AU2021107256A4

AU2021107256A4 - A Bone Graft

Info

Publication number: AU2021107256A4
Application number: AU2021107256A
Authority: AU
Inventors: Ralph Jasper Mobbs; William Chase Harington Parr
Original assignee: 1pholdings Pty Ltd
Current assignee: 1pholdings Pty Ltd
Priority date: 2021-08-25
Filing date: 2021-08-25
Publication date: 2021-12-09
Anticipated expiration: 2029-08-25

Abstract

A BONE GRAFT ABSTRACT A bone graft comprising: a body including: graft material; and one or more surfaces with a contour formed to be substantially complementary to an anatomical surface of a patient, wherein anatomical data associated with an intended location of the bone graft assists in producing the one or more surfaces. 1/11 1a 200a Figure 1

Description

1/11

1a

200a

Figure 1

A BONE GRAFT FIELD OF THE INVENTION

[0001] The invention relates to a bone graft. In particular, the invention relates, but is not limited, to a fitted bone graft as well as a method associated with a bone graft.

BACKGROUND TO THE INVENTION

[0002] Reference to background art herein is not to be construed as an admission that such art constitutes common general knowledge in Australia or elsewhere.

[0003] The technology associated with bone grafts has gradually developed over time. Bone grafts may be manufactured from a synthetic material, autograft materials (ie, bone harvested from a patient's own body) or allograft materials (ie, bone obtained from a bone bank). Bone grafts are used in a variety of medical applications.

[0004] During surgery, shaping an autograft material to achieve a suitable shape that can be implanted in a patient's anatomy (and any interfacing medical device) is difficult. This process usually means that it is necessary to harvest more graft from the donor site than will be implanted, which increases trauma to the patient and the bone defect at the donor site (comorbidities).

[0005] In a similar manner to an autograft material, when an allograft material is in the form of a bone block, it is difficult to shape a precise fit with patient anatomy, and/or an associated device geometry. This process is also time consuming, which equates to additional surgical and theatre running costs. Furthermore, there is the possibility of damaging the associated medical implant/device during the fitting of the graft to a graft window.

[0006] With the above in mind, in cases where autograft or allograft bone blocks are used, slightly oversized blocks are commonly implemented and forced into a graft window using surgical instruments such as mallets. This technique raises further complications for medical device implants with intricate design features, and using such techniques could distort or even break such features in the device. These techniques may also dislodge surface coatings on the device or alter surface topology, both of which can be important for how the body responds to, and integrates with, the device.

[0007] Another current graft option is the use of cancellous bone particles (sometimes termed 'crunch'). These can be packed into the graft window of a medical device very rapidly. However, the particles can sift and settle with repeated load cycles, such as those experienced in the body, meaning that the crunch graft will not tightly contact the medical device or anatomical surfaces, and as a result, not resist or transmit load, which may negatively affect the fusion process.

[0008] Demineralised Bone is another graft option. This alternative form of allograft involves removing the mineral content of bone, meaning that there is very little mechanical stiffness. This makes the graft material quick and easy to shape and pack into voids and/or implants. However, as the graft has no significant mechanical stiffness, it does not initially provide suitable stiffness conditions for load transfer. Mechanical stiffness occurs after the full mineralisation of the graft, with load only being transferred through the graft once bone spans the entire length of the graft.

[0009] Other material options for bone grafts include pure Hydroxy Apatite (HA). This is the formulation of calcium phosphate that is found naturally in bone. However, HA alone is brittle and easily fractures. Currently HA is commonly used as a coating on bone contacting surfaces of medical devices where it is desirable for the surface of the device to integrate (fuse) with the boney anatomy.

[0010] Synthetic bone substitutes include crystalline beta-tricalcium phosphates and bioceramic scaffolds, some of which can be manufactured by 3D printing. However, these 3D printed grafts have not been commercially successful to date as, for example, they are prone to fracture.

[0011] Suitable materials for a bone graft are only part of the picture in successful patient outcomes. Load, or strain, as well as biological and environmental factors need to be suitable for successful bone formation. For example, bone grafts are used in interbody fusion (IF) for the treatment of, for instance, degenerative disc disease. IF surgical procedures aim to accelerate the natural fusion process within a patient and control, to an extent, how and where the fusion occurs. Bone remodelling is therefore a key to the process of IF.

[0012] IF occurs when both the biological and mechanical conditions are favourable to bone formation. For the biological conditions to be right for bone formation, the chemical 'building blocks'for bone, being Calcium and Phosphate, need to be available at the fusion site. This can be achieved through transportation of these minerals through the blood supply, or supply of the minerals directly at the fusion site.

[0013] Biological factors, such as bone morphogenic protein can be added to aid the biological conditions for bone formation. Such factors may aid initial / short term bone formation, but it is not certain that they lead to long term maintenance of mature fusion in the absence of a suitable mechanical environment. Fibrous tissue can form in the place of bone, if the conditions for bone formation are sub-optimal. Once fibrous tissue has formed it prevents the formation of bone, resulting in a non-union or pseudoarthrosis.

[0014] With the above in mind, mechanical conditions influence IF: too much movement can prevent bone formation. This is the reason for the predominant use of medical devices in IF. IF surgical procedures typically include the use of a medical device in the form of an interbody cage/spacer. The interbody cage/spacer used in spinal IF procedures are intended to immobilize, stabilize and maintain the space between spinal segments in order to allow the natural biological process of bone fusion to occur. However, these medical devices provide further challenges in obtaining a successful bone fusion.

[0015] Many fail to appreciate that load cannot be transferred from vertebral bodies to the graft if the graft is not touching the vertebral body. Similarly, load cannot transfer to/from/through the graft and the medical implant. This means that, in the event the graft does not fit the graft window of an implant, or does not contact the adjacent vertebral bodies, it will not have the necessary conditions for bone formation and long-term maintenance.

[0016] To this end, to give a patient the best chance of long-term fusion to relieve pain, the biological conditions (building blocks and factors) as well as the mechanical conditions (load and strain through the graft) ideally should be optimised. This means optimal fit between graft and medical device and graft and adjacent anatomy is necessary for optimal IF conditions to be achieved. However, suitable attention has not been given to this area of development.

[0017] Thus, there are demonstrable cost and patient draw-backs for current bone grafts, particularly in relation to IF.

SUMMARY OF INVENTION

[0018] In one aspect, a bone graft is disclosed comprising:

a body including:

graft material; and one or more surfaces with a contour formed to be substantially complementary to an anatomical surface of a patient, wherein anatomical data associated with an intended location of the bone graft assists in producing the one or more surfaces.

[0019] In an embodiment, the anatomical data includes information associated with one or more anatomical scans.

[0020] In an embodiment, the one or more anatomical scans are retrieved from a database of scans relating to a number of people.

[0021] In an embodiment, the one or more anatomical scans are retrieved from the patient.

[0022] In an embodiment, the anatomical data assists in creating a model to produce the one or more surfaces.

[0023] In an embodiment, the model is a statistical shape model from the database of scans.

[0024] In an embodiment, the one or more surfaces are matched to be complementary to the anatomical surface. That is, the contours of each surface are substantially the same.

[0025] In an embodiment, the one or more surfaces include one or more curved surfaces.

[0026] In an embodiment, the one or more surfaces include at least two surfaces, on either side of the body, where one surface substantially complements the anatomical surface and another surface substantially complements a further anatomical surface.

[0027] In an embodiment, the body includes one or more (medical) device engaging surfaces.

[0028] In an embodiment, the one or more device engaging surfaces extend transversely to the one or more surfaces.

[0029] In an embodiment, the one or more device engaging surfaces extend substantially perpendicular to the one or more surfaces.

[0030] In an embodiment, the one or more device engaging surfaces are located on sides of the body that extend away from the one or more surfaces.

[0031] In an embodiment, the one or more device engaging surfaces are configured to maintain a connection with the device.

[0032] In an embodiment, the one or more device engaging surfaces maintain the connection with the device through friction.

[0033] In an embodiment, the body includes one or more fastening portions.

[0034] In an embodiment, the one or more fastening portions are configured to assist with connecting the body to the device with one or more fasteners.

[0035] In an embodiment, the one or more fastening portions include a hole.

[0036] In an embodiment, the body includes a first (weak) portion and a second (weaker) portion, the first portion having a different strength to the second portion.

[0037] In an embodiment, a fracture point is higher in the second portion compared to the first portion.

[0038] In an embodiment, the second portion is located in a central area of the body whilst the first portion is located in an outer area of the body.

[0039] In an embodiment, the first portion is configured to fracture when load from the patient's body is transferred therethrough.

[0040] In an embodiment, parts of the first portion are configured to fracture sequentially.

[0041] In an embodiment, fractured parts of the first portion are configured to release particles of suitable size and/or morphology that assist in forming bone cells.

[0042] In an embodiment, the first portion includes one or more beams.

[0043] In an embodiment, the one or more beams are thinner compared to beam(s) in the second portion.

[0044] In an embodiment, the one or more beams break sequentially from thinner to thicker.

[0045] In an embodiment, the graft material is produced through additive manufacturing. In an embodiment, the graft material is 3D printed.

[0046] In an embodiment, the graft material is a slurry. In an embodiment, the slurry dries/cures to form a solid.

[0047] In an embodiment, the graft material includes calcium and/or phosphate.

[0048] In an embodiment, the body is porous (ie, the body includes holes).

[0049] In an embodiment, the body includes one or more channels. The channels may assist in forming the holes.

[0050] In an embodiment, one or more of the channels are of different size to others of the channels.

[0051] In an embodiment, the body contains an antimicrobial agent. In an embodiment, the antimicrobial agent is located in the holes.

[0052] In an embodiment, the antimicrobial agent releases once inserted into the patient.

[0053] In an embodiment, the body includes growth promoting material.

[0054] In an embodiment, the growth promoting material releases once inserted into the patient.

[0055] In an embodiment, the growth promoting material includes bone morphogenic protein.

[0056] In an embodiment, the holes (or channels) assist with retaining putty, paste, or liquids containing growth factors or other formulations of proteins, minerals, compounds, molecules or antibiotics aimed at improving fusion results.

[0057] In an embodiment, the patient is a human or an animal.

[0058] In an embodiment, the anatomical surface is a bone surface or a joint surface.

[0059] In an embodiment, the anatomical surface may be selected from a surface of a vertebra of a spine, knee, hip, craniotomy defect, maxilla-facial reconstruction, mandible reconstruction or the like.

[0060] In a further form, an implant is disclosed comprising:

a bone graft including:

graft material;

one or more surfaces with a contour formed to be substantially complementary to an anatomical surface of a patient; and

a device that is configured to connect with the bone graft, the device having one or more device surfaces that are configured engage with the anatomical surface of the patient when implanted in the patient, wherein anatomical data associated with an intended location of the bone graft assists in producing the one or more surfaces.

[0061] In an embodiment, the device includes a graft window to receive the bone graft.

[0062] In an embodiment, the one or more device surfaces are substantially configured to evenly engage with the anatomical surface of the patient when implanted in the patient.

[0063] In an embodiment, the one or more device surfaces are associated with a component-engaging part of the device.

[0064] In an embodiment, the component-engaging part is produced through additive manufacturing. In an embodiment, the component-engaging part is 3D printed.

[0065] In an embodiment, the component-engaging part is (releasably) connectable to one or more other parts of the device.

[0066] In an embodiment, the one or more device surfaces has one or more teeth, ridges or bumps to further securely engage with the anatomical surface.

[0067] In an embodiment, the bone graft is fastened to the device.

[0068] In an embodiment, the device may be a spacer, a disc replacement, an expandable cage, a generic cage, or any type of implantable device for correcting skeletal dysfunction and/or pathology.

[0069] In an embodiment, the implant is configured to be used in at least one of the following surgical procedures: Posterior Lumbar Interbody Fusion, Transforaminal Lumbar Interbody Fusion, eXtreme Lateral Interbody Fusion, Lateral Lumbar Interbody Fusion, Oblique Lumbar Interbody Fusion or Anterior Lumbar Interbody Fusion.

[0070] In a further form, a method is disclosed comprising:

retrieving anatomical data associated with an intended location of a bone graft; and

using the anatomical data to produce the bone graft with one or more surfaces of graft material having a contour formed to be substantially complementary to an anatomical surface of a patient.

[0071] In an embodiment, the method includes producing the one or more surfaces of graft material with additive manufacturing.

[0072] In an embodiment, the step of retrieving anatomical data associated with the intended location of the bone graft includes taking a scan of the patient.

[0073] In an embodiment, the step of retrieving anatomical data associated with the intended location of the bone graft includes using a database of scans relating to a number of people.

[0074] In an embodiment, the step of producing the bone graft includes varying structure of the bone graft to create two portions with different strengths.

[0075] In an embodiment, the step of creating the two portions with different strengths includes forming columns (or holes) of different thickness.

[0076] In an embodiment, the method further includes connecting the bone graft to a device for implanting into the patient.

[0077] In an embodiment, the step of connecting the bone graft to the device includes inserting the bone graft through a graft window of the device.

[0078] In an embodiment, the step of connecting the bone graft to the device includes fastening the bone graft to the device.

[0079] In an embodiment, at least part of the device is manufactured with additive manufacturing.

[0080] Further features and advantages of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0081] By way of example only, preferred embodiments of the invention will be described more fully hereinafter with reference to the accompanying figures, wherein:

Figure 1 illustrates a front perspective view of an implant, between two vertebrae, according to an embodiment of the invention;

Figure 2 illustrates a rear perspective view of the implant shown in Figure 1;

Figure 3 illustrates a lower perspective view of a further implant, according to an embodiment of the invention;

Figure 4 illustrates a side view of a bone graft, between two vertebrae, according to an embodiment of the invention;

Figure 5 illustrates a top view of another implant, according to an embodiment of the invention;

Figure 6 illustrates a perspective view of the bone graft shown in Figure 5;

Figure 7 illustrates a top view of a further bone graft, according to an embodiment of the invention; and

Figure 8 illustrates a lower perspective view of another bone graft, according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0082] Figures 1 and 2 illustrate an implant 10a according to an embodiment of the invention. In this regard, it is noted at the outset that the use of a reference numeral followed by a lower case letter and/or apostrophe in this specification typically indicates alternative embodiments of a general element identified by the reference numeral. Thus for example implant 10a is similar to but not identical to implant 1Ob. Further, references to an element identified only by the numeral refer to all embodiments of that element. Thus for example a reference to implant 10 is intended to include both implant 10a and implant 10b.

[0083] The implant 10a is configured to be positioned between an upper vertebrae a and a lower vertebrae 22a of a patient. The implant 10a is used in anterior lumbar interbody fusion of a person in this embodiment. In other embodiments, the implant may be used in animals including domestic pets. The implant 10a includes a bone graft 100a and a device 200a. The bone graft 100a includes a body 105a formed from a graft material. That is, the bone graft 100a includes material that facilitates the growth of bone tissue. The graft material in this embodiment is 3D printed (ie, it is produced through additive manufacturing). The graft material is printed as a slurry that dries/cures to form a solid. The graft material includes calcium and phosphate.

[0084] The bone graft 100a includes surfaces with a contour formed to be substantially complementary to the anatomical surfaces of the patient. That is, the bone graft 100a includes a first surface 110a having a contour that is configured to compliment part of a lower surface of upper vertebrae 20a. The bone graft 100a also includes a second surface 115a having a contour that is configured to compliment part of an upper surface of lower vertebrae 22a. The surfaces 110a, 115a are configured to match their respective surfaces on the upper and lower vertebrae 20a, 22a. In this regard, the surfaces 110a, 115a are typically different to each other. The surfaces 110a, 115a are also located on opposite sides of the body 105a.

[0085] To produce the surfaces 110a, 115a, anatomical data associated with the intended location of the bone graft is retrieved. For example, in this embodiment, scans showing the shape of the vertebrae 20a, 22a are retrieved. This data is used to model outer surfaces of the vertebrae 20a, 22a where the bone graft 100a will engage. Using a reciprocal model of the outer surfaces of the vertebrae 20a, 22a, the shape of the surfaces 110a, 115a are designed to complement the outer surfaces of the vertebrae 20a, 22a. That is, the reciprocal model involves inverting the scanned surfaces to map the design of the surfaces 110a, 115a. In further embodiments, the surfaces 110a, 115a may be produce by a complementary area based on statistical shape models extracted from a database of scans of the anatomical surface of a number of patients. These statistical models provide a better fit compared to current practices.

[0086] The body 105a includes a plurality of holes 120a. The holes 120a assist with retaining putty, paste, or liquids containing growth factors or other formulations of proteins, minerals, compounds, molecules or antibiotics aimed at improving fusion results. The holes 120a also assist with providing some compliance between the surfaces 110a, 115a, which allows the surfaces 110a, 115a to further suitably complement the outer surfaces of the vertebrae 20a, 22a.

[0087] The bone graft 100a further includes device engaging surfaces 180a. The device engaging surfaces 180a extend between the surfaces 110a, 115a. In this regard, the device engaging surface 180a extend around side(s) of the body 105a, between upper and lower portions of the body 105a. Accordingly, the device engaging surface 180a extends transversely (or substantially perpendicularly) to the surfaces 110a, 115a. The device engaging surfaces 180a are configured to engage with the device 200a. The device engaging surfaces 180a, in this embodiment, frictionally engage with the device 200a to be retained thereby.

[0088] The device 200a in this embodiment includes first device surfaces 210a and second device surfaces 220a. The device surfaces 210a, 220a are configured to also substantially compliment respective surfaces of the vertebrae 20a, 22a (ie, the anatomical surfaces of the patient). In this regard, the device surfaces 210a, 220a have a smooth transition with the surfaces 110a, 115a to suitably engage the vertebrae 20a, 22a. In other words, the surfaces 110a, 115a and the device surfaces 210a, 220a form a contour that substantially matches the respective lower and upper surfaces of the vertebrae 20a, 22a.

The device surfaces 21Oa, 220a may include teeth or the alike to assist in engaging the vertebrae 20a, 22a.

[0089] The device surfaces 21Oa, 220a form part of separate component-engaging parts. The component-engaging parts may be releasably connected to a portion of the device 200a. Accordingly, the component-engaging parts (or device surfaces 210a, 220a) can therefore be swamped in and out, with other parts of different sizes, to find a combination of components that allows suitable engagement with the anatomical surface of the patient. In this embodiment, the device 200a forms a cage. In further embodiments, the device may be a spacer, a disc replacement, an expandable cage, or any type of implantable device for correcting skeletal dysfunction and/or pathology.

[0090] The device 200a includes a device window 230a. The device window 230a forms an aperture through the device 200a. The device window 230a is substantially in the same shape as the device engaging surfaces 180a of the bone graft 100a. To this end, the bone graft 100a is pressed into the device window 230a to retain the bone graft 100a to the device window 230a. In further embodiments, the bone graft 100a and device 200a may include fastening portions that allow these parts to be fastened together.

[0091] The device 200a further includes spine screws 240. The spine screws 240 are configured to extend through the device 200a and be fastened to the vertebrae 20a, 22a. The spine screws 240 therefore assist in locking the bone graft 100a and device 200a in place. This assists in promoting fusion of the bone graft 100a to the vertebrae 20a, 22a and fusing the spine of the patient.

[0092] Figure 3 illustrates a further implant 1Ob. The implant 1Ob is similar to implant a. In this regard, the implant 10b includes a bone graft 100a and device 200b. The bone graft 100a includes a body 105b having opposite surfaces 11Oa, 115a with contours that complement the bone anatomical surfaces of a patient. The bone graft 100a is connected to device 200b with spine screws 240. The bone graft 100a includes fastener recesses 130b for the screws 240. The recesses 130b are configured to avoid the screw thread as they are tightened. This means that as the screws 240 are tightened, the device 200b and the graft 100a will be compressed against the anatomical envelope (in this case the vertebral endplate), ensuring ideal proximity, contact and stability between graft 100a and anatomy.

[0093] Figure 4 illustrates a bone graft 100c according to an embodiment of the invention. The bone graft 100c includes body 105c having a first surface 11Oc and a second surface 115c. The surfaces 110c, 115c are configured to substantially match surfaces of the vertebras 20c, 22c. In comparison to the grafts 100a, 100b, the surfaces 11Oc, 115c include bumps/ribs on their surfaces that improve and control load transfer, and traction, between the patient's anatomy and the graft 100c. Furthermore, the graft 100c includes a plurality of columns 140c that assist in forming its structure. Multiple holes 120c are located around the column 140c.

[0094] Figures 5 and 6 illustrate another implant 1Od. The bone graft 100d includes a body 105a having first and second surfaces 11Od, 115d that are configured to complement opposing anatomical surfaces. The body 105d includes first portions 150d and a second portion 160d. The first portions 150d are located towards the lateral / outer margins of the body 105a. The second portion 160d is associated with a middle part of the body 105d. The second portion 160d is located between the first portions 150d but, in further embodiments, the first portion 150d may (for example) surround the second portion 160d. As detailed further below, the second portion 160 is stronger than the first portion(s) 150d. Parts of the first portion(s) 150d are designed to fracture sequentially, releasing mineral particles of suitable size and morphology so that they can be phagocytosed by bone forming cells. In this way, as parts of the first portion(s) 150d break towards the second portion 160, there is a constant and abundant supply of the mineral content of bone at the fusion site. This is taking advantage of the nature of 3D printed (calcium phosphate) materials, in a non-obvious manner, as typically fracturing is considered an issue for bone grafts (as opposed to a benefit).

[0095] The body 105d forms a lattice structure. The first portions 150d include (first) vertical struts 152d and (first) lateral struts 154d. The struts 152d, 154d are connected to form square-like units but it will be appreciated that, in further embodiments, other shapes may be formed. The struts 152d, 154d form grid-like layers that are connected over multiple levels. Each strut 152d, 154d is directly connected to another three struts 152, 154d on each end. The second portion 160d also includes (second) vertical struts 162d and (second) lateral struts 164d. The struts 160d, 162d form a similar lattice structure to the struts 152d, 154d in this embodiment. However, as shown in Figure 5, the thickness of the struts 152d, 154d is thinner than the struts 160d, 162d.

[0096] The thicker struts 160d align with the stronger/stiffer vertebral endplates and natural force transmission takes place through the interbody space. The struts 152d, 154d are located outboard of the thicker struts 160d and are designed to fail sequentially via planned fracture patterns. In this way, as the beams break sequentially from thinner to thicker, there is a constant and ample supply of the mineral content of bone at the fusion site. Multiple holes 120d (or channels) are also formed by / around the struts 152d, 154d. The holes 120d vary in size depending on the location and thickness of the struts 160d, 162d. Suitable growth promoting substances may be held in these holes 120d.

[0097] The graft 100d further includes apertures 170d. The apertures 170d are formed from (cylindrical) members extending through the graft 100d. A number of smaller openings branch from the apertures 170d to deliver an injected substance throughout the graft 100d. The apertures 170d, and branching, pores can vary in size (diameter) and length to (amongst other things): i) ensure that substances are distributed thoroughly, or as intended, through the graft 100d; and ii) control the delivery of substances of different viscosities - longer, thinner channels will inhibit the flow of factors into regions of the graft 100d to a greater extent than shorter wider channels. This means that the aperture 170d/ pore design can be altered (like the holes 120d), or customised, if there is preference for particular substances with particular flow characteristics and/or viscosities.

[0098] The outer struts 152d, 154d of the body 105d form device engaging surfaces 180d. These device engage surfaces 180d are configured to suitably fit within device 200d. Upon inserting the body 105d into the device 200d, it may be implant in a patient and, for example, bone morphogenetic proteins may release from the holes 120d and apertures 170d to assist in forming the bone fusion.

[0099] Figure 7 illustrates a further bone graft 100e of an implant 10e. The graft 100e is substantially similar to graft 100d. However, the graft 100e includes a plurality of lateral struts 164e that are transversely orientated to an outer perimeter of the body 105e. That is, the struts 164e extend away from the outer perimeter of the body 105e at an acute angle. The angle of the struts 164e, as well as strut thickness and material properties of the graft 100e, determines how rapidly the struts 164e fail, or, conversely, how resistant the graft 100e is to load and/or failure. Furthermore, the perimeter of the body 105e includes bump(s) 190e that are configured to engage with a graft window of a device to secure the body 105e thereto.

[00100] Figure 8 illustrates a bone graft 100f of an implant 1Of. The body 105f of the graft 100f is formed from an allograft cancellous bone block. The block has been machined to provide surfaces 11Of, 115f that match the anatomical contours of the superior and inferior endplate anatomy of a patient. This graft 100f features channels for injecting growth promoting substances, as well as recesses 130f for spine screws etc. The bone graft 100f is configured to be retained in device that is implanted in a patient.

[00101] With the above in mind, it will be appreciated that a number of devices 200 may be on hand and, through a process of using size trials, it can be determined which device 200 will restore the patient's anatomy in the appropriate manner. Furthermore, if an off-the-shelf device is used, or if there are a range of different patient specific devices that can be used, different height and / or footprint grafts 100 may be interchanged to find a suitable combination of graft 100 and device 200. Once the graft 100 and device 200 is selected, they are secured together. Due to the common interface between the graft 100 and the inner surface of the graft window of the device 200, there is the potential to swap the device 200 at the time of surgery. Furthermore, different grafts 100 may be on hand allowing for other suitable combinations. This gives, for example, surgeons much more flexibility in treatment options.

[00102] Furthermore, the bone grafts 100 assists in reducing, or eliminating, autograft (graft harvested from the patient at a different site to the primary surgical site) necessary to complete the procedure as any, or all, parts of the grafts 100 can be made out of allograft (bone bank material) or synthetic allograft materials (e.g. inorganic compounds). This reduces the potential comorbidities and imperfect fit associated with autografts. The use of different materials to manufacture the graft and, when 3D printed the design of any lattices in the graft, also allows the modulus of the graft 100 to be varied to suit a patient's needs. For example, a reduced overall stiffness of the assembled construct can be used for a patient with reduced bone density to help prevent the onset of subsidence of the construct into the adjacent bone anatomy. As noted above, the planned fracture lines in this disclosure also assist with fusion whereas, in the case of 3D printed components in the past (for example), there was a reluctance to use this technology as fracturing was undesired.

[00103] The implants 10 also reduces the cost of surgery as the pre-fabricated graft 100 saves time in the operating room involved in shaping either auto or allograft to fit the device graft window. Operating rooms cost -AUD$150/minute, with auto or allograft graft packing for a single anterior approach interbody device taking some time. Accordingly, the embodiments of the present invention reduce the overall cost of surgery.

[00104] In addition, it would be appreciated that the present disclosure has a range of medical applications. Further, it is to be understood that the present disclosure is also applicable to other graft devices whose design consists of filling a specific void shape with the aim of the graft aiding bone fusion.

[00105] In this specification, adjectives such as first and second, left and right, top and bottom, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order. Where the context permits, reference to an integer or a component or step (or the like) is not to be interpreted as being limited to only one of that integer, component, or step, but rather could be one or more of that integer, component, or step etc.

[00106] The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. The invention is intended to embrace all alternatives, modifications, and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

[00107] In this specification, the terms 'comprises', 'comprising', 'includes', 'including', or similar terms are intended to mean a non-exclusive inclusion, such that a method, system or apparatus that comprises a list of elements does not include those elements solely, but may well include other elements not listed.

Claims

Claims:

1. A bone graft comprising:

a body including:

graft material; and

one or more surfaces with a contour formed to be substantially complementary to an anatomical surface of a patient,

wherein anatomical data associated with an intended location of the bone graft assists in producing the one or more surfaces.

2. The bone graft of claim 1, wherein the anatomical data includes information associated with one or more anatomical scans.

3. The bone graft of claim 1 or 2, wherein the one or more anatomical scans are retrieved from the patient.

4. The bone graft of claim 1 or 2, wherein the one or more anatomical scans are retrieved from a database of scans relating to a number of people.

5. The bone graft of any one of the preceding claims, wherein the anatomical data assists in creating a model to produce the one or more surfaces.

6. The bone graft of any one of the preceding claims, wherein the one or more surfaces include at least two surfaces, on either side of the body, where one surface substantially complements the anatomical surface and another surface substantially complements a further anatomical surface.

7. The bone graft of any one of the preceding claims, wherein the body includes one or more device engaging surfaces that extend transversely to the one or more surfaces.

8. The bone graft of any one of the preceding claims, wherein the body includes a first portion and a second portion, the first portion having a different strength to the second portion.

9. The bone graft of claim 8, wherein the second portion is located in a central portion of the body and the first portion is located in an outer portion of the body.

10. The bone graft of claim 8 or 9, wherein one or more beams are thinner in the first portion compared to one or more beams in the second portion.

11. The bone graft of any one of claims 8 to 10, wherein parts of the first portion are configured to fracture sequentially.

12. The bone graft of any one of the preceding claims, the graft material is produced through additive manufacturing.

13. The bone graft of any one of the preceding claims, wherein the body is porous.

14. The bone graft of any one of the preceding claims, wherein the body includes growth promoting material.

15. An implant comprising:

a bone graft as claimed in any one of claims 1 to 14; and

a device that is configured to connect with the bone graft, the device having one or more device surfaces that are configured engage with the anatomical surface of the patient when implanted in the patient,

wherein anatomical data associated with an intended location of the bone graft assists in produce the one or more surfaces.

16. The implant of claim 15, wherein the device includes a graft window to receive the bone graft.

17. The implant of claim 15 or 16, wherein the one or more device surfaces are substantially configured to evenly engage with the anatomical surface of the patient when implanted in the patient.

18. A method comprising:

19. The method of claim 18, wherein the method includes producing the one or more surfaces of graft material with additive manufacturing.

20. The method of claim 18 or 19, wherein the step of retrieving anatomical data associated with the intended location of the bone graft includes taking a scan of the patient.

21. The method of claim 18 or 19, wherein the step of retrieving anatomical data associated with the intended location of the bone graft includes using a database of scans relating to a number of people.

22. The method of any one of claims 18 to 22, wherein the step of producing the bone graft includes varying structure of the bone graft to create two portions with different strengths.

23. The method of claim 22, wherein the step of creating the two portions with different strengths includes forming columns or holes of different thickness.

24. The method of any one of claims 18 to 23, wherein the method further includes connecting the bone graft to a device for implanting into the patient.

25. The method of claim 24, wherein the step of connecting the bone graft to the device includes inserting the bone graft through a graft window of the device.

EDITORIAL NOTE Aug 2021

2021107256

There are 8 pages of drawings only.