Graft release bell device

Abstract

The present invention provides an instrument and method for removing the bone cylinder from inside the humeral head without cutting the humeral head. [Solution] The graft release bell instrument comprises a central shaft, a bell detachably coupled to the central shaft, an inner blade coupled to the central shaft, and an outer blade coupled to the bell. A method for extracting a cancellous bone graft includes inserting the graft release bell instrument into the cut portion of the bone, checking the depth of the cut portion using the scale on the side of the graft release bell instrument, rotating the graft release bell instrument to cut the cancellous bone, withdrawing the graft release bell instrument from the cut portion, and separating the graft from the graft release bell instrument.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims priority to U.S. Provisional Application No. 63 / 734,342, filed on December 16, 2024, and U.S. Application No. 19 / 411,559, filed on December 8, 2025. All applications in which foreign or domestic priority claims are specified in the application data sheet filed with this application are incorporated by reference into this application for all purposes as if fully set forth herein under 37 C.F.R.§1.57.

Background Art

[0002] This disclosure relates to surgical instruments. More specifically, this disclosure relates to instruments for performing bone grafts during surgery and methods of using these instruments.

[0003] In some surgeries, it is desirable for a surgeon to harvest a portion of bone for transplantation to another location. In one example, during shoulder joint replacement, a bone graft can be harvested from the humerus and used to lateralize the glenoid implant. This may be required during reverse total shoulder arthroplasty using a reverse prosthesis where the ball - type component is placed on the socket - side (i.e., the glenoid - side) of the joint, which is anatomically opposite to the original position. Next, the corresponding socket - type component is placed at the end of the humerus. This arrangement is known as reverse total shoulder arthroplasty (RSA). Figure 1 shows an example of a reverse total shoulder prosthesis 100 that can be used in such a procedure.

[0004] Figure 1 shows that the reverse-type artificial shoulder joint prosthesis 100 can comprise a glenoid implant 110 attached to the scapula S and a humeral implant 120 attached to the humerus H. Figure 1 also shows that the glenoid implant 110 can be offset or laterally positioned from the scapula S using a bone graft G. That is, the glenoid implant 110 can be shifted laterally from the scapula S using the bone graft G as a spacer. This may be desirable to improve the stability of the prosthesis 100, reduce wear of the prosthesis 100, and increase the range of motion of the patient's shoulder.

[0005] The position of the glenoid implant 110 can be shifted laterally to create a better foundation for the prosthetic component. This lateralization improves bone coverage of the prosthesis 100 and distributes forces more evenly. Lateral bone positioning improves the stability of the prosthesis 100 and reduces the risk of dislocation. By optimizing force distribution, wear on the prosthetic component can be reduced, extending the lifespan of the prosthesis 100.

[0006] In conventional RSA, the bone graft G can be harvested from the resected humerus H. In one technique, Bony Increased Offset RSA (BIO-RSA Angled), a reamer is used in front of the graft recovery device to remove articular cartilage and hard bone in the humeral head. The graft is then excised from the humerus using a saw with a cutting guide. In the SMR® Shoulder System, another technique of modular total shoulder arthroplasty, the graft is cut and removed using an electric graft cutter after reaming the humeral head. The graft is then placed in the glenoid implant. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, it is desirable to minimize invasiveness without cutting the humeral head in order to preserve as much bone as possible and extract the bone cylinder from inside the humeral head. This disclosure provides an instrument and method for extracting the bone cylinder from inside the humeral head without cutting the humeral head. [Means for solving the problem]

[0008] To overcome the aforementioned problems, embodiments of the present disclosure include a graft release bell device comprising a central shaft, an inner blade extending from the central shaft, an outer blade extending from an outer member, and a handle for rotating the entire unit.

[0009] According to embodiments of the present disclosure, the graft release bell device comprises a central shaft, an inner blade extending from the central shaft, an outer blade extending from an outer member, and a handle for rotating the central shaft.

[0010] In one embodiment, the handle rotates the gear assembly, thereby rotating the inner and outer blades.

[0011] In one embodiment, the graft release bell device further comprises a button configured to move to a different position in order to extend the outer blade.

[0012] In one embodiment, the graft release bell device further includes a bell, which is an outer member. The diameter of the bell is 25 mm or 29 mm.

[0013] In one embodiment, the graft release bell device is provided with a scale on the bell.

[0014] In one embodiment, the handle is configured to pass through a hole in the central shaft.

[0015] In one embodiment, the outer blade fits into a slot in a cylindrical bell.

[0016] In one embodiment, the inner and outer blades are rotatable and can be opened and closed.

[0017] In one embodiment, the central shaft can be locked to the bell.

[0018] In one embodiment, the bell is configured to pass through a hole in the bone defined by the bone saw.

[0019] According to another embodiment, a method for extracting a bone graft includes placing a graft release bell instrument into a hole in the bone, opening the blades of the graft release bell instrument, rotating the graft release bell instrument to cut the cancellous bone, and removing the graft release bell instrument and the cut portion of the cancellous bone.

[0020] In one embodiment, the method may further include opening a second blade of a graft release bell device.

[0021] In another embodiment, the graft release bell device comprises a body, a gear assembly coupled to the body and comprising a handle and gears, a first cylinder extending from the body, a first blade coupled to the first cylinder, a second cylinder extending from the body, and a second blade coupled to the second cylinder, wherein when the handle is rotated in a first direction, the first blade rotates in one direction and the second blade rotates in the opposite direction. In one embodiment, there are two separate devices, one for obtaining a graft with a diameter of 25 mm and the other for obtaining a graft with a diameter of 29 mm.

[0022] In one embodiment, the first blade and the second blade are retractable into their respective cylinders.

[0023] This graft release bell device may further include a locking mechanism for locking and unlocking the rotation of the first and second blades.

[0024] In one embodiment, the locking mechanism includes a set screw.

[0025] In one aspect, rotating the handle in a second direction causes the first blade and the second blade to retract.

[0026] According to another embodiment, the graft release bell instrument includes an adapter, a bell coupled to the adapter, a blade coupled to the bell, and a knob coupled to the bell and the blade and configured to be movable to a plurality of discrete positions to deploy and retract the blade. In one aspect, there are different bells for different graft diameters (e.g., 25 mm and 29 mm).

[0027] In one aspect, the adapter is configured to be coupled to a power tool.

[0028] In one aspect, the adapter is configured to be coupled to a handle.

[0029] The graft release bell instrument may further include a scale on a side surface of the bell and configured to indicate the depth of the bell within the circular cutting portion.

[0030] The graft release bell instrument further includes a slot across the top of the bell, and the knob can move within the slot to deploy and retract the blade.

[0031] In one aspect, the blade is curved and conforms to the arc of the bell.

[0032] The graft release bell instrument may further include a pusher movable along the longitudinal axis of the graft release bell instrument to push a portion of the cut bone out of the bell.

[0033] According to another embodiment, the graft release bell instrument includes a central shaft, a bell removably coupled to the central shaft, an inner blade coupled to the central shaft, and an outer blade coupled to the bell.

[0034] The graft release bell device may further include a handle that is connected to a central shaft.

[0035] In one embodiment, the central shaft extends through the bell.

[0036] In one embodiment, the bell is connected to the central shaft via a pin on the central shaft that is fitted into a T-shaped groove on the side of the bell.

[0037] In one embodiment, the central shaft is provided with a cam and the bell is provided with a locking groove, and the central shaft and the bell are joined by inserting the cam into the locking groove and rotating the central shaft and the bell relative to each other so that the cam locks in the locking groove.

[0038] In one embodiment, the inner blade is positioned in a groove extending along the side of the central shaft and is rotatable between an extended position and a closed position by rotating an inner blade tab connected to the inner blade.

[0039] In one embodiment, the inner blade is positioned in a groove extending along the side of the bell and is rotatable between an extended position and a closed position by rotating an outer blade tab connected to the outer blade.

[0040] According to another embodiment, a method for extracting a cancellous bone graft includes inserting a graft release bell instrument into the bone cut, determining the depth of the cut using the scale on the side of the graft release bell instrument, rotating the graft release bell instrument to cut the cancellous bone, withdrawing the graft release bell instrument from the cut, and separating the graft from the graft release bell instrument.

[0041] This method may further include forming an opening in the humeral head prior to the insertion step.

[0042] This method may further include driving in a graft release bell after the insertion step.

[0043] In one embodiment, the step of rotating the graft release bell device extends the blades of the graft release bell device.

[0044] In one embodiment, the step of rotating the graft release bell device extends the two blades of the graft release bell device.

[0045] This method may further include deploying the blades of the graft release bell device before the step of rotating the graft release bell device.

[0046] This method may further include the use of a graft to laterally position the glenoid implant.

[0047] In one embodiment, the step of cutting the opening of the humeral head includes creating a circular opening with a bell saw. [Effects of the Invention]

[0048] The above and other components, elements, features, steps, and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments of the present invention and the accompanying drawings. [Brief explanation of the drawing]

[0049] [Figure 1] A reverse-type artificial shoulder joint prosthesis 100 using related technology is shown. [Figure 2] This is a perspective view of a graft release device according to one embodiment of the present disclosure. [Figure 3] A-E are alternative diagrams of the graft release device shown in Figure 2. [Figure 4] This is a perspective view of a graft release device according to another embodiment of the present disclosure. [Figure 5A] This is another diagram of the graft release device shown in Figure 4. [Figure 5B] This is another diagram of the graft release device shown in Figure 4. [Figure 5C] This is another diagram of the graft release device shown in Figure 4. [Figure 5D] This is another diagram of the graft release device shown in Figure 4. [Figure 5E] This is another diagram of the graft release device shown in Figure 4. [Figure 5F] This is another diagram of the graft release device shown in Figure 4. [Figure 5G] This is another diagram of the graft release device shown in Figure 4. [Figure 5H] This is another diagram of the graft release device shown in Figure 4. [Figure 6] This is a perspective view of a graft release device according to another embodiment of the present disclosure. [Figure 7] A to C are various diagrams of the graft release device shown in Figure 6. [Figure 8] This is a perspective view of a graft release device according to another embodiment of the present disclosure. [Figure 9A] Figure 8 shows a diagram of a graft release device. [Figure 9B] Figure 8 shows a diagram of a graft release device. [Figure 9C] Figure 8 shows a diagram of a graft release device. [Figure 9D] Figure 8 shows a diagram of a graft release device. [Figure 9E] Figure 8 shows a diagram of a graft release device. [Figure 9F] Figure 8 shows a diagram of a graft release device. [Figure 9G] Figure 8 shows a diagram of a graft release device. [Figure 10] A to E show the assembly of the shaft of the graft release device in Figure 8. [Figure 11] A to C show the assembly of the shaft of the graft release device in Figure 8. [Figure 12A] The steps of the method according to the embodiments of this disclosure are shown. [Figure 12B] The steps of the method according to the embodiments of this disclosure are shown. [Figure 13] This shows a bone graft taken from the humerus according to an embodiment of the present disclosure. [Modes for carrying out the invention]

[0050] Embodiments of the present disclosure will be described in detail below, examples of which are shown in the accompanying drawings. Where possible, the same reference numerals will be used throughout the drawings to indicate the same or similar parts. However, the present disclosure may be embodied in many different forms and should not be construed as being limited to the embodiments described herein.

[0051] The terms used herein to indicate direction, such as up, down, right, left, front, back, top, bottom, vertical, and horizontal, are for reference only to the illustrated drawings and do not imply absolute orientation.

[0052] Unless otherwise specified, none of the methods described herein are intended to be construed as requiring their steps to be performed in a particular order, nor are any particular orientations required for any of the apparatuses. Therefore, if a claim for a method does not actually describe the order in which its steps should be followed, or if a claim for any apparatus does not actually describe the order or orientation of its individual components, it is not intended that the steps should be limited to a particular order, or that no particular order or orientation of the components of the apparatus is described, unless specifically stated in the claim or specification, or that such order or orientation should be inferred in any respect. This is also true in all implicit grounds for any possible interpretation, including logical issues relating to the arrangement of steps, the flow of operations, the order of components, or the orientation of components, plain meaning derived from grammatical construction or punctuation, and the number or type of embodiments described in the specification.

[0053] As used herein, the singular forms "a," "an," and "the" include multiple referents unless the context explicitly indicates otherwise. For example, a reference to "a component" includes embodiments having two or more components unless the context explicitly indicates otherwise.

[0054] The following description includes references to accompanying drawings, which form part of it, and the drawings are shown by illustrating certain exemplary embodiments in which the disclosure may be carried out. These embodiments are described in sufficient detail to enable those skilled in the art to implement the concepts of the disclosure, and it will be understood that various modifications to the disclosed embodiments may be made without departing from the scope of the disclosure, and that other embodiments may be utilized. The following detailed description should therefore not be construed as restrictive.

[0055] A disclosed graft release instrument, called a graft release bell, can be used to remove a bone fragment called a “graft.” In some embodiments, the graft may have a size up to 30 millimeters in thickness, for example, and may be obtained from the upper part of the humeral head. The device of this disclosure can be used to harvest grafts thicker or thinner than 30 millimeters, as will be understood by those skilled in the art. It should be understood that the disclosed device, system, and method may also be used on other bones, including the bones that make up the hip, ankle, knee, and other joints. The graft can be cut directly from above the bone by inserting the instrument into a previously made circular cut with a bell saw. The diameter of the graft can be selected based on the patient’s anatomical structure, thereby limiting the number of surgeries and avoiding further damage to the patient’s bone. A bell saw can be used to create a central hole in the graft and a circular cut corresponding to the outer diameter of the bell saw. As disclosed, the diameter and thickness of the cut graft can be selected based on the configuration of the bell saw and the graft release instrument. In some embodiments, the graft may have a diameter of 25 mm or 29 mm, and the thickness for each diameter may be 20 mm, 25 mm, or 30 mm. Other suitable diameters and thicknesses are possible. Graft release devices can be customized to be unique to or specific to a single patient.

[0056] The different components of the disclosed embodiments can be assembled without the need for additional tools. Each assembly is locked into the housing and ready for use in the working position. The disassembly step is the reverse of the assembly step.

[0057] Traditionally, harvesting a bone graft for reverse total shoulder arthroplasty may involve the following: (i) Patient positioning: The patient may be positioned in a beach chair position with the shoulder laterally positioned so that the arm can be fully extended. (ii) Incision: An incision may be made from the tip of the coracoid bone along the deltoid groove. (iii) Bone preparation: The glenoid cavity may be prepared using a specialized reamer to create a precise cavity for the bone graft. (iv) Graft harvesting: A cylindrical bone graft may be harvested from the humerus using a cutting guide. (v) Graft implantation: The harvested bone graft is then implanted into the prepared glenoid cavity.

[0058] However, conventional techniques limit the surgeon's choice of graft angle and thickness. The instrument according to this disclosure provides a greater choice of graft angle and thickness while being minimally invasive. For example, a surgeon can obtain a bone cylinder of 15–30 mm and then reshape it (angle and thickness) as needed to fit the patient.

[0059] Figure 2 is a perspective view, and Figures 3A to F show a graft release device 200 according to one embodiment of the present disclosure. Figure 3 includes various figures (A to F). Figure 3B is a front view. Figure 3A is a cross-sectional view along AA of Figure 3B. Figure 3C is a side view. Figures 3D and E are top views. Figure 3F is a cross-sectional view along BB of Figure 3D.

[0060] As shown in the figure, the instrument 200 may comprise a body 210, a gear assembly 220 with a handle 222 and gear 224, a first cylinder 230, a first (internal) blade 235, a second cylinder 240, and a second (external) blade 245. The instrument 200 can be used after the humeral head has been opened using a bell saw.

[0061] As shown in the figure, the first cylinder 230 and the second cylinder 240 may extend from the bottom of the body 210, and the first blade 235 and the second blade 245 may extend outward from their respective cylinders 230 and 240. The gear assembly 220 may be located on top of the body 210 and includes a gear arrangement such that when the handle 222 is rotated in a first direction (e.g., clockwise) about its axis, one of the first blade 235 and the second blade 245 rotates in the same direction (e.g., clockwise) about its axis of rotation, and the other of the two blades 235 and 245 rotates in a second direction (e.g., counterclockwise) about its axis of rotation. In some embodiments, when the handle 222 is rotated and the gear 224 is moved, a shaft extending through their respective first cylinders 230 and second cylinders 240 and connected to their respective blades 235 and 245 rotates.

[0062] In some embodiments, the diameter of the first cylinder 230 may be the same as the diameter of the central drill (not shown) of the bell saw. The diameter of the second blade 245 may correspond to the thickness of the bell saw wall. After drilling and reaming the humerus, with the blades 235 and 245 housed, the first cylinder 230 is fitted into the hole prepared by the central drill and then driven into the humeral head, allowing the first cylinder 230, the second cylinder 240, and the blades 235 and 245 to reach deep into the humeral head. At this depth, the soft cancellous bone can be cut.

[0063] To store or retract them, the blades 235, 245 may rotate in the opposite direction (for example, counterclockwise) so that they are hidden within their respective cylinders 230, 240. For example, Figure 2 shows that the first cylinder 230 is provided with a slot 237 along the plane on which the first blade 235 rotates. The slot 237 can provide clearance for the first blade 235 from the first cylinder 230 while rotating 360 degrees in the cutting direction, so that the first blade 235 can be effectively folded into the slot 237 when the gear assembly 220 rotates in the opposite direction. Similar mechanisms may be implemented for the second cylinder 240 and the second blade 245.

[0064] Furthermore, in some embodiments, the first blade 235 and the second blade 245 can be locked and unlocked against rotation. In one embodiment, the blades 235 and 245 can be locked and unlocked using set screws 212 and 214. For example, the set screws 212 and 214 are located inside the body 210 and are tightened against gears or rotating members attached to the blades 235 and 245, preventing those components and each blade from rotating. Loosening or removing the set screws 212 and 214 allows the blades 235 and 245 to rotate. In some embodiments, a pin arrangement can be used such that pressing a pin or button on the body 210 pushes a pin or other component inside the body 210, stopping the rotation of the gear 224 or internal member. Pushing the pin in the opposite direction can unlock the device 200 and allow the blades to rotate.

[0065] After the instrument 200 is inserted into the hole in the humeral head and the blades 235 and 245 are unlocked and extended, the clinician can hold the main body 210 with one hand and rotate the handle 222 with the other hand to rotate the blades 235 and 245 and cut the cancellous bone to obtain a bone cylinder to be used as a graft. After cutting, the instrument 200 and the bone cylinder can be withdrawn from the humeral head, and the blades 235 and 245 can be retracted or closed, for example by rotating the handle 222 in a second direction (for example, counterclockwise), and the bone cylinder is separated from the instrument 200.

[0066] Figure 4 is a perspective view of a graft release device 400 according to another embodiment of the present disclosure, and Figures 5A to 5C are drawings thereof. Figure 5 includes various Figures 5A to 5H. Figure 5A is an exploded view. Figure 5C is a front view. Figure 5B is a cross section along AA of Figure 5C. Figure 5D is a side view. Figure 5E is a rear view. Figure 5F is a top view. Figure 5G is a cross section along CC of Figure 5C. Figure 5H is a cross section along DD of Figure 5C. As shown in the figures, the device 400 may comprise a bell 410, a fastener 415, a knob 420, a knob connector 425, an adapter 430, a blade shaft 440, a blade 445, and a pusher 450. The bell 410 is hollow and can be connected to the adapter 430 using the fastener 415. The bell 410 may be interchangeable with other bells having different diameters. In some embodiments, the bell 410 may have a diameter of 25 mm. In other embodiments, the bell 410 may have a diameter of 29 mm. Optionally, the bell 410 may have any suitable diameter.

[0067] As shown in Figure 5A, the adapter 430 may be elongated and may be configured to connect to a power tool (not shown) used to rotate the instrument 400 around a central axis Y. For example, the free end 432 of the adapter 430 may be fitted into the chuck or collet of the power tool. In some embodiments, a handle may be attached to the adapter 430 and used to rotate the instrument 400 by hand.

[0068] The blade 445 can be manually unfolded (for example, radially outward) from its folded position, where it is housed in a slot 414 defined by the wall of the bell 410, using the knob 420. As shown in Figure 5A, the slot 414 may be arched so as to extend a portion of the perimeter of the wall of the bell 410. Figure 5A also shows that the knob 420 may be connected to the blade 445 via an arm 425 extending between the knob 420 and a centrally located pivot 427. The pivot 427 may then be connected to a blade shaft 440 that extends vertically through the bell to the blade 445. To unfold the blade 445, the knob 420 can be manually moved to a series of positions located along an arc-shaped slot 412 extending across the top of the bell 410, or to a stopper 413, so as to rotate the blade 445 in stages within the bell 410. The stopper 413 may be defined as a appropriately shaped notch along the slot 412. The arm 425 may be elastic and may allow the blade 445 to move relative to the bone while the position of the knob 420 changes. In some embodiments, the blade 445 is curved and conforms to the arc of the bell 410, thereby allowing the blade 445 to be housed in a slot 414 along the wall of the bell 410. In some embodiments, the blade 445 may have cutting teeth.

[0069] Instrument 400 can be used after the humeral head has been opened using a bell saw. During use, instrument 400 can be inserted into the circular cut in the humerus made by the bell saw until it reaches the bottom of the cut. The depth can be confirmed using the scale 414 on the bell 410, which can be seen in Figure 5E. The scale 414 indicates the depth of the cut made by the bell saw, for example, 15 mm, 20 mm, 25 mm, and 30 mm.

[0070] The blade 445 can be operated using the knob 420 by moving the knob 420 along the slot 412 to multiple stoppers 413. When the instrument 400 is not rotating, to avoid damage to any component, the knob 420 can be pulled up, rotating the blade 445 inward and moving it to another stopper 413, prestressing the blade 445 (with cutting teeth) against the bone and pushing it back into position in the slot 412. The force of the blade 445 against the bone causes the blade 445 to cut through the bone within a few rotations at each position. In some embodiments, there are four stoppers 413, but any other suitable number is possible.

[0071] The surgeon can rotate the instrument 400 clockwise any number of times for each knob / blade position using a power tool or handle attached to the adapter 430. The number of turns can be changed based on the rotation speed and the surgical condition. For example, the number of turns may be approximately 4. After cutting at a certain position, the surgeon can move the knob 420 to the next stopper 413 to further extend the blade 445. The knob 420 may consist of an upper portion that the surgeon can grasp and a shaft 422 that extends from the upper portion through the knob connector 425 into the slot 412 or stopper 413. After moving through all the different knob stoppers 413, the blade 440 is in a position to fully open and complete the cutting of the cancellous bone.

[0072] Before removing the severed graft, the blade 445 must be closed so as not to obstruct the extraction of the graft from the bell 410. The blade 445 can be closed by moving the knob 420 to the starting position and fully retracting the blade 445. If the bone of the graft catches on the bell 410, the pusher 450, including the plate 452, can be pushed downward along the Y-axis to push the graft out of the bell 410.

[0073] Figure 6 is a perspective view of the graft release device 600 according to another embodiment of the present disclosure. Figures 7A to 7C include various views of the device 600. Figure 7A is a different perspective view from Figure 6. Figure 7B is a side view of the connection. Figure 7C is an exploded view of the graft release device 600.

[0074] As shown in Figures 6 and 7A-C, the instrument 600 may comprise a bell 610, a central shaft 620, a handle 630, an inner blade 640, and an outer blade 650. The bell 610 is removable and may be interchangeable with other bells having different diameters. In some embodiments, the bell 610 may have a diameter of 25 mm. In other embodiments, the bell 610 may have a diameter of 29 mm. The bell 610 can have any suitable diameter. The instrument 600 can be used after the humeral head has been opened using a bell saw.

[0075] As shown in Figure 7B, the selected bell 610 can be locked onto the central shaft 620 via a locking inverted T-groove 615 in the upper portion 618 of the bell 610 before use. A domed bell cap 624 can be attached to the central shaft 620 and may have a pin 622 protruding from the side. For coupling, the upper portion 618 of the bell 610 with a larger diameter can be aligned with the bell cap 624 so that the pin 622 passes through the opening slot of the T-groove 615, and then the bell 610 can be rotated to lock the pin 622 into the T-groove 615. Multiple T-grooves 615 and corresponding pins 622 may be present.

[0076] The inner blade 640 can be inserted onto the central shaft 620 by sliding it along the central shaft groove 628 to its final position. The inner blade 640 may be rotatable between the deployed and closed positions by rotating the inner blade tab 645 connected to the inner blade 640. The outer blade 650 can be inserted onto the bell 610 by sliding it along the groove 612 extending perpendicularly along the side of the bell 610 to its final position. The outer blade 650 may be rotatable between the deployed and closed positions by rotating the outer blade tab 655 connected to the outer blade 650. The handle 630 can be inserted into the hole 629 through the central shaft 620.

[0077] During use, the instrument 600 can be introduced into the circular cutting section within the humerus, prepared by the bell, until it reaches the bottom of the cutting section. The depth of the cutting section can be checked using the scale 614 on the bell 610 (e.g., 20 mm, 25 mm, or 30 mm). With the outer blade tab 655 connected to the outer blade 650 and the inner blade tab 645 connected to the inner blade 640, the blades are manually started to rotate, and then the instrument 600 is rotated clockwise via the handle 630, causing the blades 640 and 650 to rotate to the "open" position. Due to cutting resistance, the blades 640 and 650 automatically move to their fully open position as the instrument 600 rotates. Continuous rotation of the instrument 600 cuts the cancellous bone and defines the graft. After the graft is cut, the instrument 600 is withdrawn from the bone while continuing to rotate slightly clockwise. Since blades 640 and 650 are in the "open" or deployed position at the bottom of the graft, the graft remains inside the bell 610. Blades 640 and 650 can be moved to the "closed" or retracted position by moving their respective tabs 645 and 655. The bone graft can then be extracted from the bell 610 with the blades 645 and 655 rotated away from it.

[0078] Figure 8 is a perspective view of a graft release device 900 according to another embodiment of the present disclosure. Figures 9A–9C include various views of the device 900. The drawings in Figure 9 include various views of Figures 9A–9G. Figure 9B is a front view. Figure 9A is a cross-sectional view along BB in Figure 9B. Figure 9C is a side view. Figure 9D is a cross-sectional view along ZZ–ZZ in Figure 9C. Figure 9E is a bottom view. Figure 9F is a perspective cross-sectional view along YY in Figure 9G. Figure 9G is a top view. The graft release device 900 may include features similar to those of device 600, but for brevity, such features are omitted.

[0079] As shown in the figure, the graft release device 900 may comprise a bell 910, a central shaft 920 extending through the bell 910, a handle 930 attached to the central shaft 920 and defining a T-shape with the central shaft 920, an inner blade 940 extending from one end of the central shaft 920 within the bell 910, and an outer blade 950 extending inward from around the bell 910. The bell 910 may be interchangeable with other bells having different diameters. In some embodiments, the bell 910 may have a diameter of 25 mm. In other embodiments, the bell 910 may have a diameter of 29 mm. The bell 910 may have any suitable diameter. The device 900 can be used after the humeral head has been opened using a bell saw, as described with respect to the use of device 600.

[0080] Before cutting the bone graft, the instrument 900 can be assembled starting with the bell 910, then the central shaft 910, and the handle 930, as shown in Figures 10A and 11A. Unlike the inverted T-groove 615 and pin 622 mechanism of the instrument 600, a bell 910 of the appropriate size is joined in the locking groove 912 of the bell 910 and can be locked onto the central shaft 920 via the locking cam 925, as shown in the close-up in Figure 10B. First, the central shaft 920 is inserted into the selected bell 910, and the alignment indicator 922 on the central shaft 920 (shown as an arrow, for example, in Figures 11A-C) can be aligned with an "unlock" indicator such as the slot 911, as shown, for example, in Figures 10C and 11B. Once the central shaft 920 is positioned in the predetermined location within the bell 910, it is rotated (for example, by a quarter turn) to lock the central shaft 920 within the bell 910, as shown in Figure 10D and Figure 11C, and the alignment indicator 922 is aligned with the "lock" mark. Figures 10E and 11C show the arrangement of the indicator marks when the central shaft 920 and the bell 910 are aligned to lock each other.

[0081] The inner blade 940 is inserted onto the central shaft 920 by sliding at least a portion of the central shaft 920 along the central shaft groove 924, which extends vertically downward, to the final position of the inner blade 940. The inner blade 940 is placed in the "closed" position by rotating the inner blade tab 945 connected to the inner blade 940. The outer blade 950 is inserted onto the bell 910 by sliding its shaft along the bell groove 915 to the final position of the outer blade 950. The outer blade 950 is placed in the "closed" position by rotating the outer blade tab 955 connected to the outer blade 950. The handle 930 is inserted into the hole 929 through the central shaft 920.

[0082] During use, similar to instrument 600, instrument 900 is introduced into the circular cutting section within the humerus, prepared by the Bellceau, until it reaches the bottom of the cutting section. The depth of the cutting section can be confirmed using the scale 914 on the Bellceau 910 (e.g., 20mm, 25mm, or 30mm). With the outer blade tab 955 connected to the outer blade 950 and the inner blade tab 945 connected to the inner blade 940, the blades are manually started to rotate. Then, rotating instrument 900 clockwise via the handle 930 rotates blades 940 and 950 to the "open" position. Due to cutting resistance, blades 940 and 950 automatically move to the fully open position during the rotation of instrument 900. Continuous rotation of instrument 900 cuts the cancellous bone and defines the graft. After the graft is cut, instrument 900 is withdrawn from the bone while continuing to rotate slightly clockwise. The graft remains inside the bell 910 because blades 940 and 950 are in the "open" position at the bottom of the graft. Blades 940 and 950 are moved to the "closed" position by moving their respective tabs 945 and 955. Handles 930 and blades 940 and 950 can be withdrawn from the instrument 900 before the bone graft is extracted from the bell 910. The bone graft can be removed from the bell 910 using any appropriate technique, including the use of a graft extractor, and / or by vertical extrusion into the instrument 900 or the bell 910.

[0083] Figures 12A and 12B illustrate the steps of a method 1200 for extracting a cancellous bone graft from the humerus according to an embodiment of the present disclosure.

[0084] Method 1200 begins with the assembly of the graft release bell device. In step S1, the inner blade may be assembled onto the central shaft. In step S2, the bell may be assembled onto the central shaft. In step S3, the outer blade may be assembled onto the bell.

[0085] In step S4, the bell of the graft release bell device may be positioned within the opening of the humeral head cut by the bell saw. Using a hammer or other tool, the central shaft of the graft release bell device can be driven into the opening of the humeral head, allowing the device to engage with the cancellous bone at the bottom of the cut made by the bell saw. The depth can be confirmed by using the scale on the bell. In step S5, the handle can be inserted through the central shaft. In step S6, the inner blade of the graft release bell device is extended or opened. In step S7, the outer blade of the graft release bell device is extended or opened.

[0086] In step S8 of Figure 12B, the graft release bell instrument can be rotated, for example, clockwise, to cut the cancellous bone. The graft release bell instrument can be rotated until the cylindrical portion of the cancellous bone is separated from the humerus. In step S9, the graft release bell instrument, along with the cut portion of the cancellous bone, is removed from the humeral head. The cut portion of the cancellous bone is separated from the graft release bell instrument and may be examined, sized, and shaped so that it can be used, for example, as a graft for lateralizing a glenoid implant.

[0087] As shown in Figure 13, the features and elements of the disclosed instrument, including two blades and a method, enable the surgeon to extract a bone cylindrical graft from within the humeral head without shearing the humeral head. The upper part of Figure 13 shows the result of the BIO RSA method, in which the surgeon had to cut the humeral head HH1 from the humerus H1 to remove bone graft G1. The lower part of Figure 13 shows that using the instrument and method according to this disclosure, it is not necessary to cut the entire humeral head to remove bone graft G2 from the humerus H2. Instead, the humeral head H2 can be accessed using a bell saw. The surgeon can obtain a bone graft cylinder G2 with a thickness of, for example, 15 mm to 30 mm. After bone graft G2 is removed, the RSA technique can be used to laterally position the glenoid implant.

[0088] It should be understood that the foregoing description is merely illustrative of the present invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the present invention. Accordingly, the present invention is intended to encompass all such alternatives, modifications, and variations that are included within the scope of the appended claims.

Claims

1. A graft release bell device, The central shaft and An inner blade extending from the central shaft, An outer blade extending from the outer member, The graft release bell device comprises a handle for rotating the central shaft.

2. The apparatus according to claim 1, further comprising a button configured to move to a different position in order to extend the outer blade.

3. The apparatus according to claim 1, further comprising a bell.

4. The device according to claim 3, wherein the bell is the outer member.

5. The device according to claim 1, wherein the handle is configured to pass through the hole in the central shaft.

6. The apparatus according to claim 3, wherein the diameter of the bell is 25 mm or 29 mm.

7. The apparatus according to claim 3, further comprising a scale on the bell.

8. The apparatus according to claim 1, wherein the outer blade is fitted into a slot of a cylindrical bell.

9. The apparatus according to claim 3, wherein the outer blade fits into the slot of the bell.

10. The method according to claim 1, wherein the inner blade and the outer blade are rotatable to open and close.

11. The device according to claim 1, wherein the central shaft is lockable to the bell.

12. The device according to claim 3, wherein the bell is configured to pass through a hole in the bone defined by the bone saw.

13. A graft release bell device, The central shaft and A bell is detachably connected to the central shaft, An inner blade connected to the central shaft, The graft release bell device comprising an outer blade coupled to the bell.

14. The graft release bell device according to claim 13, further comprising a handle connected to the central shaft.

15. The graft release bell device according to claim 13, wherein the central shaft extends through the bell.

16. The central shaft is equipped with a cam. The bell is equipped with a locking groove, The graft release bell device according to claim 13, wherein the central shaft and the bell are joined by inserting the cam into the locking groove and rotating the central shaft and the bell relative to each other to lock the cam in the locking groove.

17. The graft release bell device according to claim 13, wherein the diameter of the bell is either 25 mm or 29 mm.

18. The graft release bell device according to claim 13, further comprising a scale on the side of the bell configured to indicate the depth of the bell within the circular cut portion.

19. The graft release bell device according to claim 13, wherein the inner blade is disposed in a groove extending along the side surface of the central shaft and is rotatable between an extended position and a closed position by rotating an inner blade tab connected to the inner blade.

20. The graft release bell device according to claim 13, wherein the outer blade is disposed in a groove extending along the side surface of the bell and is rotatable between an extended position and a closed position by rotating an outer blade tab connected to the outer blade.

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