral head, the primary cut guide member including a patient-specific bone-engaging surface, a primary elongate slot that defines a primary cutting plane, and including a pair of cylindrical apertures configured to receive a pair of guide pins; and
a secondary cut guide member including a pair of through-holes configured to mate with the pair of guide pins, the secondary cut guide member including a secondary elongate slot that defines a secondary cutting plane.

2. The humeral cut guide system according to claim 1, wherein the primary cut guide member includes a protrusion extending from an exterior surface thereof, the protrusion defining a contact surface for manipulation of the primary cut guide member relative to the humeral head.

3. The humeral cut guide system according to claim 1, wherein the primary cut guide member includes an aperture formed therein that is configured to provide a line of sight to the humeral head when coupling the primary guide member to the humeral head.

4. The humeral cut guide system according to claim 1, wherein the primary cut guide member includes a shelf protruding from an exterior surface thereof, the shelf at least partially defining the primary elongate slot.

5. The humeral cut guide system according to claim 4, wherein cylindrical apertures are formed on opposing ends of the shelf.

6. The humeral cut guide system according to claim 1, wherein the patient-specific bone engaging surface is complementary to a patient bone surface of the humeral head.

7. The humeral cut guide system according to claim 1, wherein the primary cut guide member includes a tab extending therefrom, the tab configured to correspond to a patient-specific groove of the humeral head.

8. The humeral cut guide system according to claim 1, wherein the primary cut guide member includes a plurality of grasping members coupled to a central hub.

9. The humeral cut guide system according to claim 8, wherein each of the grasping members include a patient-specific bone-engaging surface.

10. The humeral cut guide system according to claim 8, wherein at least one of the grasping members includes a hook feature configured to mate with the humeral head.

11. The humeral cut guide system according to claim 8, wherein the grasping members are differently sized.

12. The humeral cut guide system according to claim 1, wherein the primary cut guide member is composed of a humeral mating member and a humeral cut guide member.

13. The humeral cut guide system according to claim 12, wherein the humeral cut guide member is removably attachable to the humeral mating member.

14. The humeral cut guide system according to claim 1, wherein the humeral cut guide member and the humeral mating member are unitary.

15. The humeral cut guide system according to claim 12, wherein the humeral mating member includes a plurality of grasping members coupled to a central hub.

16. The humeral cut guide system according to claim 15, wherein each of the grasping members include a patient-specific bone-engaging surface.

17. The humeral cut guide system according to claim 15, wherein at least one of the grasping members includes a hook feature configured to mate with the humeral head.

18. The humeral cut guide system according to claim 15, wherein the grasping members are differently sized.

19. A method of resectioning or resurfacing a humeral head, comprising:
affixing a primary cut guide member to a humeral head, the primary cut guide member including a patient-specific bone-engaging surface, a primary elongate slot that defines a primary cutting plane, and including a pair of cylindrical apertures;
determining whether the primary cutting plane is sufficient for the resectioning or the resurfacing of the humeral head, and if the primary cutting plane is sufficient, conducting the resectioning or the resurfacing of the humeral head;
wherein if the primary cutting plane is not sufficient for the resectioning or the resurfacing of the humeral head, a pair of guide pins are coupled to the humeral head through the cylindrical apertures, the primary cut guide slot is removed, and a secondary cut guide member including a secondary elongate slot that defines a secondary cutting plane is attached to the pins.

20. The method according to claim 19, wherein the patient-specific bone engaging surface is complementary to a patient bone surface of the humeral head.

21. The method according to claim 19, wherein the primary cut guide member includes a plurality of grasping members coupled to a central hub.

22. The method according to claim 21, wherein each of the grasping members include the patient-specific bone-engaging surface.

23. The method according to claim 19, wherein the primary cut guide member is composed of a humeral mating member and a humeral cut guide member.

24. The method according to claim 23, wherein the humeral cut guide member is removably attachable to the humeral mating member.

25. The method according to claim 23, wherein the humeral cut guide member and the humeral mating member are unitary.

26. The method according to claim 23, wherein the humeral mating member includes a plurality of grasping members coupled to a central hub.

27. The method according to claim 26, wherein each of the grasping members include the patient-specific bone-engaging surface.